Darbo tikslas – sukurti patogią kompiuterizuotą sistemą, kurį leistų klientui, pagal savo parametrus, sudaryti jam tinkančią nuotekų valymo schemą. Uždaviniai: atlikti pasirinktos firmos UAB „Biovalis“ veiklos analizę ir suprasti kaip pateikiama pirminė informacija klientui apie nuotekų valymo sistemas ir jų sudedamąsias dalis; rasti sprendimą kaip galima patobulinti informacijos pateikimo sistemą; atlikti nuotekų valymo schemos sudarymo principų analizę; suprojektuoti ir realizuoti kompiuterizuotą sistemą, kurį leistų vartotojui, įvedus reikiamus parametrus, sudaryti jam tinkančią nuotekų valymo schemą; Mokslinis naujumas: Atlikus šios srities firmų veiklos analizę, pastebėta, kad analogiškos nuotekų valymo schemos sudarymo sistemos rinkoje neegzistuoja. Tai leidžia manyti, kad įdiegus šią sistemą, UAB „BIOVALIS“ pagerins klientų informavimą ir pritrauks daugiau naujų klientų. Klientai galės ne tik gauti informaciją apie nuotekų valymo schemos sudedamąsias dalis, bet ir patys apskaičiuoti jiems tinkančią nuotekų valymo schemą. Tai leis klientui tinkamai pasirinkti būsimą nuotekų valymo sistemos montavimo rangovą. / The project goal: create a user-friendly computerized scheme of wastewater treatment system, which provide our customers with the initial information about a product is suitable for him. Objectives: analysis of UAB “Biovalis” operations and understanding for customer supplied initial information about the wastewater treatment systems and their components; how to find a solution to improve the information system; analysis of the wastewater treatment scheme of the principles of; to design and implement a computerized system which allows the user account suitable wastewater treatment system entering the required parameters; Novelty of the study: The analysis of the performance of similar firms noted that a similar computerized scheme of wastewater treatment systems accounting by the parameters of the client in the market does not exist. This suggests that using such system UAB “Biovalis” can expect that this system will significantly improve customer information and attract more new customers. Customers will be able not only obtain information about the wastewater treatment system components but will be able to calculate suitable for he the wastewater treatment scheme. This will allow clients to choose a future wastewater treatment systems installation contractor. Used softwar: For the system design was used UML and the contemporary UML instrument “Magic Draw” software. For system implementation was used the open-source PHP language. MySQL relational database management... [to full text]

This research uses Bayesian analysis of fluorescence spectroscopy results to determine if wastewater from the Heber Valley Special Service District (HVSSD) lagoons in Midway, UT has seeped into the adjacent Provo River. This flow cannot be directly measured, but it is possible to use fluorescence spectroscopy to determine if there is seepage into the river.Fluorescence spectroscopy results of water samples obtained from HVSSD lagoons and from upstream and downstream in the Provo River were used to conduct this statistical analysis. The fluorescence 'fingerprints' for the upstream and lagoon samples were used to deconvolute the two sources in a downstream sample in a manner similar to the tools and methods discussed in the literature and used for source apportionment of air pollutants. The Bayesian statistical method employed presents a novel way of conducting source apportionment and identifying the existence of pollution.This research demonstrates that coupling fluorescence spectroscopy with Bayesian statistical methods allows researchers to determine the degree to which a water source has been contaminated by a pollution source. This research has applications in determining the affect sanitary wastewater lagoons and other lagoons have on an adjacent river due to groundwater seepage. The method used can be applied in scenarios where direct collection of hydrogeologic data is not possible. This research demonstrates that the Bayesian chemical mass balance model presented is a viable method of performing source apportionment.

No description available.

