紫外光辐照可改善强酸性废水中金属硫化物颗粒的聚集和沉降性能。
UV light irradiation improves the aggregation and settling performance of metal sulfide particles in strongly acidic wastewater.
机构信息
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing Key Laboratory of Industrial Wastewater Treatment and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
出版信息
Water Res. 2019 Oct 15;163:114860. doi: 10.1016/j.watres.2019.114860. Epub 2019 Jul 13.
Tiny metal sulfide particles are usually generated in the metal sulfide precipitation process, and residual dissolved sulfide (HS, HS and S) generally makes the aggregation and settling performance of these particles worse. In this work, under strongly acidic conditions with 0.102 M HSO, the characteristics of CuS, CdS and mixed metal sulfide particles (CuS and CdS) produced in strongly acidic wastewater by HS were initially studied. Then, UV light irradiation was employed to improve the aggregation and settling performance of the metal sulfide particles, and relevant mechanisms were investigated. The results showed that the residual HS in suspension can deteriorate the settling performance of metal sulfide particles. After HS was removed, CuS particles exhibited good settling performance, but the settling performance of CdS and mixed sulfide particles remained poor. Subsequent studies showed that UV light irradiation effectively improved the aggregation and settling performance of CdS and mixed metal sulfide particles in the presence of HS. After 30 min of UV irradiation, the average hydrodynamic diameter of CdS particles increased approximately 166-fold in the presence of 131.40 mg/L HS, and that of mixed sulfide particles increased approximately 105-fold with the existence of 129.30 mg/L HS. Further study revealed that HS in suspensions played an important role in the aggregation of metal sulfide particles under UV irradiation. HS• generated by the photolysis of HS oxidized a portion of S on the surface of CdS particles and a portion of S and S on the surface of mixed sulfide particles to S and S, which resulted in a decrease of negative charge and an enhanced aggregation of these particles. Finally, this study showed that the settling performance of CdS and mixed sulfide particles was effectively improved at high initial HS concentrations under UV irradiation. This study provides a clean and effective method to improve the metal sulfide precipitation process for strongly acidic wastewater treatment.
微小的金属硫化物颗粒通常在金属硫化物沉淀过程中生成，而残余的溶解硫化物（HS-、HS 和 S）通常会使这些颗粒的聚集和沉降性能变差。在这项工作中，在 0.102M HSO4 的强酸性条件下，初步研究了在强酸性废水中由 HS 生成的 CuS、CdS 和混合金属硫化物颗粒（CuS 和 CdS）的特性。然后，采用紫外光照射来改善金属硫化物颗粒的聚集和沉降性能，并研究了相关机制。结果表明，悬浮液中残余的 HS-会恶化金属硫化物颗粒的沉降性能。去除 HS-后，CuS 颗粒表现出良好的沉降性能，但 CdS 和混合硫化物颗粒的沉降性能仍然较差。随后的研究表明，在 HS-存在的情况下，紫外光照射有效地改善了 CdS 和混合金属硫化物颗粒的聚集和沉降性能。在存在 131.40mg/L HS-的情况下，CdS 颗粒的平均水动力直径在 30min 的紫外光照射后增加了约 166 倍，在存在 129.30mg/L HS-的情况下，混合硫化物颗粒的平均水动力直径增加了约 105 倍。进一步的研究表明，悬浮液中的 HS-在紫外光照射下对金属硫化物颗粒的聚集起着重要作用。HS-的光解生成的 HS•氧化了 CdS 颗粒表面的一部分 S 和混合硫化物颗粒表面的一部分 S 和 S，导致这些颗粒的负电荷减少，增强了它们的聚集。最后，本研究表明，在紫外光照射下，高初始 HS-浓度下 CdS 和混合硫化物颗粒的沉降性能得到了有效改善。该研究为强酸性废水处理中的金属硫化物沉淀过程提供了一种清洁有效的改进方法。
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