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1.
Water Res ; 168: 115181, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31630018

RESUMO

In this study, zwitterionic polymer brushes with controlled architecture were grafted on the surface of gravity-driven membrane (GDM) via surface-initiated reaction to impart antifouling property. A variety of membrane characterization techniques were conducted to demonstrate the successful functionalization of zwitterionic polymers on PVDF hollow fiber membrane. The membrane underwent 90 min of reaction time possessing strong hydrophilicity and high permeability was determined as the optimal modified membrane. Long-term GDM dynamic fouling experiments operated for 30 days using sewage wastewater as feed solution indicated zwitterionic polymer modified membrane exhibit excellent membrane fouling resistance thus enhanced stable flux. Confocal laser scanning microscopy (CLSM) imaging implied that zwitterionic polymer modification significantly inhibit the adsorption of extracellular polymeric substances (EPS) which dominates fouling propensity, resulting in the formation of a thin biofilm with high porosity under synthetic functions of foulants deposition and microbial activities. Interfacial free energy prediction affirmed the presence of zwitterionic functional layer on membrane surface could substantially decrease the interactions (e.g., electrostatic attractions and hydrophobic effects) between membrane and foulants, thereby reduced flux decline and high stable flux. Our study suggests surface hydrophilic functionalization shows promising potential for improving the performance of ultra-low pressure filtration.


Assuntos
Membranas Artificiais , Polímeros , Biofilmes , Filtração , Esgotos
2.
Water Res ; 168: 115151, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31630019

RESUMO

This study investigated nutrient removal characteristics and the related pathways in aerobic granular reactors using three pilot-scale granular sequencing batch reactors (GSBRs) treating wastewaters of diverse carbon and nutrient strength. The GSBRs were operated with alternating (AN/O/AX/O_SBR and AN/O_SBR) and purely-aerobic (O_SBR) operation modes. Mineral-rich aerobic granules with hydroxyapatite (HAp) core were cultivated in all the three GSBRs. The highest nitrogen removal efficiency (75%) was achieved in AN/O/AX/O_SBR and O_SBR and the lowest (22%) in AN/O_SBR, establishing a quasi-linear relationship with organic loading rate (OLR). Phosphorus removal efficiencies of 55-63% were achieved in the GSBRs despite different influent PO4-P concentrations. Heterotrophic nitrification and biologically-induced phosphate precipitation (BIPP) became the dominant nutrient depletion pathways, contributing 61-84% and 39-96% to overall ammonium nitrogen and phosphorus removal, respectively. A direct relation was noted between heterotrophic nitrification efficiency (ηHeterotrophic nitrification) and nutrient availability, as nitrification efficiencies of 18 and 64% were observed for COD:Ninf of 5 and 20, respectively. Whereas, BIPP efficiency (ηBIPP) established inverse relation with (COD:P)inf and (Ca:P)inf and direct relation with phosphorus concentration beyond microbial growth requirement. Core heterotrophic nitrifiers and bio-calcifying species were identified as {Thauera and Flavobacterium} and {Flavobacterium, Acinetobacter, Pseudomonas, and Corynebacterium}, respectively. Ca-P crystallization was proposed to be via phosphate precipitation on calcite surfaces. Granulation mechanism was proposed as crystallization on bio-aggregates' periphery and then crystal growth toward the core.


Assuntos
Nutrientes , Esgotos , Aerobiose , Reatores Biológicos , Minerais , Nitrificação , Nitrogênio , Fósforo , Eliminação de Resíduos Líquidos
3.
Water Res ; 168: 115166, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31634707

