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1.
Braz. j. biol ; 83: e248305, 2023. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339359

RESUMO

Abstract Fertilization with dehydrated sewage sludge can speed up the recovery process of degraded areas due to nutrients concentration, favoring the development of pioneer plants such as Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) and the emergence of insects. This study aimed the evaluation of chewing, pollinating insects, predators, their ecological indices and relationships on A. auriculiformis plants fertilized with dehydrated sewage sludge. The experimental design was completely randomized with two treatments (with and without dehydrated sewage sludge) and 24 repetitions. The prevalence of chewing insects Parasyphraea sp. (Coleoptera: Chrysomelidae), Nasutitermes sp. (Blattodea: Termitidae), and Tropidacris collaris (Stoll, 1813) (Orthoptera: Romaleidae), defoliation, and ecological indices of abundance of Coleoptera and Orthoptera were observed on fertilized A. auriculiformis. Acacia auriculiformis plants, with a superior number of branches/tree, revealed greater abundance of Coleoptera and Orthoptera, species richness of pollinating insects, defoliation, numbers of Parasyphraea sp. and T. collaris. The ones with larger leaves/branches displayed greater abundance of species richness of Coleoptera and Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae). Therefore, the use of A. auriculiformis plants, fertilized with dehydrated sewage sludge, is promising in the recovery of degraded areas due to the ecological indices increase of chewing and pollinators insects and spiders in the analyzed area.


Resumo A fertilização com lodo de esgoto desidratado pode acelerar o processo de recuperação de áreas degradadas devido à concentração de nutrientes, favorecendo o desenvolvimento de plantas pioneiras tais como Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) e de seus insetos. O objetivo deste trabalho foi avaliar os insetos mastigadores, polinizadores e predadores e seus índices e relações ecológicas em plantas de A. auriculiformis fertilizadas com lodo de esgoto desidratado, em área degradada, durante 24 meses. O delineamento foi inteiramente casualizados com dois tratamentos (com e sem adubação com lodo de esgoto desidratado) e 24 repetições (uma repetição = uma planta). O maior número de insetos mastigadores Parasyphraea sp. (Coleoptera: Chrysomelidae), Nasutitermes sp. (Blattodea: Termitidae) e Tropidacris collaris (Stoll, 1813) (Orthoptera: Romaleidae), de desfolha, e do índice ecológico abundância de Coleoptera e de Orthoptera foram maiores em plantas de A. auriculiformis fertilizadas do que nas não fertilizadas com lodo de esgoto desidratado. Plantas de A. auriculiformis, com maior quantidade de galhos/árvore, apresentaram maiores abundâncias de Coleoptera e Orthoptera, riqueza de espécies de insetos polinizadores, desfolha e números de Parasyphraea sp. e T. collaris, e as com maior folhas/galho os de riqueza de espécies de Coleoptera e Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae). Por tanto, a utilização de A. auriculiformis, adubada com lodo de esgoto desidratado, é promissora na recuperação de áreas degradadas devido ao aumento dos índices ecológicos de insetos mastigadores, polinizadores e aranhas na área.


Assuntos
Animais , Acacia , Fabaceae , Esgotos , Fertilização , Insetos
2.
Braz. j. biol ; 83: e243874, 2023. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285606

RESUMO

Abstract In recent days, cheapest alternative carbon source for fermentation purpose is desirable to minimize production cost. Xylanases have become attractive enzymes as their potential in bio-bleaching of pulp and paper industry. The objective of the present study was to identify the potential ability on the xylanase production by locally isolated Bacillus pumilus BS131 by using waste fiber sludge and wheat bran media under submerged fermentation. Culture growth conditions were optimized to obtain significant amount of xylanase. Maximum xylanase production was recorded after 72 hours of incubation at 30 °C and 7 pH with 4.0% substrate concentration. In the nutshell, the production of xylanase using inexpensive waste fiber sludge and wheat-bran as an alternative in place of expensive xylan substrate was more cost effective and environment friendly.


