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Beijing, China

Liu C.,Hohai University | Chen W.,Hohai University | Robert V.M.,Orica Watercare | Han Z.G.,Hohai University
Water Science and Technology: Water Supply | Year: 2011

Natural organic matter (NOM) fouling continues to be the major barrier to efficient application of ultrafiltration (UF) in drinking water treatment. Algogenic organic matter (AOM), the main contributor to total NOM levels in raw waters characterised by elevated algae levels, is currently the subject of much investigation. In this study, the effect of AOM on fouling of ultrafiltration and the effectiveness of magnetic ion exchange resin (MIEX®) pre-treatment for AOM removal and membrane fouling control was evaluated. The results showed that, the main species of algae in raw water were Chlorella vulgaris, which accounted for 80% of total algae. AOM was predominantly hydrophilic (50% or more) with a low SUVA (1.7 Lm-1 mg-1). Coagulation alone could not remove AOM effectively (less than 20%), however, when combined with magnetic ion exchange resin pre-treatment, more than 60% of AOM was be removed; pre-treatment followed by coagulation was observed to be very effective in controlling membrane fouling by AOM. The application of magnetic ion exchange resin technology at a bed volume treatment rate (BVTR) of 800 was observed to effectively eliminate fouling of UF membrane. Careful analyses of the molecular weight (MW) distribution of AOM and UV absorbance of treated water revealed that the effectiveness in membrane fouling control was the result of the changes in AOM molecular characteristics in treated water, namely a change in MW due to the preferential removal of high molecular proteins by coagulation and magnetic ion exchange resin pre-treatment. The results demonstrate that magnetic ion exchange resin followed by coagulation might be a new membrane pre-treatment option for UF membrane fouling control. © IWA Publishing 2011. Source


Richardson D.,Norske Skog Technical Support and Development | Murray B.,Orica Watercare | Blom L.,Norske Skog FOCUS
Appita Annual Conference | Year: 2010

Pilot scale experiments using the MIEX® process were conducted on biologically treated pulp and paper mill effluent from Norske Skog's Albury mill. The results of the pilot plant trial indicated that the treated water quality targets for both dissolved COD (120 mg L-1) and Colour (80 Hazen units (HU)) could be consistently achieved when using the following operating conditions: • Treatment rate of 250 bed volume (BV); • Counter current plant configuration; • Periodic high pH regeneration (i.e. 2 high pH regenerations/week); • Monthly plant disinfection using sodium hypochlorite. Analysis of the results achieved suggests that a treatment rate of 500BV combined with periodic high pH regeneration may be successful at achieving the dissolved COD treated water target. Using the treatment rate of 500BV would result in significant reductions of both capital and operating costs for a full scale installation, as well as minimising any increase in conductivity. Source


Liu C.,Hohai University | Chen W.,Hohai University | Cao Z.,Hohai University | Li J.-I.,Hohai University | Van Merkenstein R.,Orica Watercare
Fresenius Environmental Bulletin | Year: 2010

Natural organic matter (NOM) fouling continues to be the major barrier to efficient application of ultrafiltration (UF) in drinking water treatment. Algogenic organic matters (AOM), the main contributor to total NOM levels in raw waters characterised by elevated algae levels, is currently the subject of much investigation. In this study, the effect of AOM on fouling of ultrafiltration and the effectiveness of MIEX® pre-treatment for AOM removal and membrane fouling control was evaluated. The results showed that, the main species of algae in raw water were Chlorella vulgaris, which accounted for 80% of total algae. AOM was predominantly hydrophilic (50% or more) with a low SUVA (1.7Lm-1mg-1). Coagulation alone could not remove AOM effectively (less than 20%), however, when combined with MIEX® pre-treatment, more than 60% of AOM was be removed. MIEX® pre-treatment followed by coagulation was observed to be very effective in controlling membrane fouling by AOM. The application of MIEX® technology at a bed volume treatment rate (BVTR) of 800 was observed to effectively eliminate fouling of UF membrane. Careful analyses of the molecular weight (MW) distribution of AOM and UV absorbance of treated water revealed that the effectiveness in membrane fouling control was the result of the changes in AOM molecular characteristics in treated water, namely a change in MW due to the preferential removal of high molecular proteins by coagulation and MIEX® pre-treatment. The results demonstrate that MIEX® followed by coagulation might is a new membrane pre-treatment option for UF membrane fouling control. Source