Centralized wastewater treatment systems need substantial funds besides high-cost operation and maintenance programs, which could be considered unsuitable for low-income developing countries. As a solution, it becomes the trend towards on-site wastewater treatment systems (OWTs) due to its cost-effectiveness and flexibility of implementation and management. However, the keenness to implement these systems appropriately and monitor them continually is crucial to ensure that they do not impact the surrounding environment and human health. Constructed wetland is one of the on-site wastewater treatment systems. These systems are comparatively affordable alternative technology, and adequate systems for small communities, rural, and hilly areas. In the present study, two constructed wetlands as on-site wastewater treatment systems in Sakib - Jerash Governorate, Jordan, were investigated regarding systems performance, social acceptance, and cost-benefit analysis. The first system is a vertical flow constructed wetland (VCW) that has been operating since January 2020. The second system is a recirculation vertical flow constructed wetland (RVCW) that has been in operation since July 2015. The checking of the theoretical design parameter and the actual loading conditions of the septic tanks and wetlands in both systems showed that both implemented septic tanks and the wetlands are adequate and appropriate for the design goals. The wetlands’ treatment performance showed sufficient capability in organic matter removal efficiencies: Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), and Total Suspended Solids (TSS) removal efficiency. For pathogens: Total Coliform (TC) and Escherichia coli (E.coli), even though the removal efficiency was high, the effluents' values exceeded the local directive. Concerning nutrients removal, both systems showed low nitrogen and phosphorus removal efficiencies. Some suggestions and recommendations were proposed for improving nutrients removal and pathogen removal efficiencies. These recommendations were in desludging the septic tanks, replacing the filtering media, introduce plantation or add other carbon sources to the system, and using an additional aerobic filtration unit in the wetlands’ outlets. The study showed that the Jordanian society's nonacceptance of the on-site wastewater treatment systems could be handled through full transparency, educational workshops, and public participation. The latter contributed an increased sense of ownership robustly and increased concern of responsibilities on the operational and maintenance matters. Regarding the cost-benefit analysis, the study results demonstrated that the implementation of a constructed wetland as an on-site wastewater treatment system could be a beneficial and valuable alternative for clusters in rural areas and even in newly urbanized plans. The promising method for the treated wastewater's disinfection using clay minerals needs further investigation to determine the optimum clay mineral concentration on treatment and the needed time for exposure. / För att täcka centraliserade avloppsreningssystems drift och underhåll är det kapitalinsättningen av stor betydelse, förutom högkostnadsprogram, något som anses vara olämpligt för låginkomstländer. In-situ avloppsreningssystem verkar vara en lovande lösning till detta. För att dock säkerställa att dessa ej belastar den omgivande miljö och fungerar som det skall i förbehåll att dessa ständigt övervakas. Konstruerade våtmarker är en typ av in-situ vattenreningsteknik. Dessa system är lämpliga för småstäder, bergiga och tätortsområden. Dessa system är kostnadseffektiva och flexibla vad dess implementering och hantering anbelangar. Två dylika system är i fokus av denna studie, nämligen två konstruerade våtmarker i Sakib - Jerash i Jordanien och i synnerhet utforskas dess prestanda, social acceptans i och dessutom utfördes en nyttokostnadsanalys. Båda våtmarkerna i denna rapport har konstruerats med ett vertikalt markflöde och är i drift sedan januari 2020 och juli 2015 respektive. Dessa två system ger goda reduktioner med avseende på biokemiskt syrebehov och kemiskt syrebehov (BOD, COD), totalt suspenderat material (TSS), och effektivitet rörande patogen borttagning (TC och E. coli). Även om patogen borttagningseffektivitet i sig var hög förblev patogenhalt hög i det lokala direktivs avseende; de lokala förutsättningarna, nämligen designparameter och belastningsförhållanden, tillåter dock uppbyggande och drift av dessa två systemen som i fokus i detta studium. Beträffande borttagning av näringsämnen visade det sig att båda systemen har låg kväve- och fosforborttagningseffektivitet. Vissa förslag och rekommendationer föreslogs för att förbättra näringsämnen samt systemens effektivitet vad gäller patogenborttagning; i synnerhet dessa förslag beträffar pumpa ut slammet ur septiktanken, utbyte och backspolning av vattenfiltermedia, vattenväxterinförande eller tillägg av en extern kolkälla samt användning av en ytterligare aerobfiltreringsenhet vid utlopp. Det visade sig att det jordanska samhälle sätter käppar i hjulet vad gäller implementering av dessa våtmarker emedan dess förfarande är oacceptabelt. Dylika problem kan överbryggas genom full insyn, föredrag och workshops samt allmänhetens deltagande. Det sistnämnda gav upphov till en ökad känsla av äganderätt robust, något som ledde till ökat intresse för ansvar i drifts- och underhållsfrågor. Vad nyttokostnadsanalysen anbelangar visade det sig att implementering av ett dylikt system skulle vara fördelaktigt och värdefullt som alternativ för kluster på tätorts- och landsbygdsområden. Avloppsvattenbehandlingen med lermineraler verkar hittills vara en lovande metod vid betraktande av tidigare studier. Det behöver dock göras ytterligare undersökningar för avloppsvattenbehandlingen med lermineraler vid bestämmande av den optimala lermineral koncentration och dess exponeringstid.