Resumo Nos últimos dias, a fonte alternativa de carbono mais barata para fins de fermentação é desejável para minimizar o custo de produção. As xilanases têm se tornado enzimas atraentes como seu potencial no biobranqueamento da indústria de papel e celulose. O objetivo do presente estudo foi identificar a capacidade potencial na produção de xilanase por Bacillus pumilus BS131 isolado localmente usando lodo de fibra residual e farelo de trigo em meio de fermentação submersa. As condições de crescimento da cultura foram otimizadas para obter uma quantidade significativa de xilanase. A produção máxima de xilanase foi registrada após 72 horas de incubação a 30 °C e pH 7 com concentração de substrato de 4,0%. Resumindo, a produção de xilanase usando lodo de fibra residual de baixo custo e farelo de trigo como uma alternativa no lugar do substrato de xilano caro foi mais econômica e ecológica.


Assuntos
Bacillus/metabolismo , Bacillus pumilus/metabolismo , Esgotos , Temperatura , Fibras na Dieta , Endo-1,4-beta-Xilanases/metabolismo , Fermentação , Concentração de Íons de Hidrogênio
3.
Environ Monit Assess ; 194(11): 815, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36131097

RESUMO

Sediments are periodically dredged from the major ports in the Gulf of Gabes (GG) during maintenance operations. These sediments are dumped near the coats of Sfax and Gabes cities. In the present study, 6 trace metals (Cd, Cu, Cr, Ni, Pb, and Zn) concentrations were assessed in both sediments and column water taken from the different basins of Sfax port. This study is the first to focus on the microbial and microalgae contaminations of Sfax port sediments. The spatial distributions of trace metals in dredged sediments from the different basins of Sfax port show that the maximum concentrations of Cd (13.75 µg/g), Cu (892.5 µg/g), and Zn (1447 µg/g) exceeded the Geode standard thresholds. The same elements, also detected in the water column, exceeded the toxicity thresholds for phytoplankton, shellfish, and algae (Cd 0.095 µg/l, Cu 4.52 µg/l, and Zn 37 µg/l). The presence of coliforms, indicators of sewage pollution, as pathogenic germs (Pseudomonas), was shown through microbiological examinations of the sediments and water column. The microalgae enumeration showed the abundance of dinoflagellate cysts (stressed form) which attests to the presence of severe conditions in Sfax port. Different toxic species were identified as Prorocentrum lima and Alexandrium minutum. The same trace metal sources and abundance in Sfax port and GG sediments suggest the hypothesis of their transfer from their disposal sites in coastal areas to deeper depths in the GG and until Boughrara lagoon (BL). As trace metals, microalgae species were also transferred by hydrodynamic currents inside the GG where they found suitable conditions to their proliferation causing the seawater coloration phenomenon, eutrophication, and degradation of the aquatic system.


Assuntos
Metais Pesados , Oligoelementos , Poluentes Químicos da Água , Cádmio , Monitoramento Ambiental , Sedimentos Geológicos , Chumbo , Metais Pesados/análise , Esgotos , Oligoelementos/análise , Tunísia , Água , Poluentes Químicos da Água/análise
4.
Microb Genom ; 8(9)2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36107145

RESUMO

Delftia is a diverse betaproteobacterial genus with many strains having agricultural and industrial relevance, including plant-growth promotion, bioremediation of hydrocarbon-contaminated soils, and heavy metal immobilization. Delftia spp. are broadly distributed in the environment, and have been isolated from plant hosts as well as healthy and diseased animal hosts, yet the genetic basis of this ecological versatility has not been characterized. Here, we present a phylogenomic comparison of published Delftia genomes and show that the genus is divided into two well-supported clades: one 'Delftia acidovorans' clade with isolates from soils and plant rhizospheres, and a second 'Delftia lacustris and Delftia tsuruhatensis' clade with isolates from humans and sludge. The pan-genome inferred from 61 Delftia genomes contained over 28 000 genes, of which only 884 were found in all genomes. Analysis of industrially relevant functions highlighted the ecological versatility of Delftia and supported their role as generalists.


