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Guidelines for fertilizer use in vineyards based on nutrient content of grapevine parts

Arrobas, Margarida; Ferreira, I.Q.; Freitas, Sara; Verdial, João; Rodrigues, M.A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.21%
Plant analysis plays a major role in fertilizer recommendations for perennial tree crops and vines. Plantanalysis, however, does not quantify the rate of nutrients to apply. The approach developed in this worktakes into account the content of the nutrients in grapevine parts and their dynamic within the plantto assist in the estimation of the amount of fertilizer to apply. Groups of three vines were cut at groundlevel on four different dates from September 14th to November 28th. On the first sampling date thevines were separated into trunk, cordons, canes, leaves and clusters for determination of dry mattercontent and elemental composition. On the following dates the vines were separated into the plant partsthat were still present, since the clusters were only present on the first sampling date and the leaveson the first two. To assess the mobility of nutrients within the plant, samples of phloem vessels andsawdust of the entire trunk were taken as well as samples of chlorotic and green leaves. Nitrogen (N),potassium (K), phosphorus (P) and boron (B) showed mobility within the plant whereas calcium (Ca)and magnesium (Mg) did not. The removal of nutrients in clusters is critical for estimating N and Kfertilizer rates. Clusters removed 19.9 kg N ha?1and 28.7 kg K ha?1. In the case of N...

Nitrogen removal in a sequencing batch biofilm reactor with liquid circulation: Effect of feed strategy and carbon source in the denitrifying step

CANTO, C. S. A.; RATUSZNEI, S. M.; RODRIGUES, J. A. D.; ZAIAT, M.; FORESTI, E.
Fonte: ASOC QUIMICOS Publicador: ASOC QUIMICOS
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.09%
Ammonium nitrogen removal from a synthetic wastewater by nitrification and denitrification processes were performed in a sequencing batch biofilm reactor containing immobilized biomass on polyurethane foam with circulation of the liquid-phase. It was analyzed the effect of four external carbon sources (ethanol, acetate, carbon synthetic medium and methanol) acting as electron donors in the denitrifying process. The experiments were conducted with intermittent aeration and operated at 30+/-1 degrees C in 8-h cycles. The synthetic wastewater (100 mgCOD/L and 50 mgNH(4)(+)-N/L) was added batch-wise, while the external carbon sources were added fed-batch-wise during the periods where aeration was suspended. Ammonium nitrogen removal efficiencies obtained were 95.7, 94.3 and 97.5% for ethanol, acetate and carbon synthetic medium, respectively. As to nitrite, nitrate and ammonium nitrogen effluent concentrations, the results obtained were, respectively: 0.1, 5.7 and 1.4 mg/L for ethanol; 0.2, 4.1 and 1.8 mg/L for acetate and 0.2, 6.7 and 0.8 for carbon synthetic medium. On the other hand using methanol, even at low concentrations (50% of the stoichiometric value calculated for complete denitrification), resulted in increasing accumulation of nitrate and ammonium nitrogen in the effluent over time.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP[01/05489-0]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP[02/07504-0]

Chromium ions phytoaccumulation by three floating aquatic macrophytes from a nutrient medium

