Korea Biochar Research Center, O-Jeong Eco-Resilience Institute & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea.
Department of Environment and Energy, Sejong University, Seoul 05006, Republic of Korea.
Environ Int. 2019 Jun;127:190-198. doi: 10.1016/j.envint.2019.03.031. Epub 2019 Mar 27.
Exchangeable lead (Pb) extracted by ammonium acetate from three independent incubation studies was assessed to understand the influence of feedstock, pyrolysis temperatures, and production conditions on Pb immobilization capacities of different biochars. Vegetable waste biochar, pine cone, wood bark, cocopeat, red pepper stalk, and palm kernel shell were used as feedstocks (food supply and agricultural wastes) to produce biochars at 200-650 °C with and without N/CO. Biochars were applied at 5 and 2.5% (w w) to a Pb contaminated (i.e., 1445 mg kg) agricultural soil collected near an old mine. Lead immobilization in biochar treated soils at the end of incubation period was normalized per gram of biochar applied. Biochar produced from vegetable waste at 500 °C showed the highest Pb immobilization (87%) and highest total exchangeable cations (13.5 cmol kg) at the end of the 45 d incubation period. However, on the basis of Pb immobilization per gram of biochar, red pepper stalk biochar produced in CO at 650 °C was the best in Pb immobilization (0.09 mg kg g biochar) compared to the other biochars. The enhanced ability to immobilize Pb by biochar produced in CO could be due to the presence of siloxanes (SiOSi) on biochar surface. Pearson correlation analysis revealed that alkaline pH, ash%, and N% of biochars influence in Pb immobilization and exchangeable cation availability in soil. Biochar production atmosphere considerably change its properties that influence Pb immobilization. Further studies are needed on the modification of properties and Pb immobilization by biochars produced from various feedstocks in CO.
从三个独立的孵育研究中用乙酸铵提取的可交换铅 (Pb) 进行评估，以了解原料、热解温度和生产条件对不同生物炭固定 Pb 能力的影响。蔬菜废物生物炭、松果、木树皮、椰子纤维、红辣椒茎和棕榈仁壳被用作原料（食物供应和农业废物），在有和没有 N/CO 的情况下在 200-650°C 下生产生物炭。生物炭以 5%和 2.5%（w/w）的比例添加到受 Pb 污染的农业土壤（即 1445 mg/kg）中，这些土壤是在旧矿区附近采集的。孵育结束时，用生物炭处理的土壤中 Pb 的固定量除以添加的生物炭量进行归一化。在 500°C 下由蔬菜废物制成的生物炭在 45 天孵育期结束时表现出最高的 Pb 固定率（87%）和最高的总可交换阳离子（13.5 cmol/kg）。然而，基于每克生物炭固定的 Pb 量，在 CO 中于 650°C 下生产的红辣椒茎生物炭在 Pb 固定方面表现最佳（0.09 mg/kg g 生物炭），优于其他生物炭。在 CO 中生产的生物炭固定 Pb 的能力增强可能是由于生物炭表面存在硅氧烷（SiOSi）。Pearson 相关分析表明，生物炭的碱性 pH、灰分%和 N%影响 Pb 的固定和土壤中可交换阳离子的可用性。生物炭生产气氛会极大地改变其性质，从而影响 Pb 的固定。需要进一步研究 CO 中由各种原料生产的生物炭的性质改性和 Pb 固定。
