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1.
Braz. arch. biol. technol ; 63: e20180130, 2020. graf
Article in English | LILACS | ID: biblio-1132195

ABSTRACT

Abstract Color removal from textile effluents was evaluated using a laboratory-combined process based on an upflow anaerobic sludge blanket (UASB) reactor followed by a shallow polishing pond (SPP). The anaerobic reactor was fed with a real textile effluent, diluted 10-times in a 350 mg/L solution of pre-treated residual yeast extract from a brewery industry as nutrient source. The parameters color, COD, N-NH3 and toxicity were monitored throughout 45 days of operation. According to the results, decolorization and COD removal were highest in the anaerobic step, whereas the effluent was polished in the SPP unit. The overall efficiency of the complete UASB-SPP system for COD and color were 88 and 62%, respectively. Moreover, the N-NH3 generated by the residual yeast extract ammonification was below 5 mg/L for the final effluent. Finally, no toxicity was detected after the treatment steps, as shown by the Vibrio fischeri microscale assay.


Subject(s)
Animals , Textiles/toxicity , Waste Disposal, Fluid/methods , Water Purification/methods , Yeasts , Toxicity Tests , Bioreactors , Aliivibrio fischeri , Anaerobiosis
2.
Braz. j. microbiol ; 49(1): 38-44, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889215

ABSTRACT

ABSTRACT Discharge of coke-oven wastewater to the environment may cause severe contamination to it and also threaten the flora and fauna, including human beings. Hence before dumping it is necessary to treat this dangerous effluent in order to minimize the damage to the environment. Conventional technologies have inherent drawbacks however, biological treatment is an advantageous alternative method. In the present study, bacteria were isolated from the soil collected from the sites contaminated by coke-oven effluent rich in phenol and cyanide. Nucleotides sequence alignment and phylogenetic analysis showed the identity of the selected phenol and cyanide degrading isolates NAUN-16 and NAUN-1B as Pseudomonas putida and Pseudomonas stutzeri, respectively. These two isolates tolerated phenol up to 1800 mg L-1 and cyanide up to 340 mg L-1 concentrations. The isolates were immobilized on activated charcoal, saw dust and fly ash. The effluent was passed through the column packed with immobilized cells with a flow rate of 5 mL min-1. The isolates showed degradation of phenol up to 80.5% and cyanide up to 80.6% and also had the ability to reduce biological oxygen demand, chemical oxygen demand and lower the pH of effluent from alkaline to near neutral. The study suggests the utilization of such potential bacterial strains in treating industrial effluent containing phenol and cyanide, before being thrown in any ecosystem.


Subject(s)
Cyanides/metabolism , Phenol/metabolism , Pseudomonas putida/metabolism , Pseudomonas stutzeri/metabolism , Waste Disposal, Fluid/methods , Waste Water/microbiology , Biodegradation, Environmental , Cells, Immobilized/classification , Cells, Immobilized/metabolism , Coke/analysis , Cyanides/analysis , Industrial Waste/analysis , Phenol/analysis , Phylogeny , Pseudomonas putida/classification , Pseudomonas putida/genetics , Pseudomonas putida/isolation & purification , Pseudomonas stutzeri/classification , Pseudomonas stutzeri/genetics , Pseudomonas stutzeri/isolation & purification , Waste Water/analysis
3.
Braz. j. biol ; 75(4,supl.2): 37-42, Dec. 2015. tab, graf
Article in English | LILACS | ID: lil-769600

ABSTRACT

The present study analyzed the efficiency of the photo-electro-oxidation process as a method for degradation and inactivation of adenovirus in water. The experimental design employed a solution prepared from sterile water containing 5.107 genomic copies/L (gc/L) of a standard strain of human adenovirus type 5 (HAdV-5) divided into two equal parts, one to serve as control and one treated by photo-electro-oxidation (PEO) for 3 hours and with a 5A current. Samples collected throughout the exposure process were analyzed by real-time polymerase chain reaction (qPCR) for viral genome identification and quantitation. Prior to gene extraction, a parallel DNAse treatment step was carried out to assess the integrity of viral particles. Integrated cell culture (ICC) analyses assessed the viability of infection in a cell culture. The tested process proved effective for viral degradation, with a 7 log10 reduction in viral load after 60 minutes of treatment. The DNAse-treated samples exhibited complete reduction of viral load after a 75 minute exposure to the process, and ICC analyses showed completely non-viable viral particles at 30 minutes of treatment.


