TweetEnvironmental Applications Keeping the water in our lakes, rivers, and streams clean requires monitoring of water quality at many points as it gradually makes its way from its source to our oceans. Over the years ever-increasing environmental concerns and regulations have heightened the need for increased diligence and tighter restrictions on wastewater quality. Control of […]
Keeping the water in our lakes, rivers, and streams clean requires monitoring of water quality at many points as it gradually makes its way from its source to our oceans. Over the years ever-increasing environmental concerns and regulations have heightened the need for increased diligence and tighter restrictions on wastewater quality. Control of water pollution was once concerned mainly with treating wastewater before it was discharged from a manufacturing facility into the nation’s waterways. Today, in many cases, there are restrictions on wastewater that is discharged to city sewer systems or to other publicly owned treatment facilities. Many jurisdictions even restrict or regulate the runoff of storm water — affecting not only industrial and commercial land, but also residential properties as well.
In its simplest form, water pollution management requires impoundment of storm water runoff for a specified period of time before being discharged. Normally, a few simple tests such as pH and suspended solids must be checked to verify compliance before release. If water is used in any way prior to discharge, then the monitoring requirements can expand significantly. For example, if the water is used for once-through cooling, testing may include temperature, pH, total dissolved solids (TDS), chemical oxygen demand (COD), and biochemical oxygen demand (BOD), to name a few.
Once water is used in a process, some form of treatment is often required before it can be discharged to a public waterway. If wastewater is discharged to a city sewer or publicly owned facility, and treatment is required, the quality is often measured and the cost is based not only on the quantity discharged, but also the amount of treatment required. As a minimum requirement suspended solids must be removed. Filtering or using clarifiers often accomplishes such removal. Monitoring consists of measuring total suspended solids (TSS) or turbidity.
If inorganic materials have been introduced into the water, their concentration must be reduced to an acceptable level. Inorganics, such as heavy metals, typically are removed by raising the pH to form insoluble metal oxides or metal hydroxides. The precipitated contaminants are filtered or settled out. Afterward, the pH must be adjusted back into a “normal” range, which often requires continuous monitoring of pH.
Organic materials by far require the most extensive treatment. Many different methods have been devised to convert soluble organic compounds into insoluble inorganic matter. Most of these involve some form of biological oxidation treatment. Bacteria are used to metabolize the organic materials into carbon dioxide and solids, which can be easily removed. To insure that these processes work smoothly and efficiently requires regular monitoring of the health of the biological organisms. The level of food (organic material), nutrients (nitrogen and phosphorous), dissolved oxygen, and pH are some of the parameters that must be controlled. After bio-oxidation the wastewater is filtered or clarified. Often the final effluent is treated with an oxidizing compound such as chlorine to kill any remaining bacterial agents, but any excess oxidant normally must be removed prior to discharge. Oxidation Reduction Potential (ORP)/Redox is ideal for monitoring the level of oxidants before and after removal. The final effluent stream must be monitored to make sure it meets all regulatory requirements.
The monitoring of wastewater pollution does not end there. Scientists are continuously testing water in streams, ground water, lakes, lagoons, and other bodies of water to determine if and what effects any remaining contamination is having on the receiving waters and its associated aquatic life. Measurements may include pH, conductivity, TDS, temperature, dissolved oxygen, TSS and organic levels (COD and BOD).
Environmental testing is not limited to monitoring of wastewater systems. Control of air emissions often includes gas-cleaning systems that involve the use of water. Wet scrubbers and wet electrostatic precipitators are included in this group. A flue gas desulfurization (FGD) system is one type of wet scrubber that uses slurry of lime, limestone, or other caustic material to react with sulfur compounds in the flue gas. The key to reliable operation of these units is proper monitoring of solids levels and pH. After use, the water in these systems must be treated or added to other wastewater from the plant, where it is treated by one of the methods previously discussed.
With proper monitoring, systems that maintain cleaner air and water can be operated efficiently and effectively. Such operation will go a long way toward maintaining a cleaner environment for future generations.
Myron L Meters offers a full line of handheld instruments and in-line monitor/controllers that can be used to measure or monitor many of the parameters previously mentioned. The following table lists some of the model numbers for measuring, monitoring, or controlling pH, conductivity, TDS and ORP. For additional information, please refer to our data sheets or Ask An Expert at MyronLMeters.com.
Note: When using a monitor/controller to measure pH in streams that contain heavy metals, sulfides, or other materials that react with silver, Myron L Meters recommends using a double junction pH sensor with a potassium nitrate (KNO3) reference gel to avoid fouling the silver electrode. See our 720II Sensor Selection Guide for pH and ORP Monitor/controllers for more information.
Ultrameter II 6P
Multi-Parameter: Conductivity, TDS, Resistivity, pH, ORP, Temperature, Free Chlorine (FCE)
+/-1% Accuracy of Reading
Memory Storage: Save up to 100 samples w/ Date & Time stamp
Wireless Download Module Optional
TweetThe All NEW ULTRAPEN PT3 pen tests ORP / REDOX and Temperature with great reliability. Advanced features include highly stable microprocessor-based circuitry; automatic temperature compensation from 15ºC to … [Learn more about the ULTRAPEN PT3 pen NOW!]
The All NEW ULTRAPEN PT3 pen tests ORP / REDOX and Temperature with great reliability. Advanced features include highly stable microprocessor-based circuitry; automatic temperature compensation from 15ºC to … [Learn more about the ULTRAPEN PT3 pen NOW!]
MyronLMeters.com today announced the arrival of a new Myron L product, the Myron L Ultrameter III, a reliable, easy-to-use meter that measures 9 parameters – conductivity, resistivity, TDS, alkalinity, hardness, saturation index, ORP/free chlorine, pH and temperature.
