Chlorine is the most widely used disinfectant for drinking water treatment. Chlorine canreact with natural organic matter (NOM) in water sources resulting in the formation of potentially carcinogenic disinfection by-products (DBPs). The most common DBPs measured in chlorinated drinking water distribution systems are trihalomethanes (THMs) and haloacetic acids (HAAs). In 2005, the City of Kamloops, British Columbia upgraded the drinking water treatment system to ultrafiltration membrane treatment. The objective of this study was to determine the extent to which upgrades to a drinking water treatment system, specifically, implementation of an ultrafiltration treatment process, impacted DBP formation within a distribution system. This study used a two-phase research approach. Phase I of the study was a distribution system monitoring program that collected water samples and physical and chemical information using data loggers at five sampling sites within the distribution system. Phase II of the study used bench-scale simulations that modeled DBP formation using a flow-through reactor system, the material-specific simulated distribution system (MS-SDS), constructed of pipe material resurrected from the City of Kamloops distribution system. Phase I results suggested that implementation of the ultrafiltration treatment process and accompanying treatment system upgrade was not effective at reducing the concentration of DBPs delivered to consumers. Concentrations of THMs remained relatively constant at sampling sites, while concentrations of HAAs increased following implementation of the ultrafiltration treatment process. The increase in HAA formation was likely due to an increase in retention time of the water within the distribution system following implementation of the ultrafiltration treatment process, rather than due to the treatment process itself. The results of this study are consistent with previous work on South Thompson River water DBP precursors, which suggested that THM and HAA precursors of this source water are small and hydrophilic, and therefore cannot be removed by ultrafiltration processes. Phase II results showed that the MS-SDS was more representative of distribution system c onditions than traditional glass bottles to estimate DBP formation. It is recommended that the MS-SDS be used in parallel with a simultaneous distribution system monitoring program to estimate distribution system retention times from THM and HAA concentrations.

Assessment of long term changes in levels of biogenic substances and their amount, with regard to water yield and intensity of anthropogenic activity, in the water of different hydrological areas of Lithuania. Comparative analysis of methods for calculation of biogenic substance flows. Establishment of possibility to reduce frequency of water sampling. ATV-DVWk water quality model was for the first time in Lithuania used for forecasting of the changes in the water quality in the longitudinal profile of a river.

De-icing agents such as road salts is one of the most commonly used winter road management strategies employed in Canada and the United States. However, the use of chloride has caused negative impacts on aquatic habitats and drinking water supplies. The purpose of this study is to develop a methodology using readily available GIS data to identify salt vulnerable areas, through evaluating the impact the application of road salts have on areas of interest and quantifying the vulnerability to the area in order to prioritize implementation of best management practices. The proposed methodology for assigning a vulnerability score to a given watershed has been divided into two receiving receptors; surface water and groundwater recharge. The methodology employs a chloride mass balance approach. The vulnerability assessment was performed on seven sites in four watersheds in the Greater Toronto Area and validated using Hanlon Creek watershed in Guelph, ON.

Effective use of bioassessments requires an understanding of their performance. This study evaluated the performance of Skeena Reference Condition Approach (RCA) bioassessments by calculating Type I and Type II error rates and power using a data set of artificially-impacted test sites. Results from this study demonstrated that there are trade-offs between the two error types. Type I error rates – the chance of concluding that a site is impacted when it isn’t – were higher than expected based on decision points set in the assessments. Type II error rates – the chance of concluding that a site is not impacted when it is – were often even greater. To achieve sustainable development, resource managers who use Skeena bioassessments must carefully consider the risks associated with making errors, and may wish to set decision points that result in more Type I errors in order to reduce the likelihood of making costly Type II errors.

The Cougar Creek / Northeast Interceptor Canal watershed is located within the Corporation of Delta and the City of Surrey. Urbanization has been affecting the natural dynamic and environmental conditions of this watershed. This study was conducted to provide a preliminary evaluation of the health of the Cougar Creek, which includes physicochemical and biological aspects of water quality, and to serve as the basis for the design of a more complex water quality monitoring program. A three-tiered methodological approach, which included a literature review, field measurements and statistical analyses, was used. The stream was monitored from Fall 2010 to Fall 2011 at Westview Drive and at Nicholson Road. Chemical constituents were monitored monthly and benthic macroinvertebrates were sampled in Spring 2011. Physical parameters were recorded continuously using automated samplers. Concentrations of constituents did not exceed the BC criteria for the protection of aquatic life, except for total cadmium. Parameters such as dissolved oxygen and temperature at Nicholson Road, and streamflow at both locations during the dry season were recorded at levels that can harm aquatic life. Statistic analysis indicated that differences in streamflow are associated with concentration changes in some of the constituents between the two sites. Analysis of the benthic community indicated that only tolerant organisms were present at the sites. Differences in habitats between the sites were identified which limited the stream’s health comparability. The study identified the need for collecting first flush events data in future research and recommends BMP that could enhance the stream’s environmental condition.

