Application - Wastewater Chemistries - Final Effluent

Most Frequently Asked Questions  


Parameter Purpose of Test Method
Chlorine, Total
horine is used to disinfect WW plant effluents, prior to discharge to a receiving body. It is normally present as "combined" chlorine (chloramines). Chlorination is generally followed by dechlorination with sulfur compounds, prior to release of effluent. 8167
10070
10232
 
Turbidity Data used to monitor particulates / microbes; Per the Interim Enhanced Surface Water Treatment Rule — Turbidity measurement is required for Conventional and direct filtration systems on each filter and on the combined filter effluent. Also used to monitor raw water changes, signal storm events and to support watershed protection plans. Turbidimeter (2100xx) See instrument manual
pH Data used for monitoring of pH throughout the plant, controlling processes and corrosion. pH meter & electrode - see instrument manual
BOD5 Provides a relative measure of "food" available, the degree of stabilization of the wastewater and to estimate the effect of the effluent on the receiving water body. Used for plant loading/design, discharge rate for industrial facilities, and EPA NPDES reporting. 5 day test is too long for process control — many plants use COD or TOC as early estimate. Used to calculate % removal. 8043
8215
8229
COD
Chemical Oxygen Demand
Used as a correlative/ early indicator of BOD levels. Some NPDES permits include COD as a surrogate for BOD; however, BOD is the standard reportable parameter for oxygen demand in municipal wastewater. COD provides a measure of organic "food" available to biological treatment steps and to estimate the effect of the effluent on the receiving water. (Note: Can be correlated to BOD on a plant-by-plant basis, if influent characteristics are constant.) 8000
10067
 
Nitrate, HR
Indicative of the stage of conversion of ammonia and organic nitrogen forms to nitrate by the aerobic biological treatment steps (nitrification). 8039
10206
10020
Chlorine, Free
Not typically found in wastewawter, due to reactivity with high organic content. May be more common in industrial applications. 8021
10231
Ammonia Monitor conversion of ammonia and organic nitrogen forms to nitrite and nitrate during the WW treatment process. Provices information on process conditions in biological treatment stages. At high concentrations an pH, ammonia can be toxic to sludge digestion microbes. 8038
10031
10205
Chlorine, Total Amperometric Titration Chlorine is used to disinfect WW plant effluents, prior to discharge to a receiving body. It is normally present as "combined" chlorine (chloramines). Chlorination is generally followed by de-chlorination with sulfer compounds, prior to release fo effluent. Amperometric titration is considered the "reference" method for comparisons See AutoCAT 9000 manual
Chlorine, Total ULR Chlorine is used to disinfect WW plant effluents, prior to discharge to a receiving body. It is normally present as "combined" chlorine (chloramines). Chlorination is generally followed by de-chlorination with sulfer compounds, prior to release fo effluent. ULR — This photometric method is EPA approced for ppb level chlorine determination in WW effluent chlorination/dechlorination processes. 10014
Oxygen, Dissolved Measured to control aeration and save money. Also measures the amount of available oxygen for aquatic life in the effluent. DO is also commonly measured reportable parameter on NPDES permits. 8166
8215
8229
8316
8332
8333
Coliforms, Fecal
E.Coli
Monitor and quantify microbial concentrations in the effluent. NPDES reporting requirement for some facilities 8074

Also Consider  


Parameter Purpose of Test Method
Nitrogen, Total Total of ammonia, nitrate, nitrite, and organic nitrogen forms. 10071
10072
10208
Oil and Grease Present in wastewater from both animal and petroleum sources. Can affect settlability of solids in waste treatment processes. 10056
Nitrate, LR Indicative of the stage of conversion of ammonia and organic nitrogen forms to nitrate by the aerobic biological treatment steps (nitrification). 8192
Metals Nickel, Molybdenum, Lead, Mercury, Zinc, Chromium, Copper, Arsenic — Measure heavy metal concentrations in effluent waters and ensure compliance with NPDES permit. Of concern in effluents and land-applied biosolids due to potential toxicity.  
Solids Most commonly measured and regulated parameter on NPDES permits. Used to measure mixed liquor suspended solids concentration, return activated sludge/waste activated sludge concentration, influent suspended solids concentration, effluent suspended solids concentration, and % removal. 8006
TKN
Total Kjeldahl Nitrogen
Total of organic and ammonia forms of nitrogen. 8075
Flow Measure standard in-pipe flow rate for NPDES permit requirements and to establish concentrations/total presence of key analytes.  
TOC
Total Organic Carbon
Used as a surrogate for BOD or COD, as a measure of organic content. 10128
10129
10173