Chen Ke, Yang Yanmei, Zhao Hong, Jiang Jinyuan
Research Center of Environmental Pollution Control Technology, Chinese Research Academy of Environmental Sciences, No. 8 An Wai Da Yang Fang, Chaoyang District, Beijing, 100012, China.
School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, China.
Environ Sci Pollut Res Int. 2023 Apr;30(16):46900-46912. doi: 10.1007/s11356-023-25443-5. Epub 2023 Feb 2.
The benefits of applying manure directly compared to carbonized applications are controversial, and the impact of dissolved organic matter (DOM) released from human feces-based biochar (HFDOM) on the soil environment is not yet known. Comparing the properties of the HFDOM at different pyrolysis temperatures and its binding properties to heavy metals (HMs) can provide some valuable information for the application of human manure-based biochar for soil amendment or HM remediation in soils. The result of EEM-PARAFAC shows that HFDOM contains four components. A comparison of the maximum fluorescence intensity of HFDOM bound to HMs at different pyrolysis temperatures indicates that high pyrolysis temperatures reduce the amount of HFDOM. Upon comparative analysis of 2D-SFS-COS maps, cadmium (Cd(II)) preferentially binds to humic substances and fulvic-like substances at different pyrolysis temperatures (280 °C, 380 °C), respectively, while copper (Cu(II)) preferentially complexes with fulvic-like substances in both cases. The 2D-FTIR-COS graphs with different pyrolysis temperatures (280 °C, 380 °C) are observed, and Cd(II) binds preferentially to the C-H stretching (peak 3030 cm) of olefins, the C-O stretching vibration, and the O-H bending vibration (peak 1231 cm) of carboxyl groups, respectively, while Cu(II) binds predominantly to the C-O stretching of alcohols, ethers, and esters (peak 1084 cm), the C = O stretch of the carboxylic acid (peak 1590 cm), respectively. The variability of these findings suggests that the pyrolysis temperature exerts a significant influence on the functional groups in HFDOM. Furthermore, the complexation stability constant between Cu(II) and the components decreases as the pyrolysis temperature increases, probably because the pyrolysis temperature changes the content of HFDOM and the distribution of functional groups, but the assessment of the influence still needs to be further investigated.
与碳化施用相比，直接施用粪肥的益处存在争议，且基于人粪便的生物炭释放的溶解有机物（DOM）对土壤环境的影响尚不清楚。比较不同热解温度下HFDOM的特性及其与重金属（HMs）的结合特性，可为基于人粪便的生物炭在土壤改良或土壤中重金属修复的应用提供一些有价值的信息。EEM-PARAFAC结果表明HFDOM包含四个组分。不同热解温度下HFDOM与重金属结合的最大荧光强度比较表明，高热解温度会减少HFDOM的量。通过对二维同步荧光光谱-余弦光谱（2D-SFS-COS）图的比较分析，镉（Cd(II)）在不同热解温度（280℃、380℃）下分别优先与腐殖物质和类富里酸物质结合，而铜（Cu(II)）在两种情况下均优先与类富里酸物质络合。观察到不同热解温度（280℃、380℃）下的二维傅里叶变换红外光谱-余弦光谱（2D-FTIR-COS）图中，Cd(II)分别优先与烯烃的C-H伸缩振动（峰3030cm）、C-O伸缩振动以及羧基的O-H弯曲振动（峰1231cm）结合，而Cu(II)主要分别与醇、醚和酯的C-O伸缩振动（峰108cm）、羧酸的C=O伸缩振动（峰1590cm）结合。这些发现的差异表明热解温度对HFDOM中的官能团有显著影响。此外，Cu(II)与各组分之间的络合稳定常数随热解温度升高而降低，可能是因为热解温度改变了HFDOM的含量和官能团分布，但对其影响的评估仍需进一步研究。