Resumo O presente estudo analisou a eficiência do processo de fotoeletrooxidação como metodologia para a degradação e inativação de adenovírus em água. A concepção experimental emprega uma solução preparada a partir de água estéril contendo 5,107 cópias genômicas/L (gc/L) de uma amostra padrão de adenovírus humano tipo 5 (HAdV-5), dividida em duas partes iguais, uma para servir como controle e outra tratada por fotoeletrooxidação (PEO) durante 3 horas e com uma corrente de 5A. As amostras recolhidas durante o processo de exposição foram analisadas por PCR quantitativo em tempo real (qPCR) para identificação e quantificação do genoma viral. Antes da extração de ácidos nucleicos, um passo de tratamento com DNAse paralelo foi realizado para avaliar a integridade das partículas virais. Um ensaio de qPCR integrado à cultura de células (ICC-qPCR) permitiu analisar a viabilidade de infecção em uma cultura de células. O processo mostrou-se eficaz testada para a degradação viral, com uma redução de 7 log10 da carga viral após 60 minutos de tratamento. As amostras tratadas com DNAse exibiram redução completa da carga viral após uma exposição de 75 minutos ao processo, e a análise de ICC-qPCR mostrou partículas virais completamente não-viáveis ​​em 30 minutos de tratamento.


Subject(s)
Adenoviruses, Human/isolation & purification , Virus Inactivation , Waste Disposal, Fluid/methods , Water Purification/methods , Electrochemical Techniques , Oxidation-Reduction , Photolysis , Real-Time Polymerase Chain Reaction
4.
Braz. j. biol ; 75(2,supl): 17-24, May 2015. tab, ilus
Article in English | LILACS | ID: lil-755018

ABSTRACT

The Sinos river Basin is an industrial region with many tanneries and electroplating plants in southern Brazil. The wastewater generated by electroplating contains high loads of salts and metals that have to be treated before discharge. After conventional treatment, this study applied an advanced oxidative process to degrade organic additives in the electroplating bright nickel baths effluent. Synthetic rinsing water was submitted to physical-chemical coagulation for nickel removal. The sample was submitted to ecotoxicity tests, and the effluent was treated by photoelectrooxidation (PEO). The effects of current density and treatment time were evaluated. The concentration of total organic carbon (TOC) was 38% lower. The toxicity tests of the effluent treated using PEO revealed that the organic additives were partially degraded and the concentration that is toxic for test organisms was reduced.

.

A Bacia do Rio dos Sinos é uma região do Sul do Brasil que sedia um importante pólo da indústria coureiro-calçadista incluindo, desde o beneficiamento das peles, em curtumes, à fabricação dos acessórios, em indústrias metalúrgicas e de galvanoplastia. O efluente gerado por processos galvânicos contém carga elevada de sais e metais que devem ser tratados antes do descarte. Neste artigo foi avaliada a aplicação de um processo oxidativo avançado após o tratamento convencional do efluente, visando degradar os aditivos orgânicos presentes nos efluentes dos banhos de eletrodeposição de níquel brilhante. Um efluente sintético foi tratado pelo processo físico-químico de coagulação para a remoção do níquel. A amostra foi, então, submetida a testes de ecotoxicidade e, em seguida, o efluente foi tratado pelo processo de fotoeletrooxidação (FEO). A influência da densidade de corrente e o tempo de tratamento foram avaliados. Foi verificada uma redução de carbono orgânico total superior a 38%. Os ensaios de ecotoxicidade para o efluente tratado por fotoeletroxidação indicaram que a FEO degradou parcialmente os aditivos orgânicos e reduziu a concentração que provoca efeitos tóxicos para os organismos teste.

.


