Walkerton Clean Water Center

Walkerton, Canada

Walkerton Clean Water Center

Walkerton, Canada

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Rana D.,University of Ottawa | Scheier B.,University of Ottawa | Scheier B.,University of Waterloo | Narbaitz R.M.,University of Ottawa | And 5 more authors.
Journal of Membrane Science | Year: 2012

Pharmaceutical and personal care products (PPCPs) enter the environment mainly through municipal wastewater effluents, agricultural run-off, pharmaceutical and related chemical industry discharges. The present study was conducted to remove PPCPs through nano-filtration (NF) membranes prepared with two different tailor-made polymeric additives. The first is a novel charged surface modifying macromolecule (CSMM) additive synthesized by reactive diisocyanate and dihydroxy naphthalene disulfonate. The second additive was a tailor made hydrophi. lic SMM (LSMM), which was manufactured incorporating poly(ethylene glycol) as end groups. Cellulose acetate (CA) membranes with and without 3. wt% CSMM or LSMM were prepared by the phase inversion technique. The membranes were characterized by static contact angle, X-ray photoelectron spectroscopy, scanning electron microscopy with energy dispersive spectrometer, and atomic force microscopy. The NF filtration studies were conducted at two different operating pressures (150 and 400. psig). They consisted of pure water flux tests, sodium chloride separation tests, and individual PPCP (ppm level carbamazepine, ibuprofen, and sulfamethazine) separation tests. The long term NF performance for the removal of ibuprofen was also conducted. Significant effect of CSMM blending on the separation performance of ibuprofen for long hours operation was observed. © 2012 Elsevier B.V.


Narbaitz R.M.,University of Ottawa | Rana D.,University of Ottawa | Dang H.T.,University of Ottawa | Morrissette J.,University of Ottawa | And 4 more authors.
Chemical Engineering Journal | Year: 2013

To maximize the removal of charged pharmaceutical and personal care products (PPCPs), modified cellulose acetate (CA) nanofiltration (NF) membranes were developed by incorporating charged surface modifying macromolecules (CSMM) to increase their surface charge. The objective of this study was to evaluate their removal of trace levels of PPCPs at two water treatment plants. This new membrane and a commercial thin-film composite (TFC) NF membrane (Filmtec NF-270) were tested simultaneously in the field using two SEPA cells. The testing was conducted at the Britannia Water Treatment Plant (Ottawa, ON) and the Walkerton Clean Water Centre (Walkerton, ON). The challenge waters were filter effluents spiked with ppt and ppb levels of carbamazepine (CBZP), ibuprofen (IBUP) and sulfamethazine (SFMZ). The new experimental modified CA membrane achieved very good IBUP removals, good SFMZ removals and poor CBZP removals. The commercial TFC NF membrane (NF-270) had better removals and significantly higher fluxes than the modified CA membrane. The larger removals are not surprising given that the commercial membrane is the result of extensive development and optimization, while the modified CA membrane has undergone very limited optimization. The larger flux of the NF-270 membrane is also expected given that this is a TFC membrane, while the experimental modified membrane was prepared via a single casting step via the phase inversion technique which produces a thicker skin layer. © 2013 Elsevier B.V.


Rana D.,University of Ottawa | Narbaitz R.M.,University of Ottawa | Garand-Sheridan A.-M.,University of Ottawa | Westgate A.,University of Ottawa | And 3 more authors.
Journal of Materials Chemistry A | Year: 2014

The aim of this study was to develop novel surface-modified poly(ether sulfone) (PES) ultra-filtration (UF) membranes for removal of endocrine disrupting chemicals (EDCs) and pharmaceutical and personal care products (PPCPs). Seven tailor-made charged surface modifying macromolecules (CSMMs) were developed for use as additives in the preparation of PES UF membranes with a greater surface charge and improved PPCP and EDC removal through charge repulsion. Twenty three types of PES membranes were prepared using two amounts of different CSMMs and two drying (or evaporation) times. The experiments were designed to obtain the membranes' performances in terms of normalized standard flux (NSF), molecular weight cut-off (MWCO), surface charge (SC), static contact angle and their removal efficiency towards one EDC (bisphenol A) and three PPCPs (carbamazepine, ibuprofen, and sulfamethazine). The correlation between NSF versus SC, MWCO, pore density, and porosity was discussed. The filtration experiments showed an initial partial removal of the target compounds, but no removal in the later stages of operation, which indicated that charge repulsion was not the controlling removal mechanism. This is consistent with small changes in membrane surface charge achieved by addition of these additives. Given the decrease in the percent removal with time, removal by size exclusion was also not significant as expected because the membranes had a MWCO greater than 10 kilo-Dalton while the target compounds had molecular weights in the 200 to 300 Dalton range. Based on the decreasing level of removal with time, it appeared that adsorption was the main removal mechanism. 2014 This journal is © the Partner Organisations.


