New Approaches to Wastewater Treatment

A report on some aspects of the research and development work being carried out on waste treatment technology by the Cincinnati Water Research Laboratory of the Federal Water Polution Control Administration (FWPCA) is presented. Pilot plant activities as well as large-scale treatment plants supported partially by FWPCA Research and Development Grants to cities, sanitary districts and states are included. The individual projects range from single-unit processes to complete treatment systems incorporating biological, chemical and physical treatment techniques. Project flows range from 200 gpd to several million gpd. Project objectives include: (1) Technical and economic evaluation of a process or a complete treatment system, or (2) Development of methods for reducing water pollution of a given type or at a specific location. An example of the latter would be the production of water suitable for underground recharge to prevent salt water intrusion, or for reuse in industrial, agricultural, recreational or other applications. Typical treatment techniques are two-stage lime precipitation with lime recovery and reuse, granular activated carbon adsorption, and a variety of biological and chemical techniques for removing the algal nutrients, nitrogen and phosphorus.