Phosphorus pollution of groundwater from small wastewater system is often considered as a major threat for aquatic habitats. Recirculating biofilters are often used to treat small wastewater systems without significant removal of phosphorus. In this paper, a low-cost waste material (dried alum residual) in pre-treated effluents from recirculating biofilters was examined. Two different types of wastewater were used; one collected from a pilot scale biofilter from a municipality and the other generated in the laboratory using bench scale biofilter. Sorption-based treatment system was used to remove phosphorus using alum residual. Batch and fixed bed column tests were conducted. Results indicated that alum residual was effective in removing phosphorus. The presence of organic matter (BOD
) showed to have decreased the phosphorus sorption behaviour. The leaching of aluminium was reasonable and in many cases aluminium was adsorbed onto the alum residual.
Keywords: wastewater, phosphorus, sorption, biofiltration, alum residual