Using MyronLMeters.com

Posted by 7 Apr, 2014

Tweet Using MyronLMeters.com Stay up-to-date with an ever-changing world of water treatment regulations, industry events, news, and science at MyronLMeters.com. We believe that a strong, well-informed water industry network is essential. We’ve put together user-friendly pages for water treatment professionals with science updates, networking, news, government resources, associations, and publications for both North American and […]



Using MyronLMeters.com

Stay up-to-date with an ever-changing world of water treatment regulations, industry events, news, and science at MyronLMeters.com. We believe that a strong, well-informed water industry network is essential. We’ve put together user-friendly pages for water treatment professionals with science updates, networking, news, government resources, associations, and publications for both North American and International water industry professionals. If you have suggestions or events you’d like to see on our website, please let us know.

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MyronLMeters.com is the premier online distributor of Myron L water quality test instruments. We make it easy to shop for your water quality testing instruments online. We understand that in order to make a buying decision you need more than just a recommendation or a product description. At MyronLMeters.com you will find detailed information about every product, including demo videos and customer reviews.Since the 1960s, Myron L products have led the industry in high quality, simple to operate conductivity and pH instrumentation for municipal, commercial and industrial water quality control, chemical concentration testing and process control. Today, Myron L meters are more convenient than ever to research and buy right here at MyronLMeters.com. We provide the background, insight, product imagery and specifications you need to make the right choice—all in one convenient online store.
 

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Where You Can Find Myron L Meters: MyronLMeters.com

Posted by 7 Apr, 2014

Tweet Where You Can Find us How to Find Myron L Meters You’ll find us in some of the largest dialysis clinics in America. We’re testing some great pools. We’re testing soil on the farm. We’re helping keep your drinking water clean. We’re at NASA’s Marshall Space Flight Center. And we’re always here when you […]

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Where You Can Find Myron L Meters: MyronLMeters.com

Posted by 7 Apr, 2014

Tweet Where You Can Find us How to Find Myron L Meters You’ll find us in some of the largest dialysis clinics in America. We’re testing some great pools. We’re testing soil on the farm. We’re helping keep your drinking water clean. We’re at NASA’s Marshall Space Flight Center. And we’re always here when you […]



Where You Can Find us



How to Find Myron L Meters

You’ll find us in some of the largest dialysis clinics in America.
We’re testing some great pools.
We’re testing soil on the farm.
We’re helping keep your drinking water clean.
We’re at NASA’s Marshall Space Flight Center.
And we’re always here when you need us, with great products, technical support, literature, videos, and industry resources. Clicking any picture will help you find us.
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Ultrameter: Measuring Conductivity, TDS and Resistivity: MyronLMeters.com

Posted by 1 Mar, 2014

TweetPlease note:  These procedures apply to Ultrameters, Pool Pros, Tech Pros, and D-4 and D-6 dialysate meters. Measuring Conductivity & TDS 1. Rinse cell cup 3 times with sample to be measured. (This conditions the temperature compensation network and prepares the cell.) 2. Refill cell cup with sample. 3. Press COND or TDS. 4. Take […]

Please note:  These procedures apply to Ultrameters, Pool Pros, Tech Pros, and D-4 and D-6 dialysate meters.

Measuring Conductivity & TDS

1. Rinse cell cup 3 times with sample to be measured. (This conditions

the temperature compensation network and prepares the cell.)

2. Refill cell cup with sample.

3. Press COND or TDS.

4. Take reading. A display of [- – – -] indicates an over range condition.

Measuring Resistivity

Resistivity is for low conductivity solutions. In a cell cup the value may drift from trace contaminants or absorption from atmospheric gasses, so measuring a flowing sample is recommended.

1. Ensure pH protective cap is secure to avoid contamination.

2. Hold instrument at 30° angle (cup sloping downward).

3. Let sample flow continuously into conductivity cell with no aeration.

4. Press RES key; use best reading.

NOTE: If reading is lower than 10 kilohms display will be dashes: [ – – – – ]. Use Conductivity.

If you have further questions, please watch our Ultrameter 6P product overview video here: http://blog.myronlmeters.com/ultrameter-ii-product-review/

 IV. AFTER USING THE ULTRAMETER II

Maintenance of the Conductivity Cell

Rinse out the cell cup with clean water. Do not scrub the cell. For oily films, squirt in a foaming non-abrasive cleaner and rinse. Even if a very active chemical discolors the electrodes, this does not affect the accuracy; leave it alone.

Myron L Meters is the premier internet retailer of Myron L meters, solutions, parts and accessories. Save 10% on the Ultrameter II 6PFCe when you order online at MyronLMeters.com.

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Thank You Myron L Meters Customers 2013: MyronLMeters.com

Posted by 7 Dec, 2013

Tweet Myron L Meters is proud to be the premier internet retailer of Myron L Ultrameters, Ultrapens, and other fine products. Myron L meters have a well-earned reputation for being accurate, reliable, and easy-to-use. We’d like to thank the following 2013 customers who ordered for the first time through our MyronLMeters.com website, as well as the hundreds […]

Myron L Meters is proud to be the premier internet retailer of Myron L Ultrameters, Ultrapens, and other fine products. Myron L meters have a well-earned reputation for being accurate, reliable, and easy-to-use. We’d like to thank the following 2013 customers who ordered for the first time through our MyronLMeters.com website, as well as the hundreds not listed here. Thank you for your business.

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We hope that Myron L Meters has helped your organization continue its fine work. Thanks from the Myron L Meters team and have a great 2014!

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End of Year Sale

Posted by 4 Dec, 2013

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Electrical Conductivity Testing Applied to the Assessment of Freshly Collected Kielmeyera coriacea Mart. Seeds: MyronLMeters.com

Posted by 4 Jun, 2013

Tweet  MyronLMeters.com brings you the latest in conductivity measurement research like the article below.  Please click here for accurate, reliable, conductivity meters. Abstract Assessment of seed vigor has long been an important tool of seed quality control programs. The conductivity test is a promising method for assessment of seed vigor, but proper protocols for its […]

 

MyronLMeters.com brings you the latest in conductivity measurement research like the article below.  Please click here for accurate, reliable, conductivity meters.

Abstract

Assessment of seed vigor has long been an important tool of seed quality control programs. The conductivity test is a promising method for assessment of seed vigor, but proper protocols for its execution have yet to be established. The objective of this study was to assess the efficiency of electrical conductivity (EC) testing as a means of assessing the viability of freshly collected Kielmeyera Coriacea Mart. seeds. The test was performed on individual seeds rather than in a bulk configuration. Seeds were soaked for different periods (30 min, 90 min, 120 min., 180 min, and 240 min) at a constant temperature of 25°C. Conductivity was then measured with a benchtop EC meter.

1. Introduction

Seeds are the primary factor of the seedling production process, despite their minor contribution to the end cost of each seedling. In order to estimate the success rate of seedling production, it is essential that seed characteristics such as vigor and germinability be known [1].

The importance of knowing the characteristics of Brazilian forest species to safer and more objective management of seedling production cannot be overstated. However, such studies are scarce, particularly in light of the vast number of species with this potential [2]. Given the intensity of anthropogenic pressure and the importance of rehabilitating disrupted or degraded environments, in-depth research of forest species is warranted.

