超疏水超亲油和超亲水水下超疏油颗粒滤料混合过滤床的构建及其处理含油废水的研究

Oily water is a common wastewater with complex elements and a wide range of industries such as steel, textile, food, petrochemical and oil production. Deep bed filtration is technically and economically one of the most effective tertiary treatment procedure of oil water, suits especially for oil particles smaller than 10 μm and the lower concentration, and often used combination with other processes. For deep bed filtration process, wettability of filter media has significant influence on oil removal performance. Based on the up to date research focus and frontier in Material Field，this project puts forward preparation superhydrophobic and superoleophilic，superhydrophilic and under water superoleophobic filter media, and thorough mix these two filter media in deep bed to construct a hybrid filter bed. Thus, we provide a new thought for deep bed filtration technology and a new method of oil/water separation..Content: (1) choose different matrix filter material and method to preparation and develop two kinds of special wettability filter media as above mentioned, study the surface properties and stability;(2) research the mixing and backwash hierarchical way of the two filter media, construct hybrid filter bed;(3) study the filtration efficiency for different kinds of oil, research the influence factors such as filter media particle size and the proportion of the two kinds of filter media, bed depth, filtration velocity, oil concentration of raw water, turbidity, PH value and salinity, optimize of all kinds of parameters of oil wastewater treatment by filtration and strengthen backwash of superhydrophobic and superoleophilic filter medium;(4) observe the oil particle size before and after filtration, the coalescence process on the surface of the filter media, obtain the removal mechanism of the hybrid filter bed for oil wastewater.

含油废水是一种量大面广的工业废水，过滤是一种常用的含油废水深度处理方法，作为操作单元与其他方法联用。在过滤单元，滤料的表面润湿性对除油效率有很大的影响。基于材料领域在特殊润湿性表面的研究前沿与成果，提出了研制超疏水超亲油和超亲水水下超疏油两种硬质颗粒滤料，并让两种滤料在床内充分混合，交替排列，构建成混合过滤床，为深床过滤工艺提供一种新的思路，为油/水分离提供一种新的方法。.内容有：（1）选择不同的基质滤料和制备方法，研制上述两类特殊润湿性滤料，研究其表面性质和稳定性；（2）研究滤床的装填和反冲洗分层方式，构建混合滤料床；（3）研究不同种类的油的过滤效率，研究滤料粒径和两种滤料的比例、床深、滤速、原水油浓度、浊度、PH值及含盐量对过滤的影响，确定过滤处理含油废水的各项优化参数，优化超疏水超亲油滤料强化反冲洗参数；（4）观察油珠颗粒粒径变化及在滤料表面的聚结过程，获得混合过滤床的过滤除油机

过滤是常用的含油废水深度处理方法。滤料的润湿性是过滤处理含油废水的重要影响因素，疏水亲油性滤料可有效增大油的黏附概率，亲水疏油性滤料可减小水头损失。为了克服前述两种单一滤料床存在的问题，结合两者的优点，本项目提出了超疏水超亲油/超亲水水下超疏油滤料混合过滤床模式，让上述两种滤料在滤床内均匀混合，交替排列。当含油废水进入滤床表面时，水通过超亲水滤料表面向下流动；某粒油珠若遇到超亲油滤料，则在该滤料表面发生润湿附着，若遇到超疏油滤料，则在该滤料表面的排斥作用下，进入下一层滤料，直到迁移至超亲油滤料表面并发生附着为止。由于两种滤料在理论上是均匀混合的，因此油珠都有机会迁移至超亲油滤料表面。当某粒超亲油滤料表面被油珠全部润湿附着后，再迁移到表面的油珠要么在该滤料表面发生聚结，要么随水流至下一层滤料，截油层依此下移，直至穿过最底层滤料，出水油浓度增高时，该过滤周期结束。.选择壳聚糖作为双亲试剂，用纳米SiO2颗粒构造粗糙结构，制备了超亲水水下超疏油石英砂滤料；选择十八烷基三氯硅烷为亲水疏油基团供体，用纳米ZnO颗粒构造粗糙结构，制备了超疏水超亲油石英砂滤料。研究了化学反应机理，考察了滤料的润湿性和稳定性，获得了滤料的除油性能及机制，明确了滤料的适用范围。.首次将超疏水超亲油和超亲水水下超疏油两种石英砂滤料混合，构建了混合过滤床，研究了滤料床的除油效率和水头损失，考察了滤床参数和工艺参数的影响，发现两种滤料混合过滤具有耦合作用，研究了具体的耦合机理。.依据两种滤料对油和水的不同选择透过性，制备了双向出流的油水分离器。探究了分离器对油水混合液连续分离的性能，获得了最佳的分离器参数和工艺参数，明确了适用范围，为分离器的工业化应用提供了理论依据。.科学意义：项目研究了两种特殊润湿性滤料构建混合床处理含油废水的性能、作用机理和影响因素，为含油废水的处理以及油水分离研究提供了新的思路。