Korea Biochar Research Center and School of Natural Resources and Environmental Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
Chemical and Environmental Systems Modeling Research Group, Institute of Fundamental Studies, Kandy, 20000, Sri Lanka.
Environ Geochem Health. 2017 Dec;39(6):1409-1420. doi: 10.1007/s10653-017-9941-6. Epub 2017 Mar 22.
This study examined the effects of carbon nanotube and biochar on the bioavailability of Pb, Cu and Sb in the shooting range soils for developing low-cost remediation technology. Commercially available multi-walled carbon nanotube (MWCNT) and biochar pyrolyzed from soybean stover at 300 °C (BC) at 0.5, 1 and 2.5% (w w) were used to remediate the contaminated soil in an incubation experiment. Both DTPA (bioavailable) and TCLP (leaching) extraction procedures were used to compare the metal/loid availability and leaching by the amendments in soil. The addition of BC was more effective in immobilizing mobile Pb and Cu in the soil than that in MWCNT. The BC reduced the concentrations of Pb and Cu in the soil by 17.6 and 16.2%, respectively. However, both MWCNTs and BC increased Sb bioavailability by 1.4-fold and 1.6-fold, respectively, in DTPA extraction, compared to the control. The toxicity characteristic leaching procedure (TCLP) test showed that the leachability of Pb in the soil amended with 2.5% MWCNT was 1.3-fold higher than that the unamended soil, whereas the BC at 2.5% decreased the TCLP-extractable Pb by 19.2%. Precipitation and adsorption via electrostatic and π-π electron donor-acceptor interactions were postulated to be involved in the interactions of Pb and Cu with surfaces of the BC in the amended soils, whereas ion exchange mechanisms might be involved in the immobilization of Cu in the MWCNT-amended soils. The application of BC derived from soybean stover can be a low-cost technology for simultaneously immobilizing bioavailable Pb and Cu in the shooting range soils; however, neither of amendments was effective in Sb immobilization.
本研究考察了碳纳米管和生物炭对射击场土壤中 Pb、Cu 和 Sb 生物有效性的影响，旨在开发低成本的修复技术。本研究使用了商业上可获得的多壁碳纳米管（MWCNT）和在 300°C 下由大豆秸秆热解得到的生物炭（BC），分别在 0.5%、1%和 2.5%（w w）的浓度下，用于修复受污染的土壤。本研究采用 DTPA（生物可利用）和 TCLP（浸出）提取程序来比较土壤中金属/类金属的有效性和添加剂的浸出。与 MWCNT 相比，BC 更有效地固定土壤中可移动的 Pb 和 Cu。BC 将土壤中 Pb 和 Cu 的浓度分别降低了 17.6%和 16.2%。然而，与对照相比，MWCNTs 和 BC 分别将 Sb 的生物有效性提高了 1.4 倍和 1.6 倍。毒性特征浸出程序（TCLP）测试表明，添加 2.5% MWCNT 后土壤中 Pb 的浸出率比未添加 MWCNT 的土壤高 1.3 倍，而 2.5%的 BC 则使 TCLP 可提取的 Pb 降低了 19.2%。推测在添加 BC 的土壤中，Pb 和 Cu 与 BC 表面的相互作用涉及静电和π-π电子供体-受体相互作用引起的沉淀和吸附，而在 MWCNT 改性土壤中 Cu 的固定化涉及离子交换机制。大豆秸秆衍生的 BC 的应用可以成为一种低成本的技术，同时固定射击场土壤中生物可利用的 Pb 和 Cu；然而，两种添加剂在 Sb 的固定化方面都没有效果。
