10,993 results match your criteria activated sludge


Removal of antibiotic resistance genes from secondary effluent by processes combining nano-iron, ultrasound-activated persulfate, and ultrafiltration.

Water Sci Technol 2021 Apr;83(7):1578-1590

Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing 100044, China E-mail:

Antibiotic resistance genes (ARGs), as a new type of environmental pollutant that threaten human health, have been detected in the effluent of sewage treatment systems. In this study, the removal from water of ARGs, 16S rRNA, class 1 integron (intI1), and dissolved organic carbon (DOC) were investigated using processes combining nano-iron (nFe), ultrasound (US), activated persulfate (PS) and ultrafiltration (UF). The oxidation mechanism was also studied. Read More

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Current Trends on Role of Biological Treatment in Integrated Treatment Technologies of Textile Wastewater.

Front Microbiol 2021 25;12:651025. Epub 2021 Mar 25.

Biochemical Engineering Group, Institute of Science and Technology of Food and Environment (INCITAA), Faculty of Engineering, National University of Mar del Plata, Mar del Plata, Argentina.

Wastewater discharge is a matter of concern as it is the primary source of water pollution. Consequently, wastewater treatment plays a key role in reducing the negative impact that wastewater discharge produce into the environment. Particularly, the effluents produced by textile industry are composed of high concentration of hazardous compounds such as dyes, as well as having high levels of chemical and biological oxygen demand, suspended solids, variable pH, and high concentration of salt. Read More

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Enhanced anaerobic digestion of waste-activated sludge via bioaugmentation strategy-Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt2) analysis through hydrolytic enzymes and possible linkage to system performance.

Bioresour Technol 2021 Mar 31;332:125014. Epub 2021 Mar 31.

School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea. Electronic address:

In this study, anaerobic digestion of waste-activated sludge was bioaugmented with hydrolytic bacteria, Bacteroidetes uniformis (Bacteroidetes, B) and Clostridium sp. (Firmicutes, F) at various dosages. Bioaugmentation resulted in enhanced methane conversion of waste-activated sludge. Read More

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Biodegradation of bisphenol-A polycarbonate plastic by Pseudoxanthomonas sp. strain NyZ600.

J Hazard Mater 2021 Mar 31;416:125775. Epub 2021 Mar 31.

State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address:

Bisphenol-A polycarbonate (PC) is a widely used engineering thermoplastic and its release has caused damage to the ecosystem. Microbial degradation of plastic represents a sustainable approach for PC reduction. In this study, a bacterial strain designated Pseudoxanthomonas sp. Read More

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Aerobic sludge digestion is distinguishingly affected by the different entering pathways of zinc oxide nanoparticles.

J Hazard Mater 2021 Apr 1;416:125799. Epub 2021 Apr 1.

Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia. Electronic address:

Zinc oxide nanoparticles (ZnO NPs) are widespread emerging pollutants raising global concerns about their influences on biological wastewater treatment processes. However, the impacts of ZnO NPs on aerobic sludge digestion that is a major sludge treatment process remain unknown. Herein, this study comprehensively investigated the key influences of ZnO NPs on aerobic digestion of waste activated sludge (WAS) and the potential mechanisms involved. Read More

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Effect of microbial community structure in inoculum on the stimulation of direct interspecies electron transfer for methanogenesis.

Bioresour Technol 2021 Apr 5;332:125100. Epub 2021 Apr 5.

School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 02841, South Korea; KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, South Korea. Electronic address:

To investigate how the seed microbial community structure affects the improvement of methanogenesis efficiency through direct interspecies electron transfer (DIET), a biomethane potential (BMP) test was conducted using sludge collected from a total of six anaerobic digesters. DIET-stimulating microbial populations were investigated by 16S rRNA gene sequence analysis. Correlations between microbial community composition and methane production performance by DIET were analyzed. Read More

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Continuous anaerobic oxidation of methane: Impact of semi-continuous liquid operation and nitrate load on NO production and microbial community.

