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Due to increased concerns regarding the potential for contamination of drinking water supplies,considerable efforts have been devoted towards enhanced monitoring capabilities of priorityinorganic and organic pollutants. Bench-scale experiments were designed and performed at theU.S. Environmental Protection Agency (U.S. EPA) Test ), neat glyphosate, commercial glyphosate(Roundup), aldicarb, potassium ferricyanide, nicotine, lead nitrate, dimethylsulfoxide, sucrose,colchicine, dicamba, and anhydrous sodium thiosulfate. The test compounds were selected tosimulate some of the properties of chemical and biological agents. One multi-parameter monitorand one free-chlorine monitor were used to represent typical sensors in use at water distributionsystems. The parameters monitored were chloride, free chlorine, specific conductance, turbidity,ammonia-nitrogen, nitrate-nitrogen, oxidation-reduction potential (ORP), and pH.The bench-scale tests were conducted in a reaction vessel (4-liter beaker) using 3.5 liters ofCincinnati tap water. The tests were designed to evaluate the responses of several water qualitysensors to a number of potential contaminants [added in the increment of 0.2 milligram per liter(mg/L) every minute]. Each test was carried out for 20 minutes.The study provided the minimum detection levels of the contaminants for various water qualityparameters, which were compared to life-threatening toxicity concentrations for drinking water.Of all the parameters, free chlorine was the single most sensitive indicator in the study. Inaddition to free chlorine, specific conductance, ammonium-N, nitrate-N, ORP, chloride, and pHalso showed sensitivity for detection.Based on the study results it can be concluded that commercially available single and multiparametermonitors can trigger (below life-threatening toxicity concentrations) and providewarnings when drinking water is contaminated by toxic contaminants below life-threateninglevels (dose). Of all the parameters, chlorine was the single most important indicator of thestudy. Multiple parameters crossed the threshold limits for several contaminants namely, neatglyphosate, commercial glyphosate (Roundup), potassium ferricyanide, and anhydrous sodiumthiosulfate Includes 4 references, tables, figures.
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