Assuntos
Delftia , Metais Pesados , Animais , DNA Bacteriano/genética , Delftia/genética , Humanos , Filogenia , Análise de Sequência de DNA , Esgotos , Solo
5.
Environ Monit Assess ; 194(10): 782, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36098842

RESUMO

Hospital sewage is considered an environment with the potential to favor the spread and increase of multidrug-resistant bacteria (MDR). The increase in antimicrobial resistance is one of the greatest global threats today. Therefore, this study aimed to evaluate the profile of antimicrobial susceptibility and virulence factors in Enterobacteriaceae isolated from the sewage of a tertiary hospital located in southeastern Brazil. For bacterial isolation, membrane filtering, serial dilution, and spread-plate techniques were used. The bacterial isolates were identified using the MALDI-TOF (matrix-assisted laser desorption ionization-time of flight) technique. Antimicrobial susceptibility profile was performed by disk-diffusion test. Virulence genes were screened by Polymerase Chain Reaction (PCR) and the hypermucoviscosity phenotype by string test. In total, 13 enterobacteria distributed in three species were identified (Klebsiella pneumoniae, Escherichia coli, and Citrobacter freundii) and 76.9% (n = 10) were classified as MDR. Two K. pneumoniae demonstrated the hypermucoviscosity phenotype. The virulence genes ycfM and entB were detected in all K. pneumoniae isolates (other genes found were fimH, mrkD, and kfu). The results indicated that the sewage from the analyzed hospital receives MDR bacteria and has the potential to contaminate and spread through the environment.


Assuntos
Anti-Infecciosos , Infecções por Klebsiella , Brasil , Enterobacteriaceae/genética , Monitoramento Ambiental , Escherichia coli , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Esgotos , Centros de Atenção Terciária
6.
Bioresour Technol ; 362: 127867, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36049715

RESUMO

4-Nonylphenol is a typical endocrine-disrupting compound found in waste-activated sludge. This study evaluates the feasibility of blue-green algae (Spirulina platensis)-based biochar as a carbon-neutral material to improve sodium sulfite (S(IV))-mediated sludge purification. Blue-green algae-based biochar is an effective activator (at 500 °C and 3 × 10-6 M) of sodium sulfite and removed 75 % of 4-nonylphenol at pH 6 using at 1.7 g/L of dosage. Possible synergistic relationships among the coexisting oxidizing species (SO3•-, SO4•-, HO•, and 1O2), obvious defect structure, and abundant carbonyl oxygen groups on the surface of the biochar together dived advanced oxidation process. The bacterial consortia promoted the decomposition of biologically available substrates in the biosolid mixture, which led to the enrichment of Denitratisoma, and boosted 4-nonylphenol biodegradation. This study outlines a potential carbon-neutral, cost-effective, and sustainable sludge treatment strategy using renewable blue-green algae-based biochar, aiding 4-nonylphenol biodegradation in waste-activated sludge.


Assuntos
Microalgas , Microbiota , Spirulina , Biodegradação Ambiental , Carvão Vegetal/química , Esgotos/química , Sulfitos
7.
Bioresour Technol ; 362: 127863, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36055541

RESUMO

The morphological structure, properties, microbial community and function of anammox biofilms induced by large-pore carriers (Bls), small-pore carriers, filament carriers and non-carriers (Bn) in low-strength wastewater were comprehensively studied. The carriers promoted biomass accumulation and agglomeration, with Bls demonstrating the highest biomass proportion of 0.76, the highest specific anammox activity (0.41 kgN/(kgVSS·d)-1) and the largest aggregates. Hydraulic shearing stimulated Bn to secrete most extracellular polymeric substances and capture more inorganic ions for enhanced strength. Metagenomic sequencing showed that the four biofilms shared a common core flora, but differed in cross-metabolism. The proportion of the functional bacterium Candidatus Brocadia was highest in Bls, while the increase in heterotrophic bacteria in Bn supported stronger metabolic capacity. Finally, the proposed anisotropic or isotropic carrier structure was identified as the key to generating "uniform development" and "central development" models. This study is helpful for understanding the anammox aggregation mechanism and carrier optimization.


