Aerobic Composting of Swine Manure Solids Mixed with Cotton Gin Waste

Liquid-solid separation treatment can solve many environmental problems associated with confined livestock production. However, treatment technologies are needed to transform the separated manure solids into value-added products. Our objective was to demonstrate, at full-scale, the composting of separated swine manure solids using a centralized solids processing facility. In this facility, the solids were combined with cotton gin waste and wood chips to optimize the composting process. The produced composts conserved 95-100% of the nitrogen and other nutrients and met EPA Class A biosolids quality standards due to low pathogen levels. The composts were used for manufacture of soil amendments, organic fertilizers, and potting soil. Results from this project have demonstrated that manure and other agricultural wastes can be transformed into valueadded products using a simple and effective technology.