Lin BES-0553322 This international collaborative research project involves U.S. and Egyptian scientists in a study on the co-application of inorganic solids (primarily alum and lime) from water treatment plants with biosolids (sludge) from wastewater treatment plants to agricultural lands. Disposal of residual solids from water and wastewater treatment plants has been a long-standing problem in the United States and elsewhere. The environmental (water quality) impacts of excess nutrients in biosolids have been a major concern regarding land application as a disposal option. Heavy metal loadings also have been a concern, although this problem has been mitigated by source controls on industrial dischargers. The novel approach to be investigated in this project has the potential to solve problems related to excessive levels of phosphorus in biosolids. The hypothesis to be tested is that alum and lime from water treatment residues will immobilize the phosphorus (and also heavy metals) in the biosolids, thus retaining them on the land and minimizing their leaching into ground water or runoff into streams. The work should answer the main question to be addressed: would co-application of water treatment plant residues and biosolids have beneficial effects with regard to minimizing nutrient and heavy metal leaching/runoff when such residual solids are applied to land, which is a common disposal option for biosolids. This work is supported by the Environmental Technology Program and Office of International Science and Education (OISE).
