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Impacts of Future Climate Change in Water Resources Management at the Chao Phraya River Basin, Thailand / タイ国チャオプラヤ川流域の水資源管理に及ぼす気候変動の影響Luksanaree, Maneechot 23 September 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22760号 / 工博第4759号 / 新制||工||1744(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 清水 芳久, 教授 田中 宏明, 教授 米田 稔 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Bioflocculation of Wastewater Treatment Pond Suspended SolidsLefebvre, Louis 01 December 2012 (has links) (PDF)
Bioflocculation of Wastewater Treatment Pond Suspended Solids
Louis Lefebvre
Wastewater treatment lagoons and high rate algae ponds (HRAPs) can provide cost effective wastewater treatment, but they commonly have high effluent concentrations of total suspended solids (TSS). In this thesis algae pond effluent was treated in a beaker testing apparatus (mixed and aerated) with various mixtures of activated sludge and primary effluent simulating differing activated sludge aeration basin compositions then was allowed to settle to assess settleability. Conventionally, microalgal suspended solids are removed by chemical coagulation followed by separation methods that often have a high cost relative to the low cost lagoon or HRAP system where the solids were produced. This separation step is often cost prohibitive or operationally complex for municipalities or too energy intensive for application in algae biofuels production. This research investigates using a small amount of activated sludge material to promote bioflocculation of algae in pond effluent. It was hoped that the findings may demonstrate a path for municipalities to keep their lagoons, while increasing capacity and improving treatment without excessive cost or complexity. Experiments were conducted on microalgae samples from a pilot-scale HRAP and activated sludge and primary effluent samples from a local municipal wastewater plant. The samples were placed in a mixing apparatus and allowed to settle for a given period of time, after which TSS was analyzed for settleability. The experiments investigated the effect of various lab-scale activated sludge reactor operational schemes by varying the volumes (and masses) of activated sludge, algae-rich water, and activated sludge in the beaker. Results in the sorption test (tests with only activated sludge and algae-rich water) demonstrated algae pond effluent treated with activated sludge concentrations of 3000 mg/L or greater produced final effluent TSS concentrations near discharge requirements (40-50 mg/L) with only 30 minutes of settling and without addition of primary effluent. However, such high activated sludge concentrations are not feasible at full scale. Furthermore, beakers with activated sludge concentrations greater than 3000 mg/L reduced TSS concentrations by more than 150 mg/L with only 30 minutes of settling and without addition of primary effluent. Results in the aerobic beaker tests (tests with primary effluent, activated sludge, and algae-rich water) showed greater than 200 mg/L TSS removal and final effluent TSS concentration less than 30 mg/L was achieved using activated sludge to primary effluent volumetric ratios of 1:1 and greater which corresponded to activated sludge concentrations of 730 mg/L and greater. Activated sludge concentrations of 730 mg/L may not be feasible at full scale. This report shows that a PETRO-like process is effective in lowering wastewater pond suspended solids, however not to typical discharge standards.
