Pan Yanheng, Garg Shikha, Ouyang Yiming, Yang Xin, Waite T David
School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China; School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia.
School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia.
J Hazard Mater. 2023 Sep 15;458:131812. doi: 10.1016/j.jhazmat.2023.131812. Epub 2023 Jun 8.
Dissolved organic matter (DOM) driven-photochemical processes play an important role in the redox cycling of trace metals and attenuation of organic contaminants in estuarine and coastal ecosystems. In this study, we evaluate the effect of Cu on 4-carboxybenzophenone (CBBP) and Suwannee River natural organic matter (SRNOM)-photosensitized degradation of seven target contaminants (TCs) including phenols and amines under pH conditions and salt concentrations typical of those encountered in estuarine and coastal waters. Our results show that trace amounts of Cu(II) (25 -500 nM) induce strong inhibition of the photosensitized degradation of all TCs in solutions containing CBBP. The influence of TCs on the photo-formation of Cu(I) and the decrease in the lifetime of transformation intermediates of contaminants (TC/ TC) in the presence of Cu(I) indicated that the inhibition effect of Cu was mainly due to the reduction of TC/ TC by the photo-produced Cu(I). The inhibitory effect of Cu on the photodegradation of TCs decreased with the increase in Cl concentration since less reactive Cu(I)-Cl complexes dominate at high Cl concentrations. The impact of Cu on the SRNOM-sensitized degradation of TCs is less pronounced compared to that observed in CBBP solution since the redox active moieties present in SRNOM competes with Cu(I) to reduce TC/ TC. A detailed mathematical model is developed to describe the photodegradation of contaminants and Cu redox transformations in irradiated SRNOM and CBBP solutions.
溶解有机物（DOM）驱动的光化学过程在河口和沿海生态系统中痕量金属的氧化还原循环以及有机污染物的衰减方面发挥着重要作用。在本研究中，我们评估了在河口和沿海水域典型的pH条件和盐浓度下，铜对4 - 羧基二苯甲酮（CBBP）和苏万尼河天然有机物（SRNOM）光敏降解七种目标污染物（TCs，包括酚类和胺类）的影响。我们的结果表明，痕量的Cu(II)（25 - 500 nM）对含有CBBP的溶液中所有TCs的光敏降解具有强烈的抑制作用。TCs对Cu(I)光生成的影响以及在Cu(I)存在下污染物转化中间体（TC/TC）寿命的缩短表明，铜的抑制作用主要是由于光生成的Cu(I)对TC/TC的还原作用。随着Cl浓度的增加，铜对TCs光降解的抑制作用减弱，因为在高Cl浓度下，反应性较低的Cu(I)-Cl络合物占主导地位。与在CBBP溶液中观察到的情况相比，铜对SRNOM敏化降解TCs的影响不太明显，因为SRNOM中存在的氧化还原活性部分与Cu(I)竞争以还原TC/TC。我们建立了一个详细的数学模型来描述辐照的SRNOM和CBBP溶液中污染物的光降解以及铜的氧化还原转化。
