Water management practices to reduce mass discharge are a major point of concern for aquaculture producers. This study assessed effects of consecutive low-grade weirs on chemical retention and settling of aquaculture pond effluent in a single drainage ditch. Two control and nine treatment discharges were conducted September - October 2012. Control discharge dissolved inorganic phosphorus (DIP) load increased 154%, whereas total inorganic phosphorus (TIP), ammonia, and nitrate loads decreased (47%, 43%, and 63%, respectively). Treatment discharge nutrient loads decreased across all analytes (80% DIP, 86% TIP, 89% ammonia, 89% nitrate). However, control and treatment discharges concentrations of DIP and nitrate increased, whereas TIP and ammonia concentrations decreased. All discharges reduced total and volatile suspended solid loads 72% - 94%, with removal rates of 0.02 ± 0.01 mg/L/min total and 0.02 ± 0.001 mg/L/min volatile suspended solids. Results indicate ditches fit with low-grade weirs may be an innovative management practice.

Stormwater (SW) runoff in urban areas represents a major pathway for pollutant transfer to receiving waters. Best management practices (BMP) were introduced in the 1970s to help mitigate the negative effects of SW. In the 1990s, Stormwater management (SWM) ponds were established as a BMP to help increase the water quality of SW effluent. Many SWM ponds do not provide sufficient water quality treatment. Information on the internal processes influencing the reduction of total phosphorus (TP), soluble reactive phosphorus (SRP) and total suspended solid (TSS) concentrations in SWM ponds with different designs is lacking. Knowledge of the processes affecting TP, SRP and TSS retention can help improve the design of SWM ponds to enhance their treatment performance. The purpose of this thesis is to provide an assessment of the internal chemical processes that affect the trap efficiency (TE) and spatial and temporal variability of TP, SRP and TSS concentrations at two structurally different SWM ponds (Pond 45; conventional and Pond 33; hybrid extended detention) in Waterloo, ON. Water samples were collected at the inflow and outflow at the two SWM ponds during six storm events and 30 baseflow periods. A mass balance approach was used to quantify the TE of TP, SRP and TSS concentrations at each pond. Pond 33 had a TE of 24.3%, 26.7% and 66.8% for baseflow and stormflow samples of TP, SRP and TSS. Pond 45 performed much better with TE of 93.8%, 94.2% and 98% for TP, SRP and TSS concentrations. Pond 33 was a source of TP, SRP and TSS for 3, 4 and 2 storm events sampled during the field season, respectively. Pond 45 was a sink for all parameters on all storm events samples. The spatial and temporal variability of TP, SRP and TSS concentrations were examined to improve knowledge of external factors and internal processes that influence the TE of SWM ponds. The effects of storm magnitude, seasonality and vegetation growth and senescence on effluent water quality were investigated. Additionally, the role of sediment on P cycling in the ponds was evaluated by determining grain size distribution, porewater SRP concentrations, sediment geochemistry and mineralogy, and the sediment P buffering capacity. Vegetation senescence, anoxic conditions, porewater SRP concentrations, sediment characteristics and buffering capacity influenced the poor TE at Pond 33. Pond 45 had more favourable water column conditions, i.e. higher dissolved oxygen concentrations, therefore allowed greater amounts of P to adsorb onto sediment. Design and maintenance considerations are described to help improve the performance at Pond 33. Continual water quality monitoring of SW effluent will identify changes in quality and mitigation measures can be implemented to increase a SWM ponds performance.