Subject(s)
Animals , Chlorophyta/drug effects , Cyprinidae/metabolism , Daphnia/drug effects , Waste Disposal, Fluid/methods , Waste Water/toxicity , Water Pollutants, Chemical/toxicity , Electrolysis , Electroplating , Nickel/chemistry , Oxidation-Reduction , Photolysis
5.
Rev. argent. microbiol ; 45(1): 57-60, mar. 2013.
Article in Spanish | LILACS, BINACIS | ID: biblio-1171766

ABSTRACT

The present work sought to detect the presence of Pseudomonas spp. at different stages of an effluent treatment plant using the Australian system of stabilization ponds, and to determine the susceptibility of those isolates to different antimicrobials. Thirty-four isolates of Pseudomonas spp. derived from effluent treatment station water samples were collected near the transfer ducts between the ponds in November/2008 and december/2009. Among the Pseudomonas spp. isolates, 47.05


showed susceptibility to all antimicrobials tested, 20.58


were resistant to cefepime, and 24


showed intermediate resistance to streptomycin. No Pseudomonas spp. isolates were found in the final pond, or in post-treatment effluents. The Pseudomonas spp. isolates did not exhibit multiresistance to the antimicrobials tested.


Subject(s)
Abattoirs , Pseudomonas/drug effects , Drug Resistance, Microbial , Sus scrofa/microbiology , Animals , Anti-Bacterial Agents/pharmacology , Brazil , Waste Disposal, Fluid/methods , Medical Waste Disposal/methods , Species Specificity , Retrospective Studies , Water Microbiology , Pseudomonas/classification , Pseudomonas/isolation & purification , Industrial Waste , Swine , Disk Diffusion Antimicrobial Tests , Waste Water/microbiology
6.
Mem. Inst. Oswaldo Cruz ; 108(1): 77-83, Feb. 2013. graf, tab
Article in English | LILACS | ID: lil-666048

ABSTRACT

The presence of enteric viruses in biosolids can be underestimated due to the inefficient methods (mainly molecular methods) used to recover the viruses from these matrices. Therefore, the goal of this study was to evaluate the different methods used to recover adenoviruses (AdV), rotavirus species A (RVA), norovirus genogroup II (NoV GII) and the hepatitis A virus (HAV) from biosolid samples at a large urban wastewater treatment plant in Brazil after they had been treated by mesophilic anaerobic digestion. Quantitative polymerase chain reaction (PCR) was used for spiking experiments to compare the detection limits of feasible methods, such as beef extract elution and ultracentrifugation. Tests were performed to detect the inhibition levels and the bacteriophage PP7 was used as an internal control. The results showed that the inhibitors affected the efficiency of the PCR reaction and that beef extract elution is a suitable method for detecting enteric viruses, mainly AdV from biosolid samples. All of the viral groups were detected in the biosolid samples: AdV (90%), RVA, NoV GII (45%) and HAV (18%), indicating the viruses' resistance to the anaerobic treatment process. This is the first study in Brazil to detect the presence of RVA, AdV, NoV GII and HAV in anaerobically digested sludge, highlighting the importance of adequate waste management.


Subject(s)
Adenoviridae/isolation & purification , Hepatitis A virus/isolation & purification , Norovirus/isolation & purification , Rotavirus/isolation & purification , Sewage/virology , Water Microbiology , Anaerobiosis , Polymerase Chain Reaction , Reproducibility of Results , Waste Disposal, Fluid/methods , Water Purification/methods
7.
International Journal of Environmental Research. 2013; 7 (1): 61-68
in English | IMEMR | ID: emr-130234

ABSTRACT

The main task of this work is related with the design of a class of SISO robust control law for the regulation of substrate concentration [CDO] of an Industrial Activated Sludge Wastewater Plant. The control design is related with an uncertainty estimator [reduced order observer] based Active Control. Departing from the tracking error between the desired and the current substrate concentrations trajectories a control law is designed and the plant is regulated to the corresponding set point of the COD concentration. To be realizable the controller needs model information related with the kinetic term of COD consumption which is provides with a reduced order observer, these coupled structure [observer based controller] is robust against model uncertainties. The performance of the proposed control law is illustrated with numerical simulations employing a mathematical model of an Industrial Activated Sludge Wastewater Plant tuned with industrial data


Subject(s)
Waste Water , Waste Disposal, Fluid/methods , Industry
8.
International Journal of Environmental Research. 2013; 7 (4): 823-830
in English | IMEMR | ID: emr-138315

