Effect of Polyaluminum Chloride and Struvite Amendments On Phosphorus Removal in Constructed Wetlands Treated with Swine Wastewater.

Phosphorus removal capacity of constructed wetlands decreases with time, especially with older wetlands and high P containing wastewaters. A paucity of information exists in using Polyaluminum chloride (PAC) and struvite amendments to improve P removal in wastewaters through constructed wetlands. The objective of this research was to determine the effect of PAC and struvite on P removal in constructed wetlands applied with swine wastewater. Initially, laboratory scale experiments were conducted to obtain the optimum concentration of PAC and struvite to precipitate P in swine wastewater. The optimum concentration of PAC and struvite resulting from laboratory experiments were used to demonstrate at field scale constructed wetlands. Two cells of each type of constructed wetland systems were used for the experiment and they were: marsh-pond-marsh (MPM), marsh-floating bed-marsh (M-FB-M), and continuous marsh (CM). A 20% improvement in P removal was observed when swine wastewater was treated with PAC.