Time filter

Source Type

Yates C.N.,Environment Canada | Balch G.C.,Center for Alternative Wastewater Treatment | Wootton B.C.,Center for Alternative Wastewater Treatment
Developments in Environmental Modelling | Year: 2014

The Canadian Arctic has been steadily developing since the late 1970s and in particular, this last decade has begun an ever-steady move toward development. Ongoing natural resource exploration throughout the region has led to increased demand for infrastructure, including roads, housing, and services. In addition, many of the early developments are being decommissioned, specifically military and natural resource extraction areas. As development and human alterations to the landscape continue, there is an ever-increasing need for restoration to revegetate, rehabilitate, and even remediate degraded sites. In this chapter, we reviewed the current applications of ecological engineering principles in the Canadian Arctic, with anecdotes from Alaska and other Arctic localities. We also identify and describe the many barriers to recovery of degraded Arctic systems and how focused efforts using principles of ecological engineering could be used as beneficial management practices to overcome these barriers. Ecological engineering has been primarily represented in revegetation of anthropogenically denuded landscapes, remediation of contaminated soils, and treatment of municipal wastewater. Despite the presence of ecological engineering in the Canadian Arctic over the past decades, its widespread application and evaluation of success on large-scale projects has been limited to only a few case studies. The primary reasons for the low number of examples relate to the remoteness of the majority of the project sites and the harsh climate, which preclude establishing new biological communities and the significant economic cost associated with implementing large projects in the region. Furthermore, compliance of environmental regulations has in many cases been difficult to monitor also because of the factors indicated above. © 2014 Elsevier B.V.


Yates C.N.,Environment Canada | Balch G.C.,Center for Alternative Wastewater Treatment | Wootton B.C.,Center for Alternative Wastewater Treatment | Jorgensen S.E.,Copenhagen University
Developments in Environmental Modelling | Year: 2014

The Canadian Arctic boasts some of the oldest wetlands used for the treatment of municipal wastewater in modern society. However, these systems remain the most poorly understood, managed, and regulated systems in a developed country. Remoteness, extreme temperatures, and socioeconomic factors are among the primary reasons for our limited understanding of these systems and the application of best practices to manage them. In the past 5 years, we have only just begun to study these systems. In this chapter, we review our current understanding of these systems in the context of (i) the logistical challenges for regulating and monitoring treatment wetlands in the Arctic, (ii) our ability to now perform simple models on the wetlands, and (iii) some early best practices for wastewater management in the Arctic. The minimal research that has been conducted to date in Arctic treatment wetlands show that they perform very well during the ice-free period; however, there are significant shortcomings in understanding regarding the application of beneficial management practices and the regulation of treatment wetlands and wastewater treatment in general. Modeling of the treatment wetlands should expect to remain simplistic (first-order kinetic models), with best estimates for system flow and rate constants. © 2014 Elsevier B.V.


Yates C.N.,University of Waterloo | Varickanickal J.,University of Waterloo | Cousins S.,University of Waterloo | Wootton B.,Center for Alternative Wastewater Treatment
Ecological Engineering | Year: 2016

The purpose of this study was to determine how well Carex aquatilis would intake nitrogen to remove it from municipal wastewater with decreasing temperatures and light, simulating summer and fall conditions in Baker Lake, Nunavut. Two trials were conducted, one at 0-5 °C and another at 5-10 °C in a controlled environmental chamber with parallel planted and unplanted planted microcosms. This study specifically examined reduction rates for ammonia, (NH3-N), nitrate (NO3 - -N), nitrite (NO2 - -N) and Total Kjeldahl Nitrogen (TKN). Wastewater was pumped at a rate of 27 L/day and influent and effluent were sampled twice per week for four weeks. Our results showed that the planted trials outperformed the controlled trials at both temperature regimes. In particular, there was a 98% decrease in NH3-N concentration for the 5-10 °C and 78% decrease for the 0-5 °C trial. We believe direct uptake by the plant is the reason for the removal. The planted system also showed a 92 percent increase in SO4 2- -S concentration (p < 0.01). Further research needs to be completed to determine how effective horizontal subsurface constructed wetlands are when built on shallow soil for extreme cold climate constructed wetlands. © 2016 Elsevier B.V.


