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Tratamento de águas residuárias utilizando emissários submarinos: avaliação do nível de tratamento para uma disposição oceânica ambientalmente segura.; Wastewater treatment using submarine outfalls: evaluation on the treatmente level for environmentally safe ocean disposal.

Subtil, Eduardo Lucas
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/05/2012 PT
Relevância na Pesquisa
46.22%
Tendo em vista as questões ambientais relacionadas com a disposição oceânica de esgotos sanitários, muito tem sido debatido sobre qual nível de tratamento deve ser adotado ou quais constituintes presentes nos esgotos devem ser removidos antes do lançamento em regiões costeiras. Dentro deste contexto, este estudo teve como objetivo principal fornecer subsídios para uma tomada de decisão quanto à necessidade de remoção de nutrientes para lançamento de esgotos sanitários por meio de emissários submarinos, de maneira a garantir um nível de tratamento mínimo sem que haja um comprometimento do corpo receptor em termos de potencial de eutrofização. Para isso, foram utilizados dois sistemas de disposição oceânica de esgotos sanitários: Santos/São Vicente e Praia Grande 2. O impacto ambiental do lançamento de esgotos pelos emissários submarinos foi avaliado por um modelo numérico de eutrofização, sendo as características da pluma de esgoto no campo próximo determinada pelo software CORMIX e acoplado no modelo de campo distante. A necessidade de remoção de nitrogênio e fósforo foi estimada com base na metodologia do Plano Oceânico da Califórnia. Os resultados demonstraram que tanto para o caso do emissário submarino de Santos quanto para o de Praia Grande haveria necessidade de remover amônia e fosfato para atender a legislação CONAMA 357/2005 quando operados com vazões de 3...

Sistema cíclico de lodo ativado empregado para remoção biológica de nutrientes de esgoto sanitário.; Cyclic activated sludge system used for biological nutrient removal from sewage.

Martins Neto, Henrique
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/09/2014 PT
Relevância na Pesquisa
66.44%
Tendo em vista a crescente problemática quanto à eutrofização de corpos dágua em países em desenvolvimento, devido ao lançamento de esgoto mesmo que tratado em nível secundário, o processo de lodo ativado vem sendo estudo e aprimorado para efetuar a remoção conjunta de matéria orgânica, nitrogênio e o fósforo, nutrientes limitantes para ocorrência da eutrofização. Neste contexto, o presente trabalho pretende contribuir com informações quanto à remoção biológica de nutrientes de esgoto sanitário através de estudo em escala piloto em um sistema cíclico de lodo ativado. Este sistema, operado em regime de bateladas sequenciais, difere da configuração habitual, pois possui três compartimentos internos, zonas 1, 2 e 3 que apresentam condições anaeróbias/anóxicas, anóxicas e aeróbias respectivamente, além do retorno de lodo da zona 3 para zona 1 durante o período de reação, sob vazão de 20% da vazão afluente a unidade. Cada batelada possui duração de 4 horas, distribuídas em 4 etapas de 1h cada, sendo elas o enchimento com aeração, reação, sedimentação e descarga. Com essas características o sistema cíclico de lodo ativado do presente estudo, demonstrou no tratamento de esgoto sanitário...

High nutrient removal rate from swine wastes and protein biomass production by full-scale duckweed ponds

Belli Filho, Paulo; Costa, Rejane H. R.; Mohedano, Rodrigo A.; Tavares, Flávia A.
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.35%
Artigo publicado em: Elsevier - Bioresource Technology; Duckweed ponds have been successfully used in swine waste polishing, generating a biomass with high protein content. Therefore, the present study evaluated the efficiency of two full-scale duckweed ponds considering nutrient recovery from a piggery farm effluent (produced by 300 animals), as well as the biomass yield and crude protein (CP) content. A significant improvement in the effluent quality was observed, with the removal of 98.0% of the TKN (Total Kjeldahl Nitrogen) and 98.8% of the TP (Total Phosphorous), on average. The observed nitrogen removal rate is one of the highest reported (4.4 g/m2day of TKN). Additionally, the dissolved oxygen level rose from 0.0 to 3.0 mg/L, on average. The two ponds together produced over 13 tons of biomass (68 t/hayear of dry biomass), with 35% crude protein content. Because of the excellent nutrient removal and protein biomass production, the duckweed ponds revealed a great potential for the polishing and valorisation of swine waste, under the presented conditions.