ESPINOZA-QUINONES, Fernando Rodolfo; SILVA, Edson Antonio da; Rizzutto, Marcia de Almeida; PALACIO, Soraya Moreno; MODENES, Aparecido Nivaldo; SZYMANSKI, Nayara; MARTIN, Neiva; KROUMOV, Alexander Dimitrov
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.21%
In the present work, the trivalent and hexavalent chromium phytoaccumulation by three living free floating aquatic macrophytes Salvinia auriculata, Pistia stratiotes, and Eicchornia crassipes was investigated in greenhouse. These plants were grown in hydroponic solutions supplied with non-toxic Cr3+ and Cr6+ chromium concentrations, performing six collections of nutrient media and plants in time from a batch system. The total chromium concentrations into Cr-doped hydroponic media and dry roots and aerial parts were assayed, by using the Synchrotron radiation X-ray fluorescence technique. The aquatic plant-based chromium removal data were described by using a nonstructural kinetic model, obtaining different bioaccumulation rate, ranging from 0.015 to 0.837 1 mg(-1) d(-1). The Cr3+ removal efficiency was about 90%, 50%, and 90% for the E. crassipes, P. stratiotes, and S. auriculata, respectively; while it was rather different for Cr6+ one, with values about 50%, 70%, and 90% for the E. crassipes, P. stratiotes, and S. auriculata.; Brazilian Synchrotron Light Laboratory (LNLS); The Brazilian Light Synchrotron Laboratory (LNLS)[3364]; Brazilian Synchrotron Light Laboratory (LNLS); The Brazilian Light Synchrotron Laboratory (LNLS)[4652]

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 Português
Relevância na Pesquisa
46.25%
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 Português
Relevância na Pesquisa
66.48%
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.
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.39%
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.
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.34%
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)...

Phosphorous removal from water by polyolefins: effect of Al2O3 addition

Oliveira, M.; Nóbrega, J. M.; Machado, A. V.; Brito, A. G.; Nogueira, R.
Fonte: Universidade do Minho. Departamento de Engenharia Biológica Publicador: Universidade do Minho. Departamento de Engenharia Biológica
Tipo: info:eu-repo/semantics/conferenceobject
Publicado em /09/2008 Português
Relevância na Pesquisa
36.17%
Phosphorus is the main nutrient responsible for eutrophication of aquatic ecosystems, therefore it is important to develop new processes to remove phosphorus that avoid the formation of precipitates. Polyolefins with and without prior activation with aluminum oxide (Al2O3), processed as flat plates, were investigated for phosphate removal from an aqueous solution. The maximum amount of phosphorus removal was 0.042 ?gP/cm2 for PE (polyethylene), 0.049 ?gP/cm2 for PE-g-MA (polyethylene grafted with maleic anhydride), and 0.071 ?gP/cm2 for PE-g-MAe (PE-g-MA enriched in MA). Increasing polyolefins’ polarity did not result in a significant increase in phosphate removal. Activated polyolefins with Al2O3 presented maximum amounts of phosphorus removal of 0.863 ?gP/cm2 for PE, 0.948 ?gP/cm2 for PE-g-MA, and 0.884 ?gP/cm2 for PE-g-MAe. As expected, addition of Al2O3 considerably increased phosphate removal. In kinetic experiments carried out with polyolefins activated with Al2O3 during 3 months a very high percentage of phosphorus removal was obtained for (> 90 %) as well as a very low remaining phosphorus concentration in solution (< 10 ?gP/L). As a conclusion, polyolefins activated with Al2O3 effectively removed phosphorous from aqueous solutions with low concentrations which indicate that this material might be used for in-situ remediation of eutrophic waters. The possibility to recover the material after use to recycle phosphate and the absence of precipitates’ formation are two major advantages of this process.; Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/39085/2007.

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 Português
Relevância na Pesquisa
46.35%
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.

Nitrogen removal from landfill leachate in constructed wetlands with reed and willow: Redox potential in the root zone

Bialowiec, Andrzej; Albuquerque, Antonio; Davies, Laura; Randerson, Peter
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /04/2012 Português
Relevância na Pesquisa
46.09%
This study investigated the effects of reed and willow on bioremediation of landfill leachate in comparison with an unplanted control by measuring redox potential levels in the rhizosphere of microcosm systems in a greenhouse. Plants had a significant influence on redox potential relative to the plant-less system. Redox potential in the reed rhizosphere was anoxic (mean -102 +/- 85 mV), but it was the least negative, being significantly higher than in the willow (mean -286 +/- 118 mV), which had the lowest Eh. Redox potential fluctuated significantly in the willow rhizosphere during daylight hours, with large decreases in the morning. Levels of NH4+ decreased significantly in the first day of the experiment and remained at similar low levels in all three variants for the next four weeks of the experiment. Following this removal of ammonia significant peaks in NO2- occurred in the control and reed tanks on the 1st day, and again on 14th day in the control tank up to 13 mg/dm(3). In the willow tank there was also one significant peak of NO2- in the first week, but only up to 0.5 mg/dm(3). Significant accumulation, within 21 days of NO3- in all variants was observed, but in tanks with reed and willow the concentration of NO3- remained significantly lower (

