At present, there are more than 2000 wastewater treatments plants (WWTPs) in Sweden. Emissions of nitrogen and phosphorus from these, do contribute to the eutrophication of the Baltic Sea and watercourses on a daily basis. To reduce emissions of phosphorus, the Swedish approach has for the last 50 years been to use chemical precipitation. Today, software is used to test and evaluate different strategies in WWTPs, this in order to improve the operation and get a holistic view over the process. One model that can be used to achieve a holistic view is the Benchmark Simulation Model No. 2 (BSM2). In order to get a software like BSM2 to best mirror the reality, it is important that the model well describes the actual process. Today, BSM2 does not take the load of phosphorus into account, which, if it was included in the model, would describe the process better. In this master thesis, the author has investigated the possibility of extending the BSM2 model, to include phosphorus and chemical precipitation. Thereafter the results from simulations in BSM2 were compared with measurements from Henriksdals WWTP in Stockholm. The results showed that a model, after some simplifications, for phosphorus and chemical precipitation could be included in BSM2. The model uses primary precipitation. Precipitation chemical was added with assistance of a PI controller. Generally the results showed that the model had potential to describe the total flow of phosphorus in the WWTP. In measurements from Henriksdal the average total phosphorus effluent from primary and secondary sedimentation were 3.97 and 0.43 mg/l, respectively. From a steady state simulation in BSM2 the values were ​​4.26 and 0.44 mg/l and the average values ​​of a dynamic simulation 3.96 and 0.46 mg/l. Although the average values of total phosphorus matches quite well, it was found difficult to simulate the different fractions of phosphorus effluent from the secondary sedimentation. In order to better evaluate the results and how the simplifications of the model affects them, more measurements need to be done and a comparison with the results received from the BSM2 needs to be carried out. Also an adjustment of parameters in BSM2 must be done, this to achieve a better compliance with the given plant. / Sverige har idag drygt 2000 reningsverk. Reningsverkens utsläpp av kväve och fosfor bidrar dagligen till övergödning i Östersjön och därtill anslutna vattendrag. För att minska utsläpp av fosfor har i Sverige sedan mitten på 1960-talet kemisk fällning använts. Idag används programvara för att testa och utvärdera olika strategier i reningsverken, detta med syftet att förbättra driften och få en helhetsbild över processen. En av dessa modeller är Benchmark Simulation Model No. 2 (BSM2). För att simuleringsprogram ska ge en så bra bild som möjligt av verkligheten är det viktigt att de beskriver processen, i detta fall avloppsvattenrening, på ett bra sätt. BSM2 tar i dagsläget inte hänsyn till belastningen av fosfor, om fosfor inkluderades i modellen skulle det beskriva processen bättre. I detta examensarbete, har författaren undersökt möjligheten att utvidga BSM2, till att inkludera fosfor och kemisk fällning i modellen. Resultaten erhållna från modellen har därefter jämförts med mätdata från Henriksdals reningsverk i Stockholm. Resultatet visade att en modell för fosfor och kemisk fällning kunde, efter vissa förenklingar, inkluderas i BSM2. I modellen användes förfällning och fällningskemikalier tillsattes med hjälp av en PI regulator. Generellt visade resultaten att modellen hade förmåga att beskriva det totala flödet av fosfor i reningsverket. I mätningarna från Henriksdal var medelvärdet på total fosfor ut från försedimenteringen 3,97 mg/l och från eftersedimenteringen 0,43 mg/l. Från en steady state simulering i BSM2 blev värdena 4,26 och 0,44 mg/l och medelvärdena från en dynamisk simulering 3,96 och 0,46 mg/l. Även om medelvärdena på totalfosfor stämmer relativt bra överens, fann man det svårt att simulera olika fraktioner av fosfor ut från eftersedimenteringen. För att bättre kunna bedöma resultatet och hur förenklingar i modellen påverkar resultatet behöver flera mätningar göras och jämföras med modellens resultat. En justering av parametrar i BSM2 måste även göras, detta för att anpassa modellen till det givna avloppsreningsverket bättre. / Development and dynamic analysis of operational strategies for enhanced energy efficiency of wastewater treatment systems