Yates C.N.,University of Waterloo | Wootton B.C.,Center for Alternative Wastewater Treatment | Murphy S.D.,University of Waterloo
Ecological Engineering | Year: 2012

The treatment of municipal wastewater can be problematic in the remote cold climate environment of the Canadian Arctic, because of a variety of operational, financial, and technical and bureaucratic reasons. As a result, treatment facilities for many communities are thought to only achieve preliminary to primary treatment of municipal wastewater; wastewater often being discharged directly onto the tundra. In this study we provide the first season long study of tundra wetland systems in the Canadian Arctic. In 2008, we studied the performance of six wetland systems used for wastewater treatment in the Kivalliq Region of Nunavut, Canada. The wetland systems studied services communities of approximately 320-2300 residents, including commercial and government buildings, but generally minimal industry. In total, the systems receive a flow rate of approximately 28-163m 3/day of wastewater. We observed average weekly percent reduction in all parameters, with deviations immediately after snow-melt and at the beginning of freeze-up. For the six parameters monitored we observed reductions of 47-94% cBOD 5, 57-96% COD, 39-98% TSS, >99% TC, >99% E. coli, 84-99% NH 3-N and 80-99% TP. In three of the systems, the water discharged from the wetlands and into the receiving environment maintained similar concentrations, and significant similarities in NH 3-N and TP as observed in the natural background concentrations of nearby wetlands. The performance of tundra wetlands to treat the wastewater demonstrates that they are an appropriate technology for remote Canadian Arctic communities. This study also exemplifies the ability of natural systems to act as sinks and transformers, acknowledging that mechanistic assessments will be required to identify primary processes involved in the treatment of Arctic wastewater. © 2012 Elsevier B.V.


Chouinard A.,Queen's University | Yates C.N.,University of Waterloo | Balch G.C.,Center for Alternative Wastewater Treatment | Jorgensen S.E.,WRL Aps | And 2 more authors.
Water (Switzerland) | Year: 2014

The benefits provided by natural (e.g., non-engineered) tundra wetlands for the treatment of municipal wastewater in the Canadian Arctic are largely under-studied and, therefore, undervalued in regard to the treatment service wetlands provide to small remote Arctic communities. In this paper we present case studies on two natural tundra systems which at the time of study had different management practices, in which one consisted of a facultative lake system continuously discharging into a tundra wetland, while the second system had wastewater discharged directly into a tundra wetland. We also examine the utility of the SubWet 2.0 wetland model and how it can be used to: (i) predict the outcomes of management options; and (ii) to assess treatment capacity within individual tundra wetlands to meet future needs associated with population growth and to help municipalities determine the appropriate actions required to achieve the desired level of treatment, both currently, and in a sustainable long-term manner. From this examination we argue that tundra wetlands can significantly augment common treatment practices which rely on waste stabilization ponds, by recognizing the services that wetlands already provide. We suggest that treatment targets could be more achievable if tundra wetlands are formally recognized as part of a hybridized treatment system that incorporates the combined benefits of both the waste stabilization pond and the tundra wetland. Under this scenario tundra wetlands would be recognized as part of the treatment process and not as the 'receiving' environment, which is how most tundra wetlands are currently categorized. © 2014 by the authors.


Huang J.J.,Tianjin University | Gao X.,Tianjin University | Balch G.,Center for Alternative Wastewater Treatment | Wootton B.,Center for Alternative Wastewater Treatment | And 2 more authors.
Ecological Engineering | Year: 2015

