College of Energy and Environment, the Key Laboratory of Clean Energy in Liaoning Province, Shenyang Aerospace University, Shenyang, China.
Environ Sci Pollut Res Int. 2019 Mar;26(9):9123-9136. doi: 10.1007/s11356-019-04234-x. Epub 2019 Feb 4.
A lightweight aggregate (LWA) was manufactured from municipal sewage sludge, gangue, and coal ash. The product performance and environmental safety of the sintered material were evaluated by changing the sludge blending ratio and sintering temperature. The distribution and migratory transformation characteristics of heavy metals in LWA were examined by BCR sequential extraction in combination with inductively coupled plasma optical emission spectrometry (ICP-OES). The environmental safety performance of LWA was comprehensively evaluated by the OPTI index for the first time. The leaching concentration of the heavy metals Pb, Ni, Cu, and Zn in raw materials without sintering reached 1.17, 1.6, 7.84, and 7.56 mg/L, respectively, far exceeding the regulatory threshold value. At 1250 °C, sintering with 60% sludge content resulted in Cu and Zn leaching concentrations of only 0.41 mg/L and 0.37 mg/L, respectively. Furthermore, a big portion of heavy metals were in the residual fraction of sintered LWA. The proportion of comprehensive pollutant toxicity index is only 199.17. Additionally, the mechanical properties of sintered LWA exceed the standards stipulated in the GB/T1743.1-2010 standard. Using sewage sludge to manufacture lightweight aggregate is not only environmentally safe but also produces LWA with good engineering characteristics.
一种轻集料（LWA）是由城市污泥、煤矸石和粉煤灰制造而成。通过改变污泥掺混比和烧结温度，评估了烧结材料的产品性能和环境安全性。采用 BCR 顺序提取结合电感耦合等离子体发射光谱法（ICP-OES）研究了 LWA 中重金属的分布和迁移转化特征。首次采用 OPTI 指数综合评价了 LWA 的环境安全性能。未烧结原料中重金属 Pb、Ni、Cu 和 Zn 的浸出浓度分别达到 1.17、1.6、7.84 和 7.56mg/L，远远超过了监管阈值。在 1250°C 下，当污泥含量为 60%时，Cu 和 Zn 的浸出浓度分别仅为 0.41mg/L 和 0.37mg/L。此外，大量的重金属存在于烧结 LWA 的残余物中。综合污染物毒性指数的比例仅为 199.17。此外，烧结 LWA 的力学性能超过了 GB/T1743.1-2010 标准规定的标准。利用污水污泥制造轻集料不仅环境安全，而且还生产出具有良好工程特性的 LWA。
