Abstract:

Silica scaling led to irreversible decline of the nanofiltration/reverse osmosis (NF/RO) membrane permeation flux and severely limited the water productivity of the membrane system, which was widely considered as a difficult challenge in water treatment process. Two types of silica scale on NF/RO membrane were introduced firstly, namely inorganic scale and combined inorganic-organic scale. Then, the effects of influent water quality, membrane surface chemical properties and topology on the formation of silica scale on membrane surface were emphatically reviewed, as well as the control strategies for the formation of silica scale on membrane surface, including influent pretreatment, scale inhibitor addition, membrane surface chemical modification and morphology regulation. Finally, the existing problems and future research directions of silica scaling control on membrane surface were summarized, mainly including the research on silica scaling behavior using model substrates with controllable surface properties, the in-depth exploration of the relationship between membrane surface chemical properties and silica scaling potential, the thorough research on the delay and inhibition mechanism of polymer scale inhibitors at the molecular level, the development of novel membrane materials to simultaneously inhibit silica scaling and organic fouling, and the establishment of a comprehensive database related to membrane surface properties and silica scaling under different influent water quality conditions, which were of important guiding significance for the development of efficient silica scale control strategies.

Key words: membranes, nanofiltration, reverse osmosis, silica scale

摘要：

硅结垢会导致纳滤/反渗透（NF/RO）膜渗透通量不可逆下降，严重限制膜系统的产水率，被广泛认为是水处理过程的难题。本文首先介绍了NF/RO膜硅垢的2种类型，即无机垢和无机-有机复合垢；然后重点综述了进水水质、膜表面化学性质和拓扑结构对膜表面硅结垢的影响，以及进水预处理、阻垢剂添加、膜表面化学改性和形貌调控的硅结垢控制策略；最后总结了目前NF/RO膜表面硅垢控制存在的问题及未来的研究方向，主要包括采用表面性质可控的模型基底进行硅结垢行为研究，深入探索膜表面化学性质与硅结垢潜力之间的关系，在分子水平上深入研究高分子阻垢剂的延迟和抑制机制，研制同步抑制硅结垢和有机污染的新型膜材料，以及建立不同进水水质条件下膜表面性质与硅结垢相关联的综合数据库等，对开发高效硅垢控制策略具有重要指导意义。

关键词: 膜, 纳滤, 反渗透, 硅垢