RESUMO

This study describes the photoelectrochemical (PEC) treatment of authentic sewage from Hong Kong for H2 production and degradation of emerging pollutants (EP's) simultaneously, and disinfection of E. coli. The g-C3N4/Ag/AgCl/BiVO4 (CAB-1) coated thin film acted as the photoanode in a three-electrode configuration PEC cell and real sewage as the electrolyte. Electrochemical studies revealed the near reversible, diffusion-controlled and high electron transfer reaction at the electrode-electrolyte surface. For CAB-1, the achieved photocurrent density was 0.1-0.2 mA cm-2 at 1.23 V vs. RHE exhibiting the highest PEC degradation efficiency (11.15% h-1 cm-2) compared to other base materials like g-C3N4/BiVO4 (6.88% h-1 cm-2) or Ag/AgCl/BiVO4 (4.06% h-1 cm-2). During the same reaction, the evolved 118 µmol of H2 gas corresponds to a Faradic efficiency of 69.38%. The composition of sewage was found to influence the overall PEC efficiency. The higher amount of total suspended solids, turbidity, and anionic species decreased the efficiency while as the other parameters like alkaline pH increased the PEC efficiency. Photo-electrochemically, the CAB-1 also effectively disinfected the E. coli present in the sewage with a final discharge of ≤1000 CFU/mL which is within the permissible discharge limits (≤1500 CFU/mL), in Hong Kong.


Assuntos
Desinfecção , Poluentes Ambientais , Escherichia coli , Hong Kong , Hidrogênio , Esgotos , Prata
4.
Water Res ; 168: 115104, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31639592

RESUMO

The use of molecular probe technology is demonstrated for routine identification and tracking of cultured and uncultured microorganisms in an activated sludge bioreactor treating domestic wastewater. A key advantage of molecular probe technology is that it can interrogate hundreds of microbial species of interest in a single measurement. In environmental niches where a single genus (such as Competibacteraceae) dominates, it can be difficult and expensive to identify microorganisms that are present at low relative abundance. With molecular probe technology, it is straightforward. Members of the Competibacteraceae family, none of which have been grown in pure culture, are abundant in an activated sludge system in the San Francisco Bay Area, California, USA. Molecular probe ensembles with and without Competibacteraceae probes were constructed. Whereas the probe ensemble with Competibacteraceae probes identified a total of ten bacteria, the molecular probe ensemble without Competibacteraceae probes identified 29 bacteria, including many at low relative abundance and including some species of public health significance.


Assuntos
Sondas Moleculares , Esgotos , Reatores Biológicos , RNA Ribossômico 16S , São Francisco , Águas Residuárias
5.
Bioresour Technol ; 294: 122183, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31683455

RESUMO

Sewage nitritation is a promising process for nitrogen removal, but its practical application is limited by long start-up period and unstable operation. In this study, hydroxylamine (NH2OH) addition and real-time aeration control strategies were adopted for the promotion of sewage nitritation in a sequencing batch reactor. Initially, 4.5 mg/L NH2OH was added into reactor every 24 h to establish nitritation, increasing the nitrite accumulation ratio (NAR) from 1.7% to 93% in 19 d. In the following period, NH2OH addition was stopped and nitritation remained stable over 55 d, with NAR of 97% by real-time aeration control. The aeration duration was determined by characteristic points on pH curve. The main genera of nitrite oxidizing bacteria, Nitrobacter and Nitrospira, were both eliminated from the system, supporting the long-term stability of nitritation. Overall, NH2OH addition and real-time aeration control is an excellent strategy for establishing and maintaining effective sewage nitritation.


Assuntos
Reatores Biológicos , Esgotos , Hidroxilamina , Hidroxilaminas , Nitritos , Nitrogênio , Oxirredução
6.
J Environ Manage ; 250: 109538, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31703243

RESUMO

The partial nitritation-anammox processes implementation in the main line of wastewater treatment plants would lead them closer to the energy autarky. With this purpose, an integrated fixed film activated sludge (IFAS) reactor was operated at pilot scale. Efficient nitrogen removal (72 ±â€¯11%) was achieved for anaerobically pre-treated municipal wastewater at low temperature (21 - 15 °C), with a nitrogen removal rate of 37 ±â€¯3 g N/(m3·d) at 15 °C. The ammonium oxidizing bacteria were more abundant in the activated sludge, while anammox bacteria were primarily located in biofilm attached onto the carriers surface. Nitrite oxidizing bacteria (NOB) activity was similar between both fractions and its specific activity decreased more than that of other populations when the operating temperature was reduced. Furthermore, the IFAS operational strategy (aerobic/anoxic periods) allowed an efficient NOB activity suppression inside the reactor, which accounted only for the 10 - 20% of the maximum potential activity.


