不同分子量富里酸对藻毒素紫外光降解的影响  

EFFECT OF FULVIC ACID WITH DIFFERENT MOLECULAR WEIGHT ON UV DEGRADATION OF MICROCYSTINS

作　　者：王刚 张夏瑶 王菲凤[1] 孙启元[1] WANG Gang;ZHANG Xiayao;WANG Feifeng;SUN Qiyuan(School of Environmental Science and Engineering,Fujian Normal University,Fuzhou 350007,China)

机构地区：[1]福建师范大学环境科学与工程学院,福州350007

出　　处：《环境工程》2022年第1期32-37,共6页Environmental Engineering

基　　金：国家自然科学基金项目(52070044)。

摘　　要：蓝藻在生长繁殖过程中会向水体中释放具有生物毒性的微囊藻毒素(MC-LR),对人体健康存在潜在威胁。富里酸(FA)是水体中广泛存在的水环境介质,其不同分子量组分对MC-LR光降解的影响机理尚未明确。通过紫外光照实验,探究不同分子量FA及相关条件因素对紫外光降解MC-LR效果的影响。结果表明:MC-LR的降解率随着pH值的增大呈先降低再上升趋势;在纯水中紫外光降解120 min后,MC-LR降解率为60.10%;加入FA后,MC-LR降解率随着其浓度的增加而提高,在10 mgC/L时有62.18%的MC-LR降解;在不同分子量FA条件下,MC-LR降解率为54.52%-65.61%,且降解过程符合一级反应动力学方程,表观速率常数在分子量3-5 kDa,浓度10 mgC/L时最高,为0.03303 min^(-1)。研究可为优化FA与MC-LR之间的条件配比,促进MC-LR的降解提供参考。Cyanobacteria releases biotoxic microcystin(MC-LR) into the water column during its growth and reproduction, which is a potential threat to human health. Fulvic acid(FA) is a widely present aqueous environmental medium in water bodies, and the mechanism of its different molecular weight components on the photodegradation of MC-LR is unknown. In this study, we investigated the effects of molecular weight of FA and related condition factors on UV degradation of MC-LR through UV illumination experiments. The results showed that the degradation rate of MC-LR decreased and then increased with the increase of pH value;the degradation rate of MC-LR was 60.10% after 120 min of UV degradation in pure water;after FA was added, the degradation rate of MC-LR increased with the increase of its concentration, and 62.18% of MC-LR was degraded at 10 mgC/L. Under different molecular weight FA, the degradation rate range of MC-LR was 54.52%-65.61%, and the degradation process was in good accordance with the first-order reaction kinetic equation.The apparent rate constant was the highest when the molecular weight was 3-5 kDa and the concentration was 10 mgC/L, which was 0.03303 min^(-1). This study provided a reference for optimizing the conditional ratio between FA and MC-LR and promoting the degradation of MC-LR.

关 键 词：富里酸 藻毒素 光催化 影响因素 降解动力学 

分 类 号：X52[环境科学与工程—环境工程]