Effects of feedwater pretreatment on the removal of organic microconstituents by a low fouling reverse osmosis membrane

Effect of resin charged functional group, porosity, and chemical matrix on the long-term pharmaceutical removal mechanism by conventional ion exchange resins

“…Previous investigations have demonstrated the efficient adsorption of estrone (Zhang and Zhou, 2005;Neale et al, 2010), SMX (Choi et al, 2007;Huang et al, 2011;Fern andez et al, 2014), TC (Choi et al, 2007), and NPX (Landry et al, 2015) onto AERs in batch tests, which was also demonstrated during the first cycle in this study. In fact, AER treatment removed almost all of the microconstituents, regardless of their predominant existing forms, during short-term cyclical operation (i.e., the 1st adsorptionregeneration cycle) in this study.…”

“…Many studies have highlighted the strong potential of commercial anion exchange resins (AERs) to remove pharmaceuticals from various water matrices (Michael-Kordatou et al, 2015) (e.g., MIEX ® resins for seven sulfonamide antibiotics, seven tetracyclic antibiotics (Choi et al, 2007), estrone (Neale et al, 2010), triclosan, and sulfamethoxazole (SMX) (Huang et al, 2011); Lewatit MP500 resins for SMX and sulfamethazine (Fern andez et al, 2014); Purolite A520E resins for diclofenac (DCF) (Landry and Boyer, 2013); Dowex 22 resins for DCF, ketoprofen, and naproxen (NPX), ibuprofen, paracetamol (Landry et al, 2015); IRA938, IRA958, IRA458, and IRA402 resins for nalidixic acid (Robberson et al, 2006); and Oasis MAX resin for caffeine and metformin (B€ auerlein et al, 2012)). Due to the presence of various functional groups (e.g., eOH, eCOONa, eSO 3 Na, eN]Ne, and phenolic hydroxyl groups), many pharmaceutical molecules can simultaneously participate in both electrostatic interactions (i.e., Coulombic forces between the positively charged quaternary ammonium functional groups of AERs and the anionic moieties of pharmaceuticals) and various non-electrostatic interactions (B€ auerlein et al, 2012).…”

Removal of Dissolved Organic Matter by Magnetic Ion Exchange Resin

“…MIEX resin removed approximately 40 % of estrone at pH 8 (neutral molecule) and removal increased to approximately 70 % at pH 12 where estrone is negatively charged [77]. MIEX resin showed 0-48 % removal of 15 commonly detected pharmaceuticals and personal care products with higher removal observed for negatively charged species [78]. These results follow directly from the mechanism of ion exchange as shown by Liu et al for bentazone [75] and discussed in the next section for DOM.…”

“…MIEX treatment before NF membrane reduced the flux decline relative to raw water [99], while MIEX treatment before RO membrane showed no change in flux relative to the control condition [78]. A clear advantage of MIEX pretreatment is the high removal of DOC which contributes to an overall high contaminant rejection by combined MIEX/membrane systems [99].…”

Short Communication: Requiring Reverse Osmosis Membranes Modifications – An Overview

“…They have very elevated rejection. However, the fouling of thin film composite membranes is a very hard issue in the industrial applications [3,[86][87][88][89][90][91]. Different manners have been employed to well calculate the thin selective layer to decrease fouling [92][93][94][95][96].…”