Routine methods used for determination of seed quality and viability include germination testing and the tetrazolium test. Methods such as measurement of soak solution pH, electrical conductivity, and potassium content of leachate, all based on the permeability of the cell membrane system, are increasingly being employed in the assessment of seed vigor, as they are reliable and fast and can thus speed the decision making process.

Electrical conductivity testing, as applied to forest seeds, has yet to be standardized. Studies conducted thus far have focused on assessment of seed soaking times, which may range from 4 to 48 hours. Even at 48 hours, the conductivity test is considered a rapid technique as compared to the germination test, which, despite its status as a widespread and firmly established method, can take anywhere from 30 to 360 days to yield results (depending on species), and is limited by factors such as dormant seeds.

The total concentration of electrolytes leached by seeds during soaking has long been assessed indirectly, mostly through the conductivity test, which takes advantage of the fact that inorganic ions make up a substantial portion of these electrolytes [3–5].

Rapid assessment of seed quality allows for preemptive decision-making during harvest, processing, sale and storage operations, thus optimizing use of financial resources throughout these processes.

K. coriacea Mart. is a species of the Clusiaceae (Guttiferae) family popularly known in Brazil as pau-santo (Portuguese for “holy wood”), due to its properties as a medicinal and melliferous plant and as a source of cork. In traditional Brazilian medicine, the leaves are used as an emollient and antitumor agent, and the resin as a tonic and in the treatment of toothache and various infections. The fruits are used in regional crafts and flower arrangements. Even if the dye is of the leaves and bark. The trunk provides cork [6].

K. coriaceae specimens grow to approximately 4 meters in height. The flowering period extends from January to April and the fruiting period from May to September, and seed collection can take place from September onwards. Leaves are alternate, simple, oval to elliptical, coriaceous, and clustered at the end of the branches, and feature highly visible, pink midribs. A white to off-white latex is secreted in small amounts upon removal of leaves. Flowers are white to pale pink in color, large, fragrant, with many yellow stamens and are borne in short clusters near the apex of the branches. Seedling production requires that seeds be sown shortly after collection.

In the fruit are found 60 to 80 seeds with anemochoric. The seed varies from round to oblong, winged at the ends, light brown color, has integument thin and fragile, with smooth texture, the sizes range from 4.3 to 5.6 cm long, 1.3 to 1.9 cm wide, and 0.2 to 0.5 centimeter thick. The individual weight of the seeds ranges from. 112 to.128 grams. Nursery radicle emission occurred at 7 days and the germination rate was 90%. Germination occurs within 7 to 10 days. The species is slow growing, both in the field and in a nursery setting [7].

The present study sought to assess the applicability of the conductivity test to freshly collected K. coriacea Mart. seeds by determining the optimal soak time for performance of the test and comparing results obtained with this method against those obtained by tetrazolium and germination testing of seeds from the same batch.

2. Materials and Methods

2.1. Seed Collection

Seeds were collected in the cerrado sensu stricto, in SCA (Clean Water Farm), area of study at the University of Brasília (UNB) in August 2010, matrixes marked with the aid of GPS, after the period of physiological maturation of the seeds. The collection of fruits was directly from the tree, with the help of trimmer, then the seeds were processed and stored in paper bags at room temperature in the laboratory.

2.2. Conductivity Test

The development of tests to evaluate the physiological quality of seeds, as well as the standardization of these is essential for the establishment of an efficient quality control [8]. One of the main requirements for the seed vigor refers to obtain reliable results in a relatively short period of time, allowing the speed of decision making especially as regards the operations of collection, processing, and marketing [9]. The literature indicates that rapid tests are most studied early events related to the deterioration of the sequence proposed by Delouche and Baskin [10] as the degradation of cell membranes and reduced activity, and biosynthetic respiratory [9]. The measurement of electrical conductivity through the electrolyte amount released by soaking seeds in water has been applied by the individual method where each seed is a sample or more often, a sample of seed representative of a population (mass method). For this case, the results represent the average conductivity of a group of seeds, may a small amount of dead seeds affect the conductivity of a batch with many high-quality seed generating a read underestimated. To minimize this problem, we recommend choosing the seeds, excluding the damaged seeds.

The electrical conductivity is based on the principle that the deterioration process is the leaching of the cells of seeds soaked in water due to loss of integrity of cellular systems. Thus, low conductivity means a high-quality seed and high conductivity, that is, greater output seed leachate, suggests that less force [11].

The electrical conductivity is not yet widely used in Brazil, its use is restricted to activities related to research (Krzyzanowski et al., 1991). There are common jobs using this test to determine the physiological quality of tree seeds. However, it is a promising vigor test for possible standardization of the methodology, at least within a species. However, it is a promising vigor test for possible standardization of the methodology, at least within a species. However, there are factors which influence the conductivity values as the size, the initial water content, temperature and time of soaking, the number of seeds per sample, and genotype [12].

Five treatments were carried out to test the efficiency of the conductivity test as a means of evaluating the viability of freshly collected K. coriacea Mart. seeds.

Five runs of 20 seeds were tested for each treatment. Seeds were individually placed into containers holding 50 mL of distilled water and left to soak for 30, 90, 120, 180, and 240 minutes in a germination chamber set to a constant temperature of 25°C. The minimum time taken for the soaking of 30 minutes was adopted by the same authors and Amaral and peske [13], Fernandes et al. [14], and Matos [1] who concluded that the period of 30 minutes of soaking is more effective to estimate the germination of the seeds. After each period, the conductivity of the soak solution was immediately tested with a benchtop EC meter precise to +/−1% (Quimis). Readings were expressed as μS·cm−1/g−1 seed [15].

Data thus obtained were subjected to analysis of variance with partitioning into orthogonal polynomials for analysis of the effect of soaking times on electrical conductivity.

2.3. Tetrazolium Test

The tetrazolium test, also known as biochemical test for vitality, is a technique used to estimate the viability and seed germination. A fundamental condition for ensuring the efficiency of the test is the direct contact of the tetrazolium solution with the tissues of the seed to be tested. Due to the impermeability of the coats of most forest tree seeds, it is necessary to adopt a previous preparation of the seeds that were tested. This preparation is based on facilitating entry of the solution in the seed. Among the preparations that precede the test we have cutting the seed coat, seed coat removal, scarification by sandpaper scarification by soaking in hot water and water [16]. In the previous preparation of the seeds, factors such as concentration of the solution or even the time of the staining solution can affect the efficiency of the test in the evaluation of seed quality. The time required for the development of appropriate color according to the Rules for Seed Analysis [16] varies depending on each species, can be between 30 and 240 minutes.

The tetrazolium test has been widely used in seeds of various species due to the speed and efficiency in the characterization of the viability and vigor, and the possibility of damage to the same distinction, assisting in the process of quality control from the steps of harvest storage (GRIS et al, 2007).

The tetrazolium test was also applied to freshly collected K. coriacea Mart. seeds, for a total of three runs and 20 seeds. Seeds were soaked in a 0.5% solution of 2,3,5-triphenyl-2H-tetrazolium for 24 hours in a germination chamber set to a constant temperature of 25°C. After each run, seeds were washed, bisected, and the half-containing the embryonic axis placed under a stereo viewer for examination of staining patterns [17].

2.4. Germination Test

The standard germination test is the official procedure to evaluate the ability of seeds to produce normal seedlings under favorable conditions in the field, but does not always reveal differences in quality and performance among seed lots, which can manifest in storage or in the field [18].

