Application Of Organic Framework Materials In Wastewater Treatment

With the rapid increase of the global population,the gradual improvement of people's living standards,the pollution of water has become one of the major concerns of the world.The dyes,pharmaceuticals and personal care products?PPCPs?are major contributor to the pollution.At present,there are many materials and methods used to treat them in sewage,but most of the traditional materials and methods are difficult to remove them from wastewater.In recent years,metal-organic framework?MOFs?and covalent organic framework?COFs?,as a new class of porous framework materials,are increasingly used in wastewater treatment due to their porosity,structural adjustability and high surface area.In this paper,the materials are used to study common pollutants such as dyes,pharmaceuticals and personal care products,and laying a foundation for the design of more and better sewage treatment materials in the future.The experimental contents are as follows:we choose the UiO-66 MOFs materials and then modification a series of different groups on it,such as,-NH₂,-NO₂,-Br,-CH₃,-OH,-SO₃H and–COOH.The MOFs materials as adsorbent can adsorb methyl orange and methylene blue.The results show that the UiO-66-R with different groups?R=-H;-NH₂;-NO₂;-Br;-CH₃;-OH;-SO₃H;-COOH?have different adsorption trends for the two kinds of ionic dyes.The UiO-66-NH₂ has the highest adsorption capacity about methyl orange,while it has the lowest adsorption capacity about methylene blue.Based on the above studies,we also selected three anionic PPCPs with similar structure,size and pK_a:2,4-dichlorophenoxyacetic acid?2,4-D?,clofibric acid?CLA?and diclofenac sodium?DCF?as the adsorbents for research.Through adsorption studies,we found that the adsorption trend of these eight MOFs materials on PPCPs was the same as that of methyl orange,namely UiO-66-NH₂>UiO-66>UiO-66-CH₃>UiO-66-OH>UiO-66-Br>UiO-66-NO₂>UiO-66-SO₃H>UiO-66-COOH.According to adsorption kinetics and adsorption isotherm,we carried out a detailed analysis of the reasons for the differences in the adsorption capacity of these materials.In addition,as COFs materials have been reported more and more,many of its applications have received widespread attention.Herein,we selected several triazine rings and benzene ring COFs for the treatment of the sewage,and some preliminary findings have been obtained through experimental research.