Tałałaj Izabela Anna
Faculty of Civil Engineering and Environmental Sciences, Bialystok University of Technology, Wiejska 45E Street, 15-351 Bialystok, Poland.
J Environ Health Sci Eng. 2022 Jan 12;20(1):419-429. doi: 10.1007/s40201-022-00788-0. eCollection 2022 Jun.
In this paper the performance and effectiveness of the reverse osmosis (RO) process for the biologically pretreated leachate was investigated. The RO process was carried out separately for two different pH: 8.0 and 9.3.
A general pollution parameters as well as organic and inorganic indicators were determined in raw, biologically pretreated and RO treated leachate. The performance characteristics of the reverse osmosis system were made on the basis of permeate flux, electroconductivity removal rate, concentration factor and efficiency in removal of analyzed parameters.
The use of SBR pretreatment had very good efficiency in BOD (97.3%) and ammonia nitrogen (95.4%) removal. The lowest effectivity was observed for chloride (11.6%), boron (3.9%) and TDS (1.2%). Pretreated leachate was subjected to RO system. The normalized average flux was 0.53 (42.3 L/m·h) for pH = 8.0 and 0.68 (33.5 L/m·h) for pH = 9.3. The lower membrane fouling at higher pH can be explained by electrostatic repulsion between the negatively charged membrane surface and organic substances. Independently of the process pH, a two-step membrane fouling was observed. The greatest differences in removal rates were observed for boron, which had a higher retention rate at higher pH, and ammonia nitrogen, whose removal rate decreased at higher pH. The obtained permeate pH after RO process was lower than the feed pH in two analyzed value of pH.
The higher flux value at pH = 9.3 is result of high content of organic matter in leachate, which is better rejected at higher pH because of higher electrostatic repulsion between organic matter and membrane surface. This indicates that the organic matter content should be taken into account when determining the operating parameters (pH values) of the RO system.
本文研究了反渗透（RO）工艺处理生物预处理渗滤液的性能和效果。分别在两种不同的pH值（8.0和9.3）下进行反渗透工艺。
测定了原渗滤液、生物预处理渗滤液和反渗透处理渗滤液中的一般污染参数以及有机和无机指标。基于渗透通量、电导率去除率、浓缩因子和分析参数的去除效率，对反渗透系统的性能特性进行了评估。
序批式活性污泥法（SBR）预处理对生化需氧量（BOD）的去除效率非常高（97.3%），对氨氮的去除效率也很高（95.4%）。对氯化物（11.6%）、硼（3.9%）和总溶解固体（1.2%）的去除效果最差。将预处理后的渗滤液进行反渗透系统处理。pH = 8.0时归一化平均通量为0.53（42.3 L/m·h），pH = 9.3时为0.68（33.5 L/m·h）。较高pH值下较低的膜污染可通过带负电荷的膜表面与有机物质之间的静电排斥来解释。与工艺pH值无关，观察到了两步膜污染现象。硼的去除率差异最大，硼在较高pH值下具有较高的截留率；氨氮在较高pH值下的去除率下降。在两个分析的pH值下，反渗透处理后得到的渗透液pH值均低于进料液pH值。
pH = 9.3时较高的通量值是渗滤液中有机物含量高的结果，由于有机物与膜表面之间较高的静电排斥，在较高pH值下有机物的截留效果更好。这表明在确定反渗透系统的运行参数（pH值）时应考虑有机物含量。
