采用管式无机陶瓷膜深度处理金属表面加工废乳化液

Advanced treatment of spent metalworking emulsion using tubular ceramic membrane

以管式无机陶瓷膜作为主分离工艺,对经过聚合氯化铝和聚丙烯酰胺混凝沉淀预处理后总油和化学需氧量(COD)依然很高的金属表面加工所产生的废乳化液进行深度处理。考察了工艺参数对膜通量及出水水质的影响,探究了膜污染的原因与清洗方法。在跨膜压差为0.16 MPa,废乳化液温度为15~35°C,pH为5~9,总油初始质量浓度不超过300 mg/L的最佳条件下,处理后的COD和总油分别为315.37 mg/L和33.7 mg/L,平均去除率在70%以上。无机陶瓷膜的清洗周期为2 h,在0.20 MPa的跨膜压差下采用0.1%H_2O_2和1%NaOH溶液先后清洗之后,膜通量可恢复至原来的84%以上。

The advanced treatment of a spent metalworking emulsion which was pretreated by coagulation precipitation with polyaluminum chloride and polyacrylamide but still had high contents of total oil and COD(chemical oxygen demand)was conducted by separation based on inorganic ceramic membrane.The effects of process parameters on membrane flux and effluent quality were examined.The contamination of membrane and the cleaning method for its regeneration were studied.Averagely more than 70%of COD and total oil was removed from the spent emulsion with an initial total oil content of at most 300 mg/L under the optimized conditions(i.e.transmembrane pressure 0.16 MPa,temperature 15-30°C,and pH 5-9),and the effluent COD and total oil were 315.37 mg/L and 33.7 mg/L,respectively.The inorganic ceramic membrane should be cleaned every two hours and at least 84%of original membrane flux can be recovered by washing with 0.1%H2O2 and 1%NaOH solutions successively at a transmembrane pressure of 0.20 MPa.