Wastewater municipal

Samples from municipal wastewater treatment plants and samples of industrial discharges often are collected as 24-h composites. Samples are obtained using an automatic sampler that periodically removes individual grab samples. The volume of each sample increment and the frequency of sampling may be constant or may vary in response to changes in flow rate. 

The Clean Water Act (1972) requires discharge limits to be set on industrial and municipal wastewater, and these analyses are outlined in the National Pollution Discharge Elimination System for the 600 Series Methods. Method 624 covers the analysis of purgeable organic compounds Method 625 covers the analysis of 81 bases, neutrals, and acids Method 613 describes the analysis of dioxins and furans. 

An estimate of the potential methane production possible from existing (ca 1992) municipal wastewater treatment plants that produce and use... 

Oxygen is used to treat municipal wastewater and wastewater from the pulp and paper industry (see Aeration, water treatment Wastes, industrial Water). Many of these water appHcations can use VSA-produced oxygen (advantage /). Demonstration and development programs are in place that use oxygen to oxidize sludge from municipal waste and bum hazardous wastes and used tires (advantages 1—4). 

Pubhcly owned treatment work (municipal wastewater treatment facihty) (POTW)... 

These include wastewater cleanup for electroplating (75—78), radioactive processing (79—82), landfill leachate (76,83), and municipal wastewater (84—87) ultrapure water production for electronics-grade (88,89), laboratory-grade (90), and pharmaceutical-grade (91) materials and food processing (qv) (9). 

Nitrogen and phosphoms are required in the reaction at an approximate ratio of BOD N P of 100 5 1. Nitrogen and phosphoms are amply available in municipal wastewaters, but frequendy are deficient in industrial wastewaters. It should be noted that only ammonia nitrogen or nitrate is available for biosynthesis. 

As in all biological reactions, nitrification is a function of temperature. For municipal wastewaters, a minimum sludge age of 3.5 d is required at 20°C while the minimum sludge age must be increased to 12 d at 10°C in order to achieve nitrification. 

In one chemical plant, the required sludge age was found to be 22 d at 22°C, whereas for a nontoxic municipal wastewater, the required sludge age is 3 d. 

Biolog ic lRemoval. Certain organisms normally present in activated sludge have the abiUty to store phosphoms. The process configuration for bio-P removal involves an anaerobic step in which phosphoms is released and acetate taken up by the bio-P organisms. This is followed by an aerobic step in which phosphoms is rapidly taken up by the bio-P. Under proper operating conditions, soluble effluent phosphoms levels of 0.1 mg/L are achievable from municipal wastewater. 

C. A. Macinnis, "Municipal Wastewater," in The Engchpedia of Environmental Science and Engineering, Vol. 1, Gordon and Breach Science PubHshers, New York, 1976, pp. 587-600. 

Much of the experience and data from wastewater treatment has been gained from municipal treatment plants. Industrial liquid wastes are similar to wastewater but differ in significant ways. Thus, typical design parameters and standards developed for municipal wastewater operations must not be blindly utilized for industrial wastewater. It is best to run laboratory and small pilot tests with the specific industrial wastewater as part of the design process. It is most important to understand the temporal variations in industrial wastewater strength, flow, and waste components and their effect on the performance of various treatment processes. Industry personnel in an effort to reduce cost often neglect laboratory and pilot studies and depend on waste characteristics from similar plants. This strategy often results in failure, delay, and increased costs. Careful studies on the actual waste at a plant site cannot be overemphasized. 

The total solids in municipal wastewaters exist in a distribution of sizes from individual ions up to visible particles. Specific analytical procedures have been established to distinguish the suspended fraction of the total solids and to further distinguish the settleable fraction within the suspended solids. A typical concentration of SS (suspended solids) for raw domestic wastewaters is 200 mg/1, but this can vary substantially from system to system. The lower limiting size for the SS fraction (about 1.5 microns) is arbitrarily defined by the test procedures and it should be noted that variations in test procedures themselves can also lead to... 

Corrective Action Application Fluidized bed incineration has been used to incinerate municipal wastewater treatment plant sludge, oil refinery waste, some pharmaceutical wastes, and some chemical wastes including phenolic waste, and methyl methacrylate. Heat recovery is piossible. 

Corrective Action Application In Massachusetts, a municipal wastewater treatment plant receives a number of wastestreams containing heavy metals from local industries. When tested, the dewatered sludge failed the EP toxicity test. In order to permit landfill disposal of the sludge, solidification processes were examined. A soluble, silicate-based system, developed by Chemfix, was ultimately selected which produced a product whose leachate passed the EP toxicity test (Sullivan, 1984). 

System designed for industrial and municipal wastewater treatment facility data management, including key process parameters and plant evaluation. 

Precipitation is nonselective in that compounds other than those targeted may be removed. Both precipitation and flocculation are nondestructive and generate a large volume of sludge which must be disposed of. Coagulation, flocculation, sedimentation, and filtration, are typically followed by chlorination in municipal wastewater treatment processes. 

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