School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China.
National Engineering Research Center for Heavy Metals Pollution Control and Treatment, Changsha, China.
Environ Sci Pollut Res Int. 2018 Jun;25(18):17250-17267. doi: 10.1007/s11356-018-2135-7. Epub 2018 May 15.
Solid-liquid separation (SLS) plays a dominant role in various chemical industries. Nowadays, low efficiency of SLS also become a significant problem in heavy metal (HM) wastewater treatment, affecting the effluent quality (HM concentration and turbidity) and overall process economy. In this context, we summarize here the occurrence of solids in HM wastewater, as well as typical SLS operations used in HM wastewater treatment, including sedimentation, flotation, and centrifugation. More important, this article reviews the improvement of the SLS operations by some technologies, including coagulation, flocculation, ballasted method, seeding method, granular sludge strategy, and external field enhancement. It is noted that abiological granular sludge strategy and magnetic field enhancement often possess higher SLS efficiency (faster settling velocity or shorter separation time) than other methods. Hence, the two strategies stand out as promising tools for improving SLS in HM wastewater treatment, but further research is required regarding scalability, economy, and reliability.
固液分离（SLS）在各个化学工业中起着主导作用。如今，SLS 的低效率也成为重金属（HM）废水处理中的一个重大问题，影响出水质量（HM 浓度和浊度）和整体工艺经济性。在这种情况下，我们在这里总结了 HM 废水中固体的出现情况，以及 HM 废水处理中常用的典型 SLS 操作，包括沉淀、浮选和离心。更重要的是，本文综述了一些技术对 SLS 操作的改进，包括混凝、絮凝、加重法、接种法、颗粒污泥策略和外场增强。需要指出的是，生物颗粒污泥策略和磁场增强通常比其他方法具有更高的 SLS 效率（更快的沉降速度或更短的分离时间）。因此，这两种策略是改善 HM 废水处理中 SLS 的有前途的工具，但需要进一步研究其可扩展性、经济性和可靠性。
