Currently Vietnam is facing several problems with waste handling. For instance, a lot of the municipal organic solid waste is dumped at landfills, which contributes to environmental difficulties such as greenhouse gas emissions. Anaerobic digestion has proven to be an adequate method for solving environmental problems such as waste treatment, where biogas can be produced. The methane content in the biogas can subsequently be used as a prosperous energy source for heating, electricity and vehicle fuel. The production and utilization of biogas in Vietnam is in a developing face. However, there are issues that should be tackled to improve and expand the biogas production and use. In Vietnam the main substrate used for anaerobic digestion is animal manure as most of the biogas digesters are placed on farms. The purpose of this master thesis was to identify additional potential substrates for biogas production, with focus on Thái Nguyên city and Sông Công city in the Thái Nguyên province. In order to find suitable substrates, interviews and literature research were carried out in Vietnam. Subsequently biochemical methane potential (BMP) tests were performed for the identified and acquired substrates. The BMP-tests were first performed at Thái Nguyên University but as the results were inconclusive, further experiments were performed at Linköping University (Sweden) where eight substrates from the Thái Nguyên province were investigated. The identified substrates used for the BMP-tests were three types of beer waste from the Vicoba brewery in Thái Nguyên city, food waste from different restaurants in Sông Công city, fruit waste from the fruit market in Thái Nguyên and household vegetable waste. The highest methane yield could be observed for household vegetable waste (543 Nml/g VS) followed by beer waste (yeast) with a methane potential of 497 Nml/g VS. Beer waste (hops boiling) had the lowest methane potential with a value of 230 Nml/g VS. Estimation of the total methane potential in both cities together from food waste from restaurants, beer waste and sewage sludge from the upcoming waste water treatment plant (WWTP) in Thái Nguyen city were made by combining data from interviews, literature values and the BMP-results. The estimation showed that from Thái Nguyên City and Sông Công city about 137,500 m3 CH4/year can be produced from food waste from restaurants, about 1.7 millionCH4 m3/year can be produced from sludge from the WWTP in Thái Nguyên city (under construction) and there is also a possibility to produce about 10,700 m3 CH4/year from the beer brewery in Thái Nguyên city. Thus, the total estimated methane potential sums up to 1.8 million m3 CH4/year. The results show that Thái Nguyên city and Sông Công city have potential wastes that preferably could be used as substrates for biogas production which could add on to the biogas produced currently at farm level in the Thái Nguyên region. / I dagsläget står Vietnam inför svåra problem med rådande avfallshantering. En stor del av det organiska avfallet deponeras. Detta bidrar till miljöproblem som exempelvis utsläpp av växthusgaser. Kontrollerad rötning har visat sig vara en bra metod för avfallshantering av organiskt avfall, eftersom biogasen som produceras exempelvis kan användas som energikälla för matlagning, elektricitet och fordonsbränsle, samtidigt som avfallsmängden kraftigt reduceras. Utvecklingen av kommersiell biogasproduktion i Vietnam är fortfarande i ett inledande stadie. De främsta substraten för biogassubstratet som används i landet i nuläget är olika typer av gödsel med anledning av att de flesta rötkammare är placerade på bondgårdar. Syftet med denna studie är att undersöka kompletterande potentiella substrat som kan användas för biogasproduktion i städerna Thái Nguyên och Sông Công som är belägna i provinsen Thái Nguyên. För att identifiera möjliga biogassubstrat genomfördes intervjuer på plats tillsammans med litteraturundersökningar. Vidare