Stormwater (SW) runoff in urban areas represents a major pathway for pollutant transfer to receiving waters. Best management practices (BMP) were introduced in the 1970s to help mitigate the negative effects of SW. In the 1990s, Stormwater management (SWM) ponds were established as a BMP to help increase the water quality of SW effluent. Many SWM ponds do not provide sufficient water quality treatment. Information on the internal processes influencing the reduction of total phosphorus (TP), soluble reactive phosphorus (SRP) and total suspended solid (TSS) concentrations in SWM ponds with different designs is lacking. Knowledge of the processes affecting TP, SRP and TSS retention can help improve the design of SWM ponds to enhance their treatment performance. The purpose of this thesis is to provide an assessment of the internal chemical processes that affect the trap efficiency (TE) and spatial and temporal variability of TP, SRP and TSS concentrations at two structurally different SWM ponds (Pond 45; conventional and Pond 33; hybrid extended detention) in Waterloo, ON. Water samples were collected at the inflow and outflow at the two SWM ponds during six storm events and 30 baseflow periods. A mass balance approach was used to quantify the TE of TP, SRP and TSS concentrations at each pond. Pond 33 had a TE of 24.3%, 26.7% and 66.8% for baseflow and stormflow samples of TP, SRP and TSS. Pond 45 performed much better with TE of 93.8%, 94.2% and 98% for TP, SRP and TSS concentrations. Pond 33 was a source of TP, SRP and TSS for 3, 4 and 2 storm events sampled during the field season, respectively. Pond 45 was a sink for all parameters on all storm events samples. The spatial and temporal variability of TP, SRP and TSS concentrations were examined to improve knowledge of external factors and internal processes that influence the TE of SWM ponds. The effects of storm magnitude, seasonality and vegetation growth and senescence on effluent water quality were investigated. Additionally, the role of sediment on P cycling in the ponds was evaluated by determining grain size distribution, porewater SRP concentrations, sediment geochemistry and mineralogy, and the sediment P buffering capacity. Vegetation senescence, anoxic conditions, porewater SRP concentrations, sediment characteristics and buffering capacity influenced the poor TE at Pond 33. Pond 45 had more favourable water column conditions, i.e. higher dissolved oxygen concentrations, therefore allowed greater amounts of P to adsorb onto sediment. Design and maintenance considerations are described to help improve the performance at Pond 33. Continual water quality monitoring of SW effluent will identify changes in quality and mitigation measures can be implemented to increase a SWM ponds performance.

The ecological effects and mechanistic efficiency of chemical oil spill countermeasures must be evaluated prior to their ethical application during real spill response scenarios. Equally important is the ability to monitor the effectiveness of any spill response in real time, permitting informed response management. In-situ sensors are key components of such event based monitoring and continuous monitoring programs. This project investigates crude oil toxicity as a particulate suspension, suitability of in-situ instrumentation to measure crude oil suspensions, and the applicability of using acoustic backscatter to measure suspended solids and sub-surface oil droplet suspension concentrations. The ecological effects to inter- and sub-tidal sediment dwelling organisms exposed to crude oil, both treated with a chemical dispersant and un-treated, was evaluated. Elevated toxicity, expressed as percent mortality and reduced luminescence, and oil concentrations were observed in inter-tidal sediments receiving oil only treatments compared to oil-plus-dispersant treatments. Sub-tidal sediments showed heterogeneous distribution of crude oil with elevated amphipod mortality compared to no oil controls suggesting an oil-sediment aggregation mechanism. A separate laboratory scale study found that the soluble crude oil fractions were responsible for the observed mortality in pelagic species while the more dominant oil droplet fractions were relatively non-toxic. Subsequent studies focused on the in-situ detection of crude oil and particle suspensions in aqueous environments. The first showed that both in-situ fluorescence spectroscopy and Laser In-Situ Scattering Transmissometry (LISST) can effectively measure crude oil concentrations in aqueous environments. The applicability of the LISST implies that crude oil in an aqueous medium can be measured as a particle suspension. Acoustic backscatter (ABS) was investigated for its applicability as a surrogate measurement technology for aqueous particle suspensions. This study showed a log linear correlation between ABS and volume concentration (VC) over a variable particle size distribution. This correlation is due to the dependency of both ABS and VC to the particle size distribution. Log-linear ABS responses to oil-droplet suspension volume concentrations were also demonstrated. However, the inability to reproduce response factors suggests that more work is required to produce viable calibrations that may be used for sub-surface oil plume detection.

In 1995, the Environment Agency for England and Wales developed urban runoff treatment wetlands at two selected locations in Outer London. The systems have been monitored for a wide range of parameters including heavy metals, suspended solids and BOD over a period of two years. Seven storm events were also monitored. The ability of micro-organisms, isolated from the rhizosphere of wetland plants collected at both systems, to tolerate and accumulate heavy metals has also been investigated. This study has demonstrated that constructed wetland treatment systems are capable of reducing the pollutant loadings associated with urban runoff, and that such systems can be successfully established within urban areas. During dry weather, pollutant concentrations and loadings were typically low and associated removal efficiencies highly variable. However, during storm events, pollutant loadings increased and removal efficiencies improved, with mean removal efficiencies of 71% for Pb and 81% for Cr at the Dagenham wetland. An exception to this was for suspended solids which showed an overall increase of 99% during storm events. Several design and operational issues have been identified and addressed during the course of the monitoring programme, and recommendations for the improved design and operation of urban runoff treatment wetland systems have been made. A range of micro-organisms, isolated from both wetland systems, were able to tolerate elevated Zn and Pb concentrations. Two strains (Beauveria bassiana and Rhodotorula mucilaginosa) were selected for further work. Both strains could accumulate Zn and Pb, with B. bassiana showing a high capacity to bind Pb (maximum concentration of 136mgPb/g cells dry weight). Comparison of the growth of B. bassiana at 4°C and 30°C suggested that processes of microbial metal accumulation may occur throughout the year in treatment wetlands. The presence of Pb inside hyphae of B. bassiana, associated with hyphae walls and in the surrounding medium was confirmed. This study has found that micro-organisms isolated from urban runoff treatment wetlands can tolerate and accumulate Zn and Pb, and the application of these results to wetland treatment processes is discussed.

