Phosphorus Removal in Wastewater Using Activated Ca-Loess Complex

Abstract

In many instances phosphorus is a limiting factor for eutrophication in streams, and lakes. Because wastewater treatment plant itself may be the main phosphorus source in a natural water body, removal of phosphorus in final effluent of wastewater treatment processes is required.Amongst various technologies for phosphorus removal in wastewater, adsorption technology was investigated using activated Ca-loess complex. Ca was added in loess to enhance adsorption capacity and intensity of phosphorus. Ca added loess was activated at a high temperature of 400 ℃ which turned out to be the optimum temperature. Activated Ca-loess complex below 400 ℃ had not enough strength to be applied as an activated Ca-loess pallet column in wastewater treatment process. Ca-loess complex which activated above 400 ℃ lost its adsorption capacity as the loess surface was glassified when the activation temperature reached above 400 ℃. Even if adsorption capacity of activated Ca-loess was not very high due to the lack of abundant pores on its surface, adsorption intensity was still high because it was activated with added Ca in loess.Activated loess was made by pallets. The activated loess pallets were filled in a column, and were applied in wastewater treatment process. Using an activated Ca-loess pallet column, total phosphorus (T-P) was reduced from about 0.5 mg/l to lower than 0.1 mg/l in wastewater treatment, and ionic phosphorus (phosphate) was completely removed for the four months of pilot plant operation.