During the germination test optimum conditions are provided and controlled for seeds to encourage the resumption of metabolic activity which will result in the seedlings. The main objective of the germination test is the information about the quality of seeds, which is used in the identification of lots for storage and sowing [19].

Freshly collected K. coriacea Mart. seeds were placed in a germination chamber at a constant temperature of 25°C (Treatment 1) or an alternating temperature of 20–30°C (Treatment 2), on a standard cycle of 8 hours of light and 16 hours of dark. Each test consisted of five runs and was performed on 20 seeds.

Germination was defined as emergence of at least 2.0 mm of the primary root [20]. Assessment was conducted daily, and emergence was observed between day 6 and day 7. At the end of the 14-day test period, the germination percentage was calculated on the basis of radicle emergence [21].

Capture

3. Results

3.1. Conductivity Test

Different soaking times were not associated with any significant differences in conductivity results in K. coriacea Mart. seeds (Table 1).

Table 1: Conductivity ranges of freshly collected Kielmeyera coriacea Mart. seeds after soaking for different periods.
Seeds with a leachate conductivity range of 7–17.99 μS·cm·g were considered nonviable, confirming the hypothesis behind conductivity testing, which is the nonviable seeds that have higher soaking solution conductivity values (Table 2).

Table 2: Percentage of viable Kielmeyera coriacea Mart. seeds according to EC range.
Analysis of variance revealed a low coefficient of variation (20.26%), which suggests good experimental control (Table 3).

Table 3: Analysis of variance of various soaking times for electrical conductivity testing of Kielmeyera coriacea Mart. seeds.
After analysis of variance, the correlation between the soaking time and electrical conductivity variables was assessed. The cubic model yielded

Capture

which is indicative of a positive correlation between the study variables.

The following equation was obtained on the basis of the cubic model:

Capture

 

Analysis of a plot of the above function in the GeoGebra 2007 software package shows that variation in electrical conductivity as a function of soaking time is minor and approaches a constant, which is consistent with the study results, in which changes in soaking time had no influence on conductivity (Figure 1).

378139.fig.001
Figure 1: Leachate conductivity as a function of soaking time in Kielmeyera coriaceaMart. seeds.

Matos [1] reported that a 30-minute soak was enough for assessment of Anadenanthera falcata, Copaifera langsdorffii, and Enterolobium contortisiliquum seeds by the soaking solution pH method—that is, the amount of matter leached after this period sufficed for measurement.

Although the principle of conductivity is the same used for the test pH of exudate, the soaking time needed to analyze the differential seeds through the conductivity may be explained by the fact that this technique is quantitative, while pH in the art exudate analyzes are qualitative. In other words to the technique of pH values of the exudate it is important to detect the acidity of imbibition while on the electrical conductivity we draw a comparison between the analyzed values to separate viable from nonviable samples. To determine a value of electrical conductivity as a reference to determine viable seeds are to be considered the values obtained for fresh seeds and seeds stored.

The thickness of the K. coriacea Mart. seed coat may also have affected the soaking procedure; this species has very thin seed coats, which makes soaking a very fast process.

These results are consistent with those reported by Rodrigues [22], who subjected stored K. coriaceaMart. seeds to the conductivity test and found that 90 minutes is an appropriate soaking time for analysis.

Therefore, it can be inferred that for seed Kielmeyera coriacea Mart. the soaking time of 90 minutes can be applied to obtain satisfactory results.

3.2. Tetrazolium Test

Table 4 shows the results of tetrazolium testing of K. coriacea Mart. seeds in our sample. The mean viability rate was 96.6%. The testing procedure was based on Brazilian Ministry of Agriculture recommendations [17].

tab4
Table 4: Tetrazolium testing of Kielmeyera coriacea Mart. seeds.

The results of the tetrazolium test were quite similar to those obtained with the conductivity method, thus confirming the efficiency of the latter method as a means for assessing the viability of K. coriaceaMart. seeds.

3.3. Germination Test

The germination test results of freshly collected K. coriacea Mart. seeds are shown in Table 5. Regardless of temperature, both test batches exhibited good viability, and no seed dormancy was detected.

tab5
Table 5: Germination test results of Kielmeyera coriacea Mart. seeds.

Radicle emergence was observed between day 7 and day 9 of the test, according to the analysis criteria proposed by Labouriau [21].

These findings are consistent with those of Melo et al., [23] who reported high and relatively rapid germination rates for K. coriacea seeds kept at 25°C on paper towels, with emergence of a perfect radicle on the 7th day of assessment.

4. Conclusions

The electrical conductivity can be used as an indicator of seed viability and presents two advantages: to provide rapid and reliable results and the technique is not destructive and can use the seeds after the conductivity test, so they can be used to produce seedlings.

The present study showed that different soaking times had no effect on the results of conductivity testing of freshly collected K. coriacea Mart. seeds, suggesting that the amount of leached matter was never below the threshold required for adequate testing.

Electrical conductivity testing proved to be a feasible option for viability testing of K. coriacea Mart. seeds, as the results obtained with conductivity testing were confirmed by germination testing and by the tetrazolium test.