MyronLMeters.com today announced the arrival of a new Myron L product, the , Myron L Ultrameter III 9P , a reliable, easy-to-use meter that measures 9 parameters – conductivity, resistivity, TDS, alkalinity, hardness, saturation index, ORP/free chlorine, pH and temperature.
“The Ultrameter III is available right now at MyronLMeters.com,” said James Rutan, president. “We’ve made it easy to order, offer great training videos, technical bulletins, manuals, and a 10% discount…just for ordering online. In addition, all Myron L Meters in stock will ship the next business day. The quality of the Ultrameter III and the company’s great reputation for reliable meters is sure to make this a big hit. Don’t forget – this new Ultrameter has wireless data transfer capability when you buy the bluDock. Expect about a 10 day lead time for a week or so.”
MyronLMeters.com carries the full line of Ultrameter III accessories, including the Ultrameter III 9PTK AHL Titration kit, soft protective case, replacement sensors, and the full line of standard solutions and buffers – all at a 10% discount when you order online.
Myron L meters are renowned for their accuracy, reliability, and ease of use, and have applications in automatic rinse tank controls, boiler and cooling towers, circuit board cleanliness testing, deionized water, environmental applications, fountain solutions, dialysis, horticulture, hydroponics, ORP (oxidation reduction potential)/Redox, pool and spa, reverse osmosis, textiles.
MyronLMeters.com has a well-established web presence on Facebook, Gravatar, Twitter, Squidoo, LinkedIn, and WordPress. MyronLMeters.com encourages customers to join them on these sites for special offers and discounts.
Tags: MyronLMeters.com, Myron L, Myron L meters, Ultrameter III, conductivity, resistivity, TDS, alkalinity, hardness, saturation index, ORP/free chlorine, pH and temperature, automatic rinse tank controls, boiler and cooling towers, circuit board cleanliness testing, deionized water, environmental applications, fountain solutions, dialysis, horticulture, hydroponics, ORP (oxidation reduction potential)/Redox, pool and spa, reverse osmosis, textiles
Tweet Basic Tips For Choosing The Proper Instrument For Water Quality Tests
Basic Tips For Choosing The Proper Instrument For Water
TweetWhat is the ORP of water? ORP stands for Oxidation Reduction Potential, also known as Redox. It is a measure of the tendency of a chemical species to acquire electrons and thereby be reduced. The ORP measurement is displayed in millivolts (mV) and the usual range for ORP meters is (+1000 mV) to (-1000 mV) […]
What is the ORP of water?
ORP stands for Oxidation Reduction Potential, also known as Redox. It is a measure of the tendency of a chemical species to acquire electrons and thereby be reduced. The ORP measurement is displayed in millivolts (mV) and the usual range for ORP meters is (+1000 mV) to (-1000 mV) with no temperature compensation. It is not a direct measurement of concentration, but rather an indicator of the activity level or strength of an oxidizer or reducer.
An oxidizer gains electrons, while a reducer loses electrons. Examples of oxidizers are: chlorine, hydrogen peroxide, bromine, ozone, and chlorine dioxide. Examples of reducers are sodium sulfite, sodium bisulfate and hydrogen sulfide. Like acidity and alkalinity, the increase of one is at the expense of the other.
When measuring with an ORP meter, a positive voltage shows a solution gaining electrons (oxidizing) and a negative voltage shows a solution losing electrons (reducing). For instance, chlorinated water will show a positive ORP value and a solution with sodium sulfite will have a negative ORP value.
ORP meters are used for swimming pools and spas, drinking water, cooling tower disinfection, and groundwater remediation. ORP meters are also crucial for bleaching applications, cyanide destruction, chrome reductions, metal etching, fruit and vegetable disinfection and dechlorination.
Many organizations around the world have accepted ORP as a standard for disinfection. An ORP of 750 mV was adopted by the German Standards Agency in 1982 for public pools. The National Swimming Pool Institute also adopted an ORP of 650 mV for public spas. The World Health Organization (WHO) adopted an ORP of 700 mV as a standard for drinking water.
How to use ORP?
Oxidation Reduction Potential is a convenient measure of the oxidizer’s or reducer’s ability to perform a chemical task. It is a more consistent and reliable measurement than chlorine alone. You can establish an ORP measurement at which acceptable sanitation is achieved and maintained for your application by testing the rate of inactivation of various microorganisms. There are published standards for many applications or a lab water analysis should be able to provide these results if necessary. For example, the above paragraph mentions the 750 mV standard for public swimming pools. Once that has been determined you can use an ORP controller to maintain that level of sanitation.
Similar to pH, high purity solutions will take extra time to stabilize a reading due to the low ionic strength. Also, if the ORP measurement of a sample solution is similar to the mV of the ORP probe, it will take slightly longer for a reading to respond and stabilize. Rinsing the probe with a strong oxidizer will help to increase the reaction time and give accurate readings quickly. Ensure that there is not residual solution in the ORP probe by rinsing thoroughly with the solution to be tested.
ORP meters like the 728II are used to monitor the sanitizer level. A pH controller, such as the 723II, is also used to monitor pH. The controllers automatically turn the appropriate chemical feeders on and off, as required to maintain the proper sanitizer and pH levels. This results in good water quality and elimination of chloramines and other unpleasant contaminants, as well as in savings in chemical and labor.
Generally, ORP meters without pH control should not be used with alkaline sanitizers such as sodium hypochlorite or calcium hypochlorite. If the pH remains fairly constant, these inexpensive controllers provide a very cost effective solution to the problem of chemical control in small commercial applications.
Other handheld instruments like the POOLPRO PS6 have been designed to test ORP reliably for swimming pools and other applications. If you are in the medical dialysis industry, you will definitely be interested in the Digital Dialysate Meter D-6 that test ORP, among other parameters.