College of Environment and Energy, South China University of Technology, 510006, Guangzhou, People's Republic of China.
The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre, 510006, Guangzhou, People's Republic of China.
Environ Sci Pollut Res Int. 2017 Oct;24(30):23815-23824. doi: 10.1007/s11356-017-9994-1. Epub 2017 Sep 2.
Biochar was carbon-rich and generated by high-temperature pyrolysis of biomass under oxygen-limited conditions. Due to the limitations of surface functional groups and the weakness of surface activity in the field of environmental remediation, the raw biochar frequently was chemically modified to improve its properties with a new performance. In this study, a kind of high-efficiency and low-cost amino biochar modified by nano zero-valent iron (ABC/NZVI) was synthesized and applied to paddy soil contaminated with arsenic (As). Dynamic changes of soil properties, arsenic speciations and rhizosphere microbial communities have been investigated over the whole growth period of rice plants. Pot experiments revealed that the ABC/NZVI could decrease the arsenic concentration in rice straw by 47.9% and increase the content of nitrogen in rice straw by 47.2%. Proportion of Geobacter in soil with ABC/NZVI treatment increased by 175% in tillering period; while Nitrososphaera decreased by 61 and 20% in tillering and maturity, respectively, compared to that of control. ABC/NZVI promotes arsenic immobilization in rhizosphere soil and precipitation on root surface and reduces arsenic accumulation in rice. At the same time, ABC/NZVI would inhibit Nitrososphaera which is related to ammonia oxidation process, and it would have a promising potential as soil amendment to reduce nitrogen loss probably.
生物炭是在有限氧条件下通过生物质高温热解产生的富碳物质。由于在环境修复领域表面官能团的限制和表面活性较弱，原始生物炭经常被化学修饰以改善其性能，赋予新的性能。本研究合成了一种高效、低成本的纳米零价铁改性氨基酸生物炭（ABC/NZVI），并将其应用于砷污染的稻田。在水稻整个生长期间，研究了土壤性质、砷形态和根际微生物群落的动态变化。盆栽实验表明，ABC/NZVI 可使水稻秸秆中的砷浓度降低 47.9%，使水稻秸秆中的氮含量增加 47.2%。与对照相比，添加 ABC/NZVI 处理可使分蘖期土壤中 Geobacter 的比例增加 175%；而在分蘖期和成熟期，Nitrososphaera 分别减少了 61%和 20%。ABC/NZVI 促进了根际土壤中砷的固定和沉淀以及根表面的沉淀，从而减少了水稻对砷的积累。同时，ABC/NZVI 会抑制与氨氧化过程有关的 Nitrososphaera，作为土壤改良剂，它可能具有减少氮素损失的潜力。
