Wu Jun, Tu Wenxin, Li Chunping, He Feng
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China; Center for Membrane and Water Science & Technology, Zhejiang University of Technology, Hangzhou, China; Zhejiang University of Technology Engineering Design Group Co., Ltd, Hangzhou, China.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China; Zhejiang University of Technology Engineering Design Group Co., Ltd, Hangzhou, China.
J Hazard Mater. 2022 Aug 5;435:129021. doi: 10.1016/j.jhazmat.2022.129021. Epub 2022 Apr 27.
Dissolved organic matter released from biochar (biochar-derived DOM, BDOM) could dominate the environmental behavior and fate of trace metals by forming BDOM-metal complexes. Here general, heterospectral as well as moving-window (MW) two-dimensional correlation spectroscopy (2DCOS) analyses of synchronous fluorescence and Fourier transform infrared spectra were employed to explore the heterogeneous binding characteristics between sludge BDOM and Cu(II). The results revealed that Cu-BDOM binding first occurred in the fulvic-like (368-380 nm), then humic-like (428 nm) fluorescent fractions, followed by infrared groups of phenolic hydroxyl groups, carboxylate, COH of polysaccharide groups, CC of aromatic carbon, CH of aliphatics and COC of aliphatic ethers. The binding affinity of the hydrophilic groups was stronger than that of hydrophobic groups in BDOM towards Cu(II). Fluorescence components in BDOM played a decisive role in the binding of Cu(II) with trace concentration (1 μM), while infrared functional groups made a substantial contribution in the complexation of Cu(II) with higher concentration (10-100 μM). The concentration of final configuration transformation point (11.7 μmol/mg in this study) by MW2DCOS analysis was suggested as an actual binding threshold that was helpful for evaluating their environmental behaviors.
生物炭释放的溶解有机物（生物炭衍生的溶解性有机物，BDOM）可通过形成BDOM-金属络合物来主导痕量金属的环境行为和归宿。在此，采用同步荧光和傅里叶变换红外光谱的常规、异谱以及移动窗口（MW）二维相关光谱（2DCOS）分析，来探究污泥BDOM与Cu(II)之间的异质结合特性。结果表明，Cu-BDOM结合首先发生在类富里酸（368-380nm），然后是类腐殖酸（428nm）荧光组分中，随后是酚羟基、羧酸盐、多糖基团的COH、芳香碳的CC、脂肪族的CH以及脂肪族醚的COC等红外基团。BDOM中亲水基团对Cu(II)的结合亲和力强于疏水基团。BDOM中的荧光成分在痕量浓度（1μM）下Cu(II)的结合中起决定性作用，而红外官能团在较高浓度（10-100μM）下Cu(II)的络合中起重要作用。MW2DCOS分析得出的最终构型转变点浓度（本研究中为11.7μmol/mg）被建议作为一个实际结合阈值，有助于评估它们在环境中的行为。
