Research On The Modified β-cyclodextrin And Used In Chromium-containing Wastewater Treatment

Water resource plays a very important role in the survival and development of human society.The shortage of water resource which caused by water pollution has already become a seriousproblem that the world must to face. Industrial waste water that contained heavy metal was the mainsources of water pollution. It is urgent to develop an efficient method to removal of metal ions fromwastewater.Wastewater treatment has become a necessary way and the effective means to solve thewater shortage and water pollution problem.This paper prepared that the recrystallized β-Cyclodextrin was grafted with polyacrylamide tomodify, synthesized wastewater treatment agent of flocculation type β-CD-PAM and used inchromium-containing wastewater treatment. Experiment was conducted to discuss the optimalpreparation conditions and the performance of β-CD-PAM. Simulated Cr3+-containing wastewaterwastreated with β-CD-PAM, β-Cyclodextrin, polyacrylamide respectively. Batch of experiment werestudied the influence of removal efficiency, it consist of the amount of drug, the temperature ofwastewater, pH value, stirring intensity, standing time and the initial concentration of Cr3+.Through orthogonal design tests and analysis, it was showed that:(1) the optimal molar ratio ofβ-Cyclodextrin and P-toluene sulfonyl chloride that synthesized of β-CD-6-OTs was2:3(mass ratio4:1), the reaction temperature was20℃, pH value>12, the reaction time was3h. The acetonitrilesolution of P-toluene sulfonyl chloride must be added slowly in order to ensure the numerousβ-Cyclodextrin and to prevent the byproduct generation of muti-sulfonate isomers.(2) the optimalmass ratio of polyacrylamide and β-CD-6-OTs that grafted polyacrylamide was2:1, the reactiontemperature was50℃, polyacrylamide monomer concentration was2g/100mL, the reaction time was20h.(3) Under optimal conditions, used β-CD-PAM to treatment the wastewater of Cr3+can obtain theoptimum removal efficiency that compared with β-Cyclodextrin, polyacrylamide. The standardsolution of β-CD-PAM was10mg/L, the optimal conditions were obtained: drug dosage was0.75g/L,the temperature was40℃，pH value was5，the stirring speed was150r/min, the stirring time was3min, standing time was30min and the results showed that the removal rate of Cr3+reached91%.