Work object – Vyžuona river, which has 26 km lenght, is left affluent of Šventoji river, belongs to subbasin of Šventoji river and runs from northeast to southwest of Lithuania. Work aim – identify water quality and bounded with it live organisms of Vyžuona river. Work tasks – analyse physical-chemical water parameters of Vyžuona river, identify varietal composition of organisms, define and evaluate contamination of river objects. Work results – After the reasearch was made there was defined that Vyžuona river in Utena town (1 km from Krašuona river and Vieša river junction) belongs to average contaminated rivers category measuring by parameters of water quality: common nitrogen quantity 1.9 times exceeds permissible quotas, 68.6 % of common nitrogen is composed of nitrate nitrogen, BDS7 quantity 2,7 times exceeds the LDK, concentration of phosphates 2.3 times exceeded permissible quotas. Krašuona river and Vieša river runs trough private houses section, which has no central sewer and that is the reason why mentioned rivers are bearing domestic contaminants into Vyžuona river. According to 2004-2006 data below the outlet from drain mechanism of UAB „Utenos vandenys“ refinement system there was found concentration of phosphorus which averagely 1,75 times, common nitrogen 1,1 times and BDS7 1,7 times less in comparison with river part in centre of Utena town above UAB „Utenos vandenys“. That may be explained by UAB „Utenos vandeys“ affect, which drains large amount of enough... [to full text]

The application of natural tundra wetlands for municipal wastewater treatment is an option to meet upcoming federal wastewater systems effluent regulations for Canada’s Far North. A treatment performance assessment with physical, hydraulic and biogeochemical contextual data was conducted on the wetland treatment area of Coral Harbour, Nunavut. A modified Tanks-In-Series model was used to model treatment kinetics. The study showed seasonal variability in treatment performance and hydraulic characteristics. A decrease in vegetation diversity and deposition of organic detritus was observed in high effluent loading areas. Effective reduction in effluent concentrations was observed. Dilution from watershed contributions accounted for much of the reductions observed. The importance of the determination of the hydraulic residence time, field delineation of the wetted area, and delineation of the watershed was demonstrated. First order rate coefficients determined suggested that the selection of the lowest percentiles from literature of southern treatment wetlands is conservative in this case.

Biosolids are the nutrient-rich organic residual materials resulting from the treatment of domestic sewage at a wastewater treatment facility, and are increasingly land-applied for agricultural and land-reclamation purposes as part of the wastewater management process. While the presence and fate of estrogenic endocrine-disruptors (eEDCs) in wastewater has been extensively studied, much less focus has been given to examining the presence and fate of eEDCs during biosolids treatment. In particular, little work has been done to measure the net estrogenic potency of biosolids using in vitro bioassays, such as the Yeast Estrogen Screen (YES) assay. This is despite the fact that widespread land-application of biosolids provides for the direct introduction of eEDCs into terrestrial and aquatic environments. The relative scarcity of bioassay-based net estrogenicity data for sludges and biosolids is in large part due to the analytical challenges involved in working with such a complex sample matrix. Comprehensive sampling at wastewater treatment plants in Guelph and London, ON, demonstrated that the estrogenicity of anaerobically-treated biosolids is considerably lower (12.0-19.7 ng/g estradiol-equivalents) than that reported in earlier published studies. The results of the present study were made possible due to the development of a sample preparation methodology that overcame the toxic effects that sludge and biosolid samples typically exert on yeast cells in the YES assay. An anti-estrogenicity assay was also applied for the first time to sludges/biosolids to measure the extent to which antagonistic compounds ‘block’ the response of the YES assay. The results of these tests suggest that although the net estrogenicity of anaerobically treated solids is indeed low, up to twice the amount of estrogenicity measured by the YES assay may be masked in biosolids by the presence of antagonistic compounds. While aerobic treatment conditions reduced net estrogenicity to at-or-below detectable levels, net estrogenicity remained relatively constant throughout the unit processes of the anaerobic treatment train. Biosolid ageing during storage led to an overall decrease in net estrogenicity of both conventionally-treated “restricted use” and advanced-treated “unrestricted use” anaerobic biosolids. However, levels of net estrogenicity were observed to spike during the early stages of storage, particularly under freeze/thaw conditions. / Natural Science and Engineering Research Council of Canada (NSERC) PGS-D3 scholarship, Water Environment Association of Ontario, Canadian Water Network