genomfördes metanpotentialbestämningar (BMP) för identifierade, utvalda och, erhållna substrat. Det visade sig ej vara möjligt inom tidsramen för besöket att genomföra BMP-testerna på ett fullgott sätt vid Thái Nguyêns universitet med anledning av begränsningar i metodförutsättningar, varför BMP-tester även genomfördes på Linköpings universitet. Totalt testades metanpotentialen för åtta olika substrat från städerna Thái Nguyên och Sông Công. De identifierade substraten som användes i BMP-studien var tre typer av bryggeriavfall från Vicoba bryggeri i Thái Nguyên, matavfall från olika restauranger i Sông Công, fruktavfall från fruktmarknaden i Thái Nguyên och hushållsavfall från ett hushåll i Thái Nguyên. Det högsta metanutbytet kunde observeras för matavfall från hushåll (543 Nml/g VS) följt av bryggeriavfall i form av jäst (497 Nml/g VS). Ölavfall från vörtkokning påvisade det lägsta metanutbytet av samtliga testade substrat motsvarande 230 Nml/g VS. En uppskattning av den totala metanpotentialen i de båda städerna från matavfall från restauranger, bryggeriavfall samt avloppsslam från reningsverket som är under uppbyggnad i Thái Nguyên genomfördes baserat på intervjuer, litteraturvärden samt genomförda metanpotentialtester (BMP). Uppskattningen visade att cirka 137 500 m3 CH4/år skulle kunna produceras från matavfall från restauranger, cirka 1,7 miljoner CH4 m3/år från avloppsreningsverksslam samt från ölbryggeriet i Thái Nguyên är det möjligt att producera cirka 10 700 CH4 m3/år. Sammantaget indikerar det en uppskattad metanpotential motsvarande ca 1,8 miljoner CH4 m3/år. Slutsatsen av den här studien visar att det finns stor potential för biogasproduktion i Thái Nguyên och Sông Công. / Developing strategies and methods for participatory planning in Thái Nguyên and Linköping

Nenhuma / A pesquisa consistiu no estudo de recuperação do zinco e metais associados presentes no efluente do processo industrial, como também na reciclagem da água para o processo produtivo da Votorantin Metais Unidade Juiz de Fora, empregando-se o processo de adsorção por troca iônica, visando obter condições operacionais que viabilizasse a implantação do sistema. Os principais constituintes do efluente estudado são: Zn, Ca, Mg, Mn, Cd, Cu e Pb. A investigação realizada, se aplicada ao processo industrial, possibilita a reciclagem de alguns destes metais, tais como: Zn, Cd, Cu e Pb. Os demais metais podem ser removidos do sistema viabilizando a reutilização da água, atualmente descartada. Para a recuperação dos metais foi utilizado o processo de adsorção com trocadores iônicos, tendo sido empregadas resinas de troca iônica, zeólitas e outros adsorventes naturais, que geralmente são empregados em soluções que contenham baixas concentrações de metais, tal como a amostra investigada. A amostra foi coletada na bacia de equalização, local este que recebe todo efluente da planta industrial para tratamento final e posterior descarte no corpo receptor. / The research consisted of the study of recovery of zinc and metals associates present in the effluent of the industrial process of the Votorantin Metais, Juiz de Fora Unit. The main constituent of the shedied effluent are: Zn, Ca, Mg, Mn, Cd, Cu and Pb. The experimental work, if applied to the industrial process, will enable the recovery of some of these metals, such as: Zn, Cd, Cu and Pb. The metals can be removed from the system enabling the recicling of the water curretly discarded. This research was developed considering the conditions that enabled tha set up of the system. For metals recovery it was used the adsorption process with ionic exchangers, such as exchange zeolites and other natural adsorbents. These materials are generally used in solutions that contain low metal concentrations, as the investigated sample. This sample was collected in the Bacia de Equalização where all effluentes generated in the industrial plant are sent and the final treatment befor discarding is made.