Nutrient recovery from swine waste and protein biomass production using duckweed ponds (Landoltia punctata): Southern Brazil

Belli Filho, Paulo; Costa, Rejane H. R.; Mohedano, Rodrigo A.; Velho, Viviane F.; Horfmann, S. M.
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.3%
Artigo publicado em: IWA - Water Sciencie et Technology; Brazil is one of the most important countries in pork production worldwide, ranking third. This activity has an important role in the national economic scenario. However, the fast growth of this activity has caused major environmental impacts, especially in developing countries. The large amount of nitrogen and phosphorus compounds found in pig manure has caused ecological imbalances, with eutrophication of major river basins in the producing regions. Moreover, much of the pig production in developing countries occurs on small farms, and therefore causes diffuse pollution. Therefore, duckweed pond have been successfully used in the swine waste polishing, generating further a biomass with high protein content. The present study evaluated the efficiency of two full scale duckweed ponds for the polishing of a small pig farm effluent, biomass yield and crude protein (CP) content. Duckweed pond series received the effluent from a biodigester-storage pond, with a flow rate of 1 m3/day (chemical oxygen demand rate ¼ 186 kg/ha day) produced by 300 animals. After 1 year a great improvement of effluent quality was observed, with removal of 96% of total Kjeldahl nitrogen (TKN) and 89% of total phosphorus (TP)...

Impact of aeration conditions on the removal of low concentrations of nitrogen in a tertiary partially aerated biological filter

Albuquerque, A.; Makinia, J.; Pagilla, K.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
Relevância na Pesquisa
46.31%
A submerged biological aerated filter (BAF) partially aerated was used to study the removal of low concentrations of ammonia nitrogen (0.3 g N/m3 to 30.5 g N/m3) typically found in nutrient enriched river and lake waters, and treated effluents. Four series of experiments were performed with a synthetic wastewater at ammonia loading rates between 6 g N/m3 d and 903 g N/m3 d and C/N ratios from 2 to 20. The results showed that ammonia removal rates reached higher values (172 g N/m3 d to 564 g N/m3 d) for C/N = 2 and lower values (13.6 g N/m3 d to 34.6 g N/m3 d) for C/N = 20. Between 50% and 70% of the ammonia was removed in the upper section of the BAF, where the dissolved oxygen (DO) concentration was over 2.1 g O2/m3 and the biofilm depth ranged from 0.4 to 0.6 mm. At the bottom section of the reactor, simultaneous removal of ammonia and nitrate was observed at the DO concentrations in the range 0.4 g O2/m3 to 0.8 g O2/m3. There was no removal of ammonia nitrogen for loads below 15 g N/m3.d. The results indicate that the removal of nitrogen in partially aerated BAF may not only be explained by the conventional mechanisms of nitrification/denitrification.

SPATIAL AND TEMPORALVARIATION OF DISSOLVED INORGANIC NUTRIENTS, AND CHLOROPHYLL-α IN A TROPICAL ESTUARY IN NORTHEASTERN BRAZIL: DYNAMICS OF NUTRIENT REMOVAL

Silva,Maria Aparecida Macedo; Souza,Marcelo F. L.; Abreu,Paulo C.
Fonte: Universidade de São Paulo, Instituto Oceanográfico Publicador: Universidade de São Paulo, Instituto Oceanográfico
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2015 EN
Relevância na Pesquisa
46.27%
Monthly sampling campaigns were carried out between February 2010 and January 2011 to evaluate the spatial and temporal distribution of nutrients (ammonium, nitrite, nitrate, dissolved organic nitrogen, phosphate, dissolved organic phosphorus and silicate) and chlorophyll-α along a salinity gradient in the tropical Cachoeira River estuary, subject to the untreated effluents of a sewage treatment plant (STP). During the study period the lowest and highest river discharge occurred in February and April 2010, respectively. High river outflow promoted increased concentrations of inorganic nitrogen and silicate but did not affect the concentration of phosphate. Based on the chlorophyll-α concentration the estuary may be classified as eutrophic / hypereutrophic in its inner portion and mesotrophic in the lower region. The inner portion is more affected by the nutrient load carried out by the river and STP, while dilution by seawater contributed to the reduction of the nutrient concentrations in the lower reaches of the estuary. The results indicate that nutrient uptake by the phytoplankton is the most effective dissolved inorganic nutrient removal processes, especially for phosphate. Mixing diagrams suggest that the coupling of nitrification and denitrification processes is also responsible for the elimination of nitrogen from this ecosystem.