References

  1. J. M. M. Matos, Evaluation of pH test on exudate check feasibility of forest seeds, dissertation, University of Brasília, Brasília, Brazil, 2009.
  2. F. Poggiani, S. Bruni, and E. S. Q. Barbos, “Effect of shading on seedling growth of three species forest,” in National conference on native plants, vol. 2, pp. 564–569, Institute of Forestry, 1992.
  3. M. B. Mcdonald Jr. and D. O. Wilson, “ASA-610 ability to detect changes in soybean seed quality,” Journal of Seed Technology, vol. 5, no. 1, pp. 56–66, 1980.
  4. S. Matthews and A. Powell, “A eletrical conductivity test,” in Handbook of Vigor Test Methods, D. A. Perry, Ed., pp. 37–42, International Seed Testing Associaty, Zurich, Switzerland, 1981.
  5. J. Son Mark, W. R. Singh, A. D. C. Novembre, and H. M. C. P. Chamma, “Comparative studies to evaluate dem’etodos physiological quality of soybean seeds, with emphasis the electrical conductivity test,” Brazilian Journal of Agricultural Research, vol. 25, no. 12, pp. 1805–1815, 1990.
  6. S. R. Singh, A. P. Silva, C. B. Munhoz, et al., Guide of Cerrado Plants Used in the Chapada Veadeiros, WWF-Brazil, Brasilia, Brazil, 2001.
  7. J. M. Felfili, C. W. Fagg, J. C. S. Silva, et al., Plants of the APA Gama Cabeça de Veado: Species, ecosystems and recovery, University of Brasilia, Brasília, Department of Engineering Forest, Brasília, Brazil, 2002.
  8. M. F. B. Muniz, et al., “Comparison of methods for evaluating the physiological and health quality of melon seeds,” Journal of Seeds, Pellets, vol. 26, no. 2, pp. 144–149, 2004.
  9. D. C. F. S. Dias and J. Marcos Filho, “Electrical conductivity to assess seed vigor of soybean (Glycine max (L.) Merrill),” Scientia Agricola, vol. 53, no. 1, Article ID article id, pp. 31–42, 1996.View at Publisher · View at Google Scholar
  10. J. C. Delouche and C. C. Baskin, “Acelerated aging techniques for predicting the relative storability of seed lots,” Seed Science and Technology, vol. 1, no. 2, pp. 427–452, 1973.
  11. R. D. Vieira and F. C. Krzyzanowski, “Electrical conductivity test,” in Seed Vigor: Concepts and Tests, F. C. Krzyzanowski, R. D. Vieira, and J. B. França Neto, Eds., pp. 4.1–4.26, Abrates, London, UK, 1999.
  12. R. D. Vieira, “Electrical conductivity test,” in Seed Vigor Tests, R. D. Vieira and N. M. Carvalho, Eds., p. 103, FUNEP, Jaboticabal, Brazil, 1994.
  13. A. S. Amaral and S. T. Peske, “Exudate pH to estimate, in 30 minutes seed viability of soybeans,”Journal of seeds, vol. 6, no. 3, pp. 85–92, 1984.
  14. E. J. Fernandes, R. Sader, and N. M. Carvalho, “seed viability beans (Phaseolus vulgaris L.) estimated by the pH of the exudate,” in Congress Brazil’s Seeds, Gramado, Brazil, 1987.
  15. F. C. Krzyzanowski and R. D. Vieira, “Electrical conductivity test,” in Seed Vigor: Concepts and Tests, F. C. Krzyzanowski, R. D. Vieira, and J. B. France Neto, Eds., pp. 4.1–4.26, Abrates, London, UK, 1999.
  16. Ministry of Agriculture, Livestock and Supply, Rule for seed testing, SNPA/DNPV/CLAV, Brasilia, Brazil, 1992.
  17. Ministry of Agriculture, Livestock and Supply, Rule for seed testing, SNPA/DNPV/CLAV, Brasilia, Brazil, 2009.
  18. N. M. Carvalho and J. Nakagawa, Seeds: Science, Technology and Production, FUNEP, Jaboticabal, Brazil, 2000.
  19. Pina-Rodrigues, et al., “Quality test,” in Germination from Basic to Applied, A. Ferreira and G. F. Borghetti, Eds., pp. 283–297, 2004.
  20. A. G. Ferreira and F. Borghetti, from basic to Germination applied, Artmed, Porto Alegre, Brazil, 2004.
  21. L. G. Labouriau, seed germination, OAS, Washington, DC, USA, 1983.
  22. L. L. Rodrigues, Study of imbibition time for application the method of electrical conductivity in the verification of the feasibility forest seeds stored, monograph, University of Brasília, Brasília, Brazil, 2010.
  23. J. T. Melo, J. F. Ribeiro, and V. L. G. F. Lima, “Germination of Seeds of some tree species native to the Cerrado,” Journal of Seeds, vol. 1, no. 2, pp. 8–12, 1979.

Research article by: Kennya Mara Oliveira Ramos,1 Juliana M. M. Matos,1 Rosana C. C. Martins,1 and Ildeu S. Martins2

1Seed Technology Laboratory of Forestry, Department of Forestry, University of Brasilia, CP 04357, 70919970 Campus Asa Norte, DF, Brazil
2Department of Forestry, University of Brasilia, CP 04357, 70919970 Campus Asa Norte, DF, Brazil

Received 17 December 2011; Accepted 14 February 2012

Academic Editors: A. Berville, C. Gisbert, J. Hatfield, and Y. Ito

Copyright © 2012 Kennya Mara Oliveira Ramos et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 

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Water Quality Testing in RO Systems – MyronLMeters.com

Posted by 10 May, 2013

Tweet Water quality testing is vital to the design of an efficient, cost-effective RO system, and is one of the best ways to preserve system life and performance. Using an accurate Total Dissolved Solids (TDS) measurement to assess the system load prevents costly mistakes up front. The TDS measurement gives users the information they need […]

DH-UMIII-9PTK-2T

Water quality testing is vital to the design of an efficient, cost-effective RO system, and is one of the best ways to preserve system life and performance.

Using an accurate Total Dissolved Solids (TDS) measurement to assess the system load prevents costly mistakes up front. The TDS measurement gives users the information they need to determine whether or not pretreatment is required and the type of membrane/s to select. Ultrameter™ and ULTRAPEN PT1™ Series TDS instruments feature the unique ability to select from 3 industry standard solution models: 442 Natural Water™ NaCl; and KCl. Choosing the model that most closely matches the characteristics of source water yields measurements accurate enough to check and calibrate TDS monitor/controllers that can help alert to system failures, reducing downtime and increasing productivity. The same instruments provide a fast and accurate test for permeate TDS quality control. Measuring concentrate values and analyzing quality trends lets users accurately determine membrane usage according to the manufacturer’s specifications so they can budget consumption correctly. These daily measurements are invaluable in detecting problems with system performance where changes in the ionic concentration of post-filtration streams can indicate scaling or fouling. System maintenance is generally indicated if there is either a 10-15% drop in performance or permeate quality as measured by TDS.

Thin-film composite membranes degrade when exposed to chlorine. In systems where chlorine is used for microbiological control, the chlorine is usually removed by carbon adsorption or sodium bisulfite addition before membrane filtration. The presence of any chlorine in such systems will at best reduce the life of the membrane, thus, a target of 0 ppm free chlorine in the feedwater is desirable.

ORP gives the operator the total picture of all chemicals in solution that have oxidizing or reducing potential including chlorine, bromine, chloramines, chlorine dioxide, peracetic acid, iodine, ozone, etc. However, ORP can be used to monitor and control free chlorine in systems where chlorine is the only sanitizer used. ORP over +300 mV is generally considered undesirable for membranes. Check manufacturer’s specifications for tolerable ORP levels.

An inline ORP monitor/controller placed ahead of the RO unit to automatically monitor for trends and breakthroughs coupled with spot checks by a portable instrument will prevent equipment damage and failure. Myron L 720 Series II™ ORP monitor/controllers can be configured with bleed and feed switches as well as visible and audible alarms.

Ultrameter and ULTRAPEN portable handhelds are designed for fast field testing and are accurate enough to calibrate monitor/controllers. Our measurement methods are objective and have superior accuracy and convenience when compared to colorimetric methods where determination of equivalence points is subjective and can be skewed by colored or turbid solutions.

Monitoring pH of the source water will allow users to make adjustments that optimize the performance of antiscalants, corrosion inhibitors and anti-foulants. Using a 720 II Series Monitor/controller to maintain pH along with an Ultrameter Series or ULTRAPEN PT2™ handheld to spot check pH values will reduce consumption of costly chemicals and ensure their efficacy.

Most antiscalants used in chemical system maintenance specify a Langelier Saturation Index maximum value. Some chemical manufacturers and control systems develop their own proprietary methods for determining a saturation index based on solubility constants in a defined system. However, LSI is still used as the predominant scaling indicator because calcium carbonate is present in most water. Using a portable Ultrameter III 9PTKA™ provides a simple method for determining LSI to ensure the chemical matches the application.

The Ultrameter III 9PTKA computes LSI from independent titrations of alkalinity and hardness along with electrometric measurements of pH and temperature. Using the 9PTKA LSI calculator, alterations to the water chemistry can be determined to achieve the desired LSI. Usually, pH is the most practical adjustment. If above 7, acid additions are made to achieve the pH value in the target LSI. Injections are made well ahead of the RO unit to ensure proper mixing and avoid pH hotspots. A Myron L 720 Series II pH Monitor/controller will automatically detect and divert solution with pH outside the range of tolerance for the RO unit. ULTRAPEN PT2, TechPro II and Ultrameter Series instruments can be used to spot check and calibrate the monitor/controller as part of routine maintenance and to ensure uniform mixing.