Esta pesquisa teve como objetivo avaliar a viabilidade do uso da manipueira como meio de cultura para microalgas e determinar as melhores condições para o cultivo. As cepas avaliadas foram isoladas das lagoas de estabilização de manipueira da empresa Podium Alimentos LTDA. de Paranavaí, sendo identificadas morfologicamente como Chlorella sp., Scenedesmus sp. Monoraphidium sp. e Golenkinia sp. A presença de atividade amilolítica e a determinação da toxicidade do cianeto, composto presente no resíduo, foram avaliadas para cada uma das linhagens de microalgas isoladas. A presença de amilase foi identificada em Monoraphidium sp, Golenkinia sp. e Scenedesmus sp. quando inoculadas em meio solido de ágar-amido a 0,2%. A tolerância ao cianeto foi avaliada simulando o ambiente cianogênio com adição de KCN no meio de cultivo autotrófico. As microalgas Monoraphidium sp. e a Scenedesmus sp. demostraram capacidade para se desenvolver em meio contendo até 200ppm de KCN, enquanto as microalgas Chlorella sp. e a Golenkinia sp. suportaram concentrações máximas de 40 ppm. Para avaliação da sobrevivência das microalgas quando cultivadas no resíduo líquido do processamento da mandioca, foi utilizado como meio de cultura manipueira bruta não esterilizada, manipueira bruta estéril e manipueira pré-tratada (digestão anaeróbia) em diferentes concentrações. Os testes foram realizados em frascos Erlenmeyer de 125 mL, sob iluminação de 2500 Lux, fotoperíodo de 12 horas claro/escuro e temperatura de 25°C. As concentrações do inoculo iniciais foram de 0,2 g.L-1. Nos experimentos conduzidos com a manipueira bruta não esterilizada, todas as microalgas mostraram desenvolvimento em concentrações de 10% v/v do resíduo (manipueira/agua). Destacou-se a microalga Monoraphidium sp. que alcançou uma produtividade máxima de 0,014 dia-1, apenas 5% menor que o alcançado quando cultivada em meio autotrófico. Já nos cultivos em manipueira bruta esterilizada as quatro linhagens de microalgas avaliadas apresentaram uma maior resistência ao meio de até 30% de resíduo. Observou-se a maior produtividade com a microalga Monoraphidium sp. e Golenkinia sp. que foi de 0,078 dia-1 e 0,018 dia-1 respectivamente, na concentração de 10% v/v de manipueira. Nos ensaios conduzidos em manipueira após digestão anaeróbia, foram suportadas concentrações de até 100% do resíduo, para o isolado de Monoraphidium sp., Golenkinia sp., e Scenedesmus sp., e de até 40% v/v para a microalga Chlorella sp. A maior velocidade especifica de crescimento foi com a microalga Monoraphidium sp. na concentração de 40% de manipueira (v/v) sendo de 0,12 dia-1. As microalgas Golenkinia sp. e a Scenedesmus sp. também mostraram eficiência quando cultivadas no efluente digerido, sendo que em concentrações de 20% v/v manipueira/água apresentam crescimento semelhante ao obtido no meio sintético. Os resultados obtidos mostraram que é possível o cultivo de microalgas em manipueira bruta, tratada e mesmo manipueira digerida. Porém tratamentos adequados devem ser identificados para se obter uma maior produtividade microalgal. As microalgas Monoraphidium sp. e Scenedesmus sp. demostraram ser capazes de sobreviver e crescer melhor no cultivo em efluente digerido anaerobicamente, assim, a utilização da manipueira digerida como meio de cultivo mostra-se como uma forma eficiente de produzir grandes quantidades de biomassa microalgal. / The objective of this research was to evaluate the viability of the cassava waste water as a culture medium for microalgae and to determine the best conditions for cultivation. The strains evaluated were isolated from the stabilization lagoons of the company Podium Foods LTDA. of Paranavaí, being morphologically identified as Chlorella sp., Scenedesmus sp. Monoraphidium sp. and Golenkinia sp. The presence of amylolytic activity and determination of cyanide toxicity, a compound present in the residue, were evaluated for each of the isolated microalgae strains. The presence of amylase was identified in Monoraphidium sp, Golenkinia sp. and Scenedesmus sp. when inoculated in 0.2% agar-starch solid medium. The cyanide tolerance was evaluated by simulating the cyanogen environment with addition of KCN in the autotrophic culture medium. The microalgae Monoraphidium sp. and Scenedesmus sp. demonstrated the capacity to develop in medium containing up to 200ppm of KCN, while the microalgae Chlorella sp. and Golenkinia sp. have sustained maximum concentrations of 40 ppm. In order to evaluate the survival of microalgae when cultivated in the liquid cassava processing residue, non-sterile cassava waste water handling, sterile manipulative cassava waste water and pre-treated cassava waste water (anaerobic digestion) were used in different concentrations. The tests were carried out in 125 mL Erlenmeyer flasks, under 2500 Lux illumination, 12-hour light/dark photoperiod and 25 °C temperature. Initial inoculum