Chemosphere 2021 Mar 31;278:130441. Epub 2021 Mar 31.

Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingeniería, Unidad Académica Juriquilla, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro, 76230, Mexico. Electronic address:

This work proves the feasibility of employing regular secondary activated sludge for the enrichment of a microbial community able to perform the anaerobic oxidation of methane coupled to nitrate reduction (N-AOM). After 96 days of activated sludge enrichment, a clear N-AOM activity was observed in the resulting microbial community. The methane removal potential of the enriched N-AOM culture was then studied in a stirred tank reactor (STR) operated in continuous mode for methane supply and semi-continuous mode for the liquid phase. Read More

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Linkage among the combined temperature-retention time condition, microbial interaction, community structure, and process performance in the hydrolysis of waste activated sludge.

Bioresour Technol 2021 Mar 27;331:125029. Epub 2021 Mar 27.

School of Engineering, University of Guelph, Ontario N1G 2W1, Canada. Electronic address:

Numerous studies have revealed the effect of temperature and hydraulic retention time (HRT) on microbiota in sludge biological hydrolysis (BH). However, few scholars have explored the combined effect of these two critical BH parameters. This study explored the BH performance and community structures over 12 combined temperatures-HRT conditions for temperatures from 35 °C to 55 °C and HRTs from 1. Read More

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Overlooked Ecological Roles of Influent Wastewater Microflora in Improving Biological Phosphorus Removal in an Anoxic/Aerobic MBR Process.

Environ Sci Technol 2021 Apr 8. Epub 2021 Apr 8.

School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China.

The ecological roles of influent microflora in activated sludge communities have not been well investigated. Herein, parallel lab-scale anoxic/aerobic (A/O) membrane bioreactors (MBRs), which were fed with raw (MBR-C) and sterilized (MBR-T) municipal wastewater, were operated. The MBRs showed comparable nitrogen removal but superior phosphorus removal in MBR-C than MBR-T over the long-term operation. Read More

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Effect of iron nitrate modification on elimination of organic matter from landfill leachate by sludge-based activated carbon.

Waste Manag Res 2021 Apr 8:734242X211009966. Epub 2021 Apr 8.

School of Environmental Engineering, Nanjing Institute of Technology, Nanjing, Jiangsu, P.R. China.

Sludge-based activated carbons (SACs) prepared from sewage sludge and corn straw, were modified by ferric nitrate, and the unmodified SAC and modified SAC were used as the adsorbing agent to treat the landfill leachate, the elimination capacity for chemical oxygen demand (COD) and organic matter in leachate were studied. Based on this, the physicochemical properties of SACs and the components changes in leachate were analyzed and characterized by X-ray photoelectron spectroscopy and three-dimensional fluorescence spectroscopy. The results showed that under optimal experimental conditions, the elimination capacities of SAC372 for COD, biological oxygen demand over 5 days, and NH-N in the leachate were 81. Read More

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Occurrence, effect, and fate of residual microplastics in anaerobic digestion of waste activated sludge: A state-of-the-art review.

Bioresour Technol 2021 Mar 23:125035. Epub 2021 Mar 23.

Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.

The plastic products have large consumption over last decades, resulting in a serious microplastics (MPs) pollution. Specially, the main removal way of MPs from wastewater is to transfer MPs from liquid to solid phase, leading to its enrichment in waste activated sludge (WAS). Anaerobic digestion has been served as the most potential technique to achieve both resource recovery and sludge reduction, herein this review provides current information on occurrence, effect, and fate of MPs in anaerobic digestion of WAS. Read More

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A multi-component model for granular activated carbon filters combining biofilm and adsorption kinetics.

Water Res 2021 Mar 22;197:117079. Epub 2021 Mar 22.