Assuntos
Reatores Biológicos , Purificação da Água , Oxidação Anaeróbia da Amônia , Anaerobiose , Bactérias/genética , Bactérias/metabolismo , Biofilmes , Reatores Biológicos/microbiologia , Nitrogênio/metabolismo , Oxirredução , Esgotos
8.
Artigo em Inglês | MEDLINE | ID: mdl-36078216

RESUMO

Hydrothermal co-liquefaction (co-HTL) is a promising technology to valorize binary or even ternary biowastes into bioenergy. However, the complex biochemical compositions and unclear synergistic effect prevent the development of this technology. Thus, this study explored a comprehensive co-HTL of representative biowastes to investigate the synergistic and antagonistic effects. An apparent synergistic effect on biocrude yield was observed when sewage sludge was co-liquefied with cow manure or wheat straw. Further, the co-HTL of sewage sludge-cow manure was investigated in a detailed manner. The highest yield (21.84 wt%) of biocrude, with a positive synergistic effect (11.37%), the highest energy recovery (47.48%), and a moderate biocrude HHV (34.31 MJ/kg) were achieved from co-HTL at 350 °C for 30 min. Hydrochar and gas products were also characterized to unravel the reaction pathways. Accordingly, this work indicates that sewage sludge co-liquefied with other biowastes can serve as a multi-purpose solution for biowaste treatment and bioenergy production.


Assuntos
Esgotos , Água , Biocombustíveis/análise , Biomassa , Esterco , Fenômenos Físicos , Temperatura , Água/química
9.
Artigo em Inglês | MEDLINE | ID: mdl-36078309

RESUMO

This study investigated the effect of locally available bulking agents on the faecal sludge (FS) composting process and quality of the final FS compost. Dewatered FS was mixed with sawdust, coffee husk and brewery waste, and composted on a pilot scale. The evolution of physical and chemical characteristics of the composting materials was monitored weekly. Results indicate that bulking agents have a statistically significant effect (p < 0.0001) on the evolution of composting temperatures, pH, electrical conductivity, nitrogen forms, organic matter mineralisation, total organic carbon, maturity indices, quality of the final compost and composting periods during FS composting. Our results suggest reliable maturity indices for mature and stable FS compost. From the resource recovery perspective, this study suggests sawdust as a suitable bulking agent for co-composting with FS-as it significantly reduced the organic matter losses and nitrogen losses (to 2.2%), and improved the plant growth index, thus improving the agronomic values of the final compost as a soil conditioner. FS co-composting can be considered a sustainable and decentralised treatment option for FS and other organic wastes in the rural and peri-urban communities, especially, where there is a strong practice of reusing organic waste in agriculture.


Assuntos
Compostagem , Carbono , Compostagem/métodos , Nitrogênio , Reciclagem , Esgotos , Solo
10.
Artigo em Inglês | MEDLINE | ID: mdl-36078410

RESUMO

In many countries, along with rising rural labor transfer, the problem of rural domestic sewage discharge is becoming increasingly serious due to labor shortages in the villages. It is urgent to solve the environment pollution and health problems of residents which is caused by the massive discharge of domestic sewage in rural areas. Based on the survey data collected from Nanjing Agricultural University in 2020, this paper employs the ordered probit model and the CMP method, to empirically test the impact of non-agricultural employment and regional choice on farmers' domestic sewage discharge behavior and the moderating effect of environmental cognition and the social network. The results show that: (1) There is a significantly positive correlation between non-agricultural employment and farmers' sewage treatment behavior. (2) Environmental cognition significantly improves the participation of urban non-agricultural employment farmers in sewage treatment, and the social network has a significant role in promoting the adoption of sewage treatment behavior of local non-agricultural employment farmers. (3) Further heterogeneity analysis results show that the inhibitory effect of urban non-agricultural employment on random sewage discharge is more pronounced than that of local non-agricultural employment. Therefore, in order to effectively solve the problem of rural domestic sewage discharge, it is necessary to actively guide the sewage discharge behavior of non-agricultural employment households, strengthen the social network interaction within the village, and increase the publicity for sewage discharge knowledge.


Assuntos
Fazendeiros , Esgotos , Agricultura/métodos , China , Emprego , Humanos
11.
J Environ Public Health ; 2022: 3623141, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36133159

