Water Analysis

WATER ANALYSIS Industrial producers are required by the United States’ Environmental Protection Agency (EPA) to ensure their waste is safe before it’s discharged. But not every expeller sticks to these limits. Some make mistakes, some don’t comply. To check all wastewater is safe, the EPA and other regulators carry out tests along the water systems. This Technology Networks infographic explores which tests can be used and what they can measure. Treatment steps STEP 1 STEP 2 STEP 3 PRIMARY TREATMENT SECONDARY TREATMENT Filtration of all large Removal of Removal of ~85% of and settleable solids. suspended solids organic matter using and phosphorus. microorganisms. pH is sometimes Bacteria feed on the adjusted at this organic matter and stage. nutrients within the water, breaking them down into harmless by-products. STEP 4 STEP 5 TERTIARY TREATMENT QUATERNARY TREATMENT Reduction of nutrient loading in Removal of persistent emergent wastewater and removal of pathogenic pollutants (e.g., pharmaceutical agents. The aim at this stage is to agents, pesticides) that are poorly improve water quality. degradable. Contaminant types The EPA has limits for more than 90 contaminants, including Heavy metals Pesticides Disinfectants Microbes Radioactive material Exposure to Pesticide Disinfectants like Bacteria like heavy metals exposure has chlorine have Vibrio cholerae Drinking water (mercury, arsenic, been linked been classified as and Salmonella contaminated etc.) have been to hormone probable human enterica can lead with radioactive linked to the disruption, carcinogens by to cholera and substances development of reproductive the International typhoid fever, increases the risk various cancers. distortion and Agency for respectively. of cancer and cancers. Research on may harm fetal Cancer. development. – and each one requires a unique technique to detect it. Ion chromatography can test for inorganic ions such as nitrates and chlorite. As a form of liquid chromatography, the method measures concentrations of ionic species by separating them based on their interaction with a resin. Mass spectrometry coupled with gas and liquid chromatography, can detect heavy metals and per- and poly-fluoroalkyl substances (PFAS). In recent years, PFAS have become a contaminant of rising concern as more studies link the “forever chemicals” (which can be found in many commercial items) to health defects such as reduced bone density and higher cancer rates. Quantitative PCR (qPCR) can amplify and identify any RNA material from bacteria and viruses. For years, this kind of testing has been instrumental in monitoring levels of Legionella bacteria in drinking water. In more recent years, qPCR testing has helped government departments around the world to monitor levels of COVID-19 in communities. Geiger counters, gamma ray spectroscopy and scintillation counting can check for radiation in industrial waste. Fouriertransform infrared spectroscopy (FTIR) and Raman spectroscopy can detect the presence and number of microplastics (less than five millimeters in diameter) by plastic type. Pyrolysis–gas chromatography– mass spectrometry (py-GC/MS) can quantify concentrations of specific types of microplastics in milligrams per liter. Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is also an emerging technique that can detect plastic particles down to 100 particles per milliliter. Despite the increasing health concerns about microplastics, the testing for this emerging contaminant is often less regulated. Discrete analyzers are portable devices that use two parallel measurement techniques – photometric and electrochemical – to check that wastewater isn’t contaminated with corrosion and scaling from industrial equipment. Even post-discharge, wastewater is sometimes tested for the same contaminants to ensure quality control. Sponsored by