Biological nutrient removal with limited organic matter using a novel anaerobic–anoxic/oxic multi-phased activated sludge process

Naseer, Rusul; Abualhail, Saad; Xiwu, Lu
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.3%
An anaerobic–anoxic/oxic (A2/O) multi-phased biological process called “phased isolation tank step feed technology (PITSF)” was developed to force the oscillation of organic and nutrient concentrations in process reactors. PITSF can be operated safely with a limited carbon source in terms of low carbon requirements and aeration costs whereas NAR was achieved over 95% in the last aerobic zone through a combination of short HRT and low DO levels. PCR assay was used for XAB quantification to correlate XAB numbers with nutrient removal. PCR assays showed, high NAR was achieved at XAB population 5.2 × 108 cells/g MLVSS in response to complete and partial nitrification process. It was exhibited that low DO with short HRT promoted XAB growth. Simultaneous nitrification and denitrification (SND) via nitrate were observed obviously, SND rate was between 69–72%, at a low DO level of 0.5 mg/l in the first aerobic tank during main phases and the removal efficiency of TN, NH4+-N, COD, TP was 84.7 .97, 88.3 and 96% respectively. The removal efficiencies of TN, NH4+-N, and TP at low C/N ratio and DO level were 84.2, 98.5 and 96.9% respectively which were approximately equal to the complete nitrification–denitrification with the addition of external carbon sources at a normal DO level of (1.5–2.5 mg/l).

Influence of wastewater composition on nutrient removal behaviors in the new anaerobic–anoxic/nitrifying/induced crystallization process

Shi, Jing; Lu, Xiwu; Yu, Ran; Gu, Qian; Zhou, Yi
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.35%
In this study, the new anaerobic–anoxic/nitrifying/induced crystallization (A2N–IC) system was compared with anaerobic-anoxic/nitrifying (A2N) process to investigate nutrient removal performance under different influent COD and ammonia concentrations. Ammonia and COD removal rates were very stable in both processes, which were maintained at 84.9% and 86.6% when the influent ammonia varied from 30 mg L−1 to 45 mg L−1 and COD ranged from 250 mg L−1 to 300 mg L−1. The effluent phosphorus always maintained below 0.2 mg L−1 in A2N–IC, whereas in A2N the effluent phosphorus concentration was 0.4–1.7 mg L−1, demonstrating that A2N–IC is suitable to apply in a broader influent COD and ammonia concentration range. Under higher influent COD (300 mg L−1) or lower ammonia conditions (30 mg L−1), the main function of chemical induced crystallization was to coordinate better nutrient ratio for anoxic phosphorus uptake, whereas under high phosphorus concentration, it was to reduce phosphorus loading for biological system. Under the similar influent wastewater compositions, phosphorus release amounts were always lower in A2N–IC. To clarify the decrease procedure of phosphorus release in the A2N–IC, the equilibrium between chemical phosphorus removal and biological phosphorus removal in A2N–IC was analyzed by mass balance equations. During the long-term experiment...