TiO2 nanoparticles are one of the most suitable materials for photocatalysis, specifically for water and air treatment and removal of a wide variety of organic pollutants such as dyes, aromatic compounds, and chlorinated aromatic compounds. Methods of synthesis of TiO2 are generally categorized in two main classes of wet chemical, and dry methods. Wet chemical methods generally provide a better control over size, size distribution, and shape; all of which significantly affect photocatalytic performance of the produced nanoparticles. Despite its advantages over other semiconductor photocatalysts, wide band-gap of titania restrains its photocatalytic activity to only UV light, which only makes up to 5% of the light reaching surface of the earth. To induce visible-light activity, titania has been doped by different dopants, including transition metal-dopants such as Fe, and Co and non-metal dopants such as N, and C. Nitrogen has been shown to be a better dopant, providing a suitably placed energy state within the band-gap of TiO2, and not suffering from issues related to transition-metal dopants such as low thermal and physical stability and high electron-hole recombination rates. To dope titania with nitrogen, one could add the nitrogen source together with other precursors during synthesis, referred to as wet chemical doping methods, or anneal the synthesized titania nanoparticles under a flow of ammonia at high temperatures, referred to as dry doping methods. While different doping methods have been studied individually, the author maintains that there has been an absence of research comparing the effectiveness of these methods, on photocatalytic performance of N-doped TiO2 within a consistent experiment. In this research TiO2 nanoparticles were synthesized by a facile, inexpensive sol-gel method, and doping was done by wet chemical methods, dry methods, and a combination of both these methods. Visible-light photocatalytic activity of these nanoparticles was evaluated by their efficiency in degradation of methyl orange. The results show wet doping methods increase the efficiency of titania nanoparticles more than dry doping, or combination of both. Further investigation showed that the main reason for higher activity of wet chemically doped nanoparticles is due to their higher available surface area of 131.7 m2.g-1. After normalizing the available surface area, measured by the BET method, it was shown that a combination of wet chemical doping, and dry doping at 600 °C result in the most active nanoparticles, but high temperature dry doping severely decreases the surface area, lowering the overall efficiency of the product. Additionally, N-doped TiO2 nanoparticles were synthesized using a simple hydrothermal method, in which the nitrogen source was used not only to dope, but also to control shape, size, size distribution, and morphology of the titania nanoparticles, and to induce aqueous colloidal stability. It was shown that addition of triethylamine during the synthesis, results in ultra-small, colloidally stable, cubic TiO2 nanoparticles, while using triethanolamine results in formation of TiO2 pallets, assembled into spherical, rose-like structures. The synthesized nanoparticles show impressive efficiency in visible-light removal of phenol, 4-chlorophenol, and pentachlorophenol, achieving 100% degradation of a 100-ppm phenol solution in 90 min, more than 98% degradation of a 20-ppm 4-chlorophenol solution in 90 min, and 97% degradation of a 10-ppm pentachlorophenol in 180 min with 500 ppm loading of the catalyst in all cases. Moreover, synthesized nanoparticles showed no sign of deactivation after 5 consecutive runs, removing 4-chlorophenol, showing their reusability. / Graduate