Arias M.S.,Orica Watercare | Bourke M.,Orica Watercare | Vaughan F.,Orica Watercare | Martin B.,Orica Watercare
Water Quality Technology Conference and Exposition 2010 | Year: 2010

With fluctuations in raw water quality parameters, especially increases in bromide and dissolved organic carbon (DOC) as experienced by California Utilities fed by the State Water Project (SWP) water, consistent compliance with disinfection by product (DBP) standards has proven difficult. The DWR model developed to predict total trihalomethane (TTHM) formation on SWP water was used as a valuable tool to determine conditions necessary to assure distribution system compliance. The model demonstrated that both bromide and DOC had a large influence on the amount of TTHM formed in the distribution system. MIEX® Pretreatment lowered raw water DOC at the DWR plant to 0.95 mg/L with a UV of 0.014 cm-1, and lowered the raw water bromide by 40% to 150 μg/L, demonstrating removal for the influential precursors of TTHMs. The average difference between model predicted and experimental data TTHM was 7.5 μg/L and a maximum difference was 11.2 μg/L. Since the site calibration of the DWR Model proved to correlate well with bench-scale TTHM results after MIEX® Resin and ACH coagulation treatment, a correlation to the target DOC treatment goal was able to be set, and the full-scale plant could use this information in achieving an effluent DOC goal. 2010 © American Water Works Association WQTC Conference Proceedings All Rights Reserved. Source


Myat D.T.,Victoria University of Melbourne | Mergen M.,Orica Watercare | Zhao O.,Orica Watercare | Stewart M.B.,Victoria University of Melbourne | And 5 more authors.
Journal of Membrane Science | Year: 2014

The impact of secondary effluent wastewater from the Eastern Treatment Plant (ETP), Melbourne, Australia, before and after ion exchange (IX) treatment and polyaluminium chlorohydrate (PACl) coagulation, on hydrophobic polypropylene (PP) and hydrophilic polyvinylidene fluoride (PVDF) membrane fouling was studied. Laboratory fouling tests were operated over 3-5 days with regular, intermittent backwash. During the filtration with PP membranes, organic rejection data indicated that humic adsorption on hydrophobic PP membrane occurred during the first 24h of filtration and contributed to fouling for both raw wastewater and pre-treated wastewaters. However, after the first 24h of filtration the contribution of humic substances to fouling diminished and biopolymers that contribute to cake layer development became more prominent in their contribution to the fouling rate. For PVDF membranes, the per cent removal of humic substances from both raw wastewater and pre-treated wastewaters was very small as indicated by no change in UV254 from the feed to the permeate over the filtration period, even during the early stages of filtration. This suggested that the hydrophobic PP membrane adsorbed humic substances while the hydrophilic PVDF membrane did not. The highest mass of biopolymer removal by each PVDF membrane was from ETP water followed by PACl and IX treated water respectively. This was possibly due to differences in the backwashing efficiency linked to the filter cake contributed by biopolymers. Hydraulic backwashing was more effective during the later stages of filtration for the ETP water compared to IX and PACl treated waters, indicating that the filter cake contributed by ETP biopolymers was more extensively removed by hydraulic backwashing. It was proposed that humic substances may act to stabilise biopolymers in solution and that removing humics substances by coagulation or IX results in greater adhesive forces between the biopolymers and membrane/filter cake. Extended laboratory filtration is required to understand fouling of low pressure membranes as it relates to commercial applications, as the initial rate of fouling for new membranes can include pore constriction mechanisms from humic substances which diminish in significance as filtration continues. Filtration for >24h was required before the HIFI values became constant. © 2014 Elsevier B.V. Source

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