Effects of Sludge Retention Times on Nutrient Removal and Nitrous Oxide Emission in Biological Nutrient Removal Processes

Li, Bo; Wu, Guangxue
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.46%
Sludge retention time (SRT) is an important factor affecting not only the performance of the nutrient removal and sludge characteristics, but also the production of secondary pollutants such as nitrous oxide (N2O) in biological nutrient removal (BNR) processes. Four laboratory-scale sequencing batch reactors (SBRs), namely, SBR5, SBR10, SBR20 and SBR40 with the SRT of 5 d, 10 d, 20 d and 40 d, respectively, were operated to examine effects of SRT on nutrient removal, activated sludge characteristics and N2O emissions. The removal of chemical oxygen demand or total phosphorus was similar under SRTs of 5–40 d, SRT mainly affected the nitrogen removal and the optimal SRT for BNR was 20 d. The molecular weight distribution of the effluent organic matters was in the range of 500–3,000 Da under SRTs of 5–40 d. The lowest concentration of the effluent soluble microbial products concentration was obtained at the SRT of 5 d. Nitrifier growth was limited at a short SRT and nitrite existed in the effluent of SBR5. With increasing SRTs, mixed liquor suspended solids concentration increased while the excess sludge production was reduced due to the high endogenous decay rate at high SRTs. Endogenous decay coefficients were 0.020 d−1, 0.036 d−1...

Effect of nickel on nutrient removal by selected indigenous protozoan species in wastewater systems

Kamika, Ilunga; Momba, Maggy N.B.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.56%
Nutrient and heavy metal pollutions are major concern worldwide. This study aimed at comparing the effect of Ni2+ on nutrient removal efficiency of four indigenous wastewater protozoan species (Aspidisca sp., Paramecium sp., Peranema sp., Trachelophyllum sp.). Specific physicochemical parameters and microbial growth/die-off were measured using standard methods. The results revealed that protozoan species were able to simultaneously remove phosphate, nitrate and Ni2+ at concentrations ranging between 66.4–99.36%, 56.19–99.88% and 45.98–85.69%, respectively. Peranema sp. appeared to be the isolates with the highest removal of nutrients (Phosphate-99.36% and Nitrate-99.88%) while Paramecium sp. showed higher removal of Ni2+ at 85.69% and low removal of nutrients. Aspidisca sp. was the most sensitive isolate to Ni2+ but with significant nutrient removal (Phosphate-66.4% and Nitrate-56.19%) at 10 mg-N2+/L followed by an inhibition of nutrient removal at Ni2+ concentration greater than 10 mg/L. Significant correlation between the growth rate and nutrient removal (r = 0.806/0.799, p < 0.05 for phosphate and nitrate, respectively) was noted. Except for Peranema sp. which revealed better nutrient removal ability at 10 mg-Ni2+/L...

Characterization of the In Situ Ecophysiology of Novel Phylotypes in Nutrient Removal Activated Sludge Treatment Plants

McIlroy, Simon Jon; Awata, Takanori; Nierychlo, Marta; Albertsen, Mads; Kindaichi, Tomonori; Nielsen, Per Halkjær
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 04/09/2015 EN
Relevância na Pesquisa
46.31%
An in depth understanding of the ecology of activated sludge nutrient removal wastewater treatment systems requires detailed knowledge of the community composition and metabolic activities of individual members. Recent 16S rRNA gene amplicon surveys of activated sludge wastewater treatment plants with nutrient removal indicate the presence of a core set of bacterial genera. These organisms are likely responsible for the bulk of nutrient transformations underpinning the functions of these plants. While the basic activities of some of these genera in situ are known, there is little to no information for the majority. This study applied microautoradiography coupled with fluorescence in situ hybridization (MAR-FISH) for the in situ characterization of selected genus-level-phylotypes for which limited physiological information is available. These included Sulfuritalea and A21b, both within the class Betaproteobacteria, as well as Kaga01, within sub-group 10 of the phylum Acidobacteria. While the Sulfuritalea spp. were observed to be metabolically versatile, the A21b and Kaga01 phylotypes appeared to be highly specialized.

Plant harvesting from a constructed wetland : nutrient removal and plant attributes / Michelle Leanne Bald.

Bald, Michelle Leanne
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado Formato: 358844 bytes; application/pdf
Publicado em //2001 EN
Relevância na Pesquisa
46.31%
"...it was concluded that wetland design and management were crucial to nutrient storage and removal by aquatic plants. Appreciation of plant reponses to environmetal factors such as nutrient addition regime and water depth, was integral to an understanding of the processess which optimise nutrient removal from wetlands via aquatic plants."; Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Biology, 2001; Accompanying CD-ROM: excel spreadsheet titled "harvesting model".; Bibliography: leaves 187-205.; System requirements for accompanying CD-ROM: IBM compatible computer with Pentium processor or higher and Windows 95, 98 or NT ; 4 MB or RAM. Other software: Microsoft Excel 97 or higher.; x, 205 leaves : ill. (some col.) ; 30 cm. + 1 CD-ROM (4 3/4 in.); Title page, contents and abstract only. The complete thesis in print form is available from the University Library.