Water hardness values indicate whether or not ion exchange beds are required in pretreatment. Checking hardness values directly after the softening process with the Ultrameter III 9PTKA ensures proper functioning and anticipates the regeneration schedule.

Alkalinity is not only important in its effect on the scaling tendency of solution, but on pH maintenance. Additions of lime are used to buffer pH during acid injection. Use a 9PTKA to measure alkalinity values for fast field analysis where other instrumentation is too cumbersome to be practical.

Though testing and monitoring pressure is a good way to evaluate system requirements and performance over time, measuring other water quality parameters can help pinpoint problems when troubleshooting. For example, if the pressure differential increases over the second stage, the most likely cause is scaling by insoluble salts. This means that any degradation in performance is likely due to the dissolved solids in the feed. Using a 9PTKA to evaluate LSI and calculate parameter adjustments is a simple way to troubleshoot a costly problem.

Myron L Meters saves you 10% on all Ultrameters and Ultrapens when you order online at MyronLMeters.com, where you can find the complete selection of Myron L meters, including the Ultrameter III 9PTKA.

Original story from International Filtration News V 32, no. 2

 

Categories : Application Advice, Case Studies & Application Stories, Technical Tips

Pool Draining Tips to Protect Water Quality – MyronLMeters.com

Posted by 1 May, 2013

TweetMyronLMeters.com has the most advanced lineup of pool analysis meters for the professional pool maintenance technician from the Ultrapen to the PoolPro PS9. Pool Draining Tips to Protect Water Quality With summer right around the corner, many swimming pool owners will be readying their swimming pools in anticipation of the season’s heat. As part of […]

MyronLMeters.com has the most advanced lineup of pool analysis meters for the professional pool maintenance technician from the Ultrapen to the PoolPro PS9.

Pool Draining Tips to Protect Water Quality

With summer right around the corner, many swimming pool owners will be readying their swimming pools in anticipation of the season’s heat. As part of this process, some pool owners like to drain old swimming pool water which has been sitting all winter. Though not a necessary task, the following tips are provided for you to properly drain pool water in order to protect the water resources in your community.

Whenever possible, it is best to drain your pool onto your landscape. This recycles your pool water, conserves irrigation water, and avoids the environmental risks associated with draining your pool to the street. Before draining your pool water to the street or to your landscape, be sure to follow the guidelines outlined below.

While draining pool water to the street is a common practice, it can prove harmful to the environment if the pool owner does not properly plan and prepare prior to draining. When pool water is drained to the street, it can carry other pollutants such as oil, grease, sediment, bacteria and trash down the storm drain and into the nearest creek, river, or the ocean. Swimming pool water also often contains harmful additives and chemicals. If the water is not properly treated to remove these pollutants prior to draining, they can cause further damage to the health of our waterways and to the plants and animals that live there.

Also, prior to draining to the street, residents are asked to sweep the curb and gutter between the discharge point from their yard to the storm drain down hill from their home. This will remove any pollutants from the gutter that may be carried up by the drained pool water to the storm drain.

For chlorine pools, chlorine levels must be lowered to less than 1 part per million prior to draining. This can be done naturally, by simply allowing the pool water to sit in the sun for a minimum of three days. Alternatively, de-chlorination kits can be purchased at home supply stores at a very reasonable cost. These kits have the tools you need to reach the appropriate chlorine levels before draining your pool to the curb and gutter.

Some people have salt water pool systems which may be preferred due to the lower amount of chemicals required for their operation. However, these pools must not be drained to the storm drain system due to their high salt content relative to the fresh water systems they drain into. Total dissolved solids (TDS) must be below 500 parts per million in order to drain into the street.

Green pools,” which are pools in which algae is growing, also must not be drained to the street. In these instances, algae must first be killed and removed. This is usually done by chlorinating the swimming pool until the algae is gone, then lowering chlorine to the allowable discharge level. Cartridge filters or diatomaceous earth (DE) filters should be rinsed onto a pervious surface such as landscaped areas or grass. While DE is actually beneficial in your garden, it can build up in storm drains and clog them. DE residues can be scooped up and simply thrown in the trash or put to use fending off worms in your garden.

For more information on how to reach acceptable chemical and TDS levels, call your pool maintenance specialist.

If you are a pool maintenance specialist, consider the PoolPro PS9TKA from MyronLMeters.com – the most advanced and comprehensive pool water analysis meter on the market.

PS9TK from MyronLMeters.com

 

 

 

 

 

 

 

 

 

Pool Pro PS9TK

Measures 9 Parameters: Conductivity, Mineral/Salts, TDS, Alkalinity, Hardness, LSI, pH, ORP/Free Chlorine, Temperature
LSI Calculator for hypothetical water balance calculations
Wireless data transfer capability with bluDock option
Auto-ranging delivers increased resolution across diverse applications
Adjustable Temperature Compensation and Cond/TDS conversion ratios for user-defined solutions
Nonvolatile memory of up to 100 readings for stored data protection
Date & time stamp makes record-keeping easy
pH calibration prompts alert you when maintenance is required
Auto-off minimizes energy consumption
Low battery indicator
(Includes instrument with case and solutions)

Categories : Case Studies & Application Stories

Screening and evaluation of innate coagulants for water treatment: a sustainable approach – MyronLMeters.com

Posted by 21 Mar, 2013

TweetAbstract Access to safe drinking water is important as a health and development issue at national, regional, and local levels. About one billion people do not have healthy drinking water. More than six million people (about two million children) die because of diarrhea which is caused by polluted water. Developing countries pay a high cost […]

Abstract

Access to safe drinking water is important as a health and development issue at national, regional, and local levels. About one billion people do not have healthy drinking water. More than six million people (about two million children) die because of diarrhea which is caused by polluted water. Developing countries pay a high cost to import chemicals including polyaluminium chloride and alum. This is the reason why these countries need low-cost methods requiring low maintenance and skill. The use of synthetic coagulants is not regarded as suitable due to health and economic considerations. The present study was aimed to investigate the effects of alum as coagulant in conjunction with bean, sago, and chitin as coagulants on the removal of color, turbidity, hardness, and Escherichia coli from water. A conventional jar test apparatus was employed for the tests. The study was taken up in three stages, initially with synthetic waters, followed by testing of the efficiency of coagulants individually on surface waters and, lastly, testing of blended coagulants. The experiment was conducted at three different pH conditions of 6, 7, and 8. The dosages chosen were 0.5, 1, 1.5, and 2 mg/l. The results showed that turbidity decrease provided also a primary E. coli reduction. Hardness removal efficiency was observed to be 93% at pH 7 with 1-mg/l concentration by alum, whereas chitin was stable at all the pH ranges showing the highest removal at 1 and 1.5mg/l with pH 7. In conclusion, using natural coagulants results in considerable savings in chemicals and sludge handling cost may be achieved.

Keywords:

Alum; Chitin; Sago; Bean; Coagulation; Turbidity

Background

The explosive growth of the world’s human population and subsequent water and energy demands have led to an expansion of standing surface water [1]. Nowadays, the concern about contamination of aquatic environments has increased, especially when water is used for human consumption. About one billion people do not have healthy drinking water. More than six million people (about two million children) die because of diarrhea which is caused by polluted water[2,3].