With the increasing number of constructed wetlands being built, the modelling of wetland function and performance is valuable. This work examines the efficacy of applying a numeric model (SubWet 2.0) originally designed for horizontal subsurface flow wetlands to model wastewater treatment within vertical subsurface flow constructed wetlands (VSSF-CWs). The treatment efficiencies of two VSSF-CWs with substantially different influent characteristics, one in Canada and one in China, were modelled with SubWet 2.0 and simulated values were then compared to observed values to determine how closely SubWet 2.0 reflects the actual observed performance of these wetlands. The model was calibrated to each wetland with observed data that had been collected prior to the simulations. The correlation coefficient (R) and Nash-Sutcliff coefficient of efficiency (NSE) were used to evaluate the modelling performance for 5-day biochemical oxygen demand (BOD5), ammonium nitrogen, nitrate nitrogen and total phosphorous (TP). The results showed that the modelling performance for TP and BOD5 was better for these parameters than that observed for ammonium nitrogen and nitrate nitrogen for either of the two wetlands. For TP and BOD5, the correlation coefficient R achieved a value of 0.79 for the wetland receiving stormwater and exceeded this value for the Canadian wetland receiving domestic wastewaters. For nitrate nitrogen, the wetland treating domestic waste showed a correlation coefficient R as high as 0.97, while the wetland treating stormwater runoff had a correlation coefficient R of 0.48. For ammonium nitrogen, both wetlands showed low correlation coefficients with values of 0.70 and 0.60 for domestic wastewater and for stormwater runoff, respectively. This study demonstrated that SubWet 2.0 is suitable for the modelling of VSSF-CWs. The two case studies, with substantial differences in the characteristcs of the influents, demonstrated that Subwet 2.0 is a versatile and robust tool for modelling of constructed wetlands. © 2014 Published by Elsevier B.V.


Chouinard A.,Queen's University | Balch G.C.,Center for Alternative Wastewater Treatment | Wootton B.C.,Center for Alternative Wastewater Treatment | Jorgensen S.E.,Copenhagen University | Anderson B.C.,Queen's University
Developments in Environmental Modelling | Year: 2014

Increasingly strict water quality standards and the increasing application of treatment wetlands for wastewater treatment is an ever-growing motive for the development of better process design tools. This chapter reviews the SubWet 2.0 model, a horizontal subsurface flow modeling program initially intended to provide support for the design of constructed wetlands by providing environmental engineers and planners answers to the size of wetlands needed to accommodate anticipated flow rates and desired levels of treatment. The recent SubWet 2.0 version has been modified to allow its application to cold climate areas. This modification was accomplished by calibrating the model with data collected from natural tundra wetlands currently in use for the treatment of municipal effluents within the Kivalliq region of Nunavut, Canada. The calibration of this model with Arctic data has demonstrated its ability to model treatment performance within natural tundra wetlands and thus provide an additional predictive tool to aid northern stakeholders in the treatment of municipal effluents. Three different data sets are presented to illustrate how SubWet 2.0 can be calibrated to specific wetlands. Two data sets are from natural tundra wetlands in Arctic Canada; one is from a constructed wetland in Tanzania. The merits as well as disadvantages of some simple and some more elaborate design models with regard to the design of subsurface flow constructed wetlands are briefly compared with SubWet. Compared to other models, it is suggested that SubWet provides one of the best modeling options available for natural tundra wetlands. It uses a variety of rate constants that are calibrated to site conditions and provides a simulated response of the whole wetland that integrates both known processes and accounts for the possibility that other poorly defined influences (e.g.; inflow of melt waters) may also be operative. © 2014 Elsevier B.V.


Snow A.,Queen's University | Snow A.,Golder Associates | Anderson B.,Queen's University | Wootton B.,Center for Alternative Wastewater Treatment
Environmental Reviews | Year: 2012

