SMÅ AVLOPP FÖR KRETSLOPP – SORPTION TILL REAKTIVA FILTER / Small-scale wastewater cycling – sorption to reactive filter media
Reactive filter material, sorbents, can be used to remove phosphorus (P) from wastewater through sorption processes. The technique implies that the wastewater pass a fdter that is incorporated in a soil bed or a constructed wetland. When P-saturation is achieved, the sorbent can be recycled to agriculture, since the sorbed phosphorus is available for plant uptake. Ten sorbents were investigated: natural and heated limestone, natural and heated opoka, a spodosol, blast furnace slag (amorphous and crystalline in differenr fractions) and Leca. P-sorption was investigated in batch and column experiments, plant availability was invesugated in extraction- and pot experiments. The batch experiment showed that all tested materials, except for the natural opoka, sorbed P to a rather high extent. Column studies using Leca showed a low P-sorption capacity while slagg used in column experimenis showed a high sorption capacity at the end ofthe experiment. “Complete abstract not presented.”