In most of the cases, surface water turbidity is caused by the clay particles, and the color is due to the decayed natural organic matter. Generally, the particles that determine the turbidity are not separated by settling or through traditional filtration. Colloidal suspension stability in surface water is also due to the electric charge of particle surface. Thus, there is great importance in either the development of more sophisticated treatments or the improvement of the current ones [4].

The production of potable water from most raw water sources usually entails the use of a coagulation flocculation stage to remove turbidity in the form of suspended and colloidal material. This process plays a major role in surface water treatment by reducing turbidity, bacteria, algae, color, organic compounds, and clay particles. The presence of suspended particles would clog filters or impair disinfection process, thereby dramatically minimizing the risk of waterborne diseases [5,6].

Many coagulants are widely used in conventional water treatment processes, based on their chemical characteristics. These coagulants are classified into inorganic, synthetic organic polymers, and natural coagulants [4]. Alum has been the most widely used coagulant because of its proven performance, cost effectiveness, relatively easy handling, and availability. Recently, much attention has been drawn on the extensive use of alum. Aluminum is regarded as an important poisoning factor in dialysis encephalopathy. Aluminum is one of the factors which might contribute to Alzheimer’s disease [7-9]. Alum reaction with water alkalinity reduces water pH and its efficiency in cold water [10,11]. However, some synthetic organic polymers such as acrylamide have neurotoxicity and strong carcinogenic effect [8,12].

In addition, the use of alum salts is inappropriate in some developing countries because of the high costs of imported chemicals and low availability of chemical coagulants [3]. This is the reason why these countries need low-cost methods requiring low maintenance and skill.

For these reasons, and also due to other advantages of natural coagulants/flocculants over chemicals, some countries such as Japan, China, India, and the United States have adopted the use of natural polymers in the treatment of surface water for the production of drinking water [13]. A number of studies have pointed out that the introduction of natural coagulants as a substitute for metal salts may ease the problems associated with chemical coagulants.

Natural macromolecular coagulants are promising and have attracted the attention of many researchers because of their abundant source, low price, multi-purposeness, and biodegradation[11,14,15]. Okra, rice, and chitosan are natural compounds which have been used in turbidity removal [16-18]. The extract of the seeds has been mentioned for drastically reducing the amount of sludge and bacteria in sewage [19].

In view of the above discussion, the present work has been taken up to evaluate the efficiency of various natural coagulants on the physico-chemical contaminant removal of water. To date, most of the research has been concentrated on the coagulant efficiencies in synthetic water, but in this study, we move ahead making an attempt to test the efficiency of the natural coagulants on surface water. The efficiencies of the coagulants as stated by [20] might alter depending on many factors: nature of organic matter, structure, dimension, functional groups, chemical species, and others.

Methods

Natural coagulants and their preparation

Sago is a product prepared from the milk of tapioca root. Its botanical name is ‘Manihot esculentaCrantz syn. M. utilissima’. Hyacinth bean with botanical name Dolichos lablab is chosen as another coagulant. Both the coagulants were used in the form of powders (starches). Starch consists mainly of a homopolymer of α-D-glucopyranosyl units that comes in two molecular forms, linear and branched. The former is referred to as amylose and the latter as amylopectin [21]. These have the general structure as per [22] (Figure  1) .

thumbnailFigure 1. General structure of amylose and amylopectin.

The third coagulant was chitin ([C8H13O5N]n), which is a non-toxic, biodegradable polymer of high molecular weight. Like cellulose, chitin is a fiber, and in addition, it presents exceptional chemical and biological qualities that can be used in many industrial and medical applications. The two plant originated coagulants were taken in the form of powder or starch. Chitin was commercially procured.

Stage I

The first stage included testing the efficiency of the four coagulants on the synthetic waters. Synthetic waters with turbidity of 70 and 100 nephelometric turbidity units (NTU) were prepared with fuller’s earth in the laboratory and were used in this part of the study. The experiment was carried out using a jar test apparatus. The experiments were conducted in duplicates to eliminate any kind of error. Efficiency was evaluated by determination of reduction in turbidity of both the synthetic samples.

Stage II

In the second stage of the experiment, the individual coagulants were evaluated for their efficiency on the surface waters. The water samples for this stage and the preceding stage were collected from the surface reservoir, Mudasarlova, located at a distance of 5 km from the Environmental Monitoring Laboratory, GITAM University, where the experiments were carried out. This is the reservoir which serves as a source of domestic water for the nearby residents.

Care was taken while collecting the samples so that a representative sample is obtained. All samples were collected in sterile plastic containers. The samples were transported to the laboratory, and all the experiments were conducted within a duration of 24 h. The physical parameters like temperature and color were noted at the point of sample collection. The water samples were analyzed for the following parameters pre- and post-treatment with the coagulants (Table  1).

Table 1. Physico-chemical parameters tested (stage II)

The coagulants were tested at various concentrations like 0.5, 1, 1.5, and 2 mg/l at three pH ranges of 6, 7, and 8.

Stage III

The results obtained from the second stage of the study have encouraged us to further extend the study in terms of blended coagulants. The blending of coagulants was taken up from the fact that alum was the most widely used coagulant, and hence, it was taken as one part. The remaining combinations were 2, 3, 4, and 5 parts of the natural coagulants, i.e., 1:2, 1:3, 1:4, and 1:5.

Testing of the following parameters was adopted for evaluating the efficiency of the blended coagulants (pre- and post-coagulation) (Table  2). All the analysis has been performed as per the standard methods given by APHA, 2005 [23].

Table 2. Physico-chemical parameters tested (stage III)

E. coli presence

The E. coli bacterial presence and absence were determined in the pre- and post-coagulated water using H2S strip bottle. The water sample was filled into the bottle and allowed to stand for 24 h at room temperature. After 24 h, the water sample was observed for color change; black color change indicates the presence of E. coli.

Results

Coagulant actions onto colloidal particles take place through charge neutralization of negatively charged particles. If charge neutralization is the predominant mechanism, a stochiometric relation can be established between the particles’ concentration and coagulant optimal dose.

In the initial stage of the experiment, the coagulants were tested against synthetic turbid samples with 70 and 100 NTU. According to Figure  2a,b, the optimum dosage of alum was observed to be 1mg/l for both the turbid samples, and the optimum pH is observed to be 7.

thumbnailFigure 2. Turbidity removal efficiency of alum with initial turbidities of (a) 100 and (b) 70 NTU.

It is understood from Figure  3a,b that the optimum dosage for chitin as coagulant is 1.5 mg/l (turbidity to 40 NTU) for 100 NTU, whereas not much difference was observed between pH 7 and 8 for both the turbid samples. The optimum pH is observed to be 7 for both 70 and 100 NTU samples.

thumbnailFigure 3. Turbidity removal efficiency of chitin with initial turbidities of (a) 100 and (b) 70 NTU.

Figure  4a,b exemplifies the trends of sago on the turbidity removal of the synthetic solutions. It is observed that sago was effective at both 1 and 1.5 mg/l (turbidity reduced to 50 and 45 NTU, respectively) for 100 NTU solution, and the efficiency was stable at pH 7 and 8.

thumbnailFigure 4. Turbidity removal efficiency of sago with initial turbidities of (a) 100 and (b) 70 NTU.