Nutrient removal and recovery by the precipitation of magnesium ammonium phosphate.

Jia, Guangan
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014
Relevância na Pesquisa
56.35%
Phosphate and ammonium are the main nutrient sources in wastewater, contributing to eutrophication of water bodies. Removal of these nutrients from wastewater using conventional technologies is a challenge in water industry. Many processes have been developed to remove these two nutrients. On the other hand, phosphorus from nature is not infinite, which will be running out in about 50 – 100 years. Therefore recycling phosphorus is becoming an issue, as well as a challenge, for researchers all over the world. This research is to investigate a chemical process technology to recover the nutrients by the precipitation of magnesium ammonium phosphate (MAP), which is valuable product and nutrient fertiliser. This is a new process based on the chemical equilibrium, which is greatly affected by pH of the solution, concentrations of Mg²⁺, NH₄⁺, PO₄³⁻, and other ions and organic matters included in the wastewater. In order to implement this process, the optimal pH, and the best molar ratio of Mg²⁺, NH₄⁺ and PO₄³⁻ must be adequately studied. In this thesis, the optimal pH and optimization of the molar ratio of Mg²⁺:NH₄⁺:PO₄³⁻, were studied based on synthetic wastewater. It was found that the best pH range was 9-9.5...

Impact of aeration conditions on the removal of low concentrations of nitrogen in a tertiary partially aerated biological filter

Albuquerque, A.; Makinia, J.; Pagilla, K.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
Relevância na Pesquisa
46.31%
A submerged biological aerated filter (BAF) partially aerated was used to study the removal of low concentrations of ammonia nitrogen (0.3 g N/m3 to 30.5 g N/m3) typically found in nutrient enriched river and lake waters, and treated effluents. Four series of experiments were performed with a synthetic wastewater at ammonia loading rates between 6 g N/m3 d and 903 g N/m3 d and C/N ratios from 2 to 20. The results showed that ammonia removal rates reached higher values (172 g N/m3 d to 564 g N/m3 d) for C/N = 2 and lower values (13.6 g N/m3 d to 34.6 g N/m3 d) for C/N = 20. Between 50% and 70% of the ammonia was removed in the upper section of the BAF, where the dissolved oxygen (DO) concentration was over 2.1 g O2/m3 and the biofilm depth ranged from 0.4 to 0.6 mm. At the bottom section of the reactor, simultaneous removal of ammonia and nitrate was observed at the DO concentrations in the range 0.4 g O2/m3 to 0.8 g O2/m3. There was no removal of ammonia nitrogen for loads below 15 g N/m3.d. The results indicate that the removal of nitrogen in partially aerated BAF may not only be explained by the conventional mechanisms of nitrification/denitrification.

Improving ebpr stability in wwtps aiming at simultaneous carbon and nutrient removal: from modelling studies to experimental validation

Guerrero Camacho, Francisco Javier
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2014 ENG
Relevância na Pesquisa
56.32%
L'eliminació biològica de nutrients (EBN) a les estacions depuradores d'aigües residuals (EDARs) es considera el procés més rentable y mediambientalment més respectuós per a prevenir l'eutrofització i complir amb els cada cop més restrictius límits d'abocament. L'eliminació biològica de nitrogen (N) ha estat àmpliament estudiada i implementada en nombroses EDARs, tant urbanes com industrials. Contràriament, per a l'eliminació biològica de fòsfor, P, (procés EBPR) no existeixen encara molt exemples de la seva aplicació a escala real, principalment degut a l'aparició de fallades no esperades quan s'integrà amb l'eliminació biològica de N. La presència de nitrat a la fase anaeròbia es considera la principal causa d'aquestes fallades i, tot i la seva importància, els motius que les provoquen no es coneixen en profunditat. La hipòtesi més estesa assenyala que la presència de nitrat en condicions anaeròbies provoca la competència per la font de carboni (DQO) entre els organismes desnitrificants i els acumuladors de P (PAO). No obstant això, l'experiència en plantes reals indica que aquesta hipòtesi no és capaç de descriure l'elevada pèrdua real d'activitat EBPR tenint en compte la quantitat de nitrat present a la fase anaeròbia. Aquesta tesi té com a objectiu entendre els motius subjacents a aquesta perduda d'activitat EBPR i proposar alternatives per a minimitzar les seves causes. Per tal de fer front a aquest objectiu...

