What is water treatment waste?

Water treatment wastes are materials that are removed during various treatment processes and contain large amounts of water. These wastes include turbidity and color-forming materials, organic and inorganic solids, algae, bacteria, viruses, and precipitated chemicals. These materials are byproducts of chemical coagulation, iron and manganese precipitation, filter washing, hardening, resin regeneration, and microfilters. The resulting liquid may contain 3 to 10 percent water by volume. Depending on the type of process and the quality of the raw water, the concentration of solids in the wastes varies from 0.1 to 4 percent. These wastes should not be discharged into the streams, rivers, or lakes from which they originated. Currently, these wastes are part of the industrial wastes whose discharge to surface waters is within the scope of the Water Pollution Control Act Amendments of 1972 and the Clean Water Act of 1977. For discharges to surface waters, a national discharge permit will be required.

Management of operational and process units

Waste management generally involves settling, thickening, conditioning, dewatering, drying, recycling and disposal. Often, wastewater treatment plant effluents are allowed to be discharged into municipal sewers. The choice of these processes depends largely on factors such as the available space on site, the type and amount of sludge, the local climatic conditions, the price of the raw chemicals and the type of final disposal method.

Appropriate Pattern for Waste Management

The selection of an appropriate pattern for sludge thickening, conditioning, dewatering, disposal or recycling should be based on the size of the unit, the cost of construction and equipment, the available land and location of the unit, and operating factors such as chemicals, energy, labor, and the capabilities of each process, as well as the overall economic considerations of the treatment pattern.

Factors affecting the final selection of the appropriate treatment pattern

1. Land requirements
2. Performance in adverse weather conditions
3. Ability to handle flow variations
4. Process reliability
5. Ease of operation and maintenance
6. Prerequisites
7. Sludge and supernatant quality