Biosolids and Sludge Management

Abstract

The following literature review covers journal articles related to biosolids and sludge management that were published in 2000. The main topics covered include regulations and planning, reduction of biosolids and sludge production, biosolids and sludge characteristics, thickening, conditioning and dewatering, thermal processes, land application, alternative uses for biosolids, disposal, and articles relating to overall biosolids programs. These topics have been generated by increased regulations and scrutiny of biosolids programs, and the need for continued research and education in the field of biosolids management. REGULATIONS AND PLANNINGConcerns over possible health effects resulting from sludge land application use have reportedly initiated discussions between the EPA and the National Academy of Sciences. Rennier (2000) reported that the EPA may be interested in re-evaluating the 503 regulations. This re-evaluation would focus on human health issues, risk assessment, and ecological issues. Canning (2000) discussed the EPA's proposed dioxin standard of 300 ppt of toxic equivalent for biosolids used in land application.This will effect many treatment plants that exceed these limits indicating that they will be required to find alternative methods of disposal. Conrad (2000) stated that Section 503 regulations are not working, citing examples of improper use of sewage sludge and numerous non-protective aspects of the current standards. Three recommendations were proposed for enhancing Section 503 safeguards: 1) enforce more rigorous monitoring requirements; 2) require limits on infrequently occurring metals and biological contaminants; and 3) increase public awareness and notice of treated land, and universal labeling of sewage sludge products. Birchfield and Stetar (2000) indicated that traditional biosolids handling and disposal methods such as dewatering or incineration can concentrate radionucleotides. The proper management of the land