Studies On Modification Of Spepiolite And The Application In Dealing With Acid Dyestuff Waste Water

As a kind of water-miscible dyestuff with better coloring ability, acid dyestuffs are used commonly in area of printing and dyeing. Harmfulness of drain water containing acid dyestuffs is so great, because of it's great releasing amount, sophisticated component, and deep colourity. There are many compounds that contain benzene rings, amido, and azo group and cannot be degraded easily in the drain water, which make it more harmful. Direct release of this kind of drain water to environment will do harm to water, soil, and plants, subsequently affects human being's health and be in trouble of bladder cancer.Taking advantage of strong absorbability of sepiolite and it's function without secondary pollution after pollutant removal, organic modified treatments are done using surfactants containing anion and cations. Variation of absorption ability to eosin Y before and after treating are studied. Spepiolite/TiO₂ composites with photocatalysis ability are prepared through hydrolyzing-sintering approach. Congo red, alizarin red S, acid fuchsin, and Eosin Y with representative chemical are considered as the studied degraded objects. Through photocatalysis-oxidization method, feasibility and influencing factors of acid dyestuff's degradation by Spepiolite/TiO₂ composites, mechanisms are studied at the same time. Conclusions have been made as follows:(1)Ultimate absorption capacity of sepiolite modified by cetyl trimethyl ammonium bromide (CTMAB) to Eosin Y is 1000 times as much as that of original sepiolite. In another word, absorption coefficients of canion-modified sepiolite are high. Additionally, absorption efficiency could be influenced by concentration, acidity of Eosin Y's solution and modifying time. Among them, PH values and concentration of Eosin Y system influence more greatly than temperature and time on absorption coefficient.(2)Sepiolite is a very good candidate that can carry the nano-TiO₂.Through hydrolyzing-sintering approach, spepiolite/TiO₂ composites can been prepared. Degradation ability of spciemens, which are prepared under these conditions: PH value: 4.0, ratio of solid and liquid:1:10, slurring temperature:650℃, is best of all.(3)During process of degrading Congo red (3.0×10^-5 mol/L), alizarin red S (3.0×10^-5 mol/L), acid fuchsin (6.0×10^-5 mol/L), and eosin Y (5.0×10^-6 mol/L) solution, best additive quantities are 0.2 g/L,0.3 g/L,0.2 g/L,0.4 g/L respectively, and their photocatalyzing times are 30min, 120min,120min,180min. In addition, degradation efficiency is influenced greatly by initial concentration of acid dyestuff, distance between lingting origin and solution surface and additive quantity of H₂O₂. Initial concentration more lower, distance between lighting origin and solution surface shorter, effect of photocatalysis will be better.(4)Degradation efficiency of Spepiolite/TiO₂ to Eosin Y will still be good, while doing the same work repeatedly 3 times. After usage of 3 times, through burning the organic materials contained in the composites, degradation efficiency is as good as initial usage. Thus, the cost can be cut down greatly in practical application.