If your process water has either too low a pH or too high a pH value, it can result in poor quality products or can cause environmental harm.
pH and Water Quality Overview
If the pH of wastewater is too high or low, it will not be environmentally friendly to release and can harm aquatic life, and potentially even human life. Suppose you work in an industrial operation that uses harsh chemicals that result in extreme pH levels, such as in chemical plants or pulp mills. In that case, you likely need to neutralize the pH by first measuring with rugged pH sensors and then adjusting with chemicals before releasing water back into the environment. These types of adjustments typically happen at wastewater treatment facilities.
Some industrial processes require pH to be in a specific range in order to achieve a certain quality level or process yield. If you were refining metals using a hydrometallurgical process for example, you would need to control pH in a narrow range to ensure the maximum amount of desired metal is extracted. In cases like this, pH control is important not only before releasing to the environment but to ensure production targets are achieved.
Most industrial applications involve measuring pH under challenging conditions. Processes requires accurate adjustments by adding reagents to reach target values. If the final stage is not suitable for an environmentally safe release, an Effluent Neutralization Plant (ENP) will be needed.
pH Monitoring System Overview
There are two basic ways to measure pH levels, and one of them is the colorimetric method that is commonly used to measure pool water. The colorimetric method of measuring pH is imperfect but can be convenient. It involves measuring a solution’s acidity or alkalinity by taking what’s called a grab sample and exposing it to an indicator dye that is sensitive to pH (e.g. pool test strips). However, this method runs the risk of operator bias and inaccurate measurement.
A potentiometric system is that which is used in industrial pH sensors and is a more effective way of measuring pH in an industrial setting because it provides continuous, online measurements and won’t be affected by operator bias, unlike the previous method. The three main parts of the system are the sample (or what you’re testing), the sensing electrode that detects changes caused by hydrogen ion concentrations which also includes a reference electrode for constant voltage input, and finally, the analyzer/ transmitter which interprets the signal from the sensor and provides the measurement
pH Monitoring and Control System
Achieving a target pH, either at each stage during a production process or when treating water for discharge, is vital for optimizing quality, minimizing the amount of costly chemicals added to the process, and making sure that wastewater is safe to release to the environment
Individual control setups vary, but they all share some standard components. For instance, a reactor with agitators, chemical mixers and pumps, which you can turn on or off depending on pH levels, are common. Purpose built pH analyzers and transmitters are often used to control these devices but also Programmable Logic Controllers (PLCs) or distributed control systems (DCS) may be used.
IC Controls is a company that specializes in designing and manufacturing rugged, durable pH sensors, analyzers, meters and transmitters. IC Controls has designed robust devices that can be used in industrial settings for continuous use.
