Abstract:

The coagulation effect of different coagulants on the petrochemical secondary effluent has been investigated，and these coagulants have been matched according to their characteristics. The complex coagulant， the type of matched component， dosage， pH， and settling time of the coagulation are studied. At the same time， by means of prefab flocculant test， the removal mechanism of organisms are discussed. The results show that treatment effect of the complex coagulant， PFAC +FC +AC +PAM， has more remarkable enhancement compared to the individual coagulants. The best coagulating conditions of the system are as follows：PFAC dosage=150 mg/L， pH=5,settling time=1 h， m（FeCl₃）∶m（AlCl₃）=9∶1（the total dosage is 50 mg/L）， and the removal rate of TOC is as high as 40.39%.After the treatment， TOC is reduced to 15.51 mg/L， The effluent quality can meet the requirements of the Firstclass Standard of Integrated Wastewater Discharge Standards （GB 8978—1996）. Charge neutralization and complexation-adsorption are the main mechanisms for organism removal during the coagulation proccess.

Key words: petrochemical secondary effluent, coagulation, complex coagulant

摘要：

考察了不同混凝剂对石油化工生化出水的混凝效果,并针对不同混凝剂的特性复配,对复配组分的种类、加量、pH、混凝沉降时间进行了研究,同时通过预制絮体实验对复合混凝剂去除有机物的机理进行了探讨。结果表明,复合混凝剂PFAC+FC+AC+PAM比单独的混凝剂处理效果有显著的提高,该体系最佳混凝条件为pH=5.0、PFAC加量为150mg/L、m(FeCl3)∶m(AlCl3)=9∶1(总量保持50mg/L)、沉降时间为1h。在此条件下TOC去除率高达40.39%,处理后TOC降至15.51mg/L,水质达到污水综合排放标准的一级标准(GB 8978—1996);电中和和络合吸附是混凝过程中有机物的主要去除机理。

关键词: 石油化工二级出水, 混凝, 复合混凝剂

CLC Number: 

• X703.1