Use of Coal to Enhance Metabolic Treatment of Sewage

摘要

A newly proposed sewage treatment process in which coal particulates are suspended in mixed liquor and recirculated with activated sludge has been investigated. The premise that the suspended coal particles concentrate nutrients and organic matter by physical adsorption and provide surface area for microbial growth in this enriched micro-environment has been supported. Efficiency of biodegradation by the sewage microorganisms as measured by several parameters, appears to be increased by the process. Laboratory experiments with domestic sewage mixed liquor to which various types of coal were added lent support to the theory by demonstrating considerable improvements in sewage treatment objectives for some of the coals. However, additional work is required to establish conclusively that coal does in fact stimulate metabolic activity. In addition to the chemical and biological results, microscopic photographs taken of coal particles introduced into aerated mixed liquors show that microorganisms concentrate on the surfaces of the coal during the aeration process. Improved phosphate uptake and enhanced BOD reduction together with the photographs support the theoretical basis of the program for some of the coals tested. (Author)