Nanofiltration as tertiary treatment method for removing trace pharmaceutically active compounds in wastewater from wastewater treatment plants

Abstract

The ever-increasing occurrence and persistence of pharmaceutically active compounds (PhACs) in soils, sediments, drinking water supplies and wastewater effluents are a matter of serious environmental concern for governments and researchers worldwide. Nanofiltration as tertiary treatment method can be a viable and practical tool to remove these pollutants from aquatic environments. However, organic matter present in water sources can foul the membrane surface during operation, thus being potentially able to affect the membrane performance. Therefore, fouling mechanisms could heavily influence on the removal efficiencies. The purpose of this study was to investigate the implementation of three nanofiltration membranes (TFC-SR2, NF-270 and MPS-34) and to study both the rejection of trace PhACs and the fouling mechanisms for each membrane as a function of feed solution pH. Fouling mechanisms were predicted by Hermia's model adapted to cross-flow configurations. Results demonstrated that higher removals were obtained at slightly alkaline pH, especially for anionic trace PhACs. At the same conditions, more severe fouling was observed, which resulted in strong flux declines and an increase in hydrophobicity. This indicates that the attached organic matter on the membrane surface acts as a secondary selective barrier for separation.

Organic micropollutants in a large wastewater treatment plant: What are the benefits of an advanced treatment by activated carbon adsorption in comparison to conventional treatment?

“…To achieve OMPs removal, the most frequently used advanced technologies include activated carbon adsorption (Benstoem et al, 2017;Boehler et al, 2012;Meinel et al, 2015), advanced oxidation processes (Bourgin et al, 2017;Miklos et al, 2018;Yao et al, 2018) and membrane processes (Garcia-Ivars et al, 2017;Sahar et al, 2011;Snyder et al, 2007). Adsorption performances vary according to the type and dose of activated carbon (Kårelid et al, 2017), the operational conditions (Frank et al, 2015;Streicher et al, 2016) and the quality and composition of the water (Zietzschmann et al, 2014).…”

Physico‐Chemical Processes

“…The flux Water Environment Research, Volume 90, Number 10 -Copyright © 2018 Water Environment Federationacross NF270 was stable, while its rejection of PFHxA was very sensitive to the variation of initial feed pH. In contrast, NTR7450 showed a very good stability on rejection rate, whereas its flux was very sensitive to changing initial feed pH Garcia-Ivars et al (2017). implemented three NF membranes (TFC-SR2, to study both the removal of trace pharmaceuticals (PhACs) and the fouling mechanisms of each membrane through varying feed pH.…”

Effect of Pretreatment on Hydraulic Performance of the Integrated Membrane Process for Concentrating Nutrient in Biogas Digestate from Swine Manure

“…Among them, MF and UF are commonly used as pretreatment for NF and RO, a common practice for further concentration of nutrients [ 16 , 17 ]. Previous studies showed that clean permeates could be obtained for recycling by the NF and RO processes [ 8 , 18 , 19 ], and the concentrates with concentrated nutrients and reduced volume could be obtained as a valuable organic fertilizer [ 18 , 20 , 21 , 22 ]. Additionally, studies showed that the combined process of NF and RO (NF + RO) had lower energy consumption and better nutrient concentration performance than the single process, either NF or RO [ 23 ].…”