Figure  5a,b illustrates the effect of bean on the synthetic turbid samples and turbidity removal. It is observed that bean was effective at 1mg/l (turbidity reduced to 55 NTU) for 100 NTU solution, and the efficiency was stable at pH 7 and 8.

thumbnailFigure 5. Turbidity removal efficiency of bean with initial turbidities of (a) 100 and (b) 70 NTU.

Implications from the stage 1 experiment articulate that the coagulants are quite stable at the pH ranges tested; hence, in the proceeding experiments, all the three pH ranges were considered. In the second stage of experiment, the environmental samples from the surface water source were collected and tested for the removal of turbidity and other chemical parameters. The dosages were the same as the previous stage. The results are graphically represented as shown in Figures  67,89.

thumbnailFigure 6. Turbidity removal efficiency of individual coagulants.

thumbnailFigure 7. Total hardness removal efficiency of individual coagulants.

thumbnailFigure 8. Calcium hardness removal efficiency of individual coagulants.

thumbnailFigure 9. Chloride removal efficiency of coagulants.

The turbidity removal efficiencies of the individual coagulants are depicted in Figure  6 wherein there was a broad variation among the pH ranges. The maximum reduction was observed with 1 mg/l (87%) of bean at pH 6 followed by 1 mg/l (82%) sago at the same pH. At pH 7, the maximum efficiency was shown by bean with 1.5 mg/l dosage (85.37%) followed by bean and sago with 1 (82.49%) and 1.5 mg/l (82.49%), respectively. Removal efficiencies of 41.46% and 36.59% were reported by 1 mg/l of bean and sago, respectively, at pH 8. The minimum reductions are not reported as there was a negative competence of the coagulants at different doses and pH variations. It can be observed from the graph that there was an increase in the turbidity of the water at these dosages like with 2 g of chitin the turbidity removal was −19.51. In the entire study, the best results were obtained with total hardness removal wherein no negative competence was reported as shown in Figure  7. The utmost removal was observed with 0.5-mg/l (97.67%) sago at pH 7. At pH 6, it was (90.70%) with 1.5 mg/l of bean. At pH 8, the reduction was (93.02%) with 0.5 mg/l of alum. Apart from these, the general observation was that all the coagulants were effective in an average removal of 65% total hardness at all pH variations and doses. The tracking for the least efficiency has showed chitin at pH 6 with 2-mg/l dose (34.88%).

The calcium hardness removal efficiencies are directly proportional with the total hardness removal; the highest removal was recorded by chitin (93.33%) at pH 7 with 1.5-mg/l dose as shown in Figure  8. Removal of 90% is at pH 8 and 7 with 0.5-mg/l alum and 1-mg/l chitin, respectively. Minimum effectiveness was observed by chitin (6.67%) at pH 6 with 2-mg/l dose. On an average, the removal competence was more than 60% with all coagulants at doses at all the pH conditions.

Figure  8 illustrates the chloride removal efficiency of the coagulants tested. The average competence was observed to be 40%. The maximum competence was noted at pH 7 by chitin (83.64%) at 1.5 mg/l followed by sago (81.82%) at 1 mg/l. Indeed at pH 7, the removal was observed to be superior as a whole. Similarly, pH has shown inferior effectiveness in the amputation of chloride. The remarkable point that was noted is that at pH 8, where the removal was superior, the increase in doses of sago and bean (1.5 and 2 mg/l) has shown a depressing outcome.

With the results obtained from the second stage experimentation, the study was carried forward for the evaluation of blended coagulants. From the literature, it was understood that blended coagulants show improved competence than that of the individual ones.

The regular test of turbidity was substituted with conductivity to establish a relation and test the difference with these parameters. The conductivity diminution was observed to be preeminent at the ratio of 1:2 of all the blended coagulants 26.12%, 26.00%, and 21.35% with alum/bean, alum/chitin, and alum/sago, respectively. The highest reduction was observed with alum/sago at pH 8 with 1:2 ratio (32.28%) (Figure  10).

thumbnailFigure 10. Conductivity removal efficiency of blended coagulants.

The total hardness reduction trend of the blended coagulants was recorded as follows: at pH 7, all combinations of alum/bean have resulted in negative competence. Amputation of 100% was observed with alum/chitin and alum/sago at 1:2 and 1:4 and 1:5 doses, respectively (Figure  11). The overall competence of the alum/chitin and alum/sago were registered to be more than 80%. The calcium hardness efficiencies of the blended coagulants were similar to that of the total hardness. The highest removal efficiency was shown by alum/chitin with 1:5 ratio at pH 7 (Figure 12).

thumbnailFigure 11. Total hardness removal efficiency of blended coagulants.

thumbnailFigure 12. Calcium hardness removal efficiency of blended coagulants.

As said earlier, the turbidity was replaced by color determination taking into account the fact that turbidity is directly related to the color. pH 7 has been remarkably effective in the highest removal of color from the water. The blended coagulant alum/sago was found to be very effective with 98% to 100% reduction in color at all the ratios of dosage (Figure  13). The blended coagulants alum/chitin and alum/sago were relatively successful at an average rate of 80% decline in the color at almost all ratios of dosage at pH 7 and 8.

thumbnailFigure 13. Color removal efficiency of blended coagulants.

Alum/sago blend has a noteworthy effect on the removal of chloride from the water samples in which no negative result was noted. The highest reduction was observed with alum/chitin with dose of 1:5 (85.71%) at pH 7. Indeed, pH 7 can be optimized as perfect pH for this blend as all the ratios of dosages were quite efficient in the removal of chloride (Figure  14).

thumbnailFigure 14. Chloride removal efficiency of blended coagulants.

Discussion

Although many studies have used synthetic water in the experiments, this work chose to use raw water collected directly from the surface source. Therefore, it is important to consider that the natural compounds may cause variations in their composition, which interfere in the treatment process. All those factors are taken into account when evaluating the obtained results.

The characteristics of the superficial water used in this study are observed as that the water used has apparent color, turbidity, solids, and amount of compounds with a relatively high absorption in UV (254 nm). It is noticeable that the water has high turbidity and color.

The effectiveness of alum, commonly used as a coagulant, is severely affected by low or high pH. In optimum conditions, the white flocs were large and rigid and settled well in less than 10 min. This finding is in agreement with other studies at optimum pH [24,25]. The optimum pH was 7 and was similar to the obtained results by Divakaran [26]. At high turbidity, a significant improvement in residual water turbidity was observed. The supernatant was clear after about 20-min settling. Flocs were larger and settling time was lower. The results showed that above optimum dosage, the suspensions showed a tendency to restabilize.

The effectiveness of the chitin in the present study in the removal of various contaminants with varied pH individually and also in blended form can be traced to the explanation from the literature that chitin has been studied as biosorbent to a lesser extent than chitosan; however, the natural greater resistance of the former compared to the last, due to its greater crystallinity, could mean a great advantage. Besides, the possibility to control the degree of acetylation of chitin permits to enhance its adsorption potential by increasing its primary amine group density. Recent studies regarding the production of chitin-based biocomposites and its application as fluoride biosorbents have demonstrated the potential of these materials to be used in continuous adsorption processes. Moreover, these biocomposites could remove many different contaminants, including cations, organic compounds, and anions [27].

Chitosan has high affinity with the residual oil and excellent properties such as biodegradability, hydrophilicity, biocompability, adsorption property, flocculating ability, polyelectrolisity, antibacterial property, and its capacity of regeneration in many applications [28]. It has been used as non-toxic floccules in the treatment of organically polluted wastewater [29].

