船舶含油废水电化学氧化预处理研究

Study on pretreatment of the ship’s oily wastewater by electrochemical oxidation

采用电化学氧化法预处理船舶含油废水,考察了极板间距、电流密度、初始氯离子浓度对废水中氨氮、COD去除率的影响,并在优化条件下对比了反应前后关键指标的变化以及对有机污染物的去除情况。结果表明,优化反应条件:极板间距2 cm,电流密度20 mA/cm^2,初始氯离子质量浓度4000 mg/L,反应时间3 h。在此条件下,处理出水中的氨氮、总氮、石油类、悬浮物均达到船舶生活污水污染物排放限值;难生化降解苯系物氧化分解为易生化降解小分子烷烃类、醇酮类物质,水质可生化性明显改善。

The electrochemical oxidation process was used to pretreat the ship’s oily wastewater.The effects of ele-ctrode distance,current density and initial chloride ion concentration on the removal rates of ammonia nitrogen and COD in the wastewater were studied.In addition,changes of key indexes and removal ratios of organic pollutants be-fore and after reaction were compared under the optimized condition.The results showed the optimized reaction con-ditions were as follows:the electrode distance 2 cm,the current density 20 mA/cm^2,the initial chloride ion concen-tration 4000 mg/L and the reaction time 3 h.Furthermore,under the above conditions,the ammonia nitrogen,the total nitrogen,the petroleum and the suspended matter in effluent that all reached the pollutant emission limit of domestic sewage from ships.The refractory benzene series were oxidized and decomposed into the small molecule matters which could be easily degraded by biochemical methods,such as alkanes,alcohol ketone,etc.And the biodegradability of wastewater was obviously improved.