强化水力空化对水中石油污染物降解效能的研究

发布时间：2018-12-13 15:41

【摘要】：近年来,水中石油污染日益严重,严重影响环境安全及人体健康。传统的水中石油去除方法大都工艺复杂、成本高、易产生二次污染。本研究通过水力空化与电催化膜强化催化氧化技术去除水中石油污染物的研究,确定了水力空化与电催化膜强化氧化技术对石油污染物去除效果的影响因素,研究了电催化膜处理石油污水的稳定性,探讨了水力空化与电催化膜对石油污染物的降解机理。水力空化处理石油污水影响因素研究结果表明,水力空化对水中石油具有较好溶解性能,而且还具有一定降解性能。在石油初始浓度为90mg/L、入口压力为0.30MPa、溶液温度为35℃条件下,空化时间为2h时,水中石油初始浓度由90mg/L增加到215mg/L,达到最大值;继续空化5h时,石油去除率达到52.70%;对水力空化前后的水样进行GC-MS分析发现,水力空化后的色谱图的峰数量减少,峰强度降低,谱峰数量由原水的62个变成42个,烷烃峰的峰面积由占总峰面积的49.36%减少到35.49%。水力空化是利用气泡一方面增加石油在水中的溶解性,另一方面气泡通过孔板后溃灭产生的高温、高压和羟基自由基对石油污染物进行降解,达到去除的效果。以石油在水中空化后的溶解量达到最大值215mg/L为电催化膜处理石油污水的原水浓度,进行了电催化膜处理石油污水的研究。研究表明,在电流密度为2.0mA/cm2、pH值为6、停留时间为3.8min、电极间距为40mm、溶液温度为30℃条件下,电催化膜对水中石油污染物催化降解效果最好,石油去除率达到98.81%,COD去除率达到94.77%。GC-MS分析表明,电催化膜催化降解后的峰强度不仅降低,而且峰数量也减少,由原来的57个减少到10个,烷烃峰的峰面积由占总峰面积的44.36%变为23.49%。电催化膜是通过电催化产生氧化性自由基或物质对水中石油污染物进行降解,并利用膜对其起到分离的效果,去除石油污染物。电催化膜的响应面法模型分析及清洗结果表明,电催化膜处理石油污水具有较好的稳定性。COD去除率理论值为94.78%与5组重复实验COD去除率为94.52%基本保持一致,说明电催化膜在去除石油污水的COD方面稳定性较好。清洗后的电催化膜的水通量、石油去除率和COD去除率均基本恢复,水通量由清洗前的75L/(m2·h)恢复到72.8L/(m2·h),石油去除率由99.02%恢复到98.72%,COD去除率也由94.52%恢复到93.73%。此外,电催化膜的能耗和催化效率分别为0.797kW·h/m3和2.445kW·h/kg。水力空化与电催化膜强化催化氧化技术能有效去除水中石油污染物,作为一种新型水处理技术,在难降解有机物去除方面具有广阔的应用前景。
[Abstract]:In recent years, oil pollution in water is becoming more and more serious, which seriously affects environmental safety and human health. The traditional methods of removing oil in water are complex, high cost and easy to produce secondary pollution. In this study, hydraulic cavitation and electrocatalytic membrane enhanced catalytic oxidation (ECAO) were used to remove petroleum pollutants from water, and the influencing factors of hydraulic cavitation and electrocatalytic membrane enhanced oxidation on the removal of petroleum pollutants were determined. The stability of oil wastewater treatment by electrocatalytic membrane was studied, and the degradation mechanism of oil pollutants by hydraulic cavitation and electrocatalytic membrane was discussed. The results show that hydraulic cavitation has good solubility and degradability to petroleum wastewater. When the initial concentration of oil is 90 mg / L, the inlet pressure is 0.30 MPA, the solution temperature is 35 鈩，

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