Rahman I.,University of Waterloo | Ndiongue S.,Walkerton Clean Water Center | Jin X.,Walkerton Clean Water Center | Van Dyke M.I.,University of Waterloo | And 2 more authors.
Water Science and Technology: Water Supply | Year: 2014

Fouling is a major challenge for low-pressure membrane drinking water treatment systems. Previous research has demonstrated that under the right conditions, biofiltration is an effective method to reduce fouling of low-pressure polymeric membranes. This study provides additional insight into the effect of biofiltration as a pretreatment for fouling reduction by using river water with different raw water quality characteristics than has been examined in previous studies. Two parallel pilot-scale dual media (sand/anthracite) biological filters were operated continuously over a period of 14 months. Liquid chromatography-organic carbon detection analysis confirmed that the parallel biofilters performed similarly with both averaging on 21% biopolymer removal. Raw and treated water biopolymer concentrations were correlated, with increased absolute removals occurring at higher raw water concentrations. Ultrafiltration (UF) membrane fouling experiments showed substantial improvement in performance following biofiltration pretreatment by reducing hydraulically irreversible and reversible fouling rates by 14-68% and 8-55%, respectively. The results also reaffirm the importance of biopolymers at concentrations as low as ~0.1 mg/L on irreversible and reversible UF membrane fouling and a minimal impact of humic substances. © IWA Publishing 2014.


Rahman M.F.,University of Western Ontario | Jasim S.Y.,University of Western Ontario | Yanful E.K.,University of Western Ontario | Ndiongue S.,Walkerton Clean Water Center | Borikar D.,Walkerton Clean Water Center
Ozone: Science and Engineering | Year: 2010

Pre-coagulation ozonation has been reported to be effective in drinking water treatment processes. Limited data are available on the impact of advanced oxidation processes (AOPs) on Lake Huron water which serves as a primary source of drinking water for many communities around the Great Lakes region. Impact of ozone/hydrogen peroxide based AOP on Lake Huron water was studied. The results show that AOPs can achieve higher particles removal in finished water and deliver improved filtered water turbidity compared to the conventional treatment process. Sharp decline in ultraviolet absorbance at 254 nm (UV254) was observed immediately following AOP treatment while only minimal overall decrease in dissolved organic carbon (DOC) was achieved. © 2010 International Ozone Association.


Jasim S.Y.,International Joint Commission | Ndiongue S.,Walkerton Clean Water Center | Alshikh O.,Walkerton Clean Water Center | Jamal A.T.,Walkerton Clean Water Center
Ozone: Science and Engineering | Year: 2012

The current study undertaken by the Walkerton Clean Water Centre (WCWC) is to evaluate the application of Advanced Oxidation Processes (AOPs) involving Ozone and UV with the addition of hydrogen peroxide, as one of the methods used in the process of the removal of PPCPs and EDCs, or taste and odor. The amount of hydrogen peroxide used with UV is much higher than that used with the ozone application. The concern is the impact of the hydrogen peroxide on the chlorine residual in the water that is pumped to the distribution system. One of the methods used to deal with this problem is to increase the chlorine addition to maintain the required residual. That could increase the disinfectant by-products (DBPs), namely Trihalomethanes (THMs), in addition to increase to the cost of operation. The findings of these experiments would provide useful information regarding the AOPs application using ozone vs. UV with hydrogen peroxide. © 2012 Copyright 2012 International Ozone Association.