The untreated overflow of combined sewer system contains a variety of pollutants that can contaminate the receiving water body. Total suspended solids (TSS) transported in the sewer networks can adsorb these pollutants and become the main contaminant source. Existing models contain a numerous formulas that make the calculation process complex and time consuming. A simplified model was presented in this thesis to simulate the process of TSS transport in combined sewer pipes. The combined sewer system evaluated was a combination of an existing sewer system in Le Marais and an example system provided with the Storm Water Management Model (SWMM). SWMM was used in this research to simulate the rainfall event, pollutant build-up and wash-off process, and to provide hydraulic calculations for the combined sewer system. A spreadsheet model was created to calculate the TSS concentration profile and flow velocity profile. The total TSS transport rate was computed using a numerical estimation of the integral of the concentration in the cross-section area multiplied by the velocity. The flow depth, velocity, and Froude number of each pipe was calculated to show that the combined sewer system was under proper working conditions. The first flush phenomenon was observed by plotting the TSS concentration pollutograph of the combined sewer system. From the TSS transport pollutograph, the maximum transport rate was found (0.2609 kg/s at 6:45). The study of TSS profile showed that the concentration distribution was based on the solid density. The TSS particle also affected the transport rate. A sensitivity analysis of particle size was conducted in this thesis. A second order polynomial was used to describe the relationship between median particle size d50¬ ¬and TSS transport rate.

This study examines the wastewater treatment system on BillerudKorsnäs integrated pulpand paper mill at Karlsborg, with focus on the effluent of suspended solids. Due to lowerregulatory limits for the emissions of suspended solids BillerudKorsnäs is looking forways to improve the efficiency of the wastewater treatment. Therefore, this study seeksto create a statistical model for the emissions of suspended solids and to find which factorsin the production, wastewater treatment and surrounding environment that affects theemissions. The purpose of the study is to extend the current understanding of the treatmentsystem to create a base for future decisions. The methods used for the modelling areElastic net regression and Random forest classifier, which were selected for the variableselection properties they provide. Unfortunately, the results show that the fitted modelscan only explain a small part of the variation of the emissions of suspended solids.The lack of fit in the models indicate that the current data is not sufficient to explain thevariation in the emissions of suspended solids. During the study deficiencies in the datacollection has been detected and improvements to overcome these deficiencies are proposedin the hope of creating more reliable data for the company and to create a betterbasis for future studies. / Denna studie undersöker avloppsvattenreningen på BillerudKorsnäs integrerade massaoch pappersbruket i Karlsborg, med fokus på utsläppen av suspenderade ämnen. Pågrund ut av sänkta gränser för utsläppen av suspenderade ämnen undersöker BillerudKorsnäsmöjligheter för att öka effektiviteten i avloppsvattenreningen. Därför försöker dennastudie att skapa en statistisk modell för utsläppen av suspenderade ämnen och undersökavilka faktorer i produktion, avloppsvattenrening, och omgivande miljö som påverkar utsläppen.Syftet med studien är att förbättra förståelsen för avloppsvattenreningen och attskapa beslutsunderlag för framtida förbättringar. Metoderna som används i modellernaär Elastic net regression och Random forest classifier, vilka valdes för deras variabel selectionegenskaper. Resultaten för modellerna visar att modellerna endast kan förklara enliten del av variationen i utsläpp av suspenderade ämnen. Det dåliga resultatet indikeraratt nuvarande data inte är tillräckligt för att skapa den typ av modeller som används. Understudien så har brister i datainsamlingen upptäckts, och förbättringar för att överbryggadessa brister är föreslagna med ändamål att göra insamlad data mer pålitlig och skapa enbättre bas för framtida studier.

