Abstract Thousands of small community-based RO plants have been installed in Rajasthan in the last few years by Public Health Engineering Department in compliance with the national guidelines. Recent reports from plant managers have indicated substantial premature replacement of RO membrane modules due to accelerated fouling. This paper describes the performance analysis of community RO plants in Bharatpur having high total dissolved solids in groundwater and attempts an ion balance to understand the fouling problem through chemical analysis of raw, permeate and reject water samples. The analysis gives new insights to field operations of brackish water systems indicating that in the majority of these plants, CaCO3 was the main foulant as per SEM-EDS; attributed to high hardness, relatively lesser solubility of hardness causing substances over sodium chloride, and inverse solubility-temperature behavior of CaCO3; water temperature being higher in Rajasthan compared to that of coastal areas. Oxides of Fe and Mn were other major foulants as they are sparingly soluble in water; thus precipitate immediately and foul the membrane. Cleaning efficiencies of HCl and citric acid were also investigated. An optimum time of 9 h cleaning through citric acid was found best while use of HCl resulted in damaging polysulfone support layer.

中文翻译：

---

地下水处理反渗透膜中无机污染物的表征与分析

摘要 过去几年，公共卫生工程部按照国家指导方针在拉贾斯坦邦安装了数以千计的小型社区反渗透设备。最近来自工厂经理的报告表明，由于加速结垢，RO 膜组件大量过早更换。本文描述了 Bharatpur 社区 RO 植物在地下水中具有高总溶解固体的性能分析，并尝试通过对原水、渗透水和废水样品的化学分析来理解污染问题的离子平衡。该分析为微咸水系统的现场操作提供了新的见解，表明在大多数这些工厂中，根据 SEM-EDS，CaCO3 是主要污染物；由于硬度高，引起硬度的物质相对于氯化钠的溶解度相对较低，以及 CaCO3 的反溶解度-温度行为；与沿海地区相比，拉贾斯坦邦的水温更高。Fe 和 Mn 的氧化物是其他主要污染物，因为它们微溶于水。从而立即沉淀并污染膜。还研究了 HCl 和柠檬酸的清洁效率。发现最佳时间是通过柠檬酸清洗 9 小时，而使用 HCl 会损坏聚砜支撑层。还研究了 HCl 和柠檬酸的清洁效率。发现最佳时间是通过柠檬酸清洗 9 小时，而使用 HCl 会损坏聚砜支撑层。还研究了 HCl 和柠檬酸的清洁效率。发现最佳时间是通过柠檬酸清洗 9 小时，而使用 HCl 会损坏聚砜支撑层。