Rahman M.F.,University of Western Ontario | Yanful E.K.,University of Western Ontario | Jasim S.Y.,University of Western Ontario | Jasim S.Y.,Walkerton Clean Water Center | And 4 more authors.
Ozone: Science and Engineering | Year: 2010

The current study focuses on the occurrence of selected endocrine disrupting compounds, pharmaceuticals and personal care products in Lake Huron Water and their removal using ozone/hydrogen peroxide based pre-coagulation, advanced oxidation process (AOP). Raw Lake Huron water spiked with nine target compounds was treated in a dual train pilot scale treatment plant. None of the target chemicals showed any significant removals following conventional treatment processes (coagulation, sedimentation and filtration). Five of the nine target pollutants plummeted to concentrations below the method detection limits following AOP. For all the target compounds AOP treatment provided higher removal compared to conventional treatment. © 2010 International Ozone Association.


Borikar D.,Walkerton Clean Water Center | Borikar D.,University of British Columbia | Mohseni M.,University of British Columbia | Jasim S.,SJ Environmental Consultants Inc.
Ozone: Science and Engineering | Year: 2015

Pharmaceuticals and personal care products (PPCPs), endocrine disrupting compounds (EDCs) and disinfection by-products are suspected to have potential adverse impact on humans and hence their elimination during drinking water treatment is often desired or regulated. Based on pilot-plant experiments with three raw water sources, conventional treatment poorly removed the selected PPCPs and EDCs, while ozone/H2O2 and UV/H2O2 (both) with conventional treatment effectively removed PPCPs and EDCs. In most of the experiments, ozone/H2O2 + conventional treatment additionally removed THM formation potentials (THM-FPs) compared to those of conventional treatment. However, UV/H2O2 treatment was found to increase THM-FPs compared to conventionally treated water. © 2015, Copyright © 2015 International Ozone Association.


Jin X.,Walkerton Clean Water Center | Peldszus S.,University of Waterloo | Huck P.M.,University of Waterloo
Chemosphere | Year: 2015

Quantitative structure-property relationship (QSPR) models which predict hydroxyl radical rate constants (kOH) for a wide range of emerging micropollutants are a cost effective approach to assess the susceptibility of these contaminants to advanced oxidation processes (AOPs). A QSPR model for the prediction of kOH of emerging micropollutants from their physico-chemical properties was developed with special attention to model validation, applicability domain and mechanistic interpretation. In this study, 118 emerging micropollutants including those experimentally determined by the author and data collected from the literature, were randomly divided into the training set (n=89) and validation set (n=29). 951 DRAGON molecular descriptors were calculated for model development. The QSPR model was calibrated by applying forward multiple linear regression to the training set. As a result, 7 DRAGON descriptors were found to be important in predicting the kOH values which related to the electronegativity, polarizability, and double bonds, etc. of the compounds. With outliers identified and removed, the final model fits the training set very well and shows good robustness and internal predictivity. The model was then externally validated with the validation set showing good predictive power. The applicability domain of the model was also assessed using the Williams plot approach. Overall, the developed QSPR model provides a valuable tool for an initial assessment of the susceptibility of micropollutants to AOPs. © 2015 Elsevier Ltd.


PubMed | University of Waterloo and Walkerton Clean Water Center
Type: | Journal: Chemosphere | Year: 2015

Quantitative structure-property relationship (QSPR) models which predict hydroxyl radical rate constants (kOH) for a wide range of emerging micropollutants are a cost effective approach to assess the susceptibility of these contaminants to advanced oxidation processes (AOPs). A QSPR model for the prediction of kOH of emerging micropollutants from their physico-chemical properties was developed with special attention to model validation, applicability domain and mechanistic interpretation. In this study, 118 emerging micropollutants including those experimentally determined by the author and data collected from the literature, were randomly divided into the training set (n=89) and validation set (n=29). 951 DRAGON molecular descriptors were calculated for model development. The QSPR model was calibrated by applying forward multiple linear regression to the training set. As a result, 7 DRAGON descriptors were found to be important in predicting the kOH values which related to the electronegativity, polarizability, and double bonds, etc. of the compounds. With outliers identified and removed, the final model fits the training set very well and shows good robustness and internal predictivity. The model was then externally validated with the validation set showing good predictive power. The applicability domain of the model was also assessed using the Williams plot approach. Overall, the developed QSPR model provides a valuable tool for an initial assessment of the susceptibility of micropollutants to AOPs.

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