<p>The continuous process of urbanization results in demands on research and development for ecological and sustainable city development. Because of this, the current systems for wastewater treatment may have to be improved. In order to evaluate new technologies for municipal wastewater treatment, a development project has been initiated for the new district Hammarby Sjöstad in Stockholm. The project is lead by the company Stockholm Water. High environmental standards have been put up for the district, as it must be twice as good as an ordinary new district. To achieve this goal, a new water treatment plant is planned to be build.</p><p>In the testing facility Sjöstadsverket, several new water treatment processes for municipal wastewater are being evaluated. This thesis is concerned with the evaluation of one of these processes. The process in question is anaerobic and consists of the following steps: pre-treatment, UASB (Upflow Anaerobic Sludge Blanket), aerobic polishing for nitrogen reduction, a drum filter and reverse osmosis. The evaluation is performed by analysis of water sample taken from the whole process.</p><p>It is difficult to make any conclusions about the process as a whole, since not all of the individual parts have been in use at the same time. The production of gas in the UASB system has been quite low. The cause of this is probably that gas is dissolved in the effluent water. The aerobic polishing is sensitive and it will need adjustments of the pH-value in order to treat the water as planned. The use of chemical precipitation of phosphorus over the drum filter does not reduce the amount of phosphorus below the desired level. Furthermore, the demands on the treated water cannot be reached with the use of reverse osmosis, at least not in its current implementation.</p> / <p>Den allt större inflyttningen till städer och tätorter har gjort att behoven av forskning och utveckling kring ekologiskt hållbar stadsutveckling har ökat. Detta innebär i sin tur att det befintliga systemet för avloppsvattenrening kan behöva förändras. För att utvärdera ny och delvis obeprövad teknik inom behandling av avloppsvatten har ett utvecklingsprojekt startat för Stockholms nya stadsdel Hammarby Sjöstad. Stockholm Vatten har fått i uppgift att leda projektet. För stadsdelen har ett antal ambitiösa miljömål formulerats vilka i korthet innebär att stadsdelen skall vara dubbelt så bra som övrig nybyggnation. För att klara dessa miljömål görs förberedelser för ett eget reningsverk i stadsdelen.</p><p>I Stockholm Vattens pilotanläggning Sjöstadsverket utvärderas en rad olika behandlingslinjer för rening av avloppsvatten från hushåll och syftet med detta examensarbete är att utvärdera en av dessa försökslinjer. Försökslinjen är anaerob och består av försedimentering, UASB (Upflow Anaerobic Sludge Blanket), ett biologiskt poleringssteg för kvävereduktion, trumfilter samt omvänd osmos (RO). Utvärderingen har gjorts genom analyser av vattenprover längs försökslinjen.</p><p>Det är svårt att dra några slutsatser om linjen som helhet eftersom inte alla ingående komponenter varit igång samtidigt så som planerat. Gasproduktionen över UASB-systemet har varit relativt låg och det beror troligen på att en del av gasen löser sig i det utgående vattnet. Den biologiska poleringen för kvävereduktion är en känslig process som kommer att behöva pH-justeras för att klara att behandla vattnet från Sjöstaden. Med nuvarande utformning av anläggningen kan man inte med kemisk fällning av fosfor över trumfiltret komma ner under utsläppsgränserna. Kraven på utgående vatten kan inte heller nås med den RO som finns på Sjöstadsverket idag.</p>

With the aim of mitigating membrane fouling, an electrocoagulation (EC) based electrokinetic membrane bioreactor (EMBR) was developed and operated with real municipal wastewater under low temperatures. Both batch tests and continuous EMBR experiments demonstrated the significant advantages in membrane fouling reduction over the conventional antifouling strategies, ushering its potential applications as an attractive hybrid MBR technology for decentralized wastewater treatment in remote cold regions. The main research observations and findings could be summarized as follows: (1). Effective membrane fouling mitigation at low temperatures was due to destruction of extracellular polymeric substances (EPS) and subsequent reduction of the biocake resistance. The transmembrane pressure (TMP) increased at a much slower rate in EMBR and the filtration resistance was about one third of the control MBR prior to chemical cleaning cycle; (2). A new membrane parameter, the specific fouling rate (SFR) was proposed, relating the fouling rate with permeate flux and temperature-dependent viscosity. Pore clogging and biocake resistances were quantified for the first time with the same membrane module and operating conditions as in regular MBR, rather than resorting to the use of batch filtration setups; (3). The floc size in EMBR did not increase as a result