Norint įvertinti vandens telkinio būklę, pakanka patyrinėti kurią nors gyvųjų organizmų grupę. Viena iš tokių indikatorinių sistematinių grupių yra titnagdumbliai (Bacillariophyceae). Dauguma tyrėjų teigia, kad titnagdumbliai yra idealūs indikatoriai biologiniam monitoringui, nes didelis skaičius ekologiškai jautrių rūšių tiek vandenyje, tiek nuosėdose, tiksliai nusako esamą ekologinę situaciją (Dixit et al. 1992). Aulacoseira granulata, Fragilaria crotonensis, Asterionella formosa, Cyclotella sp. Synedra sp. Rhizosolenia sp., Diatoma, Achnanthes, Cyclotella, Stephanodiscus dažnos mezotrofiniuose vandens telkiniuose. Stephanodiscus hantzschii intensyvus vystymasis vandens telkinyje yra aukšto trofiškumo rodiklis bei užterštumo organinėmis medžiagomis indikatorius. Apskritai, išskyrus Stephanodiscus sp., titnagdumbliai stipriai eutrofinių ir hipertrofinių sąlygų ežere nepakenčia. / As is well known as a better state of body water, the more species of living organisms can live in it, and the deterioration of water quality, with a consequent reduction in plant and soil or water surface the number of living species. It remains only for not demanding, resistant to water pollution types. So in order to assess the water situation, it is sufficient to explore any group of living organisms. One such indicator is the systematic group of diatoms (Bacillariophyceae). Aulacoseira granulata, Fragilaria crotonensis, Asterionella formosa, Cyclotella sp. Synedra sp. Rhizosolenia sp., Diatoma, Achnanthes, Cyclotella, Stephanodiscus common in mesotrophic waters. Intensive development of Stephanodiscus hantzschii in water body is a high trophic rate and contamination of organic matter indicator. In general, except for Stephanodiscus sp. diatoms can not stand strongly eutrophic and hypertrophic conditions in the lake.

A two-part paleolimnological study was conducted to examine changes in historical and modern water-quality in Lake of the Woods (LoW) in response to multiple stressors, such as climate change and shoreline residential development. Changes in diatom assemblages were analyzed in the modern and pre-industrial sediment intervals of 17 study sites, and in high-resolution 210Pb-dated sedimentary records from three northwestern bays (Clearwater, Poplar, and White Partridge bays). Patterns in diatom assemblage changes revealed pronounced and synchronous shifts over the last ca. 150 years. The most notable shift in the diatom community structure (~1970 AD) was characterized by an overall shift towards a higher relative abundance of small, centric Cyclotella taxa and planktonic, pennate diatoms (e.g., Asterionella formosa, Fragilaria crotonensis), and a corresponding lower relative abundance of heavily silicified Aulacoseira taxa and small benthic Fragilaria taxa and Achnanthes taxa. Lakewater total phosphorus (TP) concentrations were inferred from sedimentary diatom assemblages. DI-TP reconstructions revealed either no change or a decline in DI-TP since pre-industrial (pre-1850) times at majority (88%) of the top-bottom study sites, and no distinct directional change over the past ca. 150 years at the northwestern bays. Therefore, we concluded that TP was not an important driver of the floristic changes we observed. Chl-a trends indicate that primary production increased during the last ca. 100 years, likely tracking increases in microbial blooms. Changes in diatom assemblage composition and primary productivity have occurred during a period of substantial warming for this region of northwestern Ontario. Strong correlations (r >0.50, p<0.005) between diatom compositional changes, chl-a trends, and local air temperature records and lake-ice phenology suggest that climate-induced changes in lakewater properties may have been key factors driving the observed changes. From these data, we conclude that climate warming, rather than changing shoreline development and TP changes, has had the most pronounced effect on algal communities in the LoW. Estimates of pre-impact lake trophic status can aid in setting realistic mitigation targets for lakes impacted by multiple stressors. Therefore, paleolimnological studies comparing pre- and post-disturbance algal assemblages, such as the investigations we have conducted, are of interest from a lake management perspective. / Thesis (Master, Biology) -- Queen's University, 2010-05-28 13:38:59.472

<p>The primary aim of the current study falls within the main framework of the Frontier Program (Pitcher 2005), namely to address aspects of &ldquo / Animal Husbandry&rdquo / . Within this research area, the determination of the effects of handling/grading and chemicals (anaesthetics) on the growth and survivorship of abalone are highlighted as key research areas and these are thus one of the focuses of this research.</p>

The removal of colour from effluent after dyeing of cellulosic fibres is a major problem due to the difficulty in treating such effluents by conventional treatment methods. Cellulosic fibres of a specific shade (colour) are produced by reacting the fibres with a mixture of reactive dyestuffs, salt and auxiliary chemicals. Reactive dye exhaustion to the fibre is about 80% i.e. 20% remains in the effluent; this is hydrolysed dye which cannot be reused for dyeing. The exhausted reactive dye bath together with first rinse represents 6 to 30 L effluent/kg of fabric and most of the colour and salt. The total water consumption for reactive dyeing ranges from 25 to 100 L effluent/kg fabric while the water consumption from total textile finishing ranges from 30 to 150 L effluent/kg fabric. Thus the concentration of the dye and salts are 5 times more concentrated when obtained at source. The use of activated carbon adsorption for the removal of colour from exhausted dyebath for the re-use of water, salt and energy has been studied. Four different commercial reactive dye chemistries and associated auxiliaries were tested and commercial activated carbon was used as an adsorbent. Different temperatures (20°C to 100°C), pH values (acidic, neutral, basic) and salt concentrations (50 g/L to 100 g/L) were evaluated and the high adsorption results were achieved when using high temperature, low pH (acidic) and high salt concentrations. The Freundlich adsorption parameters were obtained for activated carbon adsorption capacity and adsorption bond strength between reactive dyes and activated carbon. The overall removal of the reactive dye shades was 36% to 53% (based on colour in the effluent), salt recovery was about 94% to 97%, the water recovery ranged from 14% to 25% and energy savings of 17% to 32% could be achieved. Column adsorption test were performed at different temperatures and flowrates. The saturated activated carbon was regenerated and repeatedly used by elution with 1.0 M NaOH. The regenerated carbon was found to be effective up to 3 cycles of operations. A column system for treatment of reactive dyes using activated carbon was designed. The outcome of this study showed that treatment of reactive dyebath with activated carbon adsorption technique can allow re-use of water, salt and energy, thus enabling environmental improvements with a savings in salt, energy, water and treatment costs. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2007.

No description available.