UNESCO-IHE, Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands.
Water Res. 2009 Dec;43(20):5039-52. doi: 10.1016/j.watres.2009.08.030. Epub 2009 Aug 28.
The abundance of Transparent Exopolymer Particles (TEP) in surface waters has been unnoticed for many years until recently as a potential foulant in reverse osmosis systems. Recent studies indicate that TEP may cause organic and biological fouling and may enhance particulate/colloidal fouling in reverse osmosis membranes. The presence of TEP was measured in the raw water, the pre-treatment processes and reverse osmosis (RO) systems of 6 integrated membrane installations. A spectrophotometric method was used to measure TEP in the particulate size range (>0.40microm) and was extended to measure TEP in the colloidal size range (0.05-0.40microm). Ultrafiltration pre-treatment applied in 4 plants, totally removed particulate TEP while microfiltration systems (2 plants) and coagulation/sedimentation/rapid sand filtration systems (3 plants) partially removed this fraction. None of the pre-treatment systems investigated totally removed colloidal TEP. Biopolymer analysis using LC-OCD showed consistency between colloidal TEP and polysaccharide removal by UF pre-treatment and further verified the presence of TEP in the RO feedwater. TEP deposition in the RO system was determined after measuring total TEP concentrations in the RO feed and concentrate. The TEP deposition factors and specific deposition rates indicate that TEP accumulation had occurred in all plants investigated. This observation was verified by an autopsy of RO modules from two RO plants. Further improvement and verification of the (modified) TEP method, in particular the calibration, is necessary so that it can be employed to investigate the role of TEP in the fouling of RO systems.
多年来，透明质酸聚合物（TEP）在地表水中的丰富度一直未被注意到，直到最近才被认为是反渗透系统中的潜在污染物。最近的研究表明，TEP 可能导致有机和生物污垢，并可能增强反渗透膜中的颗粒/胶体污垢。在 6 个集成膜装置的原水、预处理过程和反渗透（RO）系统中测量了 TEP 的存在。使用分光光度法测量了>0.40μm 颗粒大小范围内的 TEP，并将其扩展到测量 0.05-0.40μm 胶体大小范围内的 TEP。4 个工厂应用超滤预处理，完全去除了颗粒 TEP，而微滤系统（2 个工厂）和混凝/沉淀/快速砂滤系统（3 个工厂）部分去除了这部分 TEP。研究的预处理系统都没有完全去除胶体 TEP。使用 LC-OCD 进行的生物聚合物分析表明，UF 预处理去除胶体 TEP 和多糖之间具有一致性，并进一步验证了 RO 给水中 TEP 的存在。在测量 RO 给水中总 TEP 浓度后，确定了 RO 系统中的 TEP 沉积。TEP 沉积因子和特定沉积速率表明，在所研究的所有工厂中都发生了 TEP 积累。这一观察结果通过对两个 RO 工厂的 RO 模块进行尸检得到了验证。需要进一步改进和验证（修改后的）TEP 方法，特别是校准，以便能够研究 TEP 在 RO 系统污染中的作用。