SPATIAL AND TEMPORALVARIATION OF DISSOLVED INORGANIC NUTRIENTS, AND CHLOROPHYLL-α IN A TROPICAL ESTUARY IN NORTHEASTERN BRAZIL: DYNAMICS OF NUTRIENT REMOVAL

Silva, Maria Aparecida Macedo; Souza, Marcelo F. L.; Abreu, Paulo C.
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 01/03/2015 ENG
Relevância na Pesquisa
46.27%
Campanhas de amostragens mensais foram realizadas entre fevereiro de 2010 e janeiro de 2011 para avaliar a distribuição espacial e temporal de nutrientes (amônia, nitrito, nitrato, nitrogênio orgânico dissolvido, fosfato, fósforo orgânico dissolvido e silicato) e clorofila-α, ao longo do gradiente de salinidade no estuário tropical do Rio Cachoeira. Este estuário é sujeito aos efluentes de esgotos não tratados de uma estação de tratamento de esgoto (ETE). No período estudado a maior e menor vazão do rio ocorreram em fevereiro e abril de 2010, respectivamente. A alta vazão do rio promoveu aumento das concentrações de nitrogênio inorgânico e silicato, mas não afetou as concentrações de fosfato. Baseado nas concentrações de clorofila-α, o estuário pode ser classificado como eutrófico/hipereutrófico na porção interna e mesotrófico na região externa. A porção interna é mais afetada pela carga de nutrientes do rio e da ETE, enquanto a diluição pela água marinha contribuiu para diminuir as concentrações de nutrientes na porção externa. Os resultados indicam que a absorção de nutrientes pelo fitoplâncton é o processo mais eficiente na remoção desses nutrientes, especialmente do fosfato. No entanto...

Pollution Removal Efficiency in a Restored Anabranching Wetland

Shashy, Peter Scott Jr.
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 26/04/2013 EN_US
Relevância na Pesquisa
56.39%
Improving water quality is a serious concern of many state and local governments across the U.S. Nutrients, including nitrogen and phosphorus, can significantly impair water quality when found in high concentrations. Constructed and restored wetlands are known to capture pollutants and improve water quality. Anabranching is a new design for restored wetlands in which a primary stream is diverted into smaller braided streams and wetland cells. Its effectiveness at capturing pollutants has not yet been evaluated. This study investigates the effectiveness of an anabranched wetland at removing total nitrogen and total phosphorus from urban run-off during several winter storm events. The analysis compares the mass balances of total nitrogen and total phosphorus flowing into and out of the restoration area to determine the amount of nutrient reduction. Flow regimes were manipulated to divert water out of or into a stream or wetland cells. Stream and wetland configurations were compared to determine the effectiveness of the wetland cells in nutrient removal compared to streams alone. Results show that for a given discharge, wetland cells have a residence time up to six times longer than streams. Results indicate that streams may be effective at capturing total phosphorus during low discharge events and ineffective at capturing total phosphorus during high discharge events; the stream configuration does not appear to capture total nitrogen on a consistent basis. Wetland cells appear to be ineffective at retaining total nitrogen over winter storm events; wetland cells may be able to more effectively retain total phosphorus...

