投加FeSO4对序批式生物膜反应器中DHA、EPS和处理效果的影响

针对化学协同生物除磷过程,研究了序批式生物膜反应器(SBBR)中FeSO_4对悬浮相活性污泥脱氢酶活性(DHA)、胞外聚合物(EPS)及系统处理效果的影响.结果表明,少量FeSO_4对DHA和EPS的分泌具有促进作用,但最佳投加量不一致,分别为0.10 mmol·L-1和0.20 mmol·L-1;大量的FeSO_4则会引发抑制.FeSO_4投加量少于0.30 mmol·L-1时会使污泥MLVSS、MLVSS/MLSS增加,超过0.30 mmol·L-1时则使MLVSS、MLVSS/MLSS下降,但MLSS和SVI随着FeSO_4投加量的增加分别持续增加和下降.FeSO_4对COD和TN的去除具有抑制作用,但并不显著,去除率分别在77%和72%左右;TP的去除效果明显改善,在投加量为0.30 mmol·L-1时效果最好.投加FeSO_4协同生物除磷时建议最佳投加量为0.30 mmol·L-1,此时污泥DHA被轻微抑制,但污泥浓度、EPS、TP去除率均已达到最大,出水水质满足一级A排放标准.

Effects of ferrous sulfate(FeSO4) on dehydrogenase activity(DHA), amount of extracellular polymeric substances(EPS) and the treatment efficiency in a sequencing batch biofilm reactor(SBBR)

Effects of ferrous sulfate (FeSO₄) on dehydrogenase activity (DHA), amount of extracellular polymeric substances (EPS) and the treatment efficiency in a sequencing batch biofilm reactor (SBBR) were investigated. Compared with the controlling stage, without any additions, a small amount of FeSO₄ accelerated the secretion of DHA and EPS, with the optimal dosages of 0.10 and 0.20 mmol·L^-1, respectively. While higher amount of FeSO₄ would inhibit the process. Approximately, the concentrations of MLVSS and MLVSS/MLSS increased with increasing FeSO₄ dosage less than 0.30 mmol·L^-1. The concentrations of MLSS increased persistently with increasing FeSO₄ dosage, and SVI changed conversely. The addition of FeSO₄ slightly inhibited the removal efficiencies of COD and TN, which were 77% and 72%, respectively. However, TP removal efficiency obtained a prominent improvement, indicating that biological phosphorus removal of the SBBR system was enhanced by chemical flocculant. The optimal dosage of FeSO₄ was 0.30 mmol·L^-1. Even though the DHA was slightly inhibited, the sludge concentration, amount of EPS and TP removal efficiency were strengthened, and high quality of effluent were achieved.