Technical University Darmstadt, Institute IWAR, Chair of Wastewater Engineering, Franziska-Braun-Straße 7, 64287 Darmstadt, Germany. Electronic address:

Along with the rise of biological active granular activated carbon (bGAC) filtration as advanced treatment technology for wastewater treatment plant (WWTP) effluents, the mathematical representation of such systems is gaining increasing importance. This work introduces a model that describes the performance of bGAC-filters for Dissolved Organic Carbon (DOC) removal from a WWTP effluent. The DOC removal within bGAC-filters is accomplished by two mechanisms: adsorptive removal and biological transformation. Read More

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Selective enrichment of comammox from activated sludge using antibiotics.

Water Res 2021 Mar 24;197:117087. Epub 2021 Mar 24.

Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong SAR, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong, China. Electronic address:

While the ubiquitous presence of comammox in engineered systems provides the foundation of developing a novel biological nitrogen removal process, factors contributing to the comammox dynamics in engineered systems have not been well resolved. Here, we investigate the long-term effects of ten different antibiotics on microbial community dynamics in activated sludge and the results show that both types and concentrations of antibiotics affect the taxonomic composition of nitrifiers, including comammox, ammonia-oxidizing bacteria, and canonical nitrite-oxidizing bacteria. Specifically, phylogenetically different comammox Nitrospira were selectively enriched by four types of antibiotics (i. Read More

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Changes in bacterial diversity of activated sludge exposed to titanium dioxide nanoparticles.

Biodegradation 2021 Apr 3. Epub 2021 Apr 3.

Equipe Environment et Microbiologie, MELODY Group, IPREM UMR CNRS 5254, Université de pau et des pays de l'Adour, BP 1155, 64013, Pau Cedex, France.

The rapid growth of the use of nanomaterials in different modern industrial branches makes the study of the impact of nanoparticles on the human health and environment an urgent matter. For instance, it has been reported that titanium dioxide nanoparticles (TiO NPs) can be found in wastewater treatment plants. Previous studies have found contrasting effects of these nanoparticles over the activated sludge process, including negative effects on the oxygen uptake. Read More

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Microbial Population Dynamics in Model Sewage Treatment Plants and the Fate and Effect of Gold Nanoparticles.

Toxics 2021 Mar 10;9(3). Epub 2021 Mar 10.

Department of Ecotoxicology, Fraunhofer Institute for Molecular Biology and Applied Ecology, Auf dem Aberg 1, 57392 Schmallenberg, Germany.

Adequate functioning of a sewage treatment plant (STP) is essential to protect the downstream aquatic environment (ECHA 2017), and information on the degradability of chemicals and their toxicity to activated sludge microorganisms is required. An environmental realistic higher tier test is a STP simulation test as described in OECD 303A (2001) which for nanoparticles can also be used to study their sorption behavior to activated sludge. However, information is limited on the influence of synthetic sewage on the microbial community of the activated sludge. Read More

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Freezing pretreatment assists potassium ferrate to promote hydrogen production from anaerobic fermentation of waste activated sludge.

Sci Total Environ 2021 Mar 23;781:146685. Epub 2021 Mar 23.

State Key Laboratory of Pollution Control and Resource Reuse, International Joint Research Center for Sustainable Urban Water System, College of Environmental Science & Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.

Anaerobic fermentation is an eco-friendly technology for waste activated sludge (WAS) treatment, during which resource recycle can be achieved. However, traditional sludge anaerobic fermentation is limited by the poor efficiency. We herein reported a novel high-efficiency technology by combining freezing with potassium ferrate (PF) for sludge pretreatment to promote hydrogen production from anaerobic fermentation. Read More

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An innovative cation regulation-based anaerobic fermentation strategy for enhancing short-chain fatty acids production from waste activated sludge: Metal ion removal coupled with Na-regulation.

Bioresour Technol 2021 Mar 2;331:124921. Epub 2021 Mar 2.