RESUMO

The water environment is one of the basic elements that constitute the environment. It is an important place for the survival and development of human society, and it is also the most seriously disturbed and damaged area by humans. The pollution and destruction of water environment has become one of the major environmental problems in the world today. The essence of urban water space landscape design under the concept of integrating people's ecological design is the ecological landscape design of urban water spaces, while the development of ecological landscape design in the field of urban water space landscape design is still in its infancy, and the interpretation of its concept is also different. The ecological design of the landscape reflects a new dream of human beings, a new aesthetics and value: the true cooperative and fraternal relationship between man and nature. At present, the ecological design of urban water space landscape has not put forward a more accurate concept, clear principles and standards, and a complete and systematic theoretical basis, which requires further research, discussion, and continuous practice by this generation of designers to improve it. To this end, this paper proposed a research method on the integration of water environment governance in urban and rural spaces with natural ecological landscape design. This paper mainly talked about the status quo of water environment and its network sensor algorithm research and analyzed its coverage area one by one. Then, the water quality extraction is introduced in detail. And finally, the data analysis of the Beijing river waters, the analyzer rainfall, water quality, and so on are carried out in the experimental part. It could be seen from the experimental results that there were currently 22 reclaimed water plants in six urban areas of Beijing, with a daily water treatment capacity of 4.08 million cubic meters and a sewage treatment rate of 98%. As of 2016, 440 million cubic meters of reclaimed water has been reused. With the commissioning of the new reclaimed water system, the proportion of reclaimed water in the river and lake environment will continue to increase.


Assuntos
Esgotos , Purificação da Água , China , Conservação dos Recursos Naturais , Humanos , Rios , Qualidade da Água
12.
Environ Sci Pollut Res Int ; 29(44): 67466-67482, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36056283

RESUMO

The Vibrionaceae family groups genetically and metabolically diverse bacteria thriving in all marine environments. Despite often representing a minor fraction of bacterial assemblages, members of this family can exploit a wide variety of nutritional sources, which makes them important players in biogeochemical dynamics. Furthermore, several Vibrionaceae species are well-known pathogens, posing a threat to human and animal health. Here, we applied the phylogenetic placement coupled with a consensus-based approach using 16S rRNA gene amplicon sequencing, aiming to reach a reliable and fine-level Vibrionaceae characterization and identify the dynamics of blooming, ecologically important, and potentially pathogenic species in different sites of the northern Adriatic Sea. Water samples were collected monthly at a Long-Term Ecological Research network site from 2018 to 2021, and in spring and summer of 2019 and 2020 at two sites affected by depurated sewage discharge. The 41 identified Vibrionaceae species represented generally below 1% of the sampled communities; blooms (up to ~ 11%) mainly formed by Vibrio chagasii and Vibrio owensii occurred in summer, linked to increasing temperature and particulate matter concentration. Pathogenic species such as Vibrio anguilllarum, Vibrio tapetis, and Photobacterium damselae were found in low abundance. Depuration plant samples were characterized by a lower abundance and diversity of Vibrionaceae species compared to seawater, highlighting that Vibrionaceae dynamics at sea are unlikely to be related to wastewater inputs. Our work represents a further step to improve the molecular approach based on short reads, toward a shared, updated, and curated phylogeny of the Vibrionaceae family.


Assuntos
Vibrionaceae , Animais , Ecossistema , Monitoramento Ambiental , Genes de RNAr , Humanos , Material Particulado , Filogenia , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Esgotos , Vibrionaceae/genética , Águas Residuárias , Água
13.
Sci Rep ; 12(1): 15656, 2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36123529

RESUMO

There is an urgent need to develop phage therapies for multidrug-resistant bacterial infections. However, although bacteria have been shown to be susceptible to phage therapy, phage therapy is not sufficient in some cases. PhiMR003 is a methicillin-resistant Staphylococcus aureus phage previously isolated from sewage influent, and it has demonstrated high lytic activity and a broad host range to MRSA clinical isolates in vitro. To investigate the potential of phiMR003 for the treatment of MRSA infection, the effects of phiMR003 on immune responses in vivo were analysed using phiMR003-susceptible MRSA strains in a mouse wound infection model. Additionally, we assessed whether phiMR003 could affect the immune response to infection with a nonsusceptible MRSA strain. Interestingly, wounds infected with both susceptible and nonsusceptible MRSA strains treated with phiMR003 demonstrated decreased bacterial load, reduced inflammation and accelerated wound closure. Moreover, the infiltration of inflammatory cells in infected tissue was altered by phiMR003. While the effects of phiMR003 on inflammation and bacterial load disappeared with heat inactivation of phiMR003. Transcripts of proinflammatory cytokines induced by lipopolysaccharide were reduced in mouse peritoneal macrophages. These results show that the immune modulation occurring as a response to the phage itself improves the clinical outcomes of phage therapy.


