活性炭与混凝剂预处理不同废水的效果对比

Treatment efficiency optimization and comparison of activated carbon and coagulants for different wastewater pretreatment

膜污染是制约纳滤技术在废水处理和回用应用的主要问题。吸附法和混凝法是废水预处理的常用方法,可以有效降低污水的浊度和色度物质,保障后续膜工艺的稳定运行。但由于不同类型废水中污染物含量和组成特点各不相同,对活性炭吸附或混凝处理的性能和效率有显著的影响,需要针对性的筛选和优化来选取合适的预处理工艺参数条件。本研究采用4种活性炭(A-D型)和4种混凝剂(FeCl3,Al2(SO4)3,PACla和PAClb)对城市污水、制药废水和纺织废水的预处理效率进行优化。结果表明,B型投加量为30 g·L-1对城市污水处理效率最高,对制药废水D型投加量为20 g·L-1是更可取的,针对纺织废水D型投加量为30 g·L-1时是最合适的选择。混凝预处理方法下,城市污水和纺织废水使用0.5 mmol·L-1的PACla效果最佳,而制药废水则是投加0.5 mmol·L-1的FeCl3效果更好。通过对优化后的吸附剂和混凝剂预处理效果的比较,表明采用吸附剂和混凝剂相结合的方法可以获得最佳的预处理效果,且成本更经济合理。

Membrane fouling is a serious issue hindering the application of nanofiltration in wastewater treatment and reuse.Adsorption and coagulation are recommended for the pretreatment of wastewater,however,the complexity and variation of the composition in different kinds wastewater significantly influence their performance and efficiency.In this study,four types of activated carbon(Type A-D)and four coagulants(FeCl3,Al2(SO4)3,PACla and PAClb)were investigated for the optimization of pretreatment efficiencies of three kinds of wastewater including municipal wastewater,pharmaceutical wastewater and textile wastewater.The results showed that for absorption process,Type B at the dosage of 30 g·L-1 showed the best treatment efficiency for municipal wastewater,Type D at the dosage of 20 g·L-1 was more preferable for pharmaceutical wastewater,and Type D at the dosage of 30 g·L-1 was the most appropriate choice for textile wastewater.For coagulation process,PACla at the dosage of 0.5 mmol·L-1 was most acceptable for municipal wastewater and textile wastewater,while FeCl3 at the dosage of 0.5 mmol·L-1 was more outstanding for pharmaceutical wastewater pretreatment.The comparison of pretreatment efficiency between the optimized absorbent and coagulant indicated that the combination of absorbent and coagulant would provide the best pretreatment efficiencies with more reasonable cost.