巯基聚苯乙烯树脂对FGD系统中Hg^(2+)的脱除性能

Hg^(2+) removal from FGD system by thiol polystyrene resin

以氯甲基化聚苯乙烯微球为原料,经过两步反应制得巯基聚苯乙烯树脂,用红外光谱测试、比表面分析、元素分析及热重分析表征了该巯基聚苯乙烯树脂,测试了此巯基聚苯乙烯树脂对含Hg^(2+)烟气、脱硫废水及脱硫浆液的脱汞性能。分析测试表明:巯基聚苯乙烯树脂热稳定性好,能有效脱除烟气、脱硫废水及脱硫浆液中的Hg^(2+)。巯基聚苯乙烯树脂对烟气中Hg^(2+)的脱除效率大于90%,对脱硫废水及脱硫浆液的脱汞率接近100%。将此树脂置于脱硫系统内,能捕捉脱硫系统内的Hg^(2+),避免Hg^(2+)进入脱硫石膏而造成脱硫石膏中汞的再释放。用6 mol·L^(-1)盐酸洗脱捕捉了Hg^(2+)的巯基聚苯乙烯树脂,再生3次后,巯基聚苯乙烯树脂的再生率仍高达90.2%。

Thiol polystyrene resin was prepared by two-step reaction with chloromethyl polystyrene resin as material, and then it was characterized by Fourier transform infrared spectroscopy, Brunauer-Emmett-teller, elemental and thermogravimetric analyses. The Hg^（2＋） removal performance of thiol polystyrene resin was also investigated in simulated flue gas containing Hg^（2＋）, desulfurization effluent and desulfurization slurry. It was found that thiol polystyrene resin possessed high thermal stability and could be used as an absorbent for Hg^（2＋） removal from flue gas, desulfurization effluent and desulfurization slurry. The thiol polystyrene resin showed Hg^（2＋） removal efficiencies above 90%, 100% and 100% in flue gas, desulfurization effluent and desulfurization slurry, respectively. The placation of thiol polystyrene resin in the wet flue gas desulfurization system could capture Hg^（2＋）in this system and avoid its entering to desulfurization gypsum, which could bring the mercury reemission. Moreover, thiol polystyrene resin captured Hg^（2＋） was regenerated successfully by 6 mol·L^（-1） HCl and its regeneration rate with three times regeneration reached up 90.2%.