concentrations were 0.2 g.L-1. In the experiments conducted with the non-sterilized raw cassava waste water, all microalgae showed development at concentrations of 10% v/v of the residue (cassava waste water/water). The microalga Monoraphidium sp. which reached a maximum productivity of 0.014 day-1, only 5% lower than that achieved when cultivated in an autotrophic medium. Already in the crops in sterile cassava waste water, the four microalgae strains tested showed a higher resistance to the medium of up to 30% of the residues. The highest productivity was observed with the microalga Monoraphidium sp. and Golenkinia sp. which was 0.078 day-1 and 0.018 day-1 respectively at the 10% v/v concentration of cassava waste water. In the experiments carried out in cassava waste water after anaerobic digestion, concentrations up to 100% of the residue were supported for the isolate of Monoraphidium sp., Golenkinia sp., and Scenedesmus sp., and up to 40% v/v for the microalga Chlorella sp. The highest specific growth rate was with the microalga Monoraphidium sp. in the concentration of 40% of cassava waste water (v/v) being 0.12 day-1. The microalgae Golenkinia sp. and Scenedesmus sp. also showed efficiency when cultivated in the digested effluent, and at concentrations of 20% v/v cassava waste water/water, presented growth similar to that obtained in the synthetic medium. The results showed that it is possible to cultivate microalgae in cassava waste water raw, treated and even digested cassava waste water. However, suitable treatments must be identified for increased microalgae productivity. The microalgae Monoraphidium sp. and Scenedesmus sp. demonstrated to be able to survive and grow better in anaerobically digested effluent cultivation, thus, the use of the digested cassava waste water as a culture medium is shown as an efficient way of producing large amounts of microalgae biomass.

M-Tech: Chemistry (Vaal University of Technology) / ABSTRACT The research was aimed to study the causes of excessive foaming in a waste water treatment plant. Although the activated sludge process has been adopted to treat this industrial waste water , lots of problems were experienced by the inhibitory effects of toxic compounds that are found in industrial effluents and the foaming stability that was very high. Industrial waste water treatment using sludge processes was found to be more challenging than the normal municipal waste water treatment although the principle is the same; the foaming tendencies were found to be more in industrial waste water. In this study the composition of influents to the waste water treatment plant and operating parameter’s effects on foaming tendencies were examined. The foaming potential in the plant was found to be chemically related due to high contamination of compounds such as phenols, which played a major role in formation of stable foam. It was recommended that there must be pretreatment of the incoming influents to minimize their impact to waste water treatment.

<p>This thesis investigates the adaptation to climate change that is taking place in the WaterSupply and Waste Water (WSW) sector of the Stockholm Region. The adaptation processis analyzed in terms of building adaptive capacity and implementing adaptive decisions.Theories on organizational learning and the concept of an organization’s adaptation spaceare used to understand the factors that influence the adaptation process and the capacityof the studied WSW organizations to adapt to climate change. A case study approach hasbeen used and by focusing the research on four regional WSW organizations – thatcomprise a majority of the region’s WSW activities – it is argued that conclusionsrelevant to the region’s WSW sector as a whole can be made. Semi-structured interviewswith the complete management board – in three out of four organizations – and officialdocuments and reports, are the main sources of primary data for the analysis.The results show that adaptation to climate change is occuring in the WSW sector of theStockholm Region. The adaptation is mainly taking the form of building adaptivecapacity and there is only limited evidence of implementation of adaptive decisions. Theresearch suggests that there are few technical and organizational limitations foradaptation to take place and that the main factors influencing the adaptation space of thesector is how the climate change issue and risks are interpreted and perceptions of howthe WSW organizations should function and use their limited economical resources. Twoconclusions are drawn from these results: first, factors influencing the feasibility andattractiveness of different adaptation options need to be included and analysed in order tounderstand the actual adaptation space of an organization. Second, due to the factorsidentified as influencing the adaptation space, it is unlikely, at present, that robustinfrastructure solutions – which have been suggested in the literature as a viable way todeal with the intrinsic uncertainties related to climate change – can be implemented in theWSW sector of the Stockholm Region solely due to concerns of climate change.</p>