ABSTRACT

One of the main disadvantages of anaerobic wastewater treatment at a low pH is the significant operational cost due to the addition of necessary alkali. To reduce alkali supplement and thus the cost, this study proposes a sequential multi-feed [SqMF] mode [distributed feeding] and effluent recycle [ER] mode. Experiments were conducted with a pilot-scale [2.5 m[3]] thermophilic [55°C] multi-staged up-flow anaerobic sludge blanket reactor. Alcohol distillery wastewater [shochu], a major source of industrial wastewater in Japan, was used for the study. The SqMF mode of operation [influent pH: 5.0; organic loading rate: 45 kgCOD/m[3]/day; HRT: 12 hours; influent COD concentration: 20,900 mgCOD/L] successfully reduced the alkali supplement [24% NaOH solution] requirement by 67.2% compared with the single-feed mode. For the ER mode operation [organic loading rate: 35 kgCOD/m[3]/day; HRT: 12 hours; influent COD concentration: 17,400 mgCOD/L], operation was possible without any alkali supplement since the system uses the alkalinity generated during microbial metabolism


Subject(s)
Alcohols/isolation & purification , Alkalies , Waste Water , Waste Disposal, Fluid/methods , Alkalies
9.
International Journal of Environmental Research. 2013; 7 (4): 963-972
in English | IMEMR | ID: emr-138331

ABSTRACT

In this study, feasibility of upgrading and retrofitting municipal wastewater treatment plants was investigated at laboratory scale using Moving Bed Biofilm Reactor [MBBR] process. For this purpose, an aerobic pilot was operated for nearly one year in different conditions, in which a moving bed carrier with a specific biofilm surface area of 500 m[2]/m[3] and a filling rate of 60% was utilized. System efficiency in removal of BOD[5] and COD was examined at different hydraulic retention times [HRTs] of 1, 1.5, 2, 2.5, 3 and 4 h. The obtained results indicated high ability of the system to tolerate organic loading and to remain stable at a high food to microorganism [F/M] ratio. The system produced effluents with good quality at low HRTs and led to an average BOD[5] removal efficiency of nearly 88% during the operational period. The Organic Loading Rate [OLR] applied to the system had a range of 0.73-3.48 kgBOD[5]/m[3].day and 2.43-11.6 gBOD[5]/m[2].day, at which the reactor showed a good performance and stability. In general, it was concluded that [MBBR] can be an excellent alternative for upgrading and optimizing municipal wastewater treatment plants


Subject(s)
Waste Disposal, Fluid/methods , Biomass , Water Purification/methods , Feasibility Studies , Waste Water
11.
Iranian Journal of Health and Environment. 2012; 4 (4): 411-418
in Persian | IMEMR | ID: emr-124878

ABSTRACT

Cyanide is a highly toxic compound which is Normally found in numerous industries, such as electroplating wastewater. Release of this compounds in to the Enviroment has a lot health hazards.The Purpose of this study is to Determine the efficiency of electrochemical oxidation method for Cyanide removal from industrial wastewaters. This study conducted in a pilot system experimentally .In this study the effect of pH, voltage and operation time on total cyanide removal from industrial wastewaters by Electrochemical Oxidation was investigated by applying a Stainless Steel as a Anode and copper as a cathode. The average percentage removal of cyanide was about 88 with SD=2.43. The optimal condition obtained at voltage of 9V and pH=13 and The operation time of 90 minutes. The volume of sludge which formed in this condition was about 20 percent of a one liter pilot reactor. The results statistically confirmed the significant relationship between input and cyanide concentration removal efficiency [p< 0.05], and confirmed The this confirmed The relation between cyanide and cyanat oxidation and hydroxyl ions consumption 1:2.[L.Szpyruowicz]. therefore the best pH is 12.5-13.5 by Considering the need of alkaline environment to remove cyanide


Subject(s)
Electrochemical Techniques , Waste Disposal, Fluid/methods , Efficiency , Water Pollutants, Chemical
12.
Rev. argent. microbiol ; 43(2): 127-135, jun. 2011. ilus
Article in Spanish | LILACS | ID: lil-634684

ABSTRACT

Una de las funciones principales de la biotecnología ambiental es ocuparse del estudio de comunidades microbianas que proveen servicios esenciales para la sociedad. Más allá de las similitudes que presenta con la microbiología industrial y la agrícola, la biotecnología ambiental presenta peculiaridades, tales como los objetivos de proceso, las características de la biomasa y el tipo y modo de alimentación (sustratos), que la distinguen claramente de las otras disciplinas relacionadas. En este artículo se reseñan recientes avances en la ecología microbiana, la ecofisiología, la genómica y la ingeniería de procesos, para ilustrar cómo la integración de los nuevos conocimientos permite superar las limitaciones del análisis microbiológico clásico para entender, predecir y optimizar el funcionamiento de los procesos de tratamiento de efluentes.