Assuntos
Compostos de Amônio , Esgotos , Reatores Biológicos , Nitritos , Nitrogênio , Oxirredução , Águas Residuárias
7.
Water Sci Technol ; 80(4): 659-664, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31661445

RESUMO

Low intensity ultrasonication (US) was applied to stimulate the biological activities in anaerobic digestion (AD) process. The enhancement in methane production was used to investigate the sono-biostimulation effects on the process performance. The 32% higher CH4 production was observed over control at best US intensity and irradiation time of 0.0028 W/mL and 120 s, respectively. The sono-biostimulation effects in terms of higher CH4 generation over control lasted for 45 h. The increase in the concentration of NH4+-N and K+ considered the indication of cell lysis under applied US conditions. At best US intensity and irradiation time, the NH4+-N and K+ fraction in the medium remained similar as of control, which indicated that no cell lysis occurred. The preliminary findings of the study showed that low intensity US can be a promising solution to enhance the process efficiency in terms of higher methane production with minimal energy requirement.


Assuntos
Metano , Esgotos , Anaerobiose
8.
Water Sci Technol ; 80(4): 717-726, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31661451

RESUMO

Diclofenac (DCF) is one of the most frequently detected non-steroidal anti-inflammatory drugs (NSAIDs) in the water environment. One of the main removal routes of DCF in wastewater is sludge adsorption, and the mechanisms need to be investigated. In this study, the effects of adsorption time, temperature, pH value, and ionic strength on the adsorption of DCF on suspended particles (SP), secondary sedimentation tank sludge (SSTS) and concentrated sludge (CS) were investigated. The results showed that most of the adsorption of DCF by the three matrices was conducted in the first 4 h and equilibrium was achieved at 8 h. The adsorption kinetics were well fitted with the pseudo-second-order model and the rate constants were 0.29-0.88 mg·(µg·min)-1, with chemical adsorption as the dominant one. Adsorption isotherm conformed to Freundlich, Langmuir and Linear adsorption isotherm models. The order of adsorption capacity was: CS > SSTS > SP, which was proportional to the organic matter content and specific surface area of the adsorbents. The decrease of the pH value and the increase of ionic strength promoted the adsorption of DCF. The results can provide data support for the removal of DCF from different treatment unit types in wastewater treatment plants.


Assuntos
Esgotos , Poluentes Químicos da Água , Adsorção , Diclofenaco , Concentração de Íons de Hidrogênio , Cinética , Águas Residuárias
9.
Water Sci Technol ; 80(4): 794-805, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31661458

RESUMO

The removal of polycyclic aromatic hydrocarbons (PAHs) in activated sludge was evaluated using two laboratory-scale bioreactors, coupled or not with a disintegration system (sonication). Mass balances performed on each system underlined that PAHs removal was significantly improved after sludge disintegration, especially for the higher molecular weight PAHs studied, which tended to adsorb to suspended matter. A model was developed in order to study the effect of sludge disintegration on the content of dissolved and colloidal matter (DCM), and to predict the potential impacts on PAHs availability and degradation. Results showed that this new model was efficient for capturing apparent degradation improvement trends and for discriminating between the involved mechanisms. This study showed that DCM content increased after sludge disintegration, and proved to be the main driver for improving PAHs apparent degradation.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Esgotos , Reatores Biológicos
10.
Bioresour Technol ; 294: 122196, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31574364

RESUMO

The partial nitrification process can reduce the aeration energy consumption in bioreactors by 25%. Low-intensity ultrasound (0.25 W·mL-1) was applied during the partial nitrification process to evaluate its effects on start-up and temperature resilience. Ultrasound application led to rapid start-up of the partial nitrification process (within 18 d) with a nitrite accumulation ratio of above 80% at 18 °C. Moreover, when the temperature was increased to 28 °C, the partial nitrification process was effectively maintained with a nitrite accumulation ratio of above 80%. Ultrasonic treatment for a long duration had a positive effect on ammonia oxidizing bacteria of the genus Nitrososphaera, whereas the population of nitrite oxidizing bacteria, Nitrospira, decreased. The temperature resilience of Nitrososphaera was also enhanced. These findings indicate that ultrasound induces rapid start-up of the partial nitrification process and enhances the temperature resilience of Nitrososphaera.


