Treatment of wastewater and process water is necessary to protect public health and the environment, as well as to maintain industrial process efficiency. Regular analytical testing of wastewater effluents at various treatment steps is required by most regulatory bodies. The chemical content of process water used in boiler and cooler systems is also typically analyzed.
To protect the environment and communities, almost all governments require the treatment and testing of municipal wastewater from households and industrial wastewater from chemical, pharmaceutical, food, beverage, and other production facilities. There are four main treatment steps in the wastewater treatment process. The preliminary treatment removes all large and settleable solids from the wastewater. Secondary treatments use accelerated microbiological growth to remove organic pollutants.
The tertiary treatment utilizes a combination of chemical and biological processes to reduce nutrient loading in the wastewater. The quaternary treatment removes particularly difficult emergent pollutants, like pharmaceutical compounds or other complex molecules. Analytical testing at each step is required to monitor key chemical parameters like nitrogen compounds, phosphates, and chlorine.
Analyzing cooling and boiler water is essential for power plants and industrial producers such as chemical, pharmaceutical, technical, or food and beverage companies. Monitoring silicate, calcium, and magnesium content is imperative as they form scale deposits, leading to higher maintenance costs and downtime. Additionally, iron content is also monitored as an indicator of system corrosion. Typically, a demineralizing step is performed by passing the input source water through a clarifier before entering the feedwater tank. The water is further conditioned and sent to the boiler or cooler loop to drive turbines or other activities.
Regulatory agencies, like the U.S. Environmental Protection Agency (USEPA), require the use of official methods when testing drinking water (Safe Drinking Water Act) and wastewater (Clean Water Act). These methods require microbiological testing by culture or molecular techniques, and chemical testing by spectrophotometry, pH, conductivity, and turbidity analysis. Higher sensitivity methods that analyze trace pollutants in water, wastewater, or acid-soluble solids rely on low ppb level detection via either ICP-MS or ICP-AES.