One of the main functions of environmental biotechnology is to address the study of microbial communities that provide essential services to society. Beyond the similarities with industrial and agricultural microbiology, the unique features exhibited by environmental biotechnology, such as process objectives, biomass characteristics and type and mode of feeding (substrates), allow a clear distinction from the other related disciplines. Recent advances in microbial ecology, ecophysiology, genomics and process engineering are herein reviewed to illustrate how the integration of the new knowledge can help overcome the shortcomings of classic microbiological analyses to understand, predict and optimize the performance of wastewater treatment.


Subject(s)
Environmental Microbiology , Microbial Consortia , Sewage/microbiology , Waste Disposal, Fluid/methods , Water Purification/methods , Aerobiosis , Biodiversity , Biomass , Ecosystem , Forecasting , Metagenomics , Soil Microbiology , Water Microbiology , Waste Disposal, Fluid/standards
13.
International Journal of Environmental Science and Technology. 2011; 8 (3): 649-666
in English | IMEMR | ID: emr-123906

ABSTRACT

In recent years, concerns about the occurrence and fate of active pharmaceutical ingredients, solvents, intermediates and raw materials that could be present in water and wastewater including pharmaceutical industry wastewater has gained increasing attention. Traditional wastewater treatment methods, such as activated sludge, are not sufficient for the complete removal of active pharmaceutical ingredients and other wastewater constituents from these waters. As a result, complementary treatment methods such as membrane filtration, reverse osmosis and activated carbon are often used in conjunction with the traditional methods for treatment of industrial wastewater. Most of the literature published to date has been on the treatment of municipal wastewater. However, there is a growing body of research that looks at the presence of active pharmaceutical ingredients in industrial wastewater, the treatment of these wastewaters and the removal rates. This article, reviews these treatment methods and includes both traditional methods and advanced oxidation processes. The paper concludes by showing that the problem of pharmaceuticals in wastewaters cannot be solved merely by adopting end of pipe measures. At source measures, such as replacement of critical chemicals, reduction in raw material consumption should continue to be pursued as the top priority


Subject(s)
Industrial Waste , Photolysis , Waste Disposal, Fluid/methods , Drug Industry
14.
IJB-Iranian Journal of Biotechnology. 2011; 9 (1): 37-49
in English | IMEMR | ID: emr-122387

ABSTRACT

The biological phosphorus removal is a microbial process widely used for removing phosphorus from wastewater to avoid eutrophication of water bodies. The study was aimed to screen the efficient phosphate reducing isolates and used to remove phosphate from synthetic wastewater using batch scale process. The three most efficient phosphate reducers were isolated and screened from eutrophic lake water and forest soil samples. The total heterotrophic bacterial analysis of the samples showed the presence of about 38 phosphate reducers based on the minimum inhibitory concentration [MIC] test. Among them, Bacillus sp RS-1, Pseudomonas sp. YLW-7 and Enterobacter sp KLW-2 were found to be efficient in phosphate reduction. Among the individual strains, Pseudomonas sp YLW-7 was noticed to be 68% removal in MSM with glucose at neutral pH. The consortium with combination of Bacillus sp. RS-1, Pseudomonas sp. YLW-7 and Enterobacter sp KLW-2 was effectively removed the phosphate in the synthetic medium when compared to individual strains. The phosphate removal was observed to be maximum of 92.5% in mineral salts medium [MSM] at pH 7and 5, and 63.4% in synthetic phosphate solution at neutral pH with lactose as a carbon source by the consortium after 72 h. Thus the microorganisms may use the contaminants as nutrients and as energy sources or it may be utilized by cometabolism. Therefore, these bacterial isolates might be used in the remediation of phosphate contaminated environments


Subject(s)
Water Purification/methods , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/metabolism , Industrial Waste
15.
Iranian Journal of Environmental Health Science and Engineering. 2011; 8 (4): 295-306
in English | IMEMR | ID: emr-124812

