College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
Chemosphere. 2020 Jul;250:126268. doi: 10.1016/j.chemosphere.2020.126268. Epub 2020 Feb 20.
The effectiveness of rice waste biochars on heavy metal and metalloid abatement and detoxification was investigated using comprehensive studies based on As and Cd immobilization, bioaccumulation in tubifex, and microbial community changes in contaminated sediment. The remediation effects of biochars produced at different pyrolytic temperatures (400-700 °C) were evaluated. Bioaccumulation of heavy metal and metalloid in the tubifex tissue and change of indigenous microbial community under treatment of different biochars were assessed. Biochars produced at 700 °C exhibited greater effect on decreasing the concentrations of As and Cd in aqueous phase, and TCLP extractable and bioavailable metal(loid) in solid phase of sediment. The concentration of As and Cd in water phase decreased by 26%-89% and 22%-71% under the treatment of straw biochar, and decreased by 13%-92% and 5%-64% under the treatment of rice husk biochar, respectively. As and Cd contents in the tubifex tissue were positively correlated with their concentrations in aqueous phase. High-temperature biochars significantly reduced metal(loid) bioaccumulation in tubifex. The richness and biodiversity of microbial community were both greater in all biochars remediated sediment compared to non-treated sediment. These results indicated that rice waste biochars could effectively inhibit the bio-availability and toxicity of heavy metal and metalloid in sediment, and the higher-temperature biochar exhibited better performance.
采用基于砷和镉固定、颤蚓生物累积和污染沉积物中微生物群落变化的综合研究，考察了稻壳废弃物生物炭对重金属和类金属减排和解毒的有效性。评估了在不同热解温度（400-700°C）下生产的生物炭的修复效果。评估了不同生物炭处理下重金属和类金属在颤蚓组织中的生物累积和土著微生物群落的变化。在 700°C 下生产的生物炭对降低水相中 As 和 Cd 的浓度以及 TCLP 可提取和生物可利用金属（类）的固相浓度具有更大的效果。在稻草生物炭处理下，水相中的 As 和 Cd 浓度分别降低了 26%-89%和 22%-71%，在稻壳生物炭处理下，水相中的 As 和 Cd 浓度分别降低了 13%-92%和 5%-64%。水相中 As 和 Cd 的浓度与颤蚓组织中的含量呈正相关。高温生物炭可显著降低颤蚓对金属（类）的生物累积。与未处理沉积物相比，所有生物炭修复的沉积物中的微生物群落丰富度和生物多样性都更大。这些结果表明，稻壳废弃物生物炭可有效抑制沉积物中重金属和类金属的生物有效性和毒性，且高温生物炭的性能更好。