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A performance investigation of stormwater accommodations in Stockholm : A multi-criteria decision analysis / Utvärdering av prestandan hos dagvattensystem i Stockholm : En multikriterieanalysJonsson, Martin January 2017 (has links)
Stormwater management is a problematic area and has during the last 20 years been given an increased attention due to more pollution in the cities. The increased pollution and contaminants in stormwater implicates risks for animals, humans, the ecosystem and receiving recipients. Due to the increased attention, authorities, government and other stakeholders have developed measurements to deal with the problem. Stormwater accommodations and other type of stormwater detainment has been developed with increased modern technology and functionality to fit specific areas where different type of pollutants can vary. Stormwater treatment are necessary because it creates social, environmental and technical advantages combined with protection of ecosystem, increased multifunctionality when combining for example stormwater ponds in nature, parks or urban and rural environment. This report describes seven diverse types of stormwater accommodations systems; rain garden, stormwater ponds, wells, screen basins, infiltration trenches, pipe-/concrete magazine and swales in accordance from Structor Mark Stockholm. From these seven accommodations, three were chosen to be included in Multi Criteria Decision Analysis (MCDA). The purpose of the MCDA was to evaluate four different categories linked to stormwater, which are environment, social, technology and economical categories. These categories are broad concepts; therefore, parameters were developed to narrow down the areas within the concept, from which the area of investigation was founded within. The parameters created for each category are degree of purification for the environmental category, performance and maintenance for the technological category, aesthetical and social benefits for the social category and costs and risk for the economical category. The criteria developed from these parameters are specific topics that was scored from the scale between 0-5, where 0 = insignificant, 1= Low, 2= Moderate, 3= Major, 4=High, 5= Very high. A reference option was also created, considered as “no commercial treatment of stormwater”, only to transport stormwater. This reference option was also referred to as a zero-alternative and is drainage by piping. The scoring was conducted by stakeholders and citizens of Stockholm. The scoring of the three chosen stormwater accommodations and the reference alternative after calculating the mean value and summarize it resulted in that stormwater pond received the highest overall score of 11.9 followed by rain gardens 11.4, infiltration trench 11.3 and drainage by piping 7.3. The stakeholders are influential people that works either with stormwater, layout and planning or maintenance personnel. Citizens of Stockholm provided inputs only in regards of the social aspects. A total of 20 stakeholders were contacted and 5 stakeholders participated in the scoring procedure. Citizens were interviewed on the street; a total of 60 people was asked to participate and 13 people decided to participate in the scoring procedure of the social aspects. Although, the attendance of stakeholders was low, they are still considered important to this project since they provided the scoring of the criteria for each respective category (environment, technology, social and economic). In regards of the low attendance by stakeholders, this resulted in a way that it became hard to distinguish the result between the different stormwater accommodation. Therefore, it was hard to determine which stormwater accommodation that was the best out ofthe ranking provided by the MCDA. A benefit by using MCDA as a tool in this case, gave an indication that the MCDA can work as a framework to decision makers, even though the result in this case became difficult to manage and distinguish between the different stormwater accommodations. Finally, the method, layout and analysis itself can provide means of measurements for stormwater investigations when the purpose is to choose between the best stormwater systems included in the MCDA. Inputs from stakeholders concluded that depending on what type of existing circumstances, there must be a site-specific evaluation to treat every area as a unique area, before deciding what type of stormwater accommodation to apply to that specific location. / Dagvattenhantering är ett problematiskt område som under de senaste 20 åren har fått allt mer uppmärksamhet då mer föroreningar uppdagats i städerna. Den ökande föroreningen av dagvatten tenderar att orsaka en större risk för djur, människor, ekosystem och recipienter dit dagvatten rinner. På grund av uppmärksamheten som dagvattenhanteringen har fått, har myndigheter, regering och andra intressenter utvecklat