Duan Yihang, Gao Ningbo, Sipra Ayesha Tariq, Tong Kun, Quan Cui
School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
J Hazard Mater. 2022 Feb 15;424(Pt A):127293. doi: 10.1016/j.jhazmat.2021.127293. Epub 2021 Sep 24.
In this study, the method combining hydrothermal treatment (HT) and in-situ mechanical compression (MC) is used to treat oily sludge. The possible transfer and reaction pathways of different oil components during the process of HT&MC were investigated. In addition, the leaching toxicity, distribution, and risk of heavy metals in oily sludge treated in different temperatures and residence times were evaluated. The results revealed that siloxane and heavy oil components are left in the solid residue, and the light oils and oils with hydrophilic groups are transferred to hydrothermal fluids. The content of Cd, Cr, Pb, and Zn in form of F4 (residual) in the solid residue obtained at a hydrothermal temperature of 240 °C and residence time of 60 min increased by 7.37%, 1.21%, 3.06%, and 9.97%. This reduced the biological availability and environmental risk of heavy metals in the treated oily sludge. Meanwhile, the result of FT-IR illustrated an increase in hydroxyl groups of alcohols, phenols and organic acids, which have a beneficial effect on the adsorption of heavy metals and other pollutants. All results indicated that HT&MC might be a suitable pretreatment method for the stabilization of heavy metals in oily sludge.
在本研究中，采用水热处理（HT）与原位机械压缩（MC）相结合的方法处理含油污泥。研究了不同油组分在HT&MC过程中的可能转移和反应途径。此外，还评估了在不同温度和停留时间下处理的含油污泥中重金属的浸出毒性、分布及风险。结果表明，硅氧烷和重油组分留在固体残渣中，轻质油和亲水基团的油转移到热液中。在水热温度240℃、停留时间60min条件下获得的固体残渣中，以F4（残渣态）形式存在的Cd、Cr、Pb和Zn含量分别增加了7.37%、1.21%、3.06%和9.97%。这降低了处理后含油污泥中重金属的生物可利用性和环境风险。同时，傅里叶变换红外光谱（FT-IR）结果表明醇、酚和有机酸的羟基增加，这对重金属和其他污染物的吸附有有益影响。所有结果表明，HT&MC可能是一种稳定含油污泥中重金属的合适预处理方法。