At Kungsberget ski-resort in Gävleborg county all wastewater produced at the facility is treated on-site. The treatment takes place at their own wastewater treatment plant in a so-called Sequence Batch Reactor (SBR), which has been in operation for about a year before this study. Kungsberget AB is currently in charge of the facility but their goal is to hand responsibility over to Sandviken Energy AB. In order for this handover to occur Kungsberget has to produce three approved treatment results. This means that the concentrations of BOD7 needs to lie under 0.3 mg/l and total phosphorous under 10 mg/l in the effluent water for three consecutive samples. The results show momentaneous values. These limits are stated in the permit Kungsberget received from the Environmental Protection Division. Kungsberget has had problems with high and fluctuating phosphorous concentrations and therefore the transfer has not yet taken place. In this project several parameters have been analysed in order to obtain an overview of prevailing influent and effluent concentrations. Some of the parameters that have been analysed are; phosphorous, nitrogen, BOD7, suspended solids and pH. A lot of time and effort has been put into elucidating operational routines at the wastewater treatment plant (WWTP) and gaining knowledge from available literature regarding different parameters’ effect on treatment results.   Kungsberget has had problems adapting operating routines and reaching stable treatment results as the load is highly effected of seasonal fluctuation. This has not been taken into account earlier and the WWTP has been operated in the same manner all year around. Suggestions to how operating routines can be modified in to better meeting the needs have been produced and alternative treatment methods have been presented in the report. Two of the suggestions include biological phosphorous removal and adding carrier media to increase bacteria growth. An aerobic solids retention time has been calculated in order to evaluate whether nitrifying bacteria have enough time for grow and maintain a stable population. The calculation was carried out by measuring suspended solids and aeration time and the result was a solids retention time of approximately 6 days.

Sludge accumulation, treatment and disposal can represent a high percentage of the operating cost for a wastewater system. This is especially important for small-scale and onsite wastewater treatment systems, where sludge removal can be one of the few operating costs of the system. In 2000, as a result of a large number of septic system failures, the community of Wardsville installed a Clearford Industries Inc. Small Bore Sewer™ (SBS™) system which included two-chamber 3600 L tanks located on the properties of individual homes. The tanks were collectively attached to a small bore piping system to deliver the effluent from the tanks to a small community wastewater treatment system. During the summer of 2007, a field study was initiated with a community survey, followed by a review of candidate sites, leading to the selection of 29 sites for site investigation and sampling. Sampling involved the collection of samples for sludge characterization along with the measurements of the height of solids (scum and sludge) within the tank. The data were analyzed to determine the factors having a statistically significant impact on solids accumulation rates within each of the two chambers of the tank. Household water usage was found to be the variable having the strongest association with sludge and scum accumulation, and models were estimated relating solids accumulation to water usage in order predict pump out frequency. A second field sampling program was conducted in Wardsville during April 2008, involving only the first chamber of 13 primary clarifier tanks. Overall contributions have been made in understanding and quantifying solids accumulation rates and sludge characterization in onsite primary clarifier tanks. As well, the information gained from the analysis of the data collected provides a meaningful insight into the factors influencing solids accumulation within individual residential primary clarifier tanks, and points to future research directions for understanding the factors influencing solids accumulation. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-04-25 15:34:46.243

Sludge accumulation, treatment and disposal can represent a high percentage of the operating cost for a wastewater system. This is especially important for small-scale and onsite wastewater treatment systems, where sludge removal can be one of the few operating costs of the system. In 2000, as a result of a large number of septic system failures, the community of Wardsville installed a Clearford Industries Inc. Small Bore Sewer™ (SBS™) system which included two-chamber 3600 L tanks located on the properties of individual homes. The tanks were collectively attached to a small bore piping system to deliver the effluent from the tanks to a small community wastewater treatment system. During the summer of 2007, a field study was initiated with a community survey, followed by a review of candidate sites, leading to the selection of 29 sites for site investigation and sampling. Sampling involved the collection of samples for sludge characterization along with the measurements of the height of solids (scum and sludge) within the tank. The data were analyzed to determine the factors having a statistically significant impact on solids accumulation rates within each of the two chambers of the tank. Household water usage was found to be the variable having the strongest association with sludge and scum accumulation, and models were estimated relating solids accumulation to water usage in order predict pump out frequency. A second field sampling program was conducted in Wardsville during April 2008, involving only the first chamber of 13 primary clarifier tanks. Overall contributions have been made in understanding and quantifying solids accumulation rates and sludge characterization in onsite primary clarifier tanks. As well, the information gained from the analysis of the data collected provides a meaningful insight into the factors influencing solids accumulation within individual residential primary clarifier tanks, and points to future research directions for understanding the factors influencing solids accumulation. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-04-25 15:34:46.243