College of Civil Engineering, Fuzhou University, Fujian 350116, PR China.

This study proposed a cation-regulation strategy based on metal ion removal coupled Na-regulation for enhancing anaerobic fermentation of waste activated sludge. The optimal treatment condition was: cation-exchange resin dosage of 1.75 g/g SS for 1-day treatment, followed by Na-enhanced anaerobic fermentation at NaCl concentration of 20 g/L. Read More

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Effect of carrier particle size on enrichment and shift in nitrifiers community behaviors for treating increased-strength wastewater.

Water Environ Res 2021 Apr 2. Epub 2021 Apr 2.

Department of Environmental Engineering, School of Chemical & Environmental Engineering, Jiangsu University of Technology, Changzhou, 213001, China.

In activated sludge systems, adding carriers can improve nitrifiers enrichment. Different attachment area induced by different particle sizes of carriers may result in different nitrifiers community. This research investigated the effect of different particle sizes of coal ash on nitrifiers enrichment treating increased strength wastewater. Read More

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Efficiency of integrated electrooxidation and anaerobic digestion of waste activated sludge.

Biotechnol Biofuels 2021 Apr 1;14(1):81. Epub 2021 Apr 1.

Instituto de Ingeniería, UNAM, P.O. Box 70-186, 04510, Mexico City, Mexico.

Background: Most of the organic content of waste activated sludge (WAS) comprises microbial cells hard to degrade, which must be pre-treated for energy recovery by anaerobic digestion (AD). Electrooxidation pre-treatment (EOP) with boron-doped diamond (BDD) electrode have been considered a promising novel technology that increase hydrolysis rate, by the disintegrating cell walls from WAS. Although electrochemical oxidation could efficiently solubilize organic substances of macromolecules, limited reports are available on EOP of WAS for improving AD. Read More

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Emergence of IMP-8-Producing Causing Urinary Tract Infection in China.

Front Microbiol 2021 15;12:585716. Epub 2021 Mar 15.

Department of Laboratory Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.

The emergence of carbapenem resistance (CR) caused by hydrolytic enzymes called carbapenemases has become a major concern worldwide. So far, CR genes have been widely detected in various bacteria. However, there is no report of CR gene harboring . Read More

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Connecting structure to function with the recovery of over 1000 high-quality metagenome-assembled genomes from activated sludge using long-read sequencing.

Nat Commun 2021 03 31;12(1):2009. Epub 2021 Mar 31.

Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.

Microorganisms play crucial roles in water recycling, pollution removal and resource recovery in the wastewater industry. The structure of these microbial communities is increasingly understood based on 16S rRNA amplicon sequencing data. However, such data cannot be linked to functional potential in the absence of high-quality metagenome-assembled genomes (MAGs) for nearly all species. Read More

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Enhancing methanogenic fermentation of waste activated sludge via isoelectric-point pretreatment: Insights from interfacial thermodynamics, electron transfer and microbial community.

Water Res 2021 Mar 19;197:117072. Epub 2021 Mar 19.

State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China. Electronic address:

The usefulness of waste activated sludge (WAS) as an energy source is limited by the poor generation efficiency of methane from WAS, which is mainly due to the complex nature of sludge and low abundance of functional microbes. In this study, the interfacial thermodynamics, electron transfer and microbial community of sludge were investigated to reveal the enhancing effects of isoelectric-point (pI) pretreatment on the efficiency of methane generation from WAS. Experimentally, after pI pretreatment, the methane production potential, maximum methane production rate and maximum methane proportion in the biogas increased by 122. Read More

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Microbial Communities in Full-Scale Wastewater Treatment Systems Exhibit Deterministic Assembly Processes and Functional Dependency over Time.

Environ Sci Technol 2021 Mar 30. Epub 2021 Mar 30.

School of Energy and Environment, City University of Hong Kong, Hong Kong SAR, China.