of the air scouring shear force and decrease in the extracellular polymeric substances (EPS); (4). When current intensity was less than 0.2 A, polarity reversal had minimal impact on electrode passivation reduction due to insignificant hydrogen yield, however, if current intensity was above 0.2 A, frequent polarity reversal (< 5 min per cycle) was detrimental to electrode passivation if no sufficient mixing was provided; (5). Viability of the microorganisms in the EMBR system was found to be dependent on duration of the current application and current density. The bacterial viability was not significantly affected when the applied current density was less than 6.2 A/m2; (6). Significant abiotic ammonification was found in electrocoagulation (EC). DO in the treated liquid was depleted within an hour, under the anaerobic condition in EC, nitrate was chemometrically reduced to ammonium following a two-step first order reaction kinetics. Aeration (DO > 2 mg/L) was shown effective in suppressing abiotic ammonification; (7). Magnetic resonance imaging (MRI) technology was used for the first time as an in-situ non-invasive imaging tool to observe membrane fouling status in an EMBR. / October 2016

Orientador: Oswaldo Garcia Junior / Banca: Íria Fernandes Vendrame / Banca: João Sérgio Cordeiro / Banca: Rosana Filomena Vazoller / Banca: Maria Lucia Gonsales da Costa Araujo / Resumo: A geração de lodo como resultado do tratamento do esgoto sanitário, embora possa ser minimizada, é inevitável, qualquer que seja o sistema empregado nas estações de tratamento. Sua disposição final tem sido motivo de diversos estudos, os quais apontam, como alternativa mais favorável, sua utilização em áreas agrícolas ou de produção florestal. A presença de metais no lodo, entretanto, pode inviabilizar seu uso como fertilizante ou como condicionador de solos dado ao risco de contaminação ambiental e de acumulação na cadeia trófica. A solubilização de metais presentes no lodo por meio do processo de lixiviação bacteriana tem mostrado resultados promissores, encorajando seu desenvolvimento. A lixiviação bacteriana de metais pode ocorrer diretamente, pela oxidação de sulfetos metálicos ou, indiretamente, pela oxidação de compostos reduzidos de enxofre a sulfato, com a conseqüente solubilização ácida dos metais. As principais bactérias envolvidas nesse processo pertencem ao gênero Thiobacillus, recentemente reclassificado. Neste trabalho, utilizou-se lodo de esgoto, gerado pela Estação de Tratamento de Esgoto de Franca-SP (ETE-Franca), que opera um sistema de lodos ativados convencional, com tratamento dos lodos primário e secundário por digestão anaeróbia. Amostras de lodo foram caracterizadas quanto à presença dos metais cromo, cobre, chumbo, níquel e zinco. Em um ensaio preliminar, utilizando a linhagem Acidithiobacillus thiooxidans FG01, foi verificado que a utilização de lodo digerido ou lodo não-digerido proporcionou eficiências de solubilização similares para os metais investigados. Desta forma, amostras de lodo digerido anaeróbio foram utilizadas para estudo do efeito dos parâmetros temperatura, pH inicial e concentração de sólidos totais sobre a eficiência e a cinética da lixiviação bacteriana. Nesses ensaios,...(Resumo completo clicar acesso eletrônico abaixo) / Abstract: Although sewage sludge generation from sanitary wastewater treatment can be minimized, its production cannot be avoided at any system employed in the wastewater treatment facilities. Sludge final disposal has motivated several research studies, which have pointed out as the most suitable alternative the application of sludge in agricultural and forestry production. However, the presence of metals in sewage sludge may jeopardize its application as fertilizer or soil amendment due to the risk of environmental contamination or accumulation through the trophic chain. Solubilization of metals from sewage sludge by bacterial leaching has showed promising results, encouraging its process development. Bacterial leaching of metals occurs directly by metal sulphide oxidation or, indirectly by oxidation of reduced sulphur compounds to sulphate, with the consequent sludge acidification and metal solubilization. Bacteria from Thiobacillus genus, recently reclassified, are the most important species involved in bacterial leaching. In this work, sludge samples were obtained at the municipal wastewater treatment facility in the city of Franca, state of São Paulo, Brazil, which operates a conventional activated sludge system with treatment of the primary and secondary sewage sludges by anaerobic digestion. Samples were characterized for concentration of the metals chromium, copper, lead, nickel, and zinc. A preliminary assay was conducted by using Acidithiobacillus thiooxidans FG01, which resulted in similar solubilization efficiencies for digested or not-digested sludges. Effects of temperature, initial pH and total solids concentration were investigated in leaching experiments using anaerobically digested sludge inoculated...