In this project, by adding selected co-substrates and by incorporating optimum pre-treatment strategies, four experimental phases were conducted to assess the enhancement of biogas production from anaerobic co-digestion using wastewater treatment plant sludge as the primary substrate. In the first phase, the feasibility of using municipal organic wastes (synthetic kitchen waste (KW) and fat, oil and grease (FOG)) as co-substrates in anaerobic co-digestion was investigated. KW and FOG positively affected biogas production from anaerobic co-digestion, with ideal estimated substrate/inoculum (S/I) ratio ranges of 0.80-1.26 and 0.25-0.75, respectively. Combined linear and non-linear regression models were employed to represent the entire digestion process and demonstrated that FOG could be suggested as the preferred co-substrate. The effects of ultrasonic and thermo-chemical pre-treatments on the biogas production of anaerobic co-digestion with KW or FOG were investigated in the second phase. Non-linear regressions fitted to the data indicated that thermo-chemical pre-treatment could increase methane production yields from both FOG and KW co-digestion. Thermo-chemical pre-treatments of pH=10, 55°C provided the best conditions to increase methane production from FOG co-digestions. In the third phase, using the results obtained previously, anaerobic co-digestions with FOG were tested in bench-scale semi-continuous flow digesters at Ravensview Water Pollution Control Plant, Kingston, ON. The effects of hydraulic retention time (HRT), organic loading rate (OLR) and digestion temperature (37°C and 55°C) on biogas production were evaluated. The best biogas production rate of 17.4±0.86 L/d and methane content 67.9±1.46% was obtained with thermophilic (55°C) co-digestion at HRT=24 days and OLR=2.43±0.15 g TVS/L•d. In the fourth phase, with the suitable co-substrate, optimum pre-treatment method and operational parameters identified from the previous phases, anaerobic co-digestions with FOG were investigated in a two-stage thermophilic semi-continuous flow co-digestion system modified to incorporate thermo-chemical pre-treatment of pH=10 at 55°C. Overall, the modified two-stage co-digestion system yielded a 25.14±2.14 L/d (with 70.2±1.4% CH4) biogas production, which was higher than that obtained in the two-stage system without pre-treatment. The positive results could provide valuable information and original contribution to justify full-scale investigation in a continuing research program and to the field of research on anaerobic co-digestion of municipal organic wastes. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2012-09-20 09:00:09.719

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The aim of this Master Thesis was to calculate and visualize performance indicators for the secondary treatment step in municipal wastewater treatment plants. Performance indicators are a valuable tool to communicate process conditions and energy efficiency to both management teams and operators of the plant. Performance indicators should be as few as possible, clearly defined, easily measurable, verifiable and easy to understand. Performance indicators have been calculated based on data from existing wastewater treatment plants and qualified estimates when insufficient data was available. These performance indicators were then evaluated and narrowed down to a few key indicators, related to process performance and energy usage. Performance indicators for the secondary treatment step were calculated for four municipal wastewater treatment plants operating three different process configurations of the activated-sludge technology; Sternö wastewater treatment plant (Sweden) using a conventional activated-sludge technology, Ronneby wastewater treatment plant (Sweden) using a ring-shaped activated-sludge technology called oxidation ditch, Headingley wastewater treatment plant (Canada) and Kimmswick wastewater treatment plant (USA), both of which use sequencing batch reactor (SBR) activated-sludge technology. Literature reviews, interviews and process data formed the basis of the Master Thesis. The secondary treatment was studied in all the wastewater treatment plants. Performance indicators were calculated, to the extent it was possible, for this step in the treatment process. The results showed that all the wastewater treatments plants, studied in this master thesis, were well below regulatory requirements of effluent concentrations of organic matter and nutrients. This gap between legislated requirements and performance provides an opportunity for improving energy efficiency and maintaining discharge requirements. The removal of organic matter was consistently high at all wastewater treatment plants studied but the removal of nitrogen was slightly lower during the colder months. The results further showed that the discharge of nitrogen from wastewater treatment plants is the largest stress on the recipient. Data regarding the energy usage was almost nonexistent and energy for aeration was therefore calculated when possible since it is aeration that accounts for the largest fraction of energy usage in a wastewater treatment plant. Sternö wastewater-treatment plant proved to be more energy efficient than Rustorp wastewater treatment plant.