The overall goal of this thesis is to present a comprehensive understanding of the Nottawasaga River system. In the first chapter, we will examine how landscape features (geomorphology and land cover) drive spatial variation in nutrient and sediment loading from 11 sub-watersheds to the Nottawasaga River. The second chapter will relate how tributary loading and other in-stream processes (riffles, substrate, dissolved oxygen) contribute to the longitudinal variation in water quality along with middle and lower reaches of the Nottawasaga River. Finally, in the last chapter we use 13 water quality variables to develop a Stream Water Quality Index (SWQI) to identify critical areas in the NRW that are most at risk. This thesis will provide environmental agencies with useful information to help implement management strategies to improve the health of riverine systems at a watershed scale. / Eutrophication from agricultural runoff is a global problem, often resulting in formation of anoxic zones in receiving water bodies. The Nottawasaga River Watershed (2,900 km2) is dominated by agricultural land-use, and is a major source of nutrients and sediment to Nottawasaga Bay, Georgian Bay (Lake Huron). The primary objective of our study was to develop a holistic understanding of the different sources and processes that influence spatial variation of water quality across the Nottawasaga River (121 km). In our first chapter, we use landscape features to develop 6 models that predict daily base flow loading rates of total phosphorus (TP) and total suspended solids (TSS) from 11 sub-watersheds. We found that drainage area and % pasture land were the most significant predictive variables driving spatial variability in TP and TSS loading. We also found a significant positive relationship between TP and % wetland, suggesting that the Minesing Wetlands (largest inland wetland in southern Ontario) are a source of nutrients to the river. In our second chapter, we evaluate how tributary inputs and in-stream processes contribute to the longitudinal variation in water quality along the Nottawasaga River. We found that tributary concentration and discharge significantly predict downstream turbidity (TURB), but do not predict downstream TP. We also found that riffles improve water clarity, and that silt and clay substrate is significantly associated with high TURB. In our third chapter, we develop a Stream Water Quality Index (SWQI) using 13 variables collected at 15 stations along the Nottawasaga River. To predict SWQI scores for any site, we have provided 9 equations that use various combinations of available variables. Understanding landscape variables, as well as tributary and in-stream processes that influence water quality will enhance the development of restoration initiatives to improve ecosystem health in lotic systems at a watershed scale. / Thesis / Master of Science (MSc) / Eutrophication from agricultural runoff is a global problem, often resulting in formation of anoxic zones. The Nottawasaga River Watershed is dominated by agricultural land-use, and is a major source of nutrients and sediment to Georgian Bay, Lake Huron. The objective of our study was to develop a holistic understanding of sources and processes that influence spatial variation of water quality across the Nottawasaga River. We found that landscape features (drainage area, pasture, wetland), tributary inputs, and in-stream processes (riffles, substrate) significantly influence water quality. Our results will enhance restoration initiatives to improve health of riverine systems at a watershed scale.

Afin de caractériser la physico-chimie des matières en suspension de la Moselle et de ses affluents, ce travail s’est appuyé sur une approche géochimique et minéralogique. Notre étude s’est concentrée sur l’analyse des polluants dans les compartiments dissous et particulaire. Ces études ont notamment permis de déterminer (i) la composition des constituants inorganiques dans les particules et colloïdes du milieu aquatique de la Moselle et d’un de ses affluents : la Fensch, (ii) l’évolution des contributions inorganiques le long de la Moselle et de la Fensch ainsi que leur transfert à la confluence Fensch-Moselle, tout en déterminant les sources principales de contamination, (iii) les associations organo-minérales et l’organisation des agrégats présents et (iv) d’étudier la spéciation de certains éléments par des microanalyses. Ce travail a ainsi permis de mettre en évidence l’importance des matières en suspension, souvent négligées par rapport aux autres compartiments Eau et Sédiments / This work uses geochemical and mineralogical approaches to characterize physical and chemical properties of suspended solids in the Moselle and its tributaries. The study focused on analyzing the pollutants in dissolved and particulate compartments. This allowed (i) the identification of inorganic components composition in particles and colloids in the aquatic environment of the Moselle and one of its tributaries: the Fensch, (ii) the determination of the evolution of inorganic contributions along Moselle and the Fensch and their transfer to the confluence Fensch-Moselle in addition to the determination of main contamination sources, (iii) the identification of organo-mineral associations and the determination of the organization of aggregates, (iv) the analysis of the speciation of some elements by microanalysis. This work highlighted the importance of studying suspended solids that are often neglected compared to water and sediments compartments

Three suspended solids types containing a range of physicochemical characteristics were used to determine the effect of suspended solids on the bioavailability of acenaphthene, 1,2,4,5-tetrachlorobenzene, zinc, and chlordane to Daphnia magna and Pimephales promelas. Generally, the bioavailability of zinc and chlordane decreased due to interactions with all suspended solids types while bioavailability of acenaphthene and 1,2,4,5-tetrachlorobenzene were not clearly reduced. Partition coefficients and slope of dose-response curves related chemical characteristics and organism sensitivity, respectively, to experimentally determined results. It is believed that the biologically available form of these chemicals to Daphnia magna and Pimephales promelas resides in the aqueous phase.