dagvatten teknologin ytterligare för att skapa en modern dagvattenstrategi för att handskas med problemet. Dagvattenhantering är nödvändigt eftersom den skapar sociala, miljömässiga och tekniska fördelar samt om dagvattensystemen kombineras med funktionalitet så kan detta ge ökat skydd för ekosystemen samt förbättrad hälsa hos befolkningen i städerna. Den här rapporten beskriver sju olika typer av dagvattensystem så som; rain gardens, dagvattendammar, brunnar, skärmbassänger, svackdiken, rör-/betong magasin samt krossdiken på begäran av Structor Mark Stockholm. Utav dessa 7 dagvattensystem, ingick 3 anläggningar i en så kallad multi-criteria decision analysis (MCDA). Syftet med en MCDA är att utvärdera fyra olika kategorier som kan förknippas med dagvattenhantering. Kategorierna är miljömässiga, sociala, tekniska och ekonomiska. Dessa kategorier utger dock ett brett budskap och för att begränsa analysen så skapades parametrar. Dessa parametrar skapas utifrån varje enskild kategori. För den miljömässiga kategorin skapades parametern grad av rening, för den tekniska kategorin skapades parametern prestanda och underhåll, för den sociala kategorin skapades parametern estetiska och sociala fördelar, och slutligen för den ekonomiska kategorin skapades parametern kostnader och risker. Utifrån dessa parametrar skapades sedan kriterier med specifika huvudämnen som kan bedömas enligt en poängskala från 0-5 där 0 = insignificant, 1=Low, 2= Moderate, 3= Major, 4= High, 5= Very high. Tre dagvattensystem inkluderas i MCDA vilket var; rain gardens, dagvattendammar, krossdiken vars syfte är att rena och fördröja dagvatten. Ett referensalternativ skapades också som ävenkallas ”zero-alternative”, vilket anses inte ha någon rening av dagvatten utan är endast ett transportsystem för dagvatten. Detta referensalternativ kallas drainage by piping. Poängsättningen gjordes av intressenter och invånare i Stockholm. Intressenterna är människor som arbetar med dagvattenhantering antingen på planeringsstadiet eller ute i fält som drift och underhålls personal. Invånare i Stockholm bedömde endast den sociala kategorin eftersom det kan sakna kunskap och insyn i det miljömässiga, tekniska och ekonomiska detaljerna. Totalt kontaktades 20 intressenter där 5 personer valde att medverka i MCDA. Invånare i Stockholm intervjuades på stan, totalt frågades ca 60 personer varav 13 personer valde att medverka i poängsättningen. Poängsättningen av de tre valda dagvattensystemen samt referensalternativet, efter beräkningav medelvärdet samt den totala summeringen resulterade i att dagvattendammar fick den hösta poängen 11,9 hamnade rain garden på andra plats med 11,4, krossdike på tredje plats med 11,3 samt referensalternativet på en fjärde plats med 7,3. De tre dagvattensystemen hade ett relativt liknande slutgiltigt resultat. Dock så skilde sig den individuella kategoriska bedömningen av miljömässiga, tekniska, sociala samt ekonomiska aspekten med större varierande resultat. Även om deltagandet av intressenter var relativt lågt, endast 25 % av det kontaktade intressenterna valde att ställa upp, så anses dessa intressenter vara viktiga för det här projektet då de, utifrån deras kunskap, bedömer det uppsatta kriterierna och det är denna bedömning som resultatet baseras på. Resultaten mellan det olika dagvattenanläggningarna som var inkluderade i MCDA var svåra att särskilja, troligtvis beroende på att ingen viktningsmetod användes. Däremot så är en fördel med MCDA som verktyg i det här fallet, att det gav en indikation på att MCDA kan fungera som ett stödjande verktyg för beslutsfattare även om resultatet i det här fallet var svårt att särskilja. Själva metoden, upplägget och analysen kan användas som medel för att avgöra vilken typ av dagvattenanläggning som passar bäst utifrån de kriterier som är uppsatta. Slutligen så gav intressenterna en påvisning att dagvattenanläggningar ska konstrueras så att hänsyn tas till omkringliggande omständigheter, där varje plats ska ansesvara unik. Det krävs en platsspecifik utredning där hänsyn till geologiska, geotekniska,hydrologiska samt infrastrukturella och miljömässiga aspekter bör utredas innan valet av dagvattensystem bestäms.
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Adaptive Laboratory Evolution of Scenedesmus obliquus for Increased Carbohydrate Content and Biomass ProductivityAli, Nahel 01 March 2021 (has links) (PDF)
The economics of microalgal bioproduct commercialization would benefit from increased accumulation of energy storage compounds, such as carbohydrates and lipids, and increased biomass productivity. This thesis explores two adaptive laboratory evolution strategies for improving Scenedesmus obliquus: single UV-mutagenesis and low light cultivation at a high dilution rate to produce cultigens with greater carbohydrate content and iterative UV-mutagenesis and selection under outdoor conditions in a raceway pond at a high dilution rate to increase biomass productivity.
