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A 14 month pilot-scale coagulation optimization study was conducted at the Peterborough Water Treatment Plant (Ontario, Canada) to compare treatment performance resulting from the application of aluminum sulfate vs. polyaluminum chloride (PACl). This paper describes results obtained from applying a statistical analysis approach to evaluate impacts on pH, turbidity, total organic carbon (TOC), ultraviolet absorbance (UVA), particle counts, chlorine residuals, filter head loss, flow rate, trihalomethanes (THMs), and nine haloacetic acids (HAA9). To allow a direct comparison, parallel pilot trains were operated such that they achieved equal settled water TOC by adjusting PACl dose, (52-74% of the alum dose by weight). Settled water turbidity was significantly higher (on average 0.23 NTU) in the alum treated water when compared to PACl. For equivalent filter run-times, head loss was greater by 0.002-0.011 m hr1 when applying alum. An increase in pH by approximately 0.7 units when using PACl was observed to cause a significant increase in THM formation (10-30%). [ABSTRACT FROM AUTHOR]

The application of pre-coagulation ozone in drinking water treatment to provide primary disinfection, has an impact on coagulation and flocculation, and needs to be evaluated further for cold water temperatures, especially when accompanied by episodes of high alkalinity and dissolved organic carbon (DOC). Ozone application to raw water, prior to the addition of coagulants and coagulant aides, was shown to reduce coagulant and coagulant aide doses, and improve settled and filtered water turbidity. The impact on particle count was also noticeable, filtered water particle count was reduced after the application of pre-coagulation ozonation. Pilot-scale experiments were conducted at the Walkerton Clean Water Centre, Walkerton, Ontario, Canada, to investigate the effect of pre-coagulation ozonation, on filtered water turbidity, particle count, and filter performance, during periods when water temperatures could be lower than 5°C. [ABSTRACT FROM AUTHOR]

Long column settling and jar tests were undertaken as part of a treatability study of combined sewage at the Lou Romano Water Reclamation Plant (LRWRP) in Windsor, Ontario. Different types of cationic polymers were examined in jar tests, and the appropriate dosage and its relationship with the TSS removal were determined for the polymer coagulation process. Settling column tests were used to develop settling rate distribution curves under both chemically aided and unaided conditions, and to examine the performance of polymer coagulation in improving the settleability of wet-weather sewage during CSO events. The results of the long column settling tests for settling rate distributions show that the characteristics of the wet-weather sewage at the LRWRP during CSO events were similar to those of samples collected at actual overflow sites along the Windsor Riverfront. Settling rate distributions demonstrated that polymer addition to the wet-weather sewage significantly improved the settling characteristics. [ABSTRACT FROM AUTHOR]

The performance of three different low-pressure water treatment membrane pilot plants was evaluated on a low-turbidity, low-colour water in British Columbia. All membrane units were hollow-fibre, hydrophilic membranes with nominal pore sizes of 0.01 to 0.2 µm. In addition to finished water quality, specific flux of each membrane was used to compare the performance of the three membrane units. The effect of feed pretreatment on the performance of the membranes and removal of disinfection byproduct (DBP) precursors was evaluated using chemical coagulation and powdered activated carbon (PAC) addition. Chemical coagulation proved to be very effective in removing DPB precursors and reducing the rate of membrane fouling. Powdered activated carbon addition, on the other hand, resulted in moderate removal of DBP precursors but increased the rate of membrane fouling. The nature and causes of membrane fouling as well as the impact of pretreatment methods on membrane fouling are discussed. Key words: ultrafiltration, microfiltration, coagulation, PAC, fouling, hollow fibre membranes, pretreatment, water treatment.Le rendement de trois différentes usines pilotes de traitement des eaux par membrane à basse pression a été évalué sur une eau de faible turbidité et peu colorée en Colombie-Britannique. Toutes les unités filtrantes à membrane étaient de type à fibre creuse et hydrophiles; les pores avaient un diamètre de 0,01 à 0,2 µm. La qualité finale de l'eau et le débit spécifique de chaque membrane ont été utilisés pour comparer le rendement des trois unités à membrane. L'effet du prétraitement de l'alimentation sur le rendement des membranes et le retrait des précurseurs DBP a été évalué en utilisant la coagulation chimique et l'ajout de charbon actif en poudre (PAC). La coagulation chimique s'est avérée très efficace pour le retrait des précurseurs DBP et pour réduire le taux d'encrassement des membranes. La nature et les causes de l'encrassement des membranes ainsi que l'impact des méthodes de prétraitement sur l'encrassement des membrane sont abordés.Mots clés : ultrafiltration, microfiltration, coagulation, PAC, encrassement, module à fibre creuse, prétraitement, traitement des eaux.[Traduit par la rédaction] [ABSTRACT FROM AUTHOR]