Assuntos
Nitrificação , Esgotos , Amônia , Reatores Biológicos , Nitritos , Temperatura Ambiente , Águas Residuárias
11.
Bioresour Technol ; 294: 122161, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31581041

RESUMO

A two-sludge system with separated phosphorus removal unit and nitrification unit was used to treat the actual municipal sewage deficient in organic carbon sources, with the carbon/nitrogen (C/N) ratio of 4.39. The system was first operated as anaerobic/oxic-nitrification (A/O-N) mode for 60 days (phase I), and then transformed into anaerobic/anoxic/oxic-nitrification (A/A/O-N) mode for the next following 80 days (phase II). Noteworthy, oxygen and nitrate acted as electronic acceptors for phosphorus removal in chronological order. Results indicated that deep phosphorus removal and complete nitrification were achieved at both phase I and phase II, and the system exhibited a higher microbial diversity. Microbial community abundance on genus level analysis indicated that Dechloromonas and Accumulibacter were respectively accumulated with 11.6 and 2.42% abundance (A/A/O sludge); and 9.31 and 1.29% Nitrospira and Nitrosomonas occupied the biofilm, and they performed denitrifying phosphorus removal (DNPR) and nitrification, respectively.


Assuntos
Microbiota , Águas Residuárias , Reatores Biológicos , Carbono , Desnitrificação , Nitrificação , Nitrogênio , Nutrientes , Fósforo , Esgotos , Eliminação de Resíduos Líquidos
12.
Bioresour Technol ; 294: 122218, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31606600

RESUMO

Fermentation slurry from food waste (FSFW) generated by acidogenic fermentation at mesophilic temperature was utilized to improve the nutrients removal from wastewater. Organic acids (such as lactate and volatile fatty acids) in the FSFW behaved as readily biodegradable carbon sources, while the particulate and macromolecular organics acted as slowly biodegradable carbon sources during denitrification processes. The FSFW dosage significantly influenced the nitrogen removal performance, and a C/N ratio (in terms of chemical oxygen demand to nitrogen ratio) of 8 could achieve complete denitrification in the batch tests. In a sequencing batch reactor (SBR) using FSFW for long-term wastewater treatment, extracellular polymeric substances (EPS) gradually accumulated, sludge particle size significantly increased, and microbial communities were selectively enriched, which contributed to promoting the nitrogen (>80%) and phosphate (90.1%) removal efficiencies. Overall, the FSFW produced by acidogenic fermentation under mesophilic temperature served as an excellent intermediary between FW valorization and wastewater treatment.


Assuntos
Eliminação de Resíduos , Águas Residuárias , Reatores Biológicos , Carbono , Desnitrificação , Fermentação , Alimentos , Nitrogênio , Nutrientes , Esgotos , Eliminação de Resíduos Líquidos
13.
Bioresour Technol ; 294: 122234, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610488

RESUMO

In this study, a biological thermal-alkaline synergistic system was successfully established to enhance the hydrolysis-acidification efficiency of high-solids and low-organic-content sludge (HS-LOC-S). The results indicated that the highest hydrolysis rate was obtained at pH of 12 (52.62%) leading to the highest production of soluble chemical oxygen demand (SCOD) and soluble protein (SP). The highest acidification rate was observed at pH of 10 (32.15%), leading to the highest production of volatile fatty acids (VFAs). At pH of 10, average sludge size reduced by 24.60%, and the proportion of biodegradable dissolved organic matter (DOM) produced by synergistic system increased by 15.82%, when compared with those of raw sludge. Moreover, results of 16S rRNA clearly validated that the relative abundance of hydrolytic and acidogenic microbes (e.g. Tepidimicrobium, Coprothermobacter) abundantly enriched at pH of 10 (49.88%) was greatly higher than others, which was the main reason for its maximum VFAs accumulation.


