含油废水异质结微通道分离机理及实验

Mechanism and experiment of micro-channel filtration by heterostructure media particles for oily wastewater treatment

石油炼制废水等石化行业含油废水普遍存在油分与悬浮物高度复合、油分乳化且水质剧烈波动等特征,其达标处理成为关乎企业绿色发展与产能拓展的关键因素。针对含油废水分离资源化需求,采用聚二甲基硅氧烷(PDMS)、四氢呋喃(THF)、聚甲基丙烯酸甲酯(PMMA)、固化剂等配制涂敷剂,通过喷涂石英砂制备了改性颗粒,并混合常规石英砂构建了异质结颗粒群,由此开发出异质结微通道沸腾床分离实验装置,考察了其对复合污染乳化废水中污染物的分离效果。结果表明:涂覆改性颗粒的接触角明显增加,且改性颗粒与油滴接触的微界面动态识别过程表明其较原始石英砂的疏油性显著增加;异质结颗粒群经过撕裂、剥离和聚并过程,将乳化液中10μm以下的细小油滴有效聚结并确保废水油分去除率超过92%。针对油分和悬浮物质量浓度不超过50000 mg·L^(-1)的实际石化废水,现场10 m^(3)·h^(-1)规模的异质结微通道沸腾床侧线实验结果表明,在常规工况和波动工况条件下,其出水平均油分质量浓度分别为11.4 mg·L^(-1)和18.2 mg·L^(-1),悬浮物质量浓度则分别降至21.3 mg·L^(-1)和29.1 mg·L^(-1),且经过20 min反洗后沸腾床分离器满足长期稳定运行要求。

The petroleum refinery wastewater and other oily wastewater were characterized as the mixture of oil and suspended solids(SS),oil emulsification,and severe water quality fluctuations.Its compliance treatment has become a key factor related to the green development of enterprises and the expansion of production capacity.In response to the resource utilization of oily wastewater,polydimethylsiloxane(PDMS),tetrahydrofuran(THF),polymethylmethacrylate(PMMA)and curing agent were used to configure the coating agents for sand modification.The raw and modified sands were mixed as heterostructure media particles(HMPs)and filled in the fluidized bed for micro-channel filtration of oily wastewater.The results showed that the contact angle of the modified sand increased significantly as well as its oleophobicity through dynamic recognition of the micro-interface in contact.After tearing,peeling and coalescence of emulsified oil in heterostructure media particles,the fine oil droplets below 10μm in the emulsion were effectively coalesced and the oil removal efficiency exceeded 92%.A 10 m^(3)·h^(-1) pilot-scale microchannel fluidized bed separator with heterostructure media particles was set up to treat the actual petroleum refinery wastewater with oil and SS contents over 50000 mg·L^(-1).Under the normal and fluctuating conditions,the average effluent oil contents decreased to 11.4 mg·L^(-1) and 18.2 mg·L^(-1),as well as the SS contents decreased to 21.3 mg·L^(-1) and 29.1 mg·L^(-1),respectively.The fluidized bed separator can also satisfy the long-term stable operation requirements after 20 min backwashing.