Assuntos
Bacteriófagos , Staphylococcus aureus Resistente à Meticilina , Animais , Citocinas/farmacologia , Imunidade , Inflamação , Lipopolissacarídeos/farmacologia , Camundongos , Esgotos
14.
Lancet Planet Health ; 6(9): e707-e708, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36087599
15.
Huan Jing Ke Xue ; 43(9): 4636-4646, 2022 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-36096604

RESUMO

Efficient utilization of organic materials based on the rich resources in the karst region can promote soil fertility. Microorganisms have a crucial influence on soil phosphorus availability. phoD is considered to be the encoding phosphatase gene that can reflect the hydrolysis of organophosphorus compounds for the soil bacterial community. Molecular analysis of the phoD-harboring bacterial gene provides insight into promoting soil phosphorus availability under different fertilization managements. However, the effects of organic materials on soil phosphorus fractions associated with phoD-harboring bacterial communities are poorly understood. This study comprehensively investigated the effects of organic materials on soil phosphorus availability and explored environmental drivers of phoD-harboring bacteria in the Karst region. Here, six treatments were designed in the field as follows:non-fertilized control (CK), inorganic fertilization (NPK), inorganic fertilization combined with straw (NPKS), inorganic fertilization combined with manure (NPKM), inorganic fertilization combined with sludge (NPKL), and inorganic fertilization combined with sugarcane ash (NPKA). The phoD-harboring bacterial community in Karst region soil was analyzed using high-throughput sequencing. The results showed that the content of total P (TP), Olsen-P, and Ca2-P increased with the years after organic material application, whereas the content of CaCl2-P first decreased and then increased. Compared to that under the CK treatment, organic material application, especially NPKL treatment, significantly increased soil total nitrogen (TN), TP, Olsen-P, CaCl2-P, and Ca2-P contents, followed by those in the NPKA and NPKM treatments. Correlation analysis showed that the contents of CaCl2-P, Ca2-P, and Olsen-P were significantly positively correlated with soil exchangeable calcium (Ca-ex) content. Redundancy analysis (RDA) showed that TN, Ca-ex, soil organic carbon (SOC), and total potassium (TK) contents were the key factors affecting soil P fractions. Using high-throughput sequencing, we found that only NPKS increased the richness of phoD-harboring bacteria compared to that under the control treatment. No significant difference was observed in the phoD-harboring bacterial community among all treatments. The RDA model selected the Ca-ex, TK, Olsen-P, pH, and SOC as the key environmental predictors for the phoD-harboring bacterial community. In summary, soil phosphorus availability can be improved through the input of organic materials and inorganic fertilizer combined with manure, sludge, and ash. These additions were suitable for nutrient management and sustainable development in farmland soil in the Karst region of Guangxi.


Assuntos
Fósforo , Solo , Bactérias/genética , Cloreto de Cálcio , Carbono , China , Esterco , Nitrogênio/análise , Fósforo/análise , Esgotos , Solo/química
16.
Huan Jing Ke Xue ; 43(9): 4697-4705, 2022 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-36096610

RESUMO

Microplastics are widely distributed in the biogeochemical cycle driven by microbes. Their surface is enriched with unique microbial communities, called plastispheres. Various redox environments that exist widely in the natural environment can affect the microbial composition in the plastisphere and the fate of the microplastics. To explore the microbial community composition and construction mechanism on the surface of microplastics in typical redox environments, three microplastics, PHA (polyhydroxyalkanoates), PLA (polylactic acid), and PVC (polyvinyl chloride), were placed in five specific redox environments:aerobic, nitrate reduction, iron oxide reduction, sulfate reduction, and methane production. The culture experiment simulated the microcosm, which was inoculum by sludge. The results showed that microplastic factors affected 18.94% and 46.67% of the microbial communities on the plastisphere in taxonomy and phylogeny, respectively. Redox factors affected 31.04% and 90.00% of the microbial communities on the plastisphere in taxonomy and phylogeny, respectively. Compared with that in sludge, the microbial community richness and diversity were reduced on the three microplastics. The most apparent reduction was found on the plastisphere of more degradable PHA. At the same time, microbial communities on the refractory PLA and PVC surfaces remained similar. Anaerocolumna (26.44%) was the dominant genus on the surface of PHA microplastics, whereas microbes related to the redox reaction were less enriched. Clostridium_sensu_stricto_7 (15.49% and 11.87%) was the dominant strain on PLA and PVC microplastics, and the microbes related to the redox reaction were significantly enriched. Thus, characteristic microbes involved in the redox reaction will be enriched in the surface of refractory microplastics, and microplastics may affect the rate of biogeochemical cycling.