Two cultigens were generated with the goal of increased carbohydrate content: K5 and K7. Both were mutagenized for 5 seconds and cultivated in 50-mL Klavins reactors. K5 was maintained at 95 μmol/m2-sec for 16 hours/day, and K7 was maintained at 250 μmol/m2-sec for 6 hours/day. When evaluating the two cultigens in triplicate 800-mL bubble columns against wild-type Scenedesmus obliquus, neither K5 nor K7 demonstrated an increase in carbohydrate content.
To increase biomass productivity, Scenedesmus obliquus was iteratively UV-mutagenized (aliquots exposed for 5-60 seconds were combined) and cultivated in a 100-L, 0.5-m2 outdoor raceway pond fed with filtered reclaimed wastewater at a high dilution rate. Three rounds of mutagenesis and selection took place during the spring, summer, and winter months, with the MBE 509 and MBE 510 cultigens being produced after the summer and winter selection rounds, respectively. When evaluated in triplicate 800-mL bubble column reactors: MBE 509 (491 ± 42 mg/L-day, expressed as the mean of the time series ± SD) was 24% more productive than wild-type (397 ± 39 mg/L-day), and MBE 510 (443 ± 26 mg/L-day) was 13% more productive than wild-type (391 ± 9 mg/L-day). When evaluated in replicate 1,350-L, 4.5-m2 raceway ponds, MBE 509 (15.2 ± 2.2 g/m2-day) and MBE 510 (16.1 ± 1.8 g/m2-day) were 5% and 12% more productive than wild-type (14.5 ± 2.4 g/m2-day), respectively.
Selection under low light and high dilution did not result in cultigens with higher carbohydrate content relative to wild-type Scenedesmus obliquus, but iterative mutagenesis and selection in an outdoor raceway pond did generate cultigens with higher biomass productivity in both indoor and outdoor environments.
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Nutrient Transformations in Algae Raceway Ponds Fed Municipal WastewaterReiff, Carter Michael 01 June 2015 (has links) (PDF)
While treating domestic wastewater, algae can be grown and harvested for biofuel production. Water is a vital resource and it is imperative to conserve and reuse as much as possible. Several pilot and lab scale experiments were conducted to further research into a full scale wastewater treatment and biofuel production facility. This thesis will include these topics: nitrogen and phosphorus concentrations of clarified wastewater pond feed, nitrogen and phosphorus transformations by algae, and the potential of algae cell disruption technologies to increase nutrient solubilization.
The pilot scale experiments were conducted using nine 33 m2, 0.3 m deep multi-culture raceway algae ponds being continuously mixed. These ponds were setup in triplicates and fed municipal wastewater in the form of primary clarifier effluent. The three experiments conducted using these pilot scale ponds were: grab and 24-hour composite influent comparison, nitrogen and phosphorus of various hydraulic residence times (HRTs), and nitrogen and phosphorus nutrient depletion with water recycle.
The grab and 24-hour composite comparison was conducted from July 30 to December 3, 2014 and compared the dissolved reactive phosphorus (DRP) and total ammonia nitrogen (TAN) concentrations of the two sample types. Equations were made to convert from grab to 24-hour concentrations. The sample types for both DRP and TAN were on average within 10% and essentially the same.
A comparison of data from ponds operating at different HRTs was collected from October 30 and November 6, 2013 and October 29 and November 5, 2014. There were linear correlations between different HRTs and both soluble nitrogen and DRP. Equations were made to calculate the expected removal of ponds using the HRT.
The nutrient depletion with water recycle experiment was conducted during October 15-29, 2015. Soluble nitrogen removal was linear with a rate of 1.5 mg-N/L-day and required 14 days to drop below 5 mg-N/L in the ponds. DRP removal was also linear with a rate of 0.18 mg-P/L-day.
The algae cell disruption solubilization experiments were conducted using homogenization, sonication, autoclaving, and boiling pretreatment technologies. Algae harvested from the pilot ponds was anaerobically digested and then aerobically digested in an attempt to reuse nutrients for continued growth. It was found that there was no significant difference between the pretreated and non-pretreated digested samples.
