Preparation Of Modified Palygorskite And Chitosan And It’s Adsorption Properties For Arsenic And Malachite Green

With the rapid development of modern industry, waste water contained of heavymetals and dyes, because of their difficult or non-degradable and easily through thefood chain in vivo enrichment, the environment and human life constitutes a greatthreat, is currently significant environmental and human health and safety issues.Based on the review of the form, source, hazards, application，separation andanalysis methods of arsenic and malachite green, the following studies were includedin this thesis.1. Thioglycolic acid modified palygorskite was prepared and characterized by themethods of FT-IR, XRD and SEM. FT-IR and XRD results show that thioglycolic acidsuccessfully linked to the surface of palygorskite. The optimized synthesis conditionwas that the feed mass ratio of palygorskite to thioglycolic acid is1:10, the synthesistemperature is315K, the reaction time is24h and the catalyst of concentrated sulfuricacid is in amount of0.15ml.2. The adsorption behavior of thioglycolic acid modified palygorskite asadsorbent for arsenic was study. The results show that the adsorption capacity ofthioglycolic acid modified palygorskite has good arsenate is30.72mg/g under theconditions that pH at7.0. Thermodynamics examination indicated that the adsorptioncan be better simulatied by the Langmuir model. Dynamics study show that theadsorption meets a pseudo-second-order process.3. Triethylenetetramine modified chitosan was prepared and characterized by theFT-IR and SEM analysis. Characterization analysis showed that there are coordinationreaction between chitosan and triethylenetetramine. The adsorption behavior ofmalachite green triethylenetetramine modified chitosan was studied. Experimentsshowed that its adsorption capacity of malachite green adsorbent is129.53mg/g underthe condition on pH at7.01, adsorbent dosage of0.05g, initial concentration of200mg/L. Thermodynamics examination indicated that the adsorption can be bettersimulatied by the Freundlich model. Dynamics study show that the adsorption meets apseudo-second-order process.