Integrated ion exchange mixed bed with reverse osmosis and nanofiltration for isolation of neutral dissolved organic matter from natural waters

Abstract

The aim of this study was to isolate the neutral dissolved organic matter (NDOM) and the low molecular weight neutrals (LMWN) from natural waters. The coupling of an ion exchange mixed bed (IEXMB) with reverse osmosis (RO) and nanofiltration was the main hypothesis. IEXMB removed charged species, while the neutral molecules were isolated in the demineralised water and then concentrated by RO without any osmotic pressure or fouling limits. Neutrals isolation and unlimited concentration, gives this paper its originality. The nanofiltration (NF) step allows for the isolation of the LMWN. The studied reservoir water NDOM and LMWN represented respectively 35% of the dissolved organic matter (DOM) and 34% of the NDOM. Aromatic compounds were found in both fractions. The UV254 absorbance measured before and after the IEXMB evidenced the water quality 'signature'. IEX has never been studied as fractionation method of DOM. This IEXMB approach is thus quite novel.

Investigation on two integrated membrane systems for the reuse of electroplating wastewater

“…b), because of that performance of RO membrane still can keep constant regardless of the variation of Ni 2+ concentration (Khettaf et al . ).…”

“…Figure 4(b) shows that salt rejection also kept approximately stable with feed water concentration ranging from 250 mg/L to 600 mg/L for both systems (Fig. 4b), because of that performance of RO membrane still can keep constant regardless of the variation of Ni 21 concentration (Khettaf et al 2016).…”

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“…Due to its fixed-color properties, high resistance to corrosion, oxidation, and microbial degradation classified as a major pollutant [4]. The existence of dyes in the aquatic environment is one of the biggest problems facing scientists due to the health and environmental problems because of their carcinogenic and toxic properties and their ability to pollute water resources [5]. Tri vinyl methane pigments (methyl green) are widely consumed in various industries for coloring textile, plastic leather, and food products, medicine, gelatin film awareness [6][7][8], and biology [9,10], green methyl dye is a basic cation [7].…”