Cranfield Water Science Institute, Cranfield University, Beds, UK.
PWNT, Velserbroek, the Netherland.
Water Res. 2022 May 15;215:118269. doi: 10.1016/j.watres.2022.118269. Epub 2022 Mar 8.
The continued technological developments and decreased purchase costs of ceramic membranes have seen increased recent interest in the technology as an alternative to the more widely used polymeric membranes. This paper assesses the relative technical, practical and economic merits of the two membrane materials in the context of potable water production from surface water sources. The work focuses on phenomena of direct technoeconomic significance, namely cleaning efficacy (manifested as permeability recovery), membrane integrity and incurred labour effort. Topics reviewed thus comprise: (a) practical comparison of the two technologies challenged with the same feedwater, (b) comparative technoeconomic analyses, (c) membrane integrity studies of polymeric membranes - incorporating aged samples extracted from operating installations, (d) sludging incidents, and (e) pilot and full-scale data. Available relevant data reveal: (a) bench-scale comparative tests do not indicate a consistent significant difference in the net permeability between the two membranes; (b) polymeric membranes are subject to a decline in both mechanical strength and permeability from the loss of the hydrophilic agent over a period of years from the action of hypochlorite used for cleaning; (c) the decreased mechanical strength with age of polymeric membranes increases the manual repair requirement and shortens membrane life, respectively impacting on labour and membrane replacement costs where the latter is also determined by the permeability; (d) the chemical and mechanical robustness of ceramic membranes permits more aggressive chemical cleaning, which then affects the chemicals consumption cost; and (e) anecdotal evidence suggests that polymeric membranes challenged with pre-coagulated surface waters may be subject to sludging, the agglomeration of solids in the membrane channels, which may also be age-related. Notwithstanding the above, data from published comparative technoeconomic studies indicate a linear relationship between the overall cost benefit and the membrane module cost ratio mitigated by the relative membrane life and operating flux.
陶瓷膜的技术不断发展，购置成本降低，使得这项技术越来越受到关注，成为更广泛使用的聚合物膜的替代技术。本文评估了这两种膜材料在地表水饮用水生产方面的相对技术、实际和经济优势。研究工作主要集中在直接具有技术经济意义的现象上，即清洗效果（表现为渗透率恢复）、膜完整性和所涉及的劳动强度。因此，综述的主题包括：（a）用相同的给料水对两种技术进行实际比较，（b）比较技术经济分析，（c）聚合物膜的膜完整性研究——包括从运行装置中提取的老化样品，（d）结垢事件，以及（e）中试和全规模数据。现有的相关数据表明：（a）在实验室规模的比较测试中，两种膜的净渗透率之间没有一致的显著差异；（b）聚合物膜的机械强度和渗透率都会随着亲水性试剂的损失而下降，这是由于用于清洗的次氯酸盐的作用，这种损失会在几年内发生；（c）聚合物膜随着时间的推移机械强度下降，增加了人工修复的要求，从而缩短了膜的寿命，这分别影响了劳动力和膜更换成本，后者也由渗透率决定；（d）陶瓷膜的化学和机械稳定性允许更具侵略性的化学清洗，从而影响化学清洗成本；（e）传闻证据表明，用预凝聚地表水进行挑战的聚合物膜可能会发生结垢，即固体在膜通道中的团聚，这也可能与膜的老化有关。尽管如此，来自已发表的比较技术经济研究的数据表明，整体成本效益与膜模块成本比之间存在线性关系，这种关系由相对膜寿命和操作通量来缓解。