In the pilot plant at Hammarby Sjöstad, Sjöstadsverket, several new methods are tested in order to achieve a good use of resources. When a new technique is considered it is often the performance of the technique itself, under given conditions, that is evaluated. However, in order to evaluate the overall function the whole picture is needed. With a system analysis it becomes possible to make a comparison where all the positive aspects are put up against the negative ones, for the technique itself as well as its requirements. In this way the influence that minor components have on an entire system can be considered. This report presents a system analysis of an anaerobic membrane reactor (MBR) with a VSEP-membrane (Vibratory Shear Enhanced Process). The MBR is tested at the research treatment plant at Hammarby Sjöstad. In the analysis presented two different treatment techniques treating two different types of wastewaters are compared. The considered techniques are conventional (represented by an active sludge process) and the MBRtechnique. The waters treated are a mixed wastewater and wastewater from a separating system where closet water is separated from greywater and mixed with food waste from waste disposers. The system analysis has been carried out with the URWARE (URban WAter REsearch) system analysis tool. A new URWARE-model that describes the anaerobic reactor and the VSEP membrane was created in order to generate the system structures needed for the analysis. The model consists of two submodels, which as the other URWARE-models are mass-flow, steady-state models based on yearly average-values. The model was tested and calibrated from the test-results at the Hammarby Sjöstad pilot plant. In the study the systems are compared considering energy, exergy and recirculation of nutrients. The VSEP-technique has some advantages compared to the conventional system as it ensures that a large part of the nutritional content in the wastewater can be retained. The advantage is more obvious with the separated system, where food waste is mixed with closet water. Also the global warming potential of the new technique is lower. However, conventional treatment is better from an exergy-perspective. This is mostly due to the high energy consumption as a result of the reversed osmosis (RO) required for post treatment. / I försöksanläggningen vid Hammarby Sjöstad, Sjöstadsverket undersöks flera olika metoder för att uppnå största möjliga resursutnyttjande. När en ny teknik utprovas är det i allmänhet funktionen hos den givna metoden under givna förutsättningar som undersöks. För att få ett helhetsperspektiv krävs emellertid att den sätts in i sitt sammanhang. En systemanalys gör det möjligt att få en bild av alla för- och nackdelar, såväl av tekniken i sig som av de förutsättningar den kräver. Även effekter som små delar har på ett helt system kan då belysas och dess betydelse för helheten fastställas. Föreliggande studie möjliggör en systemanalytisk utvärdering av en anaerob membranbioreaktor (MBR) kopplad till ett VSEP-membran (Vibratory Shear Enhanced Process) som är under utprovning vid Sjöstadsverket. Studien jämför två vattenreningstekniker för behandling av två olika typer av avloppsvatten. Dels rör det sig om konventionell teknik (aktiv slam-rening liknande den behandlingsmetod som används idag), dels den nya MBRtekniken. De vatten som behandlas är blandat avloppsvatten respektive sorterat klosettvatten blandat med matavfall från avfallskvarnar. Systemanalysen har utförts med hjälp av systemanalysverktyget URWARE (URban WAter REsearch). För att kunna bygga upp önskade systemstrukturer har en ny modell för att beskriva den anaeroba reaktorn och VSEP-membranet skapats inom ramen för detta examensarbete. Modellen består av två delmodeller, som liksom övriga modeller i URWARE är substansflödesmodeller där beräkningar är baserade på årsmedelvärden. Modellen har utprovats och kalibrerats mot mätresultat från pilotförsöken vid Sjöstadsverket. I studien jämförs systemen med avseende på energi, exergi och återföring av närsalter. Utifrån systemanalysen konstateras att MBR-tekniken ger vissa fördelar gentemot konventionell teknik då en stor del av näringsinnehållet från avloppsvattnet kan fångas upp. Detta gäller speciellt då tekniken används i kombination med ett separerat avloppssystem där matavfall blandas med klosettvatten. Även växthuspotential för den nya tekniken är lägre totalt sett. Ur exergisynpunkt är konventionell teknik emellertid mer fördelaktig. Till stor del beror detta på hög energiförbrukning pga. den efterbehandling med omvänd osmos (RO) som systemet i dess nuvarande utformning kräver.

