Wang Ting, Cao Weiyuan, Wang Yingqi, Qu Chao, Xu Yufeng, Li Haixiang
Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541006, China; Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541006, China.
Handan Environmental Monitoring Center Station, Handan 056000, China.
Ecotoxicol Environ Saf. 2023 Jun 23;262:115179. doi: 10.1016/j.ecoenv.2023.115179.
Quartz sand (SiO) is a prevalent filtration medium, boasting wide accessibility, superior stability, and cost-effectiveness. However, its utility is often curtailed by its sleek surface, limited active sites, and swift saturation of adsorption sites. This review outlines the prevalent strategies and agents for quartz sand surface modification and provides a comprehensive analysis of the various modification reagents and their operative mechanisms. It delves into the mechanism and utility of surface-modified quartz sand for adsorbing heavy metal ions (HMIs). It is found that the reported modifiers usually form connections with the surface of quartz sand through electrostatic forces, van der Waals forces, pore filling, chemical bonding, and/or molecular entanglement. The literature suggests that these modifications effectively address issues inherent to natural quartz sand, such as its low superficial coarseness, rapid adsorption site saturation, and limited adsorption capacity. Regrettably, comprehensive investigations into the particle size, regenerative capabilities, and application costs of surface-modified quartz sand and the critical factors for its wider adoption are lacking in most reports. The adsorption mechanisms indicate that surface-modified quartz sand primarily removes HMIs from aqueous solutions through surface complexation, ion exchange, and electrostatic and gravitational forces. However, these findings were derived under controlled laboratory conditions, and practical applications for treating real wastewater necessitate overcoming further laboratory-scale obstacles. Finally, this review outlines the limitations of partially surface modified quartz sand and suggests potential venues for future developments, providing a valuable reference for the advancement of cost-effective, HMI-absorbing, surface-modified quartz sand filter media.
石英砂（SiO）是一种常见的过滤介质，具有广泛的可获取性、卓越的稳定性和成本效益。然而，其光滑的表面、有限的活性位点以及吸附位点的迅速饱和常常限制了它的效用。本综述概述了石英砂表面改性的常见策略和试剂，并对各种改性试剂及其作用机制进行了全面分析。它深入探讨了表面改性石英砂吸附重金属离子（HMI）的机制和效用。研究发现，所报道的改性剂通常通过静电力、范德华力、孔隙填充、化学键合和/或分子缠结与石英砂表面形成连接。文献表明，这些改性有效地解决了天然石英砂固有的问题，如表面粗糙度低、吸附位点迅速饱和以及吸附容量有限。遗憾的是，大多数报告缺乏对表面改性石英砂的粒径、再生能力和应用成本以及其更广泛应用的关键因素的全面研究。吸附机制表明，表面改性石英砂主要通过表面络合、离子交换以及静电力和重力从水溶液中去除HMI。然而，这些发现是在受控的实验室条件下得出的，处理实际废水的实际应用需要克服进一步的实验室规模障碍。最后，本综述概述了部分表面改性石英砂的局限性，并提出了未来发展的潜在方向，为开发具有成本效益的、吸附HMI的表面改性石英砂过滤介质提供了有价值的参考。