The effects of coagulation process on hardness are observed for varying levels of hardness, which resulted in significant decrease of hardness removal. The study correlates with the results obtained by [27], wherein they had a maximum hardness removal of 84.3% by chitosan in low turbid water with initial hardness of about 204 mg/l as CaCO3.

Several experiments were carried out to determine the comparative performance of chitosan on E. coli in different turbidities. E. coli negative is present in the chitin-treated waters in all of the turbidities. The conclusive evidence was found for the negative influence of chitosan on E. coli. The regrowth of E. coli was not observed in the experiments after 24 h, which was similar to the observations by [27].

As far as sago is considered, the starch was effective both individually and as blended coagulant. Unlike polyaluminium chloride, the efficiency of the natural coagulants is not affected by pH. The pH increased their efficiency, which is one of the advantages of natural coagulants. The principle behind the efficiency of the sago from the literature can be stated as follows: Sago starch is a natural polymer that is categorized as polyelectrolyte and can act as coagulant aid. Coagulant aid can be classified according to the ionization traits, which are the anions, cations, and amphoteric (with dual charges). Bratskaya et al. [30] mentioned that among the three groups, cation polymer is normally used to remove adsorbed negatively charged particles by attracting the adsorbed particles through electrostatic force. They discovered that anion polymer and those non-ionized cannot be used to coagulate negatively charged particles.

The chemical oxygen demand (COD) reduction is influenced by the concentration of sago used; the lower the concentration the better the removal of the COD. Using less than 1.50 g L-1, better COD reduction is observed. At this low concentration, settling time did not influence the COD reduction. Similarly, concentration of sago used at lower than 1.50 g L-1 reduced the turbidity in less than 15 min of settling time. Sago concentration higher than 1.50 g L-1 increased the turbidity; however, settling time has an influence on the turbidity reduction at higher sago concentrations. This pattern is congruent with the COD removal [31].

The sago starch-graft-polyacrylamide (SS-g-PAm) coagulants were found to achieve water turbidity removal up to 96.6%. The results of this study suggest that SS-g-PAm copolymer is a potential coagulant for reducing turbidity during water treatment [32].

At its optimum concentration, D. lablab seed powder does not affect the pH of the water. Total and calcium hardness remained almost constant and were within acceptable levels according to World Health Organization standards for drinking water. Moreover, coagulation of medium to high turbidity water with D. lablab seed powder with the finest grain size reduced turbidity further. The best performance of the finest seed powder could be due to its large total surface area, whereby most of the water-soluble proteins are at the solid–liquid interface during the extraction process as stated by Gassenschmidtet al. [33]. This might have increased the concentration of active coagulation polymer in the extract, which improved the coagulation process. The coagulant extract from seeds has shown antimicrobial activity in the comparative culture test, which was also observed in the study of Tandonet al. [34].

D. lablab demonstrated the best performance with turbid water, in which a turbidity removal efficiency of 87% was observed. The restabilization of destabilized colloidal particles, which was associated with higher residual turbidities, occurred at dosages above the optimum. It is commonly observed that particles are destabilized by small amounts of hydrolyzing metal salts and that optimum destabilization corresponds with neutralization of the particles’ charge. Larger amounts of coagulants cause charge reversal so that the particles become positively charged and, thus, restabilization occurs, which results in elevated turbidity levels [35]. It has also been observed that the reduction in turbidity is associated with significant improvements in bacteriological quality. The effect of natural coagulants on turbidity removal and the antimicrobial properties against microorganisms may render them applicable for simultaneous coagulation and disinfection of water for rural and peri-urban people in developing countries [36].

It is observed that blended coagulants gave utmost efficiency as compared to the traditional alum coagulants. Here in this blending process, we reduce the alum dose up to 80%; thus, we reduce the drawbacks of the alum. Also, we can reduce the cost of the treatment using the natural coagulants instead of the traditional coagulant.

E. coli is the best coliform indicator of fecal contamination from human and animal wastes. E. colipresence is more representative of fecal pollution because it is present in higher numbers in fecal material and generally not elsewhere in the environment [37]. Results showed the absence of E. coli increases with increasing time. A greater percentage of E. coli was eliminated in higher turbidities. The aggregation and, thus, removal of E. coli was directly proportional to the concentration of particles in the suspension. Chitosan and other natural coagulants showed antibacterial effects of 2 to 4 log reductions.

Antimicrobial effects of water-insoluble chitin and coagulants were attributed to both its flocculation and bactericidal activities. A bridging mechanism has been reported for bacterial coagulation by chitosan [38]. Especially with reference to chitosan, molecules can stack on the microbial cell surface, thereby forming an impervious layer around the cell that blocks the channels, which are crucial for living cells [39]. On the other hand, cell reduction in microorganisms, such as E. coli, occurred without noticeable cell aggregation by chitosan.

This indicates that flocculation was not the only mechanism by which microbial reduction occurred. It was found that when samples were stored during 24 h, regrowth of E. coli was not observed for all turbidities. It should be noted that the test water contained no nutrient to support regrowth of E. coli, and chitosan is not a nutrient source for it. Another experiment was designed to check the effect of alum alone. Regrowth of E. coli was not observed for unaided alum after 24 h. The number of E. coli after resuspension of sediment reached to the initial numbers after 24 h and showed that it cannot be inactivated by alum. Such findings have been previously reported by Bina[40].

Conclusion

Access to clean and safe drinking water is difficult in rural areas of India. Water is generally available during the rainy season, but it is muddy and full of sediments. Because of a lack of purifying agents, communities drink water that is no doubt contaminated by sediment and human feces. Thus, the use of natural coagulants that are locally available in combination with solar radiation, which is abundant and inexhaustible, provides a solution to the need for clean and safe drinking water in the rural communities of India. Use of this technology can reduce poverty, decrease excess morbidity and mortality from waterborne diseases, and improve overall quality of life in rural areas.

The application of coagulation treatment using natural coagulants on surface water was examined in this study. The surface water was characterized by a high concentration of suspended particles with a high turbidity. At a varied range of pH, the suspended particles easily dissolved and settled along with the coagulants added. Research has been undertaken to evaluate the performance of natural starches of sago flour, bean powder, and chitin to act as coagulants individually and in blended form. In all three cases, the main variable was the dosage of the coagulant. The study shows that natural characteristics of starch and other coagulants can be an efficient coagulant for surface water but would need further study in modifying it to be efficient to the maximum. Thus, it can be concluded that the blended coagulants are the best which give maximum removal efficiency in minimum time.

It is chitin and chitosan which can readily be derivatized by utilizing the reactivity of the primary amino group and the primary and secondary hydroxyl groups to find applications in diversified areas. In this work, an attempt has been made to increase the understanding of the importance and effects of chitin at various doses and pH conditions, upon the chemical and biological properties of water. In view of this, this study will attract the attention of academicians and environmentalists.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 

Saritha Vara

Author Affiliations

Department of Environmental Studies, GITAM Institute of Science, GITAM University, Visakhapatnam, Andhra Pradesh 530045, India

International Journal of Energy and Environmental Engineering 2012, 3:29 doi:10.1186/2251-6832-3-29
The electronic version of this article is the complete one and can be found online at:http://www.journal-ijeee.com/content/3/1/29

Received: 24 May 2012
Accepted: 30 July 2012
Published: 5 October 2012

© 2012 Vara; licensee BioMed Central Ltd.

 

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