Fabrication And Studies Of Novel Materials Towards Oil And Dye Polluted Water Treatment

With the improvement of people's pursuit for the material standard of living,all kinds of wastewater consequently followed.On one hand,oily sewage is increasingly generated from industrial production and daily life,as well as the frequent marine oil spill accidents.On the other hand,large amounts of dye wastewater are directly discharged into the environment caused by the technical defects of dye use and post-treatment in the dyeing industries.Currently,superwetting oil/water separation materials have become an effective technology for oily wastewater treatment.However,most of these materials are still faced with the drawback that they can only separate the free or immiscible oil/water mixtures in the process of gradually forward development.In this thesis,facing multiple types of surfactant stabilized emulsion systems and complex dye polluted oil/water mixtures,we firstly devote to developing graphene-based emulsion separation material.In combination of special wettability and material functionality,a series of functional oil/water separation materials have been successively designed,which expand the application research of superwetting materials towards dye polluted wastewater treatment,at the same time,lay a solid foundation for the application of multifunctional water treatment.The main works are as follows,1)Reduced graphene oxide membrane for oil-in-water emulsion separation has been fabricated by using benign dopamine as the reductant benefiting from its fascinating properties of high adhesion and self-polymerization.The as-prepared membrane is capable of separating multiple types of surfactant stabilized oil-in-water emulsions with high separation efficiency,which may provide a forward outlook for graphene-based materials in applications of emulsified wastewater treatment.2)Preparation of dual-functional water purification mesh for oil/water separation and in situ dye degradation under visible light irradiation.?-FeOOH nanorods,a kind of inorganic semiconductor photocatalytic materials,have been anchored on the polydopamine pretreated substrate surface via low-temperature hydrolysis route.The obtained mesh enables to achieve “water removing” type of oil/water separation and exhibits excellent visible light catalytic performance for the degradation of dyes at the same time.This approach may lay a foundation for integration of special wettability and photocatalytic activity of semiconductor materials for the applications in dual-functional water purification field.3)Preparation of dual-functional water purification mesh for oil/water separation and in situ catalytic reduction of aromatic dyes.Ag nanoparticles have been anchored on the mesh support coated with polydopamine through electro-deposition approach.The asprepared mesh is capable of achieving “water removing” type of oil/water separation and superior catalytic performance in the reduction of sundry aromatic dyes in situ.Besides,the mesh possesses robust immobilization capability and strong resistance to oxidation,which extends the service life and provides new potential prospects in water purification.4)Preparation of oil-in-water emulsion separation membrane with in situ dye adsorption.Catechol/polyethyleneimine composite has been deposited onto the mixed cellulose ester microfiltration membrane surface by one-step immersion method based on Michael addition and Schiff base reaction.The composite deposited membrane presents excellent separation efficiency and high adsorption performance towards dye polluted surfactant-stabilized oil-in-water emulsion.In addition,the dye adsorption-desorption cycle can be quickly accomplished,which makes the recycling of membrane easy and will facilitate its versatility and practicability in sophisticated and emulsified effluents decontamination.