Parameter optimization and performance analysis of nanofiltration membrane in treatment of compound-contaminated high-hardness water

• Published in: Aqua (London, England) Vol. 70; no. 8; pp. 1145 - 1158
• Main Authors: Li, Guifang, Gao, Yuting, Song, Wuchang, Xu, Fei, Wang, Yonglei, Sun, Shaohua, Ruibao Jia
• Format: Journal Article
• Language: English; French
• Published: Oxford IWA Publishing 01.12.2021
• Subjects: Alkalinity; Calcium ions; composite-contaminated; Contaminants; Contamination; Desalination; Drinking water; Economic development; Economics; Experiments; Fouling; Groundwater; high-hardness; Influents; Inorganic salts; Magnesium; Membrane separation; Membranes; Nanofiltration; Optimization; parameter optimization; Parameters; Pollutants; Regression models; Removal; Response surface methodology; Salts; Socioeconomic aspects; Software packages; Surface water; Variables; Water desalting; Water hardness; Water pollution; Water quality; Water yield; China; Japan
• ISSN: 1606-9935; 2709-8028; 1605-3974; 2709-8036
• DOI: 10.2166/aqua.2021.225

Increased pollution caused by socio-economic development has led to compound-contaminated high-hardness water pollution. In this study, laboratory-scale nanofiltration (NF) treatment of such water was investigated. Response-surface methodology was used to optimize the NF operating parameters, and a regression model with desalination rate and transmembrane pressure changes as response values was established. The NF membrane efficiencies in contaminant removal from groundwater and surface water with compound-contaminated high hardness and the membrane-fouling characteristics during long-term operation were investigated. The results show that the optimal operating parameters for the NF membrane in the removal of inorganic salts from groundwater are as follows: influent pH 8, influent pressure 1 MPa, and water yield 27.976%. The removal rates for groundwater total hardness, total alkalinity, total soluble solids, K+, Na+, Ca2+, Mg2+, ⁠, Cl−, ⁠, and were 99.4, 90.3, 84.7, 63.2, 56.8, 99.6, 95.2, 99.6, 68.3, 86.1, and 65.9%, respectively. Surface water contains more complex components; therefore, membrane fouling during surface water is more serious. The NF membrane was operated continuously for more than 35 days under the optimal operating conditions with no serious membrane fouling.