Assuntos
Ácidos Graxos Voláteis , Esgotos , Concentração de Íons de Hidrogênio , Hidrólise , RNA Ribossômico 16S
14.
Bioresour Technol ; 294: 122235, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610493

RESUMO

This study compared the effects of sewage sludge-derived pyrochar (PC300, PC500, and PC700) and hydrochar (HC180, HC240, and HC300) on mesophilic anaerobic digestion of waste activated sludge (WAS). It was demonstrated that hydrochar can better promote the methane production compared with pyrochar. The highest accumulative methane yield of 132.04 ±â€¯4.41 mL/g VSadded was obtained with HC180 addition. In contrast, the PC500 and PC700 showed a slightly negative effect on methane production. Sludge-derived HC not only accelerated the solubilization and hydrolysis of sludge floc, but also improved the production of acetic acid and propionate, further resulting in improved methane production. Simultaneously, the syntrophic microbes facilitating direct interspecies electron transfer (DIET) such as Syntrophomonas, Peptococcaceae, Methanosaeta and Methanobacterium bred rapidly with the addition of HCs. These results indicated that the hydrochar is more ideal as the accelerant to promote the methane production from mesophilic anaerobic digestion of WAS than the pyrochar.


Assuntos
Carvão Vegetal , Esgotos , Anaerobiose , Reatores Biológicos , Metano
15.
Bioresour Technol ; 294: 122236, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610499

RESUMO

A 10-liter single chamber vertical baffle flow biocathode microbial electrochemical system (MES) with microbial separator was designed for wastewater treatment. The anode and cathode compartments were incompletely isolated by the microbial separator, which enabled module integration and centralized sludge collection of MES. The effluent COD was <50 mg L-1 with COD removal of 86 ±â€¯2% and low sludge yield rate of 0.05 ±â€¯0.02 g-sludge g-1 -COD. The MES performance was mainly restricted by biocathodes and supporting matrixes with higher permeability resulted in better cathode performance. The MES obtained the maximum power density of 67.5 ±â€¯7.8 mW m-2 with two layers of filter cloth and one layer of polyurethane sponge (S2P1) and supporting matrix with moderate permeability was more suitable in overall power generation and anode stability. The influences on bio-community of both cathodes and separators by the permeability of supporting matrixes were observed.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Esgotos , Têxteis , Águas Residuárias
16.
J Environ Manage ; 252: 109684, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31622794

RESUMO

In the present study, an artificial neural network (ANN) was implemented to estimate the hydrogen production from confectionery wastewater. From the experimental investigation, it could be concluded that maximum COD removal efficiency of 99% and hydrogen production rate of 6570 mL/d was achieved at 7.00 kg COD/m3d and 24 h HRT. To validate this, a back propagation ANN configuration of 4-12-4-2 was opted. The modelling was performed using the input parameters like time, influent chemical oxygen demand (COD), effluent pH and volatile fatty acids (VFA). The correlation coefficient between the experimental and predicted hydrogen production rate was 0.996. The result of the tested data for hydrogen production rate was successful. The calculated average percentage error (APE) for hydrogen production rate was 0.0004. As the APE values were closer to zero, the trained ANN model fitted well with the experimental data.


Assuntos
Eliminação de Resíduos Líquidos , Águas Residuárias , Anaerobiose , Reatores Biológicos , Hidrogênio , Redes Neurais (Computação) , Esgotos
17.
Waste Manag ; 100: 306-317, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31574459

RESUMO

Thermal drying is an increasingly common post-treatment for digestate-solids, but prone to N losses via ammonia (NH3) volatilization. Acidification with strong acids prior to drying may retain ammonium (NH4+) in the solids. Natural zeolites can provide adsorption sites for exchangeable cations as ammonium and porosity for free ammonia, which has the potential to contribute to higher N retention in the dried solids. The present study investigated whether the zeolite addition increases NH4+-N retention during thermal drying of two digestate solids (manure based, MDS; sewage sludge based, SDS), and whether any synergistic effects of combining acidification with sulfuric acid and the addition of zeolite exist. Operating conditions included four pH levels (non-acidified control, adjusted to 8.0, 7.5, 6.5 with concentrated sulfuric acid), four zeolite addition rates (0%, 1%, 5% and 10%), fixed drying temperature (130 °C) and fixed air ventilation rate (headspace exchange rate of 286 times hour-1). Zeolite addition significantly increased NH4+-N retention from 18.0% of initial NH4+-N in the non-acidified control up to a maximum of 57.4% for MDS, and from 76.6% to 94.5% for SDS. No positive synergistic effect between acidification and zeolite addition was observed, with acidification being the dominant. Nevertheless, zeolite has the potential to be a safe and easy-to-handle alternative to concentrated sulfuric acid.