(Complete abstract, click electronic access below) / Doutor

Este trabalho avaliou o desempenho de um reator piloto de eletroflotação, que utilizou placas de alumínio em arranjo monopolar em paralelo como eletrodos de sacrifício para o tratamento de esgoto sanitário. O processo foi auxiliado pela adição de cloreto de sódio para melhorar a condutividade do esgoto bruto. Preliminarmente, testaram-se em ensaios de eletroflotação em bancada, densidades de corrente entre 8 e 21 A m-2 e determinou-se que o melhor desempenho na diminuição da turbidez era obtido aplicando uma densidade de corrente próxima a 13,8 A m-2. Posteriormente foram conduzidos ensaios no reator piloto para determinar a vazão e a dosagem de cloreto de sódio. A partir destes foram determinadas as variáveis operacionais, que foram: densidade de corrente de 14,2 A m-2, vazão de 0,33 m3 h-1, dosagem de cloreto de sódio de 0,5 g L-1 e tempo de detenção hidráulica de 18,2 min. O reator piloto de eletroflotação foi testado com duas configurações de posição dos eletrodos: transversal e paralelo ao fluxo. O melhor desempenho do reator de eletroflotação foi obtido com o arranjo em paralelo ao fluxo; este permitiu aumentar a vazão para 0,5 m3 h-1 e diminuir a dosagem de cloreto de sódio para 0,25 g L-1. Amostras de esgoto bruto e esgoto eletroflotado obtidas do reator operando em ambas as configurações da posição dos eletrodos foram coletadas e submetidas a análises físico-químicas. Estas análises permitiram determinar a eficiência da remoção de: cor verdadeira em 82% e 86% para os arranjos das placas em transversal e paralelo ao fluxo respectivamente, da mesma forma a turbidez em 96% e 93%, sólidos totais em 90% e 97%, carbono orgânico total em 60% e 58%, nitrogênio amoniacal em 42% e 51%, demanda bioquímica de oxigênio em 91%, demanda química de oxigênio em 89% concentração de óleos e graxas em 100%, fósforo total em 99%, coliformes termotolerantes e E coli. em duas unidades log e aumento de oxigênio dissolvido em 400% e 366%. Uma análise de espectroscopia de emissão atômica também foi feita para determinar a concentração de espécies metálicas e não metálicas. Esta análise revelou que as espécies encontravam-se em concentrações baixas e em alguns casos abaixo do limite de detecção, mas após tratamento por eletroflotação estas concentrações também sofreram diminuição. O cálculo da massa teórica de alumínio desgastada nos ânodos foi calculada em 4 g m-3, a quantidade de lodo gerado foi de 0,16 m3 e os custos operacionais totais estimados em R$0,64 e R$0,38 kw h m-3 com o reator operando nas configurações de posição dos eletrodos transversal e paralelo respectivamente. Os valores dos parâmetros observados nas análises físico-químicas do esgoto eletroflotado se encontram dentro dos limites estipulados pela Resolução CONAMA No. 357 para o lançamento de efluentes e para águas de classe 3. A comparação das eficiências de remoção alcançadas pela eletroflotação com eficiências típicas de remoção dos principais poluentes nos esgotos domésticos, alcançadas por diversos métodos de tratamento permite afirmar que a eletroflotação é uma técnica eficiente no tratamento de esgoto sanitário e é economicamente viável, por isto deve ser considerada como uma alternativa aos métodos de tratamento convencionais. / This study assessed the performance of a domestic sewage treatment pilot unit of electroflotation, which used aluminum plates in a monopolar parallel arrange as sacrifice electrodes for sewage treatment. The process was aided by the addition of sodium chloride to improve the conductivity of the raw sewage. First, it was tested in lab-scale experiments, current densities between 8 and 21 A m-2. The best performance in the