Assuntos
Microbiota , Microplásticos , Oxirredução , Plásticos , Poliésteres , Cloreto de Polivinila , Esgotos
17.
Huan Jing Ke Xue ; 43(9): 4727-4735, 2022 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-36096613

RESUMO

The activated sludge of a biochemical unit (WLK_OD) and an advanced denitrification unit (WLK_AD) were collected from a municipal wastewater treatment plant (WWTP), in which the TN concentration of effluent was less than 1.5 mg·L-1, and their microbial community structure and function profiles were analyzed using 16S rRNA gene high-throughput sequencing. The microorganisms in WLK_AD had lower evenness compared with that in WLK_OD, which was attributed to environmental selection. Furthermore, PCoA revealed that different incoming wastewaters had an impact on microbial community structure. At the phylum level, Proteobacteria (70.11%) was enriched in WLK_AD. At the genus level, Thauera, Flavobacterium, Hydrogenophaga, and Zoogloea served as distinct-dominant denitrifying bacteria in WLK_AD; however, Trichococcus (3.50%) and Terrimonas (1.10%) were enriched in WLK_OD. Through the comparison between groups (P<0.05), the biomarkers detected in each WWTP were different. Furthermore, the results of the co-occurrence network showed that the bacteria from module I had a higher proportion in WLK_AD; the bacteria from module II had a higher proportion in WLK_OD, and they were common microorganisms in WWTPs, implying that wastewater environments drpve the differences in the microbial community structure. Among the types of environmental parameters, the removal efficiency of COD and TN had the greatest impact on the microbial community by the RDA. The removal efficiency of COD was positively correlated with the dominant bacteria from WLK_OD, such as Saccharibacteria, Thermomarinilinea, Terrimonas, and Comamonas; the removal efficiency of TN was positively correlated with the denitrifying bacteria from WLK_AD, such as Dokdonella, Thauera, Flavobacterium, and Zoogloea. WLK_AD was enriched with Novosphingobium, Dokdonella, Thauera, and Sphingomonas, which synergistically removed TN, leading to the TN of the effluent being less than 1.5 mg·L-1. Moreover, based on the results of function prediction, WLK_AD had a higher proportion of genes that could code the denitrification enzymes.


Assuntos
Microbiota , Zoogloea , Bactérias/genética , Reatores Biológicos/microbiologia , Desnitrificação/genética , Nitrogênio , RNA Ribossômico 16S , Esgotos/microbiologia , Thauera/genética , Águas Residuárias/química , Zoogloea/genética
18.
Huan Jing Ke Xue ; 43(9): 4736-4747, 2022 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-36096614

