基于二氧化铅阳极的电催化氧化深度处理钻井废水的研究

Advanced treatment of drilling wastewater by electrocatalytic oxidation with lead dioxide anode

对泥浆池上清液与泥浆板框压滤出水两类典型的实际钻井废水进行预处理,得到4类电催化进水:泥浆池上清液稀释样(水样1)、泥浆池上清液絮凝处理样(水样2)、泥浆池上清液絮凝气浮处理样(水样3)和泥浆板框压滤出水稀释样(水样4).以钛基二氧化铅(Ti/PbO_(2))为阳极构建双阴极电催化体系,对上述4类水样(进水COD范围为95.58~131.7mg/L)进行深度处理,探究钻井废水的电催化去除规律.实验表明,电催化能够高效、无选择性地去除钻井废水中的有机污染物,处理40min后水样3的COD去除率最高达到84.31%.水样2、3、4的出水氨氮与总氮浓度显著降低,但浊度升高.这可能是因为氯离子的存在提高了氨氮与总氮的去除率,铝离子有助于羟基络合物的形成.

In this study,two typical actual drilling wastewaters(slurry tank supernatant and slurry plate and frame filter effluent)were pre-treated to obtain four types of electrocatalytic influents:slurry tank supernatant diluted sample(water sample 1),slurry tank supernatant flocculation treatment sample(water sample 2),slurry tank supernatant flocculation air flotation treatment sample(water sample 3)and slurry plate and frame filter filtrate diluted sample(water sample 4).The double cathode electrocatalytic system was constructed with titanium-based lead dioxide(Ti/PbO_(2))as anode,to perform advanced treatment of the above four types of water samples(influent COD range:95.58~131.7mg/L)in order to explore the electrocatalytic removal of drilling wastewaters.The results showed that the organic pollutants in drilling wastewaters could be efficiently and non-selectively removed by electrocatalysis.The highest COD removal efficiency of water sample 3 reached 84.31% after 40 min of treatment.The effluent ammonia nitrogen and total nitrogen concentrations of water samples 2,3 and 4decreased significantly,but the turbidity increased.This may be because the presence of chloride ions improved the removal efficiency of ammonia nitrogen and total nitrogen,and aluminium ions contributed to the formation of hydroxyl complexes.