Keywords: algae, raceway pond, nutrient transformation, anaerobic digestion, aerobic digestion, assimilation, volatilization, nitrogen, phosphorus, pretreatment of algae, nutrient resolubilization, nutrient solubilization
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Nutrient Removal Using Microalgae in Wastewater-Fed High Rate PondsRodrigues, Matthew N 01 June 2013 (has links) (PDF)
This thesis discusses the mechanisms associated with the removal of organic matter, nitrogen and phosphorus in wastewater-fed high rate algae ponds (HRAP) designed to operate as triplicates. Research was conducted at the San Luis Obispo Water Reclamation Facility (SLOWRF) as a pilot-scale study of nine 30-square meter ponds one foot in depth. During period of study, triplicates were operated at hydraulic retention times (HRT) of 4, 3 or 2-days. Main objectives for the study were to determine minimum HRTs required to achieve secondary and tertiary treatment. Experimental conditions such as CO2 supplementation, nighttime aeration and operation of ponds in series were employed to evaluate optimal conditions for efficient nutrient removal. Ponds were continuously fed primary effluent with the following water quality characteristics: 5-day total biochemical oxygen demand (TBOD5) of 124mg/L, 5-day soluble carbonaceous biochemical oxygen demand of 67mg/L (scBOD5), total suspended solids (TSS) of 66mg/L, volatile suspended solids (VSS) of 65mg/L, total ammonia nitrogen (TAN) of 34mg/L-N, oxidized nitrogen of 1.1mg/L-N, total K̇jeldahl nitrogen (TKN) of 42mg/L-N and dissolved reactive phosphorus (DRP) of 3.3mg/L-P. Nutrient removal efficiencies were compared between summer months (April – October) and winter months (November – February). Average pond temperatures during summer and winter were 20.4 °C and 14.9 °C, respectively. Average TAN removal efficiencies of 2-day HRT ponds ranged from 62% in winter to 78% in summer. Operation of ponds at an increased 3-day HRTs resulted in corresponding seasonal increases of TAN removal by 14% and 12%. In 4-day HRT ponds operating in series after a 3-day HRT set, TAN removal efficiency was 98% in winter and 99% in summer. Aeration increased nitrification and nitrate concentrations in 2-day HRT ponds to10mg/L-N ± 4.4mg/L-N. DRP concentrations and BOD removal efficiencies within replicate ponds were similar throughout seasonality. DRP was 1.2mg/L-P ± 0.66mg/L-P at a 4-day HRT operating in series, 2.2mg/L-P ± 0.57mg/L-P at a 3-day HRT and 2.6mg/L-P ± 0.58mg/L-P at a 2-day HRT. Aeration had no measureable effect on BOD removal. BOD removal efficiency was 97% at a 4-day HRT in series with a 3-day HRT and 95% at 3-day and 2-day HRTs.
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Aspects of the Geology in the Peter Strides Pond Area, Southwestern NewfoundlandFerguson, John D. 06 1900 (has links)
<p> The Peter Strides Pond study area, approximately 150 km^2, is located in the Southern Long Range Mountains in southwestern Newfoundland. It lies at the southern margin of the Paleozoic Central Mobile Belt in the Dunnage tectonostratigraphic zone. A felsic intrusion, granoblastic gneiss, heterolithic conglomerate and basalt form foliated, linear bodies across the study area parallel to the regional, northeast striking, structural grain; gabbro, diabase and rhyolite have non-linear exposure and no internal fabric. Two parallel mylonite zones traverse the study area. The Victoria River Shear Zone (VRSZ) to the north and the Peter Strides Pond Shear Zone (PSPSZ) to the south are concordant with the regional fabric and separate domains which increase in metamorphic grade from lower greenschist in the northwest to upper amphibolite facies to the southeast. Veins and lenses of variable form and composition are observed in several lithologies but the focussed occurrence of milky white, foliation parallel quartz veins in both the VRSZ and the felsic pluton is significant to these
units.</p> <p> A tentative stratigraphic succession for the study area utilizes regional correlations, radiometric ages and fossil evidence because limited exposure does not reveal contacts between adjacent lithologies. Basalt of the Victoria Lake Group and gneiss of the Bay du Nord Group are the oldest units in the area. Conglomerate unconformably overlies the Victoria Lake Group and contains volcanic and sedimentary clasts derived from the underlying group. Mafic to felsic plutonic igneous rocks intrude volcanic rocks of the Victoria Lake Group. Undated gabbro, diorite and diabase may be coeval with Devonian adamellite-granodiorite.