ABSTRACT

Nowadays formaldehyde is used as raw material in many industries. It has also disinfection applications in some public places. Due to its toxicity for microorganisms, chemical or anaerobic biological methods are applied for treating wastewater containing formaldehyde.In this research, formaldehyde removal efficiencies of aerobic biological treatment systems including moving bed biofilm [MMBR] and sequencing batch reactors [SBR] were investigated. During all experiments, the efficiency of SBR was more than MBBR, but the difference was not significant statistically. According to the results, the best efficiencies were obtained for influent formaldehyde COD of 200 mg/L in MBBR and SBR which were 93% and 99.4%, respectively. The systems were also capable to treat higher formaldehyde concentrations [up to 2500 mg/L] with lower removal efficiency. The reaction kinetics followed the Stover-Kincannon second order model. The gram-positive and gram-negative bacillus and coccus as well as the gram-positive binary bacillus were found to be the most dominant species. The results of [13]C-NMR analysis have shown that formaldehyde and urea were converted into N-[[[aminocarbonyl] amino] methyl]urea and the residual formaldehyde was polymerized at room temperature


Subject(s)
Bioreactors , Waste Disposal, Fluid/methods , Formaldehyde , Industrial Waste/analysis , Biodegradation, Environmental
16.
KOOMESH-Journal of Semnan University of Medical Sciences. 2011; 12 (2): 215-221
in Persian | IMEMR | ID: emr-125120

ABSTRACT

Formaldehyde is used in many industrial applications as raw material and therefore high concentrations are found in their effluents. Activated sludge processes based on biofilm growth are increasingly used because of appreciate abilities in controlling of high organic load industrial effluents. The main objective of this study was to determine the effect of biofilm in improvement of activated sludge efficiency for treatment of industrial effluents containing formaldehyde. Two lab scale activated sludge reactors [with and without fixed bed for biofilm growth] were investigated in organic loading rate of 0.7-10.5 kgCOD/m3.d, aerobic condition and the room temperature. In this study, the effects of organic and hydraulic loads were investigated for the mentioned two processes. The most COD removal efficiency for biofilm activated sludge was 98.86%. The reactor containing biofilm had removal efficiency of more than 64% up to the organic loading rate of 10.5 kgCOD/m3.d, while the conventional activated sludge reactor collapsed in organic loading rate of 7.5 kgCOD/m3.d. Findings of this study indicate that activated sludge reactor containing fixed bed for biofilm growth is significantly more efficient than the conventional activated sludge one


Subject(s)
Formaldehyde/metabolism , Sewage/microbiology , Waste Disposal, Fluid/methods , Water Pollutants, Chemical , Water Purification/methods , Bioreactors/microbiology , Biodegradation, Environmental
17.
Iranian Journal of Environmental Health Science and Engineering. 2011; 8 (3): 255-264
in English | IMEMR | ID: emr-137349

ABSTRACT

Activated sludge flow rheology is a very complicated phenomenon. Studies related to activated sludge tend to classify sludge as non-Newtonian fluid. Until now, several theories have been built to describe the complex behavior of activated sludge with varying degrees of success. In this article, seven different models for viscosity of non-Newtonian fluids [i.e., Power law, Bingham plastic, Herschel-Bulkley, Casson, Sisko, Carreau and Cross] were considered to evaluate their predictive capability of apparent viscosity of activated sludge. Results showed that although evaluating the constants in the four-parameter models is difficult, they provide the best prediction of viscosity in the whole range of shear rates for activated sludge. For easier prediction of viscosity at different mixed liquor suspended solids [2.74-31g/L], temperature [15-25°C] and shear rate [1-1000/s], simple correlations were proposed. Comparing the results with the experimental data revealed that the proposed correlations are in good agreement with real apparent viscosities


Subject(s)
Bacterial Physiological Phenomena , Biodegradation, Environmental , Rheology/instrumentation , Sewage/analysis , Viscosity , Waste Disposal, Fluid/methods
18.
International Journal of Environmental Science and Technology. 2009; 6 (1): 149-158
in English | IMEMR | ID: emr-91339