Removal of organic matter and nutrients from slaughterhouse wastewater by using Eichhornia crassipes and evaluation of the generated biomass composting

Mees,Juliana B. R.; Gomes,Simone D.; Boas,Márcio A. Vilas; Fazolo,Ajadir; Sampaio,Sílvio C.
Fonte: Associação Brasileira de Engenharia Agrícola Publicador: Associação Brasileira de Engenharia Agrícola
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2009 Português
Relevância na Pesquisa
46.12%
The objective of this research was to evaluate the performance of the aquatic macrophyte Eichhornia crassipes applied in situ in a slaughter house treatment system, located in the west of the Paraná state, Brazil, regarding the nutrients removal and organic matter. Moreover, it aimed to obtain data from the production, management and composting practices of the biomass generated in the system. During 11 months of macrophytes development, physic and chemical parameters were monitored and plant density was controlled by periodical removal of excess biomass, which was weekly monitored and it is expressed in kg of aquatic plant per m² covered area. The degradation of the macrophytes removed from the treatment system was evaluated at the pilot scale in eight composting piles of 0.60 m³ that underwent four different treatments and two repetitions: T1 - water hyacinth (Eichhornia crassipes); T2 - water hyacinth and swine excrement (7:1), T3 - water hyacinth, swine excrement and earth (7:1:0,67), and T4 - water hyacinth, swine excrement and cellulosic gut (7:1:0,67), for a period of 90 days. The results indicated maximum removal efficiencies of 77.2% for COD; 77.8% for BOD, 87.9% for total nitrogen, 47.5% for ammonia nitrogen and 38.9% for total phosphorus for a five-day retention time. For biomass stabilization by composting...

Nitrogen removal from swine wastewater by combining treated effluent with raw manure

Kunz,Airton; Steinmetz,Ricardo; Damasceno,Simone; Coldebela,Arlei
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 Português
Relevância na Pesquisa
46.09%
Effluents from swine raising can be harmful to the environment if not correctly managed. Nitrogen (N) is usually the main element present at high concentrations in the effluent. Since the use as biofertilizer is not always a feasible alternative, the treatment of swine wastewater is necessary. Variations in N species and water solubility make the treatment difficult and expensive. Additional N removal at low cost via denitrification may be possible by recirculating nitrified effluent in the barns. In this study, raw manure (RM) was homogenized with treated effluent (TE) at RM/(RM + TE) ratios of 1.0, 0.9, 0.8, 0.7, 0.6, 0.5 and 0 in order to simulate the effect of reused water on swine wastewater nitrogen removal. Samples were collected daily during four days and analyzed for pH, oxidation-reduction potential, NH4-N, NO2-N, NO3-N and chemical oxidation demand. The oxidized nitrogen (NOx-N) half-life degradation was estimated using linear regression. NOx-N species half-life less than one day was obtained when treated effluent was combined and thoroughly homogenized with raw manure. It is suggested that combining raw manure with treated effluent (e.g. water reuse) can be a simple and cost-effective strategy to remove nitrogen from swine wastewaters.

SPATIAL AND TEMPORALVARIATION OF DISSOLVED INORGANIC NUTRIENTS, AND CHLOROPHYLL-? 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 Português
Relevância na Pesquisa
46.31%
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-? 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-? 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
Tipo: text
Português
Relevância na Pesquisa
46.34%
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
Tipo: text
Português
Relevância na Pesquisa
46.39%
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: text
Português
Relevância na Pesquisa
46.5%
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...