turbidity decrease was obtained by applying a current density close to 13.8 A m-2. Later experiments were conducted in the pilot reactor to determine the flow rate and dosage of sodium chloride. From these, the operational variables were determined, which were: current density of 14.2 A m-2, a flow rate of 0.33 m3 h-1, sodium chloride dosage of 0.5 g L-1 and hydraulic detention time of 18.2 min. The electroflotation pilot reactor was tested with two sets of electrode position: transverse and parallel to the flow. The best performance of the electroflotation reactor was achieved with the parallel arrangement; this allowed increase the flow to 0.5 m3 h-1 and reduce the amount of sodium chloride to 0.25 g L-1. In comparison to raw sewage, the treated effluent presents a decrease of 82% and 86% for the true color for the arrangement of plates in transverse and parallel respectively, just as a decrease in the turbidity by 96% and 93%, total solids by 90% and 97% total organic carbon by 60% and 58%, nitrogen by 42% and 51% biochemical oxygen demand at 91%, chemical oxygen demand at 89%, oils and greases concentration by 100 %, total phosphorus by 99%, fecal coliforms and E. coli. in two log units and increased dissolved oxygen in 400% and 366%. An atomic emission spectroscopy analysis was also done to determine the concentration of metal and non-metallic species. This analysis revealed that the species were in low concentrations and in some cases below the detection limit, but after electroflotation treatment these concentrations also decrease. The calculation of the theoretical mass of the worn aluminum anodes was estimated in 4 g m-3, the amount of sludge generated was 0.16 m3 and the total operating costs estimated at R$ 0.64 and R$ 0.38 kw h m-3 with the reactor operating in transverse and parallel settings of electrode position, respectively. The values of the parameters observed in the physicochemical analysis of electroflotated sewage are within the limits set by CONAMA Resolution No. 357 for the release of effluents and for Class 3 waters. Comparison of removal efficiencies achieved by electroflotation with typical removal efficiencies of major pollutants in domestic sewage, achieved by various treatment methods suggest that the electroflotation is an efficient technique for the treatment of sewage and is economically viable, therefore must be considered as an alternative to conventional treating methods.

A presente pesquisa estudou a viabilidade do emprego de sais de magnésio em estações de tratamento de esgoto sanitário visando a remoção do fósforo, bem como a produção de estruvita, mineral que pode ser utilizado diretamente no solo como fertilizante. As estações estudadas nesta pesquisa foram a Estação de Tratamento de Esgoto Sanitário de Franca-SP e a Estação de Tratamento de Esgoto Sanitário Jardim das Flores, localizada no município de Rio Claro-SP, e a Estação de Tratamento de Esgoto Sanitário Piçarrão, no município de Campinas. No caso da ETE Jardim das Flores (Rio Claro-SP), observou a possibilidade do emprego de sais de magnésio para se remover fósforo no efluente dos reatores UASB. Com ensaios de Jar-Test, atingiu-se cerca 49% de remoção de fosfato na amostra precipitada por gravidade e cerca de 90% na amostra centrifugada. No caso da ETE-Franca-SP, constatou-se, apesar do emprego de sais de magnésio não ter sido viável, verificou-se os benefícios do emprego de cloreto férrico em estações de tratamento de esgoto sanitário. / The present research studied the use of magnesium salts to remove phosphorus. With the phosphorus removal, magnesium salts, produce, as well, struvite, mineral that can be use directly on soil as fertilizer. The wastewater treatment plants objects of studies in this research was Wastewater Treatment Plant of Franca (SABESP) city Wastewater Treatment Plant of Jardim das Flores (Foz do Brasil), at Rio Claro city, and Wastewater Treatment Plant of Piçarrão (SANASA), at Campinas city. All three WWTP\'s are at São Paulo state, Brazil. In WWTP Jardim das Flores/Foz do Brasil (Rio Claro-SP), the results shown the viability of magnesium salts use at effluent of UASB reactors. In Jar-test essays, the phosphorus removal reached among 49% and in centrifuged samples, phosphorus removal was among 90%. In WWTP Franca-SP/SABESP, the results shown the benefits of iron salts in wastewater treatment.