Creation of Artificial Soil Aggregates for Wastewater Treatment

Abstract

　To develop a new wastewater treatment system using soil, artificial soil aggregates were produced using a stirring granulation method. The water purification performance of artificial soil aggregates was evaluated under high-speed treatment conditions. Artificial soil aggregates contained high levels of organic matter and phosphorus removal capacities compared to earthworm cast aggregates and silica sand. However, the purification performance of sawdust mixed artificial soil aggregates was relatively low, which was likely due to the formation of a thick biofilm. The purification performance of iron powder mixed artificial soil aggregates decreased when excessively aerated, which was likely due to the production of excessive iron oxides around them. Zeolite mixed artificial soil aggregates had higher levels of ammonia and nitrogen removal capacities. Although artificial soil aggregates displayed the same nitrogen removal rate as conventional soil-based systems, further studies are needed to improve its nitrogen removal capacity.