Reducing Soluble Phosphorus in Dairy Effluents through Application of Mine Drainage Residuals

Abstract

Three different dairy manure wastewater effluent samples were amended with mine drainage residuals (MDR) to evaluate the suitability of MDR for sequestration of phosphorus (P). Geochemical modeling of the manure wastewater compositions indicated that partially soluble P-bearing minerals including hydroxyapatite, octacalcium phosphate, and vivianite were all oversaturated in each of the manure wastewater samples. Initial MDR amendment test results indicated that these partially soluble P minerals suspended in the wastewater replenished P in the water phase as it was sorbed by the MDR samples. Further investigations revealed that the MDR samples were effective in decreasing soluble P when the amended manure was tested using the water-extractable P procedure. Under these conditions, up to 90 percent of the soluble P in the manure was converted to a sorbed, water-insoluble state. Water contamination and large-scale validation tests of the process were also conducted.

Keywords:

• Nonpoint source pollution
• wastewater
• water quality

Additional information

Funding

This project was funded, in part, by a grant from the National Fish and Wildlife Foundation’s Chesapeake Bay Stewardship Fund. The authors also thank Trout Unlimited’s Eastern Abandoned Mine Program for additional support.