RESUMO

To assess the problem of sewage treatment under the condition of low carbon sources, we carried out a study of activated sludge and a biofilm symbiosis system (IFAS). The occurrence characteristics and interaction law of microorganisms in two phases of sludge membrane under low carbon source conditions were discussed, and their niche and influence on treatment efficiency were clarified. Through a pilot-scale experiment in actual water plants, the biofilm characteristics, sludge membrane activity, and succession law of flora were analyzed, and the microbial structure and interaction in sludge membrane in two phases under the control of different activated sludge ages were compared. The results showed that the sludge concentration in the reactor increased with the increase in SRT under variable SRT. Because the microbial concentration in SRT-H was much higher than that in SRT-L, the competition between mud films in SRT-H was more intense than that in SRT-L, and the pollutant removal efficiency in SRT-H was lower than that in SRT-L. Under the condition of low-carbon feed water, the sludge activity in the IFAS process decreased with the increase in SRT. Under the condition of low SRT(5 d), the nitrification, denitrification, phosphorus accumulation, and phosphorus absorption rate of activated sludge increased by 122%, 88%, 34%, and 44%, respectively, compared with that of high SRT (25 d). However, SRT had little effect on biofilm activity, and there was little difference in nitrification activity and denitrification activity between the two SRTs. Microbial sequencing analysis showed that the functional bacteria of the IFAS process were enriched and transferred with the change in SRT between the two phases of mud membrane. In SRT-L, the functional bacteria that were enriched and transferred between the two phases of mud film owing to the "seeding" effect were mainly unclassified_g__Enterobacteriaceae, whereas in SRT-H, Acinetobacter was mainly used. At the same time, by analyzing the distribution of dominant functional bacteria, it was found that there was some competition between denitrifying bacteria and phosphorus-accumulating bacteria in activated sludge. Under the condition of a lack of organic substrate in the influent, the relative abundance of denitrifying bacteria was obviously higher than that of phosphorus-accumulating bacteria, which indicated that denitrifying bacteria could better adapt to low-carbon source conditions. Thus, they could occupy a dominant competition position, which was mainly reflected in the increase in the relative abundance of aerobic denitrifying bacteria. In addition, the SRT change in the mud phase reacted in the membrane phase, making the residence time of biofilm change correspondingly, thus changing the flora structure, screening out different dominant bacteria genera, and further increasing the difference.


Assuntos
Reatores Biológicos , Esgotos , Bactérias , Reatores Biológicos/microbiologia , Carbono , Interações Microbianas , Fósforo , Esgotos/microbiologia , Água
19.
Water Environ Res ; 94(9): e10789, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36102325

RESUMO

Some wastewaters contain high concentrations of ammonia coexisting with large amounts of salt, which might negatively affect the anaerobic ammonium oxidation (anammox) process. In this study, the performance of the anammox process under different saline conditions was investigated using an upflow anaerobic sludge bed-anammox system. After long-term operating for 275 days, the results indicated that the nitrogen removal efficiency remained high under the 0-40 g NaCl/L, and low salinity (15 g NaCl/L) substantially promoted specific anammox activity. Affected by the saline environment, the appearance, color, and shape of sludge notably changed, and the amount of extracellular polymeric substances gradually increased with increasing salinity, which might be one of the reasons for the strong salt tolerance of the system. Chloroflexi and Planctomycetes were the dominant strains under long-term salinity, and Brocadiaceae_g_ unclassified exhibited halophilic characteristics. The redundancy analysis results showed that the concentration of influent NH4 + -N and salinity were the main environmental factors affecting the microbial community of the system. PRACTITIONER POINTS: Provides data to support the maximum value for salinity wastewater treatment with anammox processes' tolerance of 40 g NaCl/L. EPS changes may be responsible for the response to salinity challenges and provide direction for high salinity wastewater treatment. Brocadiaceae_g_ unclassified exhibited a halophilic quality. And it can be focused on to improve treatment efficiency.


Assuntos
Salinidade , Esgotos , Oxidação Anaeróbia da Amônia , Reatores Biológicos , Cloreto de Sódio
20.
Sci Rep ; 12(1): 15521, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36109540

RESUMO

Considering the presence of 274 dusty days in 2021 in Zabol city, Iran, the present study aimed to evaluate the feasibility of using treated sewage effluent (TSE) for dust mitigation with natural methods of increasing land cover. Hence, first of all, the identification of sewage treatment facilities along with the volume and chemical status was carried out and compared to the various national and international legislation. Then, field investigation on land use and land cover, along with literature review on dust origins, sand detachment areas, and sand corridors in the study area will be assisted for optimal area suggestion. Note that, in the present study it was assumed that the application of TSE for wetting the surface to vegetation restoration resulted in wind erosion control in critical foci. The results showed that, so far, a total of 39,000 m3/day could be treated, in the whole study area. The TSE volume calculated based on two scenarios consisting, (1) data obtained from the related organization, and (2) based the capacity of the wastewater plant is 2.8 and 5.1 mcm/year, respectively. Additionally, the study of TSE quality and its comparison to various regulation such as FAO, USEPA, INS, and CWQI indicated the applicability of transforming TSE to 14 km away from the WWT planet daily for rehabilitation of Hammon Hirmand through irrigation of T.stricta to increase the vegetation cover to above 30%.


Assuntos
Poeira , Esgotos , Irã (Geográfico) , Areia , Águas Residuárias
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