Wang Mengyang, Huang Yao, Liu Hui
Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences Wuhan 430078 China
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences Wuhan 430078 China.
RSC Adv. 2023 Apr 18;13(17):11853-11864. doi: 10.1039/d3ra01168b. eCollection 2023 Apr 11.
To overcome the safety risks and low utilization efficiency of HO in traditional Fenton processes, production of HO by enzymatic reactions has attracted increasing attention recently. In this study, magnetite-immobilized glucose oxidase (MIG) was prepared to catalyze the heterogeneous Fenton reaction for the removal of trichloroethene from water. The successful immobilization of glucose oxidase on magnetite was achieved with a loading efficiency of 70.54%. When combined with substrate glucose, MIG could efficiently remove 5-50 mg L trichloroethene from water with a final removal efficiency of 76.2% to 94.1% by 192 h. This system remained effective in the temperature range of 15-45 °C and pH range of 3.6-9.0. The removal was slightly inhibited by different cations and anions (influencing degree Ca > Mg > Cu and HPO > Cl > SO ) and humic acid. Meanwhile, the MIG could be recycled for 4 cycles and was applicable to other chlorinated hydrocarbons. The results of reactive oxidative species generation monitoring and quenching experiments indicated that HO generated by the enzymatic reaction was almost completely decomposed by magnetite to produce ·OH with a final cumulative concentration of 129 μM, which played a predominant role in trichloroethene degradation. Trichloroethene was almost completely dechlorinated into Cl, CO and HO without production of any detectable organic chlorinated intermediates. This work reveals the potential of immobilized enzymes for generation of ROS and remediation of organic chlorinated contaminants.
为克服传统芬顿工艺中羟基自由基(HO)的安全风险和低利用效率问题,近年来通过酶促反应生产HO受到越来越多的关注。在本研究中,制备了磁铁矿固定化葡萄糖氧化酶(MIG)以催化非均相芬顿反应从水中去除三氯乙烯。葡萄糖氧化酶成功固定在磁铁矿上,负载效率为70.54%。当与底物葡萄糖结合时,MIG能够在192小时内从水中有效去除5 - 50 mg/L的三氯乙烯,最终去除效率为76.2%至94.1%。该系统在15 - 45°C的温度范围和3.6 - 9.0的pH范围内仍然有效。不同的阳离子和阴离子(影响程度Ca > Mg > Cu和HPO > Cl > SO)以及腐殖酸对去除有轻微抑制作用。同时,MIG可以循环使用4次,并且适用于其他氯代烃。活性氧化物种生成监测和淬灭实验结果表明,酶促反应产生的HO几乎完全被磁铁矿分解以产生·OH,最终累积浓度为129μM,其在三氯乙烯降解中起主要作用。三氯乙烯几乎完全脱氯生成Cl、CO和HO,没有产生任何可检测到的有机氯代中间体。这项工作揭示了固定化酶在产生活性氧和修复有机氯污染物方面的潜力。