Gong Pei-Yun, Sun Li-Juan, Song Ke, Sun Ya-Fei, Qin Qin, Zhou Bin, Xue Yong
College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
ECO-Environment Protection Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
Huan Jing Ke Xue. 2022 Jun 8;43(6):3211-3220. doi: 10.13227/j.hjkx.202109165.
Twelve biochar types were derived from animal manure (cow manure, chicken manure, and pig manure) and crop straw (wheat straw, rice straw, and corn straw) at different temperatures (300℃/700℃ and 300℃/500℃) for Cd in a solution system in the present study. A scanning electron microscope, Fourier infrared spectrometer, X-ray diffraction, and CHN analyzer were applied to analyze the physical and chemical properties, surface structure, and elemental composition of the biochar. The adsorption capacity and related mechanism of biochar for Cd in an aqueous solution was studied. The results showed that the maximum adsorption capacity of cow manure, chicken manure, and pig manure biochar for Cd increased from 83.40, 19.65, and 96.74 mg·g to 106.54, 268.89, and 164.53 mg·g, respectively, with the increase in pyrolysis temperature. With the increase in pyrolysis temperature, the pore structure of biochar became more abundant, oxygen-containing functional groups increased, and the aromatic structure appeared. Quantitative analyses revealed that ion exchange accounted for 12%-52%, chemical precipitation accounted for 27%-79%, complexation accounted for 1%-8%, and cation-π accounted for 1%-28% of the total adsorption capacity of Cd. With the increase in pyrolysis temperature, the proportion of cation-π interaction increased from 1%-13% to 8%-30%, but the proportion of chemical precipitation and ion exchange were still very high (70%-93%). Therefore, ion exchange and chemical precipitation could be the main mechanisms of agricultural waste biochar adsorption for Cd.
在本研究中，通过在不同温度（300℃/700℃和300℃/500℃）下对动物粪便（牛粪、鸡粪和猪粪）以及农作物秸秆（小麦秸秆、水稻秸秆和玉米秸秆）进行热解，制备了12种生物炭类型，用于溶液体系中镉的研究。运用扫描电子显微镜、傅里叶红外光谱仪、X射线衍射仪和CHN分析仪对生物炭的物理化学性质、表面结构和元素组成进行了分析。研究了生物炭对水溶液中镉的吸附容量及相关机制。结果表明，随着热解温度的升高，牛粪、鸡粪和猪粪生物炭对镉的最大吸附容量分别从83.40、19.65和96.74 mg·g增加到106.54、268.89和164.53 mg·g。随着热解温度的升高，生物炭的孔隙结构变得更加丰富，含氧官能团增加，出现了芳香结构。定量分析表明，离子交换占镉总吸附容量的12% - 52%，化学沉淀占27% - 79%，络合占1% - 8%，阳离子-π作用占1% - 28%。随着热解温度的升高，阳离子-π相互作用的比例从1% - 13%增加到8% - 30%，但化学沉淀和离子交换的比例仍然很高（70% - 93%）。因此，离子交换和化学沉淀可能是农业废弃物生物炭吸附镉的主要机制。