The growing of finfish, crustaceans, molluscs, and aquatic plants is termed aquaculture and it is currently the fastest growing animal food producing sector in the world. Flow-through aquaculture facilities are the most commonly used production system for the culture of salmonids. Flow-through land-based aquaculture facilities place great demands on water resources because they require large volumes of high quality source water to grow fish and they also discharge their wastewaters into the aquatic environment. The main source of waste in aquaculture wastewaters is the addition of formulated feed to the culture structure. Discharge of untreated aquaculture wastewaters can lead to physicochemical and biological degradation of receiving waters. Despite advances in feed quality and feeding practices, the treatment of wastewaters from flow-through land-based aquaculture facilities is a necessary practice. Conventional wastewater treatment from flow-through land-based aquaculture facilities has focused on gravitational sedimentation and mechanical screening of the wastewater, which successfully addresses the particulate fraction of the waste. In the past decade, the use of subsurface flow constructed wetlands (SSFCWs), which treat both the particulate and the dissolved fraction of the waste have been gaining attention for the treatment of wastewater from flow-through land-based salmonid farms. Existing studies have demonstrated that SSFCWs have the potential to successfully remove solids, oxygen demanding materials and nutrients from flow-through land-based salmonid wastewaters. © 2012 Published by NRC Research Press.


Pouladi S.F.,Queen's University | Anderson B.C.,Queen's University | Wootton B.,Center for Alternative Wastewater Treatment | Rozema L.,Aqua Treatment Technologies
Water (Switzerland) | Year: 2016

The dissolved salt ions that are not absorbed during irrigation of greenhouse crops are gradually accumulated in the nutrient solution resulting in levels of salinity high enough to damage the crops. This water salinity presents operational and environmental challenges as the nutrient-rich greenhouse effluent should be discharged to the environment when deemed unsuited for irrigation. In this pilot-scale study, the potential of passive salt reduction (phytodesalination) in gravel and wood-chip flow-through reactors was evaluated using seven plant species including Schoenoplectus tabernaemontani, Andropogon gerardii, Typha angustifolia, Elymus canadensis, Panicum virgatum, Spartina pectinata and Distichlis spicata along with an unplanted control reactor. While the unplanted system outperformed the planted units with gravel media, the wood-chip bioreactors with S. tabernaemontani and S. pectinata improved the greenhouse effluent reducing the solution conductivity (EC) by a maximum of 15% (average = 7%). S. tabernaemontani and D. spicata showed higher accumulated contents of Na+ and Cl- in comparison with T. angustifolia and S. pectinata. Overall, S. tabernaemontani was selected as the most capable species in the wood-chip bioreactors for its better salt management via EC reduction and salt accumulation. It was however concluded that further treatment would be required for the greenhouse effluent to meet the stringent irrigation water quality guidelines in order not to pose any adverse effects on sensitive crops. Finally, the present hydraulic residence time (HRT = 3.7 days) and the solution salinity concentration were identified as the potential factors that may be limiting the efficiency of plant salt uptake, emphasizing the need for conducting more research on the optimization and enhancement of passive desalination systems for the greenhouse effluent. © 2016 by the authors.


Chouinard A.,Queen's University | Anderson B.C.,Queen's University | Wootton B.C.,Center for Alternative Wastewater Treatment | Huang J.J.,Nankai University
Environmental Reviews | Year: 2015

This paper aims to be a cursory relative comparison between applications of custom-designed constructed wetland systems for specific water resources protection in Canada and northern China. Comparing constructed wetlands can be difficult and at times misleading; they are custom built to deal with specific target wastewater at specific locations and differ not only in physical shape and dimension, but in vegetation cover, hydraulic retention time, and pollutant loading rates. Treatment efficiencies defined by the Canadian and northern Chinese experience vary considerably. Experience in both countries shows that the majority of effluent values are generally better than those required by discharge standards in Canada and China. Examples provided from both countries demonstrated that plants can play a role in constructed wetland systems and make a difference in treatment efficiency. A review of the available case studies on cold weather treatment in both countries indicates that this technology is feasible in Canada and northern China, although further monitoring data are needed to optimize wetland design and ensure that the effluent quality standards are consistently met. Constructed wetland systems in both countries have an apparent advantage in construction costs, and the costs for treatment and operation and maintenance of these systems are much lower than those of conventional wastewater treatment plants. Land requirements for constructed wetlands present one of the factors most limiting their broader use, especially in China, where land resources are scarce and population density is high. © 2015 Published by NRC Research Press.

Loading Center for Alternative Wastewater Treatment collaborators
Loading Center for Alternative Wastewater Treatment collaborators