.; Desempenho da macrófita Lemna valdiviana no tratamento terciário de efluentes de suinocultura e sua contribuição para a sustentabilidade da atividade

Tavares, Flávia de A.; Departamento de Engenharia Sanitária e Ambiental, Universidade Federal de Santa Catarina. Caixa Postal 476, CEP 88010-970, Florianópolis – SC, Brasil; Rodrigues, João Bosco R.; Departamento de Aqüicultura, Universidade Federa
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 22/09/2011 POR
Relevância na Pesquisa
46.22%
Performance of the macrophyte Lemna valdiviana in tertiary pig waste treatment and its contribution to the sustainability of swine production. The present study aims to contribute to the sustainability of swine production by evaluating usage of the aquatic macrophyte Lemna valdiviana in the tertiary treatment of pig waste. Five assays (1 to 5) in triplicate were conducted using swine effl uent with different COD(Che mical Oxygen Demand) concentrations: 400, 550, 700, 850 and 1,000 mg.L-1,respectively. The trial lasted for 21 days and the evaluated variables were: (a) pollutant removal effi ciency, (b) biomass production and (c) plant protein content under the different detention times of 7, 14 and 21 days. In general, assays 1 and 2 (CODs of 400 and 550mg.L-1) presented the best removal effi ciencies under a detention time of 21 days. Regarding the purpose of both nutrient removal and production of high protein biomass, assay 3 (COD of 700mg.L-1) showed the bestresults under 14 days’ detention time (36.81% crude protein). It was established that the use of duckweeds in the tertiary swine waste treatment was able to provide a sustainable alternative regarding its advantages such as effl uent polishing, minimization of environmental impact...

TREATMENT CHARACTERISTICS AND OPERATIONAL PARAMETERS OF A NEWLY DEVELOPED REACTOR WITH SLUDGE SEPARATION FILTER AND AIRLIFT PUMP FOR CARBON AND NITROGEN REMOVAL

Nishimura, Fumitake
Fonte: JUEE Press Publicador: JUEE Press
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 20/09/2015 ENG
Relevância na Pesquisa
46.25%
Nutrient removal from sewage is one of the most urgently required issues from the viewpoint of prevention of eutrophication and preservation of water quality for water supply system. Among several nutrient removal methods, biological treatment, which is a modified activated sludge system is widely applied. However, biological nitrogen removal process, which consists of nitrification and denitrification steps, needs opposite operations at several stages such as necessity of oxygen and requirement of electron donor of organic compounds. In this study, treatment characteristics of a reactor with both sludge separation filter and airlift pump are investigated. This reactor has sludge separation filter in the middle part and airlift pump that supplies oxygen and circulate liquid from aerobic zone to anoxic zone in order to cut down the required energy. From laboratory scale experiments, design and operational parameters are investigated and it is shown that NH4-N loading rate of 35 mgN/(L-media・hr) at aerobic zone and DO loading rate of less than 0.15 kgDO/(kgMLSS・d) to anoxic zone are required for stable treatment.

The removal of N and P in aerobic and anoxic-aerobic digestion of waste activated sludge from biological nutrient removal systems

Vogts,M; Ikumi,DS; Ekama,GA
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
Relevância na Pesquisa
56.3%
Biological nutrient removal (BNR) activated sludge (AS) systems produce a waste activated sludge (WAS) that is rich in nitrogen (N) and phosphorus (P). When this sludge is thickened to 3-6% total suspended solids (TSS) and digested (aerobic or anaerobic), a high proportion of N and P are released to the bulk liquid resulting in high concentrations of ammonia/nitrate and orthophosphate up to several hundred mg/ℓ (without denitrification or P precipitation). This research investigates P removal by P precipitation in anoxic-aerobic digestion of P-rich BNR system WAS. The experimental setup for this work was a lab-scale membrane UCT BNR system fed real settled sewage with added acetate, orthophosphate, and cations Mg and K to increase biological excess P removal. This WAS was fed to batch aerobic digesters at various TSS concentrations, and to two 20-day retention time continuous anoxic-aerobic digesters (AnAerDig) with aeration cycles of 3-h air on and 3-h air off, one fed concentrated WAS (20 g TSS/ℓ ) and the other fed diluted WAS (3 g TSS/ℓ). Nitrogen removal has been discussed in the previous paper. This paper focuses on the P removal by P precipitation observed in the batch tests and continuous systems. The rate of polyphosphate release (bGP) during batch aerobic digestion at low TSS without P precipitation was found to be 2.5 times faster than the endogenous respiration rate (bG) of phosphorus accumulating organics (PAO)...