Lime softening, chlorination, clarification and filtration have been long recognized treatment processes for beverage water specifically the carbonated soft drink (CSD) because it provides consistent water quality required for bottling plants, however these processes are becoming uneconomical and causes more problems than the benefits they offer. These processes require very large foot print, occupy large plant volume, and generate large volume of sludge which causes disposal problems. Chlorination produces trihalomethanes (THMs) and other by-products which are detrimental to health and imparts tastes to the final products. Using the newly developed submerged spiral wound ultrafiltration membranes in conjunction with lime softening may replace the conventional lime softening, clarification and filtration processes. This research was conducted to demonstrate the feasibility of integrating immersed ultrafiltration (UF) membrane with lime softening. The objectives of this research was to achieve the water quality required by the CSD bottlers; determine the relationships of operating parameters such as pH and membrane flux with trans-membrane pressure (TMP), and membrane permeability; determine the optimum dosage of lime; evaluate the operating parameters as basis for the design and construction of the full scale plant; and predict the membrane cleaning intervals. A pilot unit consisting of lime reactor and UF system was designed and built for this research. The pilot unit was operated at various pH ranging from 7.3 to 11.2 and at membrane flux rates of 15, 30 and 45 gfd. The pilot unit was also operated at the CSD bottler’s operating conditions which is pH 9.8 at flux of 30 gfd. The pilot unit operated for a total of 1800 hours. The raw water source was from city water supply. The filtrate from the pilot unit achieved alkalinity reduction to 20 to 30 mg/L preferred by CSD bottlers, with lime dosage close to the calculated value. The filtrate turbidity during the test was consistently within 0.4 to 0.5 NTU. The TMP values obtained during the test ranges from 0.1 to 2.5 psi, while the permeability values ranges from 18.19 to 29.6 gfd/psi. The increase in flux results to corresponding increase in TMP, and increase in operating pH, increases the rate of TMP. Permeability decreases with increasing operating pH. The TOC reduction ranges from 2.6 % to 15.8% with increasing operating pH. No scaling of the UF membranes was observed during the test. Thirty days UF membrane cleaning interval was predicted. The results from this research can use as the basis of designing and operating a full scale Lime Softening UF Treatment Plant.

Many parts of the United States are facing water shortages. Planners have to ensure that there will be an adequate water supply to meet the needs of the growing population. Though many places encourage water conservation, and some even enforce water restrictions, this is not always enough to make up for the shortages. Thus, alternative water sources need to be considered in some cases. The states of Texas and Florida both face uncertainties with their future water supply. To meet the needs of their current and future populations, both states have recently been using desalination at a large scale to supplement their water supplies. This report examines the desalination facilities in El Paso, Texas and Tampa Bay, Florida to determine if desalination is a feasible water supply and to explore the consequences of pursuing the development of this water resource. / text

No description available.

Although wood floor production does not use water in the production process, water consumptionis related to cleaning and washing of floor and machineries in different steps of the process line,which generate a number of small flows that are highly polluted.Besides this, the industry has a need to store large amounts of wood outside to be able to havecontinuity in the production. This takes up a lot of space outdoors and once it rains the water thathas been in contact with wood, oil and metals forms stormwater, which transports pollutants.Stormwater has for a long time not been seen as a problem and has often been discharged intorecipient water bodies without any treatment. During cold seasons, this also involves snowmelt thatcan transport high concentrations of different pollutants.This report describes the composition of process- and stormwater from a wood floor industry inNybro, Sweden regarding parameters such as COD, phenol, tannin and lignin. The concentrationsof phenols in the stormwater were found in a range considered toxic to marine life.Regarding the process water, high values was found for COD (Chemical Oxygen Demand) and forother substances and elements potentially toxic (e.g. formaldehyde, wood resins, detergents andmetals). If these waters are directly released to a sewage treatment plant without any pre-treatmentprocess it can disturb the plant treatment efficiency; if released to a recipient water body, it cancause oxygen deficiency and consequently, death to marine life.The possibility of reducing the levels of pollutants through the use of electrocoagulation has beenexamined in this study. This has been done both for process water and stormwater from the woodfloor industry. A 250 ml batch unit for electrocoagulation EC was setup with iron (Fe) andaluminium (Al) electrodes for treating process water and stormwater. The results show that the ECprocess can reduce COD concentration from stormwater at least 70%. On the other hand, lessefficiency of EC for treating process water was observed.A method for simulating a snowmelt period in lab scale was also developed. Snow collected from awood floor industry was melted according to real temperature and the quality of these samples hasthen been compared to on-site samples of stormwater / Development of an integrated approach for industrial wastewater and stormwater management in the wood-industry sector