Parallel shear zones are concordant with the regional structural grain and follow lithologic contacts closely. Megacrystic granite cross-cuts PSP mylonite, adamellite and Bay du Nord gneiss. It is the youngest unit in the study area. The study area's tectonic framework represents a compressional environment which dominated during, and continued after Iapetus closure. Mafic volcanic rocks adjacent to ophiolite complexes represent back arc basins preserved via obduction. Continued compression was accomodated by crustal thickening through reverse, northwest directed, thrust faults. The inhomogeneously thickened crust provided a host of potential magma compositions to be intruded locally.</p> / Thesis / Master of Science (MSc)
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Climate Change Impact Assessment at Watershed ScaleAhmed, Sadik January 2017 (has links)
Climate model projections revealed a likelihood of increased frequency and magnitude of hydrological extremes in future climate due to continued emissions of greenhouse gases. Considering that it will significantly affect the planning and designing of flood management systems, for instance stormwater management infrastructures, and designation of flood risk area, it is vital to investigate the climate change impact on the hydrological processes and respective consequences on the flood management systems. The primary objective of this research is to investigate the climate change impact at watershed scale, and the goal was achieved by investigating the climate change impact on hydrological processes, assessing the potential impact of changed hydrological processes on drainage systems and flooding scenarios. The study area in this research includes Spencer Creek watershed, West Central Mountain drainage area and Clearview Creek drainage area located in Southern Ontario, Canada. The climate projections used in this study were the North American Regional Climate Change Assessment Program (NARCCAP) climate simulations based on SRES A2 scenario.
For Spencer Creek watershed, NARCCAP provided eight RCM+GCM pair’s climate projections were bias- corrected, and used as input in a calibrated hydrological model HBV to simulate flows at the outlet of the watershed. A significant improvement of bias-corrected precipitation and temperature was revealed by Brier and Rank Probability Skill Score. The results revealed an increase in winter daily average flows and decrease in other seasons, and approximately 13% increase in annual evapotranspiration, and an increase in high flows and decrease in low flows under future climate conditions. Consequences for changed hydrological processes on urban stormwater management systems were investigated for West Central Mountain drainage area. Design storm depths were calculated by using the best fitted distribution among twenty seven distributions and by applying delta change factor. The PCSWMM model was used for flow simulation and hydraulic analysis for the storm-water management system, specifically storm sewer and detention pond. The assessment results indicate that the performance of the detention pond as well as the storm sewer network will deteriorate under future climate condition as design storm depths increase. For Clearview Creek drainage area, a single event hydrologic model Visual OTTHYMO and hydraulic analysis tool HEC-RAS were used to simulate flow and water level. The results revealed an increase of peak flows ranging from about 26 % to 64% for 2yr and 100yr return periods at the outlet of the Creek, and an average increase of water surface elevation and extents by 30 cm and 37.1 m, respectively, for a 100 year return period flood. Finally, non-stationary frequency analyses for design storm calculation were recommended for more robust and accurate investigation of climate change impact. / Thesis / Doctor of Philosophy (PhD)
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Autonomous water-cleaning machine using solar energy in shrimp ponds: Research articleDang, Thien Ngon 14 November 2012 (has links)
