Experimental study on factors controlling anaerobic P-release
控制BNR工艺厌氧释磷效果因素的实验研究

Anaerobic P-release directly controls the total effect of bio-P removal in biological nutrient removal (BNR) processes. Based on a lab-scale BNR process (BCFS), batch experiments were applied to study the effects of initial COD concentrations, carbon sources and HRT on anaerobic P-release. The results from batch experiments indicate that P-release increased with increasing influent COD. The average rates of P-release were not affected by initial COD concentrations if the anaerobic HRT was sufficient. The P-release effect was good as long as the rate of uptake of volatile fatty acids (VFAs) per unit of sludge (VSS) was above 0.04 g·h-1. With glucose used as carbon source, anaerobic P-release within 3 h was less than with acetate and propionate. The final amount of P released in the presence of acetate was lower than that released with propionate, but the reaction time (HRT) required to reach the same amount of P-release within 3 h with acetate was half of that required with propionate.