Microbial communities constitute the core component of biological wastewater treatment processes. We conducted a meta-analysis based on the 16S rRNA gene of temporal samples obtained from diverse full-scale activated sludge and anaerobic digestion systems treating municipal and industrial wastewater (collected in this study and published previously) to investigate their community assembly mechanism and functional traits over time, which are not currently well understood. The influent composition was found to be the main driver of the microbial community's composition, and relatively large proportions of specialist (26. Read More

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Paracoccus binzhouensis sp. nov., isolated from activated sludge.

Arch Microbiol 2021 Mar 28. Epub 2021 Mar 28.

School of Biological Science and Technology, University of Jinan, 250022, Jinan, PR China.

A gram-stain-negative, non-motile and rod-shaped strain, designated wg1, was isolated from activated sludge obtained from wastewater treatment plant in Binzhou (Shandong province, PR China). Growth of strain wg1 occurred at 25-45 °C (optimum, 37 °C), at pH 7.0-9. Read More

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Sulfite pretreatment enhances the biodegradability of primary sludge and waste activated sludge towards cost-effective and carbon-neutral sludge treatment.

Sci Total Environ 2021 Mar 20;780:146634. Epub 2021 Mar 20.

Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.

Sulfite pretreatment is effective for enhancing the biodegradability of waste activated sludge (WAS). However, the mixture of primary sludge (PS) and WAS is normally collected and treated together, and the effect of sulfite on the sludge mixture remains unclear. Here, we reported that sulfite pretreatment could disintegrate the flocs of the sludge mixture and improve sludge biodegradability. Read More

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A review of the adsorption-biological hybrid processes for the abatement of emerging pollutants: Removal efficiencies, physicochemical analysis, and economic evaluation.

Sci Total Environ 2021 Mar 18;780:146554. Epub 2021 Mar 18.

Catalysis, Reactors, and Control Research Group (CRC), Department of Chemical and Environmental Engineering, University of Oviedo, Julián Clavería s/n, 33006 Oviedo, Spain. Electronic address:

The limited efficiency of conventional wastewater treatment plants (WWTPs) in emerging pollutants (EPs) removal encourages the development of alternative technologies for the adequate treatment of wastewater, due to its adverse effects on human health and ecosystems. The biological, physical or chemical hybrid technologies to treat EPs results interesting since they can enhance the performance of WWTPs. Among them, hybrid adsorption/biological technology could offer different possibilities that are explored in this work (PAC-MBR, PACT/GAC-CAS, BAC configurations). Read More

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Heterotrophic enzymatic biotransformations of organic micropollutants in activated sludge.

Sci Total Environ 2021 Mar 18;780:146564. Epub 2021 Mar 18.

Cretus Institute, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain.

While heterotrophic microorganisms constitute the major fraction of activated sludge biomass, the role of heterotrophs in the biotransformation of organic micropollutants (OMPs) has not been fully elucidated. Yet, such knowledge is essential, particularly when conceiving novel wastewater treatment plants based on a two-stage process including an A-stage under heterotrophic conditions and a B-stage based on anammox activity. Biotransformation of OMPs in activated sludge is thought to mostly occur cometabolically thanks to the action of low specificity enzymes involved in the metabolism of the primary substrates. Read More

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Shaping biofilm microbiomes by changing GAC location during wastewater anaerobic digestion.

Sci Total Environ 2021 Mar 17;780:146488. Epub 2021 Mar 17.

Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada. Electronic address:

The addition of granular activated carbon (GAC) to up-flow anaerobic sludge blanket (UASB) reactors treating synthetic wastewater enhanced methane production by stimulating direct interspecies electron transfer (DIET). A modified UASB reactor with GAC packed in plastic carriers that allowed the GAC to float in the upper reactor zone achieved enhanced performance compared to a UASB reactor with GAC settled at the bottom of the reactor. Microbial communities in the biofilms developed on settled or floated GAC were compared. Read More

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