Limited water exchange shrimp culture technology is commonly used today in many shrimp farms in Vietnam to reduce water usage, input of diseases and discharge of nutrient-rich effluents into environment as well as to increase the production per unit area. However, a remaining problem in this technology is that the water quality in shrimp ponds will be reduced due to limitation of water exchange for a long period. The accumulation of inorganic components such as waste feed, bacterial deposits or other biological debris at the pond bottom will lead to low dissolved oxygen, high ammonia-nitrogen level, high fecal coliform bacteria and high turbidity which cause a severe degradation of water quality and detriment to shrimp growth and survival. To solve this remaining problem, an autonomous water-cleaning machine for shrimp ponds was designed to control the waste accumulation in the pond. This is an effective solution to replace manual cleaning methods for water quality management in shrimp farming in the coastal area of the Mekong delta of Vietnam. Especially, this technique can be used for biosecure shrimp production systems according to GMP standards to meet the objectives for sustainable development of shrimp aquaculture in Vietnam. / Kỹ thuật nuôi tôm không thay nước đang được sử dụng rộng rãi ở các trại nuôi tôm Việt Nam vì giúp giảm lượng nước sử dụng, hạn chế thải nước vào môi trường và giúp tăng diện tích nuôi trồng tôm. Tuy nhiên, bản thân kỹ thuật này cũng tạo nên một sản phẩm chất thải là phân tôm, thức ăn và chế phẩm sinh học xử lý nước dư thừa. Chất thải này dần dần tích tụ dưới đáy ao tạo thành lớp bùn độc, rất thiếu ôxy và chứa nhiều chất gây hại như ammonia, nitrite, hydrogen sulfide. Để tránh làm giảm diện tích ao nuôi do chất thải tích tụ làm tôm lảng tránh và tăng mật độ tôm nuôi trồng, thiết bị tự hành thu gom chất thải làm sạch nước trong vuông nuôi tôm đã được nghiên cứu, thiết kế và chế tạo thành công. Thiết bị đã thay thế các hoạt động làm sạch chất thải thủ công của con người, không sử dụng các nguồn năng lượng gây ô nhiễm, giảm nhu cầu về điện góp phần phát triển sản xuất tôm sạch đạt chuẩn GMP và phát triển bền vững ở các tỉnh ven biển miền Tây Việt Nam.
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Modeling frameworks to evaluate energy autarky of wastewater treatment systemsSarpong, Gideon 01 May 2020 (has links)
This research demonstrates the use of two novel methodologies to evaluate energy autarky status of wastewater treatment plants (WWTPs) in two steps. Step I (analysis 1 and 2) focuses on overall energy performance evaluation of a conventional activated sludge process (CAS) using a quantitative mass balance model. Step II involves development of a dynamic model that simulates a future wastewater resource recovery facility (WRRF). The step I (analysis 1) focused on small WWTPs with treatment capacities less than 5 MGD. The results revealed that a CAS process can achieve energy autarky or energy-positive status when old technology equipment is replaced with new, high efficiency equipment to save 10-12% energy; aeration energy is reduced by installing nitritation/anammox nitrogen removal process; and energy production is enhanced with the addition of FOG for co-digestion. Analysis 2 of step I focusing on large plant capacities (i.e., > 20 MGD) evaluated the effect of influent wastewater strength (IWWS), primary treatment COD removal efficiency (PT-COD), and proper design of combined heat and power (CHP) systems on the overall energy performance. The results showed that energy autarky is feasible when PT-COD is 60% for low IWWS, 40% or greater for medium IWWS, and 30% or greater for high IWWS. In step II analysis, a new and dynamic model was developed by integrating high rate algal pond (HRAP) and anaerobic digester (AD) systems. The model was calibrated using the experimental data from recent studies. The results showed that this system can achieve energy autarky when advanced solids separation and co-digestion systems are included. Solids separation efficiency was increased from 75 to 90% to reduce the winter effluent COD concentrations from HRAP (by 20%). Similarly, nitrogen effluent concentrations were reduced by increasing the solids retention time. Future studies should focus on techno-economic and environmental life cycle impact analysis of these novel process configurations.
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