Numerous organic reagents of diverse structural composition are employed in the froth flotation process for the beneficiation of non-metallic and sulphide ores. Alkyl xanthates are used as collectors for sulphide ores while amines and fatty acids are used for non-metallic ore beneficiation. Although these collector reagents react preferentially with the concerned minerals in the treated ore pulp, excess and unreacted concentration of these organic collectors end up in the mill process effluents. It has been known that even small concentrations of these organic reagents in water streams are toxic to water life, besides their deleterious influence on end stream processes during recycling. Bioremediation has long been recognised as an inexpensive, flexible and environmentally benign technique for waste water treatment. These organic flotation reagents are amenable to biological degradation. The major objective of this work is the degradation of solubilized collector reagents from aqueous solutions using a microbial technique. Bacillus polymyxa, a Gram-positive, neutrophilic, periflagellated heterotroph that occurs indigenously in soils and certain mineral deposits has been used in the bioremediation studies. Organic flotation reagents namely, dodecyl ammonium acetate (DAA), which is used as a collector for oxides and silicates, sodium isopropylxanthate which finds application in sulphide flotation and sodium oleate, mainly used for oxide and salt-type minerals, have been chosen for the degradation studies. Pure minerals of galena, pyrite, magnetite, quartz and calcite have been typically selected for these investigations. The growth of Bacillus polymyxa in the presence of these organic reagents at different concentrations has been assessed and the degradation of these reagents monitored. Attempts have been made to grow the bacterium in the presence of the organic reagents, both in the absence and presence of sucrose, by adaptation technique. Electrokinetic studies on the chosen minerals namely, galena, pyrite, quartz, calcite and magnetite have been carried out both in the presence of the organic reagents and Bacillus polymyxa cells or metabolite. Biological stripping of the adsorbed collector reagents from the mineral surfaces have been examined through FTIR spectroscopy. The progress of bioremoval of the organic reagents along with the generation of newer reaction products has also been monitored through uv-visible spectroscopic technique. The results of this study highlight that Bacillus polymyxa and its metabolic products bring about the degradation of the chosen organic flotation collectors. Further, the bacteria are able to utilise the collector reagents as carbon source for their growth, in the absence of added organic carbon (sucrose). Electrokinetic studies and examination by FTIR spectroscopy reveal that consequent to interaction with Bacillus polymyxa, significant surface modification on the mineral takes place. Probable mechanisms in the biodegradation processes are illustrated. Biological metabolic products responsible for bringing about the bio-deterioration have been analysed and characterised.

Pertinent abiotic and biotic factors and their interdependencies necessary to comprehend the ecology of saline systems are investigated and evaluated. A designed saline ecosystem is proposed as a constructive method to reduce waste volume. Landscape pattern is investigated as the vehicle for an evapotranspiration induced directional saline gradient. A demonstration site is used to explore conceptual design application of the idea of ecosystem pattern consisting of a linear sequence of ecotopes, each displaying its own ecological community in relation to salinity range and site context. Biota is relinquished to self-organization. Potential for research use of the ecosystem is illustrated.

Visų hidroelektrinių veikimo principas pagrįstas dviem pagrindiniais parametrais, - slėgio aukščiu ir debitais. Lietuvoje iki 2009 metų buvo pastatyta 82 MHE. Šis etapas jau baigiasi, kadangi potencialių vietų mažajai hidroenergetikai plėtoti Lietuvoje beveik neliko ir buvo paskelbtos upės, kuriose draudžiama statyti užtvankas. Šiame tyrime buvo ieškoma alternatyvaus, netradicinio sprendimo – vandentiekos ir vandenvalos tinklų panaudojimui. Tyrimų tikslas – išnagrinėti Kauno nuotėkų tinklų galimybes elektros energijos gamybai. Buvo apžvelgtos galimybės Pabaltijo šalyse panašaus tipo projektams įgyvendinti. Taip pat buvo apžvelgtos Kauno nuotėkos ir ištirta galimybė panaudoti esamą infrastruktūrą elektros energijos gamybai Kauno nuotėkų pirmose ir antrose valymo grotose. Šiame darbe pateikiama metodika, leidžianti apskaičiuoti projektinius hidrografus programa SMADA kurią naudoja JAV universiteto studentai projektuojantys užtvankas, krantines ir kitką. Vadovaujantis