ABSTRACT

Hybrid integrated fixed film activated sludge is a promising process for the enhancement of nitrification, denitrification and phosphorus removal in conventional activated sludge systems that can be used for upgrading biological nutrient removal, particularly when they have space limitations or need modifications that will require large monetary expenses. In this research, successful implementation of hybrid integrated fixed film activated sludge process at temperate zone wastewater treatment facilities has been studied by the placement of fixed film media into aerobic, anaerobic and anoxic zones. The primary objective of this study was to investigate the incorporation of enhanced biological phosphorus removal into hybrid integrated fixed film activated sludge systems and study the interactions between the fixed biomass and the mixed liquor suspended solids with respect to substrate competition and nutrient removal efficiencies. A pilot-scale anaerobic-anoxic-oxic configuration system was used. The system was operated at different mean cell residence times and influent chemical oxygen demand/total phosphorus ratios and with split influent flows. The experimental results confirmed that enhanced biological phosphorus removal could be incorporated successfully into hybrid integrated fixed film activated sludge system, but the redistribution of biomass resulting from the integration of fixed film media and the competition of organic substrate between enhanced biological phosphorus removal and denitrification would affect performances. Also, kinetic analysis of the reactor with regarding to phosphorus removal has been studied with different kinetic models and consequently the modified Stover-Kincannon kinetic model has been chosen for modeling studies and experimental data analysis of the hybrid integrated fixed film activated sludge reactor


Subject(s)
Waste Disposal, Fluid/methods , Phosphorus/isolation & purification
19.
Iranian Journal of Health and Environment. 2009; 2 (2): 114-123
in Persian | IMEMR | ID: emr-93666

ABSTRACT

Leachate is one of the landfill products and also a wastewater bearing the most advers effects on the environment. Biological methods are usually employed for treatment of young leachate [1-2 years] wich is of high concentration of organic compounds with low molecular weight. However these methods are not approprate for mature leachate [5-10years] due to having high rate of compounds with molecular weight and the presence of materials resistant to biodegradation and toxic compounds. Advanced oxidation process such as Fenton reagent used in treatment or biodegrability improvement of strong wastewater. In the present study the degrability improvement of mature leachate through oxidation fenton process in bench scale and in batch reactor has been investigated. The samples have been taken from Ahwaz landfill and factors such as initial COD and BOD, pH, BOD5/COD were studies as degradability, the amount of Hydrogen Peroxide, Fe[II], optimal reaction time and optimal pH. The highest amount of COD removal was observed in PH=3-3.5 and 90 minutes of reaction time. H2O2=29700mg/land Fe2+=16500 mg/l in [Fe2+]/[H2O2]=1/14.8 molarity ratio were obtained as optimal amounts BOD5/COD was equal to 0.38. This study indicates that Fenton oxidation enhances the biodegradability of leachate


Subject(s)
Environmental Restoration and Remediation/methods , Oxidation-Reduction , Hydrogen Peroxide/chemistry , Organic Chemicals/metabolism , Waste Disposal, Fluid/methods , Refuse Disposal , Iron/chemistry
20.
J Environ Biol ; 2008 Mar; 29(2): 155-8
Article in English | IMSEAR | ID: sea-113760

ABSTRACT

The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia and Nostoc spongiaeforme isolated from salt affected soils using uni-algal and bi-algal systems. Besides distinct halophilism, the two strains exhibited remarkable tolerance to chromium (VI) and revealed 1.2 to 2.8 times more chlorophyll in the presence of the metal. While phycobilins and carotenoids also increased in Nostoc linckia with total dissolved salts (TDS) as well as metal, a decline was observed in Nostoc spongiaeforme in the presence of Cr (VI). Relative algal biomass (as % of control) showed significantly higher values (123-239) in Nostoc linckia in the presence of salt, metal and combination of the two. In Nostoc spongiaeforme it declined in the presence of metal (72-81) but increased in the presence of salts (143-249) and also in the binary systems (121-440). The bi-algal consortium showed relatively less tolerance to salt and metal stress. Nostoc linckia (20 day culture) showed upto 40% chromium removal whereas Nostoc spongiaeforme showed up to 12% removal, indicating greater suitability of the former for use in bioremediation studies.


Subject(s)
Biodegradation, Environmental , Biomass , Chromium/isolation & purification , Industrial Waste/adverse effects , Nostoc/drug effects , Sodium Chloride/chemistry , Soil Pollutants/isolation & purification , Time Factors , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/isolation & purification
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