皮革废水处理中絮凝沉降工艺的改进与应用

以皮革污水处理中的絮凝沉降工艺为研究对象，研究了聚丙烯酰胺（PAM）用量、聚合氯化铝铁（PAFC）用量及污水pH值对COD去除率的影响。结果表明，污水pH值是影响絮凝沉降效果的关键因素，将污水pH调节为7.0后，即可用0.4 mg·L-1的PAM与1 g·L-1的PAFC实现54%的COD去除率。同时研究了活性炭及硅藻土对污泥膨胀的应急处理效果，当添加量均为1 g·L-1时，活性炭能够在1 h时迅速使沉降比下降20%，而硅藻土虽见效较慢，但其长时间的沉降效果远好于活性炭（能够在8 h时使沉降比下降64%），说明两种物质的投加时机应有所不同。以上研究成果应用于皮革污水处理厂后，提高了污水处理效果，并取得了明显的经济效益。

Improvements and application of flocculation technology in leather wastewater treatment

The effects of the amount of polyacrylamide (PAM), ferric chloride (PAFC), and sewage pH on the COD removal rate in the flocculation process of leather sewage treatment were investigated. The results indicate that sewage pH is the key factor that affects the COD removal rate; the COD increased to 54% at pH 7.0, when the dosage of PAM and PAFC was as low as 0.4 mg·L-1 and 1 g·L-1, respectively. Moreover, activated carbon and diatomite were investigated to improve the settling performance of sludge when sludge bulking occurred. A loading of 1 g·L-1 of activated carbon reduced 20% of the settled volume in 1 h, while a loading of 1 g·L-1 of diatomite reduced 64% of the settled volume in 8 h. This shows that diatomite is more effective than activated carbon over extended periods, and implies that the addition time of the two substances should be different. Application of these findings would result in a leather-processing factory that has enhanced efficiency for wastewater treatment and significant economic benefits.