Processing of municipal wastewater sewage sludge into a soil conditioner/fertilizer.

A process has been designed for transforming wastewater sewage sludge into a marketable soil conditioner and/or fertilizer for residential use and agricultural land applications. Several alkaline stabilizing materials were examined for their effectiveness in producing a stable and safe product. It was concluded that a quicklime addition at 8% to 9% by mass was the optimal choice based upon temperature rise, pH level, vector attraction, pathogen reduction and cost. Cement kiln dust (CKD) and lime kiln dust (LKD) are good bulking agents. Since CKD provides K$\sb2$O and P$\sb2$O$\sb5$, which are valuable plant nutrients, CKD is preferred for marketing purposes. Subsequent research focused on transforming the stabilized sludge into a physical form which would facilitate material handling, storage and usage. Cylindrical pellets were found to be a shape that facilitated processing, handling and spreading. A pilot plant was set up to lime stabilize sludge obtained from the Little River Sewage Treatment Plant, Windsor, Ontario. All representative samples were analyzed for selected pathogenic bacteria, selected opportunistic pathogenic bacteria and protozoa/platyhelminthes. Although there was a limited regrowth of opportunistic pathogenic bacteria, the U.S. EPA Class A Pathogen Reduction requirements (with the exception of viruses) for non-heat treatment stabilization methods were achieved. No protozoa or platyhelminthes were found in any samples. (Abstract shortened by UMI.)Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1991 .W453. Source: Masters Abstracts International, Volume: 30-04, page: 1474. Co-Supervisors: C. C. St. Pierre; J. K. Bewtra. Thesis (M.A.Sc.)--University of Windsor (Canada), 1991