Nitrogen Removal over Nitrite by Aeration Control in Aerobic Granular Sludge Sequencing Batch Reactors

Lochmatter, Samuel; Maillard, Julien; Holliger, Christof
Fonte: MDPI Publicador: MDPI
Tipo: text
Português
Relevância na Pesquisa
36.37%
This study investigated the potential of aeration control for the achievement of N-removal over nitrite with aerobic granular sludge in sequencing batch reactors. N-removal over nitrite requires less COD, which is particularly interesting if COD is the limiting parameter for nutrient removal. The nutrient removal performances for COD, N and P have been analyzed as well as the concentration of nitrite-oxidizing bacteria in the granular sludge. Aeration phase length control combined with intermittent aeration or alternate high-low DO, has proven to be an efficient way to reduce the nitrite-oxidizing bacteria population and hence achieve N-removal over nitrite. N-removal efficiencies of up to 95% were achieved for an influent wastewater with COD:N:P ratios of 20:2.5:1. The total N-removal rate was 0.18 kgN·m?3·d?1. With N-removal over nitrate the N-removal was only 74%. At 20 °C, the nitrite-oxidizing bacteria concentration decreased by over 95% in 60 days and it was possible to switch from N-removal over nitrite to N-removal over nitrate and back again. At 15 °C, the nitrite-oxidizing bacteria concentration decreased too but less, and nitrite oxidation could not be completely suppressed. However, the combination of aeration phase length control and high-low DO was also at 15 °C successful to maintain the nitrite pathway despite the fact that the maximum growth rate of nitrite-oxidizing bacteria at temperatures below 20 °C is in general higher than the one of ammonium-oxidizing bacteria.

Evaluation of Simultaneous Nutrient and COD Removal with Polyhydroxybutyrate (PHB) Accumulation Using Mixed Microbial Consortia under Anoxic Condition and Their Bioinformatics Analysis

Jena, Jyotsnarani; Kumar, Ravindra; Dixit, Anshuman; Pandey, Sony; Das, Trupti
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Publicado em 17/02/2015 Português
Relevância na Pesquisa
36.31%
Simultaneous nitrate-N, phosphate and COD removal was evaluated from synthetic waste water using mixed microbial consortia in an anoxic environment under various initial carbon load (ICL) in a batch scale reactor system. Within 6 hours of incubation, enriched DNPAOs (Denitrifying Polyphosphate Accumulating Microorganisms) were able to remove maximum COD (87%) at 2g/L of ICL whereas maximum nitrate-N (97%) and phosphate (87%) removal along with PHB accumulation (49 mg/L) was achieved at 8 g/L of ICL. Exhaustion of nitrate-N, beyond 6 hours of incubation, had a detrimental effect on COD and phosphate removal rate. Fresh supply of nitrate-N to the reaction medium, beyond 6 hours, helped revive the removal rates of both COD and phosphate. Therefore, it was apparent that in spite of a high carbon load, maximum COD and nutrient removal can be maintained, with adequate nitrate-N availability. Denitrifying condition in the medium was evident from an increasing pH trend. PHB accumulation by the mixed culture was directly proportional to ICL; however the time taken for accumulation at higher ICL was more. Unlike conventional EBPR, PHB depletion did not support phosphate accumulation in this case. The unique aspect of all the batch studies were PHB accumulation was observed along with phosphate uptake and nitrate reduction under anoxic conditions. Bioinformatics analysis followed by pyrosequencing of the mixed culture DNA from the seed sludge revealed the dominance of denitrifying population...

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

Kamika, Ilunga; Momba, Maggy N.B.
Tipo: text
Português
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46.54%
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 

Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal*

Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi
Fonte: Zhejiang University Press Publicador: Zhejiang University Press
Tipo: text
Publicado em /04/2015 Português
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The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-?-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49–5.99 g N/(kg MLVSS?h) (MLVSS is mixed liquor volatile suspended solids) and 6.63–6.81 g N/(kg MLVSS?h)...