College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
Bioresour Technol. 2016 Oct;218:183-8. doi: 10.1016/j.biortech.2016.06.085. Epub 2016 Jun 24.
In this study, the effect of feed-water pH (pH=2-12) on fate and risk of heavy metals (HMs) in hydrochars (HCs) was investigated. Hydrothermal carbonization (HTC) of sewage sludge (SS) was carried out with different feed-water pH at 270°C. The research results showed that changing feed-water pH had a positive effect on accumulating Pb, Ni, Cd and Zn in HCs. Chemical forms of Cu and Cr converted from an unstable state to stable in the alkaline environment while in the acidic condition was opposite. The effect of feed-water pH on the chemical forms of HMs was variable but not significant. Risk assessments of Igeo, Er(i), RAC and RI were applied to evaluate the accumulation levels of individual metal, the potential ecological risks, the bio-availabilities and the comprehensive toxicity and sensitivity of HMs, respectively. The lowest pollution level of HMs was obtained at 270°C with pH=11.
在这项研究中，考察了进水 pH 值（pH=2-12）对水热炭（HCs）中重金属（HMs）的赋存形态和风险的影响。采用不同的进水 pH 值在 270°C 下对污水污泥（SS）进行水热碳化（HTC）。研究结果表明，改变进水 pH 值对 Pb、Ni、Cd 和 Zn 在 HCs 中的积累有积极影响。在碱性环境中，Cu 和 Cr 的化学形态从不稳定态转化为稳定态，而在酸性条件下则相反。进水 pH 值对 HMs 化学形态的影响是可变的，但不显著。采用 Igeo、Er(i)、RAC 和 RI 风险评估分别评估了各金属的积累水平、潜在生态风险、生物可利用性以及 HMs 的综合毒性和敏感性。在 pH=11、270°C 下，HMs 的污染水平最低。
