Abstract：
The effect of coagulant dosage in a chemically enhanced primary treatment (CEPT) on the performance of a conventional wastewater treatment plant (WWTP) has been investigated. Lab-scale experiments simulations were carried out in order to evaluate the effect of coagulant addition on the primary settling performance. In these experiments, FeCl3 was used as coagulant. Later, the WWTP was theoretically simulated using a commercial software (WEST®) to evaluate the effect of coagulation/flocculation on the global system, based on the results obtained at lab-scale. According to these results, the CEPT modifies the organic matter balance in the WWTP, decreasing the contribution of readily (SS) and slowly (XS) biodegradable fractions of COD to the aerobic biological process up to 27.3% and 80.8%, respectively, for a dosage of FeCl3 of 24 mg L-1. Consequently, total suspended solids in the aerobic reactor and the secondary purged sludge decreased up to 33% and 13%, respectively. However, the influence on effluent quality was negligible. On the contrary, suspended solids concentration in the sludge to be treated by anaerobic digestion increased, mainly regarding the Ss and Xs fractions, which caused an 8.1% increase in biogas production potential, with approximately 60% of CH4 concentration.
摘要：
已研究了化学强化一级处理（CEPT）中混凝剂用量对常规污水处理厂（WWTP）性能的影响。进行实验室规模的实验模拟以评估添加混凝剂对初级沉降性能的影响。在这些实验中,FeCl3用作凝结剂。稍后，使用商业软件（WEST®）对污水处理厂进行了理论模拟，以评估混凝/絮凝对全球系统的影响，基于在实验室规模获得的结果。根据这些结果,CEPT改变了污水处理厂中的有机物平衡，将COD的易（SS）和缓慢（XS）可生物降解部分对好氧生物过程的贡献降低到27.3%和80.8%，分别,对于24mgL-1的FeCl3剂量。因此,好氧反应器和二级吹扫污泥中的总悬浮固体减少了33%和13%，分别。然而,对出水水质的影响可以忽略不计。相反,厌氧消化处理污泥中的悬浮物浓度增加，主要是关于Ss和Xs馏分，这导致沼气生产潜力增加了8.1%，与大约60%的CH4浓度。
