Biological Waste Treatment at Elevated Temperatures and Salinities

Abstract

The subject of waste treatment at elevated temperatures and salinities is, perhaps, best introduced by briefly reviewing the history, technology, and fundamentals of waste treatment under ordinary conditions of climate and water quality. The biological treatment of liquified human wastes as an essential municipal activity has been a development of the last 100 years, initiated primarily in Northwestern Europe and Northeastern United States in response to stream pollution and epidemics of cholera and other water-borne diseases brought about by indoor plumbing and the discharge of wastewaters into drainage channels, streams, rivers, lakes, and the sea. The waste treatment processes were designed first to remove large floatable and settleable solids from waste streams by screening and sedimentation and to dispose of these solids in separate systems by burial, drying, incineration, or fermentation. In the late 1800’s, it became evident that physical removal of solids from waste streams was often not sufficient and that colloidal and soluble organic materials in waste streams also had to be removed if the depletion of life-giving dissolved oxygen in waters receiving the wastes was to be avoided. During this period, it became evident that by aerating the wastes under controlled conditions of time and temperature, aerobic microbial growth would occur which would remove most of the biologically degradable organic matter from the waste and incorporate it in particulate biomass subject to physical removal.