Assuntos
Esterco , Zeolitas , Amônia , Nitrogênio , Esgotos
18.
J Environ Manage ; 252: 109639, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31586744

RESUMO

Microalgae are a potential source of biomass for the production of energy, which is why the amount of research on this topic has increased in recent years. This work describes the state of the art of microalgae production from wastewater treatment plants (WWTP), its potential to generate electricity and the scale in which it is possible. The methodology used was a systematic review of the gasification of microalgae from 49 articles selected. Based on the review, a conceptual scenario for microgeneration in WWTP using as feedstock microalgae for thermal gasification was developed. The most consistent assumptions for a real scale microgeneration are microalgae production in open ponds using domestic sewage as a nutritional medium; the use of the flocculation process in process of harvesting; microalgae to energy through thermal gasification process using a downdraft gasifier. Considering a WWTP with a 3000 m3/d flux capacity, 860 kg/d of dry microalgae biomass might be produced. For which, gasification has a production potential of 0.167 kWh/m3 of treated sewage, but the energy balance is compromised by the drying process. However, when the biogas produced in anaerobic treatment enter in the model, it is possible to add a surplus of electricity of 0.14 kWh/m3 of treated sewage. Finally, a cost estimate is made for the acquisition of drying and gasification-electricity generation systems. For this scenario, the results suggest that the investments may be financially returned after five years, with additional potential for further optimization.


Assuntos
Microalgas , Biocombustíveis , Biomassa , Esgotos , Águas Residuárias
19.
Water Sci Technol ; 80(3): 418-425, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31596253

RESUMO

There are hundreds of full-scale upflow anaerobic sludge blanket (UASB) reactors in operation in various parts of the tropical world, notably in India and Latin America, Brazil being the holder of the largest park of anaerobic reactors for sewage treatment in the world. Despite the recognized advantages of UASB reactors, there are problems that have prevented their maximum operational performance. Neglecting the existence and delaying the solution of these challenges can jeopardize the important advances made to date, impacting the future of anaerobic technology in Brazil and in other countries. This work aims to evaluate the operational performance of five full-scale UASB reactors in Brazil, taking into account a monitoring period ranging between two and six years. The main observed design, construction, and operational constraints are discussed. Some outlooks for important upcoming developments are also provided, considering that most of the observed drawbacks can be tackled without significant increases on reactor costs.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Anaerobiose , Reatores Biológicos , Brasil , Índia
20.
Water Sci Technol ; 80(3): 487-498, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31596260

RESUMO

Methylparaben and triclosan are antimicrobial agents widely used as preservatives in a variety of personal care and pharmaceutical products. Wastewater is considered the main source of these compounds in the environment. Expanded granular sludge bed (EGSB) reactors are a high rate technology for wastewater treatment based on biological processes and have been shown to be efficient in removing different types of compounds; however, little is known about the effect of contaminants such as methylparaben and triclosan on their behavior and effectiveness. In this study, we evaluate and compare the microbial and physicochemical behavior of EGSB systems during methylparaben and triclosan removal. The presence of different concentrations of pollutants had an influence on the cluster organization of microbial communities, especially bacteria. However, this did not affect the stability and performance of the EGSB systems. The banding patterns of the denaturing gradient gel electrophoresis of archaea demonstrated the constant presence and abundance of Methanosaeta concilii throughout all stages of operation, showing that this microorganism played a fundamental role in the stability of the reactors for the production of methane. The type of compound and its concentration influenced the expression of the mcrA and ACAs genes; however, these changes did not alter the stability and performance of the EGSB systems.


Assuntos
Parabenos/análise , Triclosan/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Reatores Biológicos , Esgotos
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