Influence of anaerobic pre-conditioning on phosphorus removal in swine manure by aeration

A feasibility study with three pre-conditioning times was carried out to examine the effect of anaerobic pre-treatment on phosphorus removal by aeration. The results showed that soluble phosphorus could be decreased from 120 mg L-1 to about 40 mg L-1 within one-day aeration. However, soluble phosphorus concentration was found not affected by pre-conditioning, but more pH dependent. Anaerobic pre-treatment significantly increased the uptake of phosphorus by microbes indicated by the increase in concentration of organic phosphorus fraction. The presence of a large proportion of inorganic insoluble phosphorus considerably eclipsed the biological removal of soluble phosphorus, which suggested that the solids/liquid separation before aeration could be important to improve the biological uptake of soluble phosphorus.