Water supply systems aim, among other objectives, to protect public health by reducing the concentration of, and potentially eliminating, microorganisms pathogenic to human beings. Yet, because water supply systems are engineered systems facing variable conditions, such as raw water quality or treatment process performance, the quality of the drinking water produced also exhibits variability. The reliability of a treatment system is defined in this context as the probability of producing drinking water that complies with existing microbial quality standards. This thesis examines the concept of reliability for two physicochemical treatment technologies, conventional rapid granular filtration and ultrafiltration, used to remove the protozoan pathogen Cryptosporidium parvum from drinking water. First, fault tree analysis is used as a method of identifying technical hazards related to the operation of these two technologies and to propose ways of minimizing the probability of failure of the systems. This method is used to compile operators’ knowledge into a single logical diagram and allows the identification of important processes which require efficient monitoring and maintenance practices. Second, an existing quantitative microbial risk assessment model is extended to be used in a reliability analysis. The extended model is used to quantify the reliability of the ultrafiltration system, for which performance is based on full-scale operational data, and to compare it with the reliability of rapid granular filtration systems, for which performance is based on previously published data. This method allows for a sound comparison of the reliability of the two technologies. Several issues remain to be addressed regarding the approaches used to quantify the different input variables of the model. The approaches proposed herein can be applied to other water treatment technologies, to aid in prioritizing interventions to improve system reliability at the operational level, and to determine the data needs for further refinements of the estimates of important variables.

Parameters associated with the detection and quantification of microorganisms (or discrete particles) in water such as the analytical recovery of an enumeration method, the concentration of the microorganisms or particles in the water, the log-reduction achieved using a treatment process, and the sensitivity of a detection method cannot be measured exactly. There are unavoidable random errors in the enumeration process that make estimates of these parameters imprecise and possibly also inaccurate. For example, the number of microorganisms observed divided by the volume of water analyzed is commonly used as an estimate of concentration, but there are random errors in sample collection and sample processing that make these estimates imprecise. Moreover, this estimate is inaccurate if poor analytical recovery results in observation of a different number of microorganisms than what was actually present in the sample. In this thesis, a statistical framework (using probabilistic modelling and Bayes’ theorem) is developed to enable appropriate analysis of microorganism concentration estimates given information about analytical recovery and knowledge of how various random errors in the enumeration process affect count data. Similar models are developed to enable analysis of recovery data given information about the seed dose. This statistical framework is used to address several problems: (1) estimation of parameters that describe random sample-to-sample variability in the analytical recovery of an enumeration method, (2) estimation of concentration, and quantification of the uncertainty therein, from single or replicate data (which may include non-detect samples), (3) estimation of the log-reduction of a treatment process (and the uncertainty therein) from pre- and post-treatment concentration estimates, (4) quantification of random concentration variability over time, and (5) estimation of the sensitivity of enumeration processes given knowledge about analytical recovery. The developed models are also used to investigate alternative strategies that may enable collection of more precise data. The concepts presented in this thesis are used to enhance analysis of pathogen concentration data in Quantitative Microbial Risk Assessment so that computed risk estimates are more predictive. Drinking water research and prudent management of treatment systems depend upon collection of reliable data and appropriate interpretation of the data that are available.

Water contaminated due to mining activities is often acidic and can contain high concentrations of dissolved metals. Cement kiln dust (CKD) is a fine-grained, alkaline material that is generated as a by-product of cement production. Its high lime (CaO) content makes it attractive as a substitute for quicklime in the generation of slurries for the treatment of mine water. The first part of this study analyzed six CKD samples for several physical and chemical properties to determine their variability and to compare them to the characterization of a commercial quicklime sample. Neutralization and precipitation experiments using acidic mine water containing high concentrations of zinc and iron determined that all slaked CKD slurries performed comparably to the quicklime slurry in terms of precipitation of soluble metals. The results of this research show that CKD can be effectively used to neutralize mine water and precipitate and remove dissolved metals.

