College of Natural Resource and Environment, Northwest A&F University, Yangling 712100, PR China.
College of Natural Resource and Environment, Northwest A&F University, Yangling 712100, PR China; Key Laboratory of Plant Nutrition and Agri-environment in Northwest China, Ministry of Agriculture, Yangling 712100, PR China.
Bioresour Technol. 2018 Feb;249:487-493. doi: 10.1016/j.biortech.2017.10.020. Epub 2017 Oct 7.
This study aimed to evaluate the chemical forms, behavior and environmental risk of heavy metal (HMs) Zn, Pb and Cd in phytoremediation residue (PMR) pyrolyzed at 350 °C, 550 °C and 750 °C, respectively. The behavior of HMs variation during the PMR pyrolysis process was analyzed and the potential HMs environmental risk of phytoremediation residue biochars (PMB) was assessed which was seldom investigated before. The results showed that the pyrolysis temperature increase decreased the soluble/exchangeable HMs fraction and alleviated the HMs bioavailability. When the temperature was over 550 °C, the adsorbed Zn(II), Pb(II) and Cd(II) were turned into oxides forms and concentrated in PMB with more stable forms exhibiting lower risk assessment code and potential ecological risk index. The ecotoxicity test showed higher pyrolysis temperature favored the reduction of PMB ecotoxicity. It is suggested that pyrolysis temperature above 550°C may be suitable for thermal treatment of PMR with acceptable environmental risk.
本研究旨在评估重金属（HMs）Zn、Pb 和 Cd 在分别于 350°C、550°C 和 750°C 热解的植物修复残渣（PMR）中的化学形态、行为和环境风险。分析了 HMs 在 PMR 热解过程中的变化行为，并评估了植物修复残渣生物炭（PMB）的潜在 HMs 环境风险，这在以前的研究中很少涉及。结果表明，热解温度的升高降低了可溶/可交换态 HMs 分数，减轻了 HMs 的生物可利用性。当温度超过 550°C 时，吸附的 Zn(II)、Pb(II) 和 Cd(II) 转化为氧化物形式，并集中在具有更稳定形态的 PMB 中，表现出更低的风险评估码和潜在生态风险指数。毒性试验表明，较高的热解温度有利于降低 PMB 的生态毒性。因此，建议将热解温度提高到 550°C 以上，以进行具有可接受环境风险的 PMR 热解处理。