sudarytais hidrografais, pasirenkama turbina ir apskaičiuojamas jos galingumas bei komponavimo tipas programa RETScrean. RETScrean sukurta Kanadoje. Ji skirta įvertinti atnaujinamų energijos technologijų projektus. Skaičiuojant šia programa, buvo pasirinkti vidutinio 50 % tikimybės vandeningumo metai. Žinant tai buvo apskaičiuoti instaliuotas galingumas, metinis išdirbis ir turbinos tipas. Vertinant turbinų komponavimo tipus, buvo atliekama daugiakriterinė analizė programine įranga DAM ir pasirinktas optimaliausias... [toliau žr. visą tekstą] / The way of working of all hydroelectric power stations is based on two main parameters: the pressure height and the rate. 82 SHP were built in Kaunas till 2009. This period is coming to the end since there are not many places left for the Small Hydropower development in Lithuania. In addition to this, the list of rivers was announced in which it is forbidden to build dams. Therefore, the untraditional way of producing the electric power in the waste water network was explored. The aim of this research is to analyze the possibilities of Kaunas Waste Water Network for the Electric Power Generation. The opportunities to realize similar types of projects in the Baltic States as well as to adapt them to the existing infrastructure in primary and secondary wastewater grating of Kaunas were discussed in this research. Methodology that is presented in this paper enables to calculate hydrographs by the use of SMADA which influences the choice of the turbine and calculations of its power as well as the type of composition by the use of RETScrean. SMADA is widely used by the students of universities in the USA. The program RETScrean, that is used to evaluate the renewed projects of energetic technologies, was created in Canada. The year with the probability 50 % of wateriness was chosen. This information was used to calculate the installed powerfulness, production per year as well as the type of the turbine with a programme RETScrean. Multicriteria analysis was performed by the use of... [to full text]

Magistriniame darbe nagrinėjama rekonstruotos Jurbarko nuotekų valyklos efektyvumas. Tyrimo tikslas – nustatyti nuotekų valyklos darbo efektyvumą po aeracinės sistemos rekonstrukcijos. Tyrimo objektas – Jurbarko nuotekų valyklos iškeliama aeracinė sistema, kuri buvo sumontuota 2008 m. Šiems tikslams pasiekti buvo išsikelti šie uždaviniai: teoriškai apibūdinti biologinio valymo įrenginius, įtakojančius biologinio valymo proceso efektyvumą ir įvertinti veikliojo dumblo sistemos pokyčius; nustatyti nuotekų išvalymo efektyvumą Jurbarko nuotekų valykloje; atlikti palyginamąją analizę vamzdinės ir diskinės aeracinės sistemos; nustatyti Jurbarko nuotekų valyklos elektros energijos sąnaudas. Nuotekų valyklos efektyvumas tirtas, pagal BDS7, bendrojo azoto (Nb), bendrojo fosforo (Pb) pasišalinimą iš vandens prieš aeracinės sistemos pakeitimą ir po aeracinės sistemos pakeitimo. Atlikus tyrimus nustatyta, kad nuotekų valykla po rekonstrukcijos dirba patikimai. Nuotekų liekamoji tarša neviršija DLK. BDS7 valytame vandenyje sumažėjo 16 %, bendrojo azoto (Nb) – 27 %, o bendrojo fosforo (Pb) – 56 %, lyginant su BDS7, Nb ir Pb prieš aeracinės sistemos pakeitimą. Cheminio reagento proceso veiksmui sunaudojama 488,8 kg/m, mažiau, o tuo pačiu sudaro 22295,2 Lt/m. mažiau išlaidų. Elektros energijos sąnaudos sumažėjo apie 14%. / The paper examined the reconstructed Jurbarkas domestic wastewater treatment plants performance. Purpose of the survey - the wastewater treatment plant efficiency of aeration system reconstruction. The object of research - Jurbarkas domestic wastewater treatment plants enters an aeration system that was installed in 2008. To achieve these goals has been to move the following tasks: a theoretical description of the biological treatment plant, which affect the biological treatment process and evaluate the effectiveness of the active sludge system changes, the efficiency of wastewater remediation Jurbarkas wastewater treatment facilities, to carry out a comparative analysis of linear and circular aeration system, the sewage treatment plant Jurbarkas electricity costs. Sewage treatment plant efficiency has been studied by BOC7 nitrogen (Nb), phosphorus (Pb) elimination of the water before aeration system replacement and the replacement of aeration systems. The investigation showed that sewage treatment facilities after renovation work reliably. Effluent residual contamination does not exceed the MRL. BOC7 treated water decreased by 16%, total nitrogen (Nb) - 27%, and total phosphorus (Pb) - 56%, compared with BOC7, Nb and Pb before aeration system replacement. Chemical reagent process steps used 488.8 kg/m and less, while at the same time is 22295.2 Lt/m. less cost. Electricity costs have fallen about 14 percent.