Forest catchments can produce high quality source water with a low turbidity. However, the combination of low turbidity, low organic carbon, and low temperature water conditions presents operating challenges in conventional water treatment processes. In this study, in-line filtration was tested using pilot-scale filter columns, and was found to be an appropriate option to treat a typical low turbidity water originating from the Rocky Mountains near Calgary, Alberta, Canada. When alum and cationic polymer were dosed simultaneously, in-line filtration produced high quality effluent with a turbidity and a particle count value of less than 0.1 NTU and 50 counts/mL, respectively. However, the alum and polymer doses and their ratios played important roles in the filtration efficiency. In general, short filter ripening times (i.e. <15 min) required an alum dose of at least 3 mg/L and an alum to polymer dose ratio of less than 180:1. A longer filter stable period was associated with lower alum and polymer doses, as long as their doses were at least 2 and 0.024 mg/L, respectively, and their dose ratio was maintained in the range of 30:1 to 130:1. The optimal alum and polymer doses were observed to be 3 and 0.072 mg/L, respectively. Filter performance was enhanced when higher alum and polymer doses were used for ripening, and lower doses were applied during the stable filtration period. In addition, in-line filtration resulted in the reduction of microspheres by 3.6 logs under the tested water conditions. Hence, a similar removal efficiency is anticipated for Cryptosporidium .

Abstract: Purpose: The purpose of this study is to determine the effect of a multifaceted behavior-change strategy on inappropriate use of frozen plasma (FP) transfusions in the intensive care unit (ICU). Materials and Methods: A prospective, time-series study was conducted in a 15-bed medical-surgical ICU in 3 phases: (1) baseline observation; (2) educational campaign, audit and feedback to prescribers, and implementation of an FP request form; and (3) FP request form only. Independently, in triplicate and blinded to study phase, appropriateness of each FP request was adjudicated based on published guidelines and clinical context. Results: Over the 15-month study period, 626 FP transfusions (210 FP requests) were administered to 88 patients. Inappropriate FP requests decreased slightly from phases I to III (60% vs 46%; P = .09), FP requests that were consistent with the guidelines did not change (23% vs 22%; P = .86), and FP requests that were appropriate for the ICU yet inconsistent with the guidelines increased (17% vs 32%; P = .04). Although uptake of the FP request form decreased in phase III, it was associated with fewer inappropriate transfusions. Conclusions: The behavior-change strategy modestly improved appropriate use of FP transfusions in the ICU. Improving FP request form accuracy, completeness, and compliance may be required to achieve maximum effect and ensure sustainability. [Copyright &y& Elsevier]

Background: Transfusable plasma is obtained by processing whole blood donations, by apheresis, or as solvent/detergent plasma (SD plasma), a pooled pathogen-reduced plasma product. The quality of plasma is typically assessed by testing the activities of multiple coagulation-related plasma proteins, due to a lack of clinical trial data linking plasma composition to clinical endpoints. We sought to update previous quality surveys of Canadian frozen plasma (FP; manufactured from single donor whole blood donation and frozen within 24h of phlebotomy), to provide transfusionists with a more complete picture of its characteristics., Study Design and Methods: FP units (n=131) were tested for: the activity of factors V, VII, VIII, X, and XI, protein S (PS), α2-antiplasmin (AP), and fibrinogen; and the activated partial thromboplastin (APTT) and prothrombin (PT) times. Comparisons were made to: previous Canadian FP surveys; and to studies of single-donor plasma and SD plasma from other nations., Results: Mean FVIII, fibrinogen, or APTT values did not differ from the previous annual survey of Canadian FP; FV activity was increased and PT values decreased. FP produced with or without leukoreduction differed only in mean APTT. Canadian FP exhibited generally similar quality to that reported by other organizations in Europe and Asia for similarly manufactured single-donor plasma, but contained notably higher PS and AP (≈ four-fold) activities than did SD plasma., Conclusion: Our results indicate that Canadian FP is of similar quality to single-donor products produced in other jurisdictions. While it is of arguably superior in vitro quality to an SD plasma product recently licensed in Canada, these differences are highly unlikely to have clinical significance for most indications for plasma transfusion., (Copyright © 2013 Elsevier Ltd. All rights reserved.)