Study On Fabrication And Applications Of The Versatile Water Purification Materials

With the rapid development of industrialization,the release of hazardous waste such as heavy metals,organic dyes and oils into the environment has seriously impaired the global water quality.Common methods usually need connect several components to remove multiple contaminants from water,which lead to complicated operation,multi-device,low efficiency and high cost.In this study,we fabricated three versatile materials for simultaneous removal both soluble contaminants and insoluble oils from wastewater by combining the properties of underwater superoleophobicity and a large number of absorption sites.When these materials are used to separate oil/water mixture,the absorption sites can capture soluble contaminants simultaneously,which really simplify the operation processes of water purification.?1?One-step synthesis of cationic hydrogel for efficient dye adsorption and its seconduseforemulsifiedoilseparation.Acationicabsorbent poly-epichlorohydrin-ethylenediamine hydrogel?PEE-Gel?was fabricated by a simple one-step copolymerization and it can be a successful use for removal of toxic dyes and insoluble oil from wastewater.The adsorption towards anionic dyes shows high efficiency and high selectivity in both acid and alkali conditions.The adsorption capacity at low equilibrium concentration(10 mg·L^-1)is as high as 1411.4 mg·g^-1which is very close to the maximum adsorption capacity(1540.2 mg·g^-1).The adsorption of dyes onto PEE-Gel is very steady and can hard be regenerated.The PEE-Gel with full dye adsorption?PEE-Gel-Dye?shows superoleophobicity under water,and PEE-Gel-Dye is reused to separate toluene-water emulsion with high efficiency and durability.These results suggest that PEE-Gel is a promising and competitive material for water purification.?2?Fabrication of a versatile bio-based material?CH-PAA-T?for efficiently removing toxic dyes,heavy metal ions and emulsified oil droplets from water simultaneously.CH-PAA-T was synthesized by simple thermal cross-linking chitosan and polyacrylic acid,which exhibits excellent performances for removing insoluble oil,soluble toxic dyes and heavy metal ions from water,simultaneously.The adsorption capacities are 990.1 mg·g^-1 for methylene blue?MB?and 135.9 mg·g^-1 for Cu²⁺,which are higher than most of present advanced absorbents.The adsorption towards organic dyes possesses high selectivity which makes CH-PAA-T be able to efficiently separate dye mixtures.The stable superoleophobicity under water endows CH-PAA-T good performance to separate toluene-in-water emulsion stabilized by Tween 80.Moreover,CH-PAA-T can be recycled for 10 times with negligible reduction of efficiency.Such versatile bio-based absorbent is a potential candidate for water purification.?3?Developing versatile porous 3D polyurethane/polyacrylic acid?PU-PAA?membrane for one-step multiple contaminants water purification.This work fabricates a porous 3D PU-PAA membrane by simple solvent casting-salt leaching and thermal crosslinking,which combines the properties of underwater superoleophobicity and quantities of carboxyl groups.The stable superoleophobicity can be used for efficient surfactant-stabilized oil-in-water microemulsions separation.And the negative carboxylic ions are able to capture cationic dyes and heavy metals,simultaneously.Using the PU-PAA membrane in filtration column enables one-step multiple pollutants water treatment with high flux,selectivity,recyclability,efficiency and capacity.Moreover,PU-PAA can be used for efficient dyes mixture separation.These results indicate that this versatile porous 3D membrane can be a very potential candidate for advanced purification applications.