Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China.
Environ Sci Pollut Res Int. 2021 Apr;28(14):17395-17404. doi: 10.1007/s11356-020-11931-5. Epub 2021 Jan 4.
Biochar has been applied widely as an amendment in the remediation of contaminated soil to immobilize the heavy metals. However, the role of ultraviolet (UV) irradiation modified biochar derived from the residues of phytoremediation plants in the contaminated soil not investigated yet. In this study, the UV-modified biochars were obtained from Brassica napus L. and Lolium perenne L. by pyrolysis at 600 °C. They were applied in a pot experiment to investigate their effect on Cd bioavailability and uptake in Coriandrum sativum L. in a Cd-contaminated soil at four addition rate (0%, 0.2%, 0.4%, and 0.6%). The results showed that the Cd was effectively stabilized in the biochar with environmentally acceptable leaching toxicity. The specific surface area and carboxyl functional group of biochar were greatly increased after UV modification. The application of biochar progressively increased the soil pH and electrical conductivity (EC). Furthermore, the CaCl-extractable Cd was significantly reduced by 18.4-51.4% with biochar amendments. The concentration of Cd in shoots and roots was significantly reduced by biochars. In conclusion, the UV-modified biochar obtained from phytoremediation residue could effectively deal with hazardous waste and repair Cd-contaminated soil.
生物炭作为一种改良剂广泛应用于污染土壤的修复中，以固定重金属。然而，用植物修复植物残渣热解制备的经紫外（UV）辐射改性的生物炭在污染土壤中的作用尚未得到研究。本研究采用油菜（Brassica napus L.）和黑麦草（Lolium perenne L.）残渣，在 600°C 下进行热解，制备了 UV 改性生物炭。将其应用于盆栽实验，研究了其在添加率为 0%、0.2%、0.4%和 0.6%的 Cd 污染土壤中对芫荽（Coriandrum sativum L.）中 Cd 生物有效性和吸收的影响。结果表明，Cd 被有效地固定在生物炭中，其浸出毒性符合环境可接受标准。UV 改性后，生物炭的比表面积和羧基官能团大大增加。生物炭的应用使土壤 pH 值和电导率（EC）逐渐升高。此外，用生物炭进行改良可使 CaCl2 可提取 Cd 减少 18.4%至 51.4%。生物炭还显著降低了茎叶和根系中 Cd 的浓度。总之，用植物修复残渣制备的经 UV 改性的生物炭可以有效地处理危险废物和修复 Cd 污染土壤。