Water utilities in Nova Scotia face numerous challenges treating low turbidity water and complying with stringent guidelines and treatment standards. Problems associated with the treatment of low-turbidity water are not confined to Nova Scotia; several other provinces, British Columbia, Manitoba and Ontario share similar water characteristics of drinking water sources. The treatment of low turbidity water is a challenge for these utilities as it requires maintaining the appropriate coagulant dosage that will ensure adequate particle and natural organic matter removal, while at the same time not enhancing the formation of disinfection by-products. Another concern associated with the treatment of such water is that when the particle content of the water is very low, charge neutralization will not be effective due to the weak contact between destabilized particles. Currently, nanoparticles are not regulated as water contaminants, and thus it is unclear whether the existing filtration treatment practices are capable of removing them from drinking water. Obtaining in-depth information on nanoparticle characteristics in drinking water sources will provide a valuable resource that can assist in the development of future treatment strategies. In this research, characteristics of four synthetic nanoparticles cerium dioxide (CeO2), ferric oxide (Fe2O3), silicon dioxide (SiO2) and titanium dioxide (TiO2) were investigated in Milli-Q water for particle size, surface area, and surface potential using different characterization techniques. Water samples from Pockwock Lake were also characterized for naturally occurring nanoparticles. After initial testing, titanium dioxide (TiO2) nanoparticles were selected to examine particle removal at bench-scale filtration experiments, under operating conditions similar to those practiced at the J.D. Kline Water Supply Plant, Halifax, NS, Canada. Filter performance for the deposition of TiO2 nanoparticles was evaluated through the calculation of its attachment efficiency and coefficient under various water chemistry conditions. The calculated filter efficiency was then applied to simulate natural nanoparticles removal from water. The results of the research indicate that the investigated nanoparticles behaved similar to natural particles and formed aggregates with larger particle sizes in Milli-Q water. Among the tested nanoparticles, only titanium dioxide could be coagulated with alum, as its negative surface charge and zero point of charge were closer to that of alum. Filtration experiments revealed that TiO2 nanoparticles, when present in water, could successfully be removed by an alum dose of 8 mg/L. Indeed, removal in excess of 99.5% was achieved under the study conditions. Under the investigated water chemistry conditions, very low attachment efficiencies (?) of 0.001, 0.002 and 0.01, and filter coefficients (?) of -0.003, -0.001 and -0.02 were determined for the filters. Based on the calculated attachment efficiencies, and under the studied conditions, natural nanoparticles remain dispersed in the water and would not likely to be removed by direct filtration. The overall research findings represent a major step forward in nanoparticle removal by direct filtration.

Research has shown biological filtration can be a successful treatment for manganese (Mn) removal from groundwater and surface water. In this study, bench-scale direct biofiltration was used to remove Mn and dissolved organic carbon (DOC) from a pH 6 surface water source in Halifax, Canada. The removal of Mn in pH 6 surface water was significantly (? = 0.05) removed with 200-300 µg/L phosphorus (P), and 500 µg/L hydrogen peroxide (H2O2). DOC removal was significantly (? = 0.05) improved with granular activated carbon (GAC) media, P enhancement at 200-300 µg/L, and H2O2 enhancement at 500 µg/L. Mn was likely removed by biological oxidation and physical adsorption to biogenic Mn and iron (Fe) oxides. These results show direct biofiltration of surface water at pH 6 can remove Mn below the 50 µg/L aesthetic guideline from a Mn loading of over 1 mg/L. Further research is required to verify the microbial mechanism.

Natural organic matter (NOM) is present in all surface waters as a result of decaying vegetation, biological activity, and organic soil. Alternative NOM removal processes such as anion exchange resins (AERs) have shown NOM removals typically ranging between 50 to 90%, with up to 99% removal achieved in some cases. The first portion of this study evaluated the performance of two AERs; a conventional Type 1 AER and magnetic ion exchange resin (i.e. MIEX®) for NOM removal from surface water quantified by UV254, dissolved organic carbon (DOC), and specific UV absorbance (SUVA). Samples were also characterized for chloride, sulphate, and chloride-to-sulphate mass ratio (CSMR) to provide additional information on water quality characteristics of AER treated waters. Overall, the results showed that both AERS were effective for removing NOM. However, the MIEX® resin provided greater removal of NOM with shorter contact times compared to the conventional resin investigated. Water treated with MIEX® resin showed significantly higher chloride and lower sulphate concentrations than the conventional AER. Higher CSMR values were found with MIEX® treated water compared to conventional AER system, although both resins showed CSMR much greater than 0.5, which can increase galvanic corrosion effects with lead. Bench-scale jar tests were conducted to investigate the impact of temperature on the efficacy of three NOM removal treatment technologies; enhanced coagulation with alum, MIEX® and a combined MIEX® treatment followed by coagulation with a low dose of alum. Higher settled water turbidity was observed during cold water operating conditions for all three processes. At cold-water operating conditions, DOC removal was reduced with combined MIEX® -Alum treatment, and UV254 removal was impacted for both MIEX® and MIEX® -Alum processes. The combined MIEX®-Alum process was found to provide the lowest THMFP and HAAFP at both temperatures to concentrations lower than current regulatory maximum acceptable concentration (MAC) guidelines in Canada. Surface charge analysis experiments were performed at bench-scale using synthetic water containing humic acid to determine the relationship between NOM and the charge of AER-treated waters. Further bench and pilot-scale studies were performed to investigate the use of surface charge measurements to monitor and optimize NOM removal during treatment with AER systems. Strong correlations were observed between UV254 and respective charge measurements (i.e. ZP, SC) of AER-treated synthetic and raw waters. The results of this research has shown that it is possible to use charge to optimize the MIEX® process for NOM removal. Additionally, it was found that SC measurements could be used as an operational tool for AER processes, where deviations in SC from optimum treatment would indicate the requirement for fresh resin addition or resin regeneration.