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1.
PLoS One ; 15(8): e0237261, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804957

RESUMO

Soil fertilization with dehydrated sewage sludge (DSS) accelerates the recovery process of degraded areas by improving nutrient concentration, and favors the development of trophic webs with pioneer plants such as Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae), phytophagous Hemiptera, predators, and protocooperanting ants. This study aimed to evaluate the development and production of A. auriculiformis litter with or without dehydrated sewage sludge application and the ecological indices of sucking insects (Hemiptera), their predators and protocooperating ants, as bioindicators, in a degraded area for 24 months. Complete randomization was applied for two treatments (with or without application of dehydrated sewage sludge) in 24 replications (one repetition = one plant). We evaluated the number of leaves/branch and branches/plant, percentage of soil cover (litter), ecological indices of phytophagous Hemiptera, their predators, and protocooperating ants. The plants of A. auriculiformis, that were applied with dehydrated sewage sludge, had superior development when compared to plants where DSS were not applied. The highest abundance and richness of phytophagous Hemiptera species and Sternorrhyncha predators occurred on A. auriculiformis plants that were applied with dehydrated sewage sludge. The increase in richness of species of protocooperanting ants that established mutualistic relationships positively influenced the phytophagous Hemiptera. The use of A. auriculiformis, with application of dehydrated sewage sludge, can increase recovery of degraded areas due to its higher soil cover (e.g., litter) and results in higher ecological indices of phytophagous Hemiptera and their predators.


Assuntos
Acacia/fisiologia , Fertilizantes , Hemípteros/fisiologia , Esgotos/química , Solo/química , Animais , Formigas/fisiologia , Biodiversidade , Fertilizantes/análise , Cadeia Alimentar , Água/química
2.
Chemosphere ; 260: 127600, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32758769

RESUMO

Granules initiation and development is the backbone of aerobic granular sludge technology. Feed composition can notably affect initiation and development of aerobic granules, and yield aerobic granules with distinct microbial community, morphology and structure. This paper reports an unexpected formation of aerobic granules in an aspartic acid fed SBR under unfavorable hydrodynamic selection conditions. Detailed characteristics of these aerobic granules were investigated in terms of morphology, structure, bioactivity and EPS. The results showed that due to the absence of favorable hydrodynamic selection pressure, the formed aerobic granules had an irregular shape with a rough outline and loose internal structure, which was quite different from mature aerobic granules. Bacteria in these aerobic granules were mainly presented in the form of microcolony with calcium and ß-polysaccharides responsible for its mechanical stability. The high N/C ratio of aspartic acid enabled the enrichment of significant amount of nitrifiers within aerobic granules and thus resulted in high nitrification activity of these aerobic granules. The negatively charged and hydrophilic aspartic acid also induced the bacteria to secrete more exopolysaccharides for contributing to more neutral and hydrophilic surface of the aerobic granules, which was beneficial for aspartic acid capture. As a result, polysaccharides, rather than proteins, became the major components of EPS in these aerobic granules. This paper provides us a foundation to better understand the granulation potential of proteinaceous substrates that is frequently encountered in industrial wastewaters.


Assuntos
Ácido Aspártico/química , Reatores Biológicos/microbiologia , Esgotos/microbiologia , Purificação da Água/métodos , Aerobiose , Análise da Demanda Biológica de Oxigênio , China , Matriz Extracelular de Substâncias Poliméricas/química , Hidrodinâmica , Microbiota , Modelos Teóricos , Nitrificação , Proteobactérias/isolamento & purificação , Esgotos/química , Propriedades de Superfície , Águas Residuárias/química
3.
Ecotoxicol Environ Saf ; 202: 110882, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619891

RESUMO

Extracellular polymeric substances (EPS) which wrapped on sludge particles were deemed to hinder the outflowing of combined water in sludge system. The complex composition of EPS was the bottleneck for revealing its relationship with sludge dewaterability. In this study, a combined modified corn-core powder (MCCP) and sludge-based biochar (SBB) condition was executed to treat sludge for enhancing dehydration performance, and the concentration and the form distribution of organics in EPS, the variances of protein secondary structures were investigated. Correlation between the sludge dewaterability and EPS components were performed, found strong correlations among the net sludge solids yield (YN) and the specific resistance of filtration (SRF) (R = -0.923), Zeta potential (R = -0.971). Furthermore, the relationship between the secondary structures of protein and dehydration performance were strong related. With the optimal dosage of SBB and MCCP, aggregated strands and α -helix were released, indicated that the unfolding and despiralization in soluble EPS (S-EPS) were improved, disordered the sludge network, reduced the flowing resistance of bound water, finally enhancing sludge dewaterability.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Eliminação de Resíduos Líquidos , Carvão Vegetal , Filtração , Pós , Esgotos/química , Água/química , Zea mays
4.
Environ Monit Assess ; 192(7): 471, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32607692

RESUMO

Sewage irrigation has been widespread in the water shortage area of eastern China and inevitably tends to result in heavy metal accumulation in soils. A total of 148 surface soil samples from five land-use types were collected in Longkou, a typical sewage irrigation area of China, and As, Cd, Cu, Pb, and Zn concentrations were determined. The Nemerow index method and improved fuzzy comprehensive evaluation method were used to examine the pollution status of heavy metals. The potential ecological risk was evaluated by the Hakanson model by adjusting the assessment threshold, and its spatial distribution was interpolated using geostatistical techniques. As, Cd, Cu, Pb, and Zn accumulated in different amounts in the five land-use types. Urban industrial land and mining land were moderately polluted, irrigated land was slightly polluted, orchards were minimally polluted, and bare land was at a safe level of pollution. Cd exhibited high percentages of strong and severe levels of potential ecological risks. For Cd, irrigated land, orchard, and bare land mainly presented moderate risks, whereas urban industrial land and mining land mainly presented high risks. The comprehensive ecological risk of the five heavy metals was at a severe level for all tested land-use classes except for bare land.


Assuntos
Monitoramento Ambiental , Metais Pesados , Esgotos , Poluentes do Solo , China , Metais Pesados/análise , Medição de Risco , Esgotos/química , Solo/química , Poluentes do Solo/análise
5.
PLoS One ; 15(7): e0235508, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614917

RESUMO

This study examined the influence of bioaugmentation on metal concentrations (aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel and zinc) in anaerobically digested sewage sludge. To improve the digestion efficiency, bioaugmentation with a mixture of wild-living Archaea and Bacteria (MAB) from Yellowstone National Park, USA, was used. The total concentration of all metals was higher in the digestate than in the feedstock. During anaerobic digestion, the percent increase in the concentration of most of metals was slightly higher in the bioaugmented runs than in the un-augmented runs, but these differences were not statistically significant. However, the percent increase in cadmium and cobalt concentration was significantly higher in the bioaugmented runs than in the un-augmented runs. At MAB doses of 9 and 13% v/v, cadmium concentration in the digestate was 211 and 308% higher than in the feedstock, respectively, and cobalt concentration was 138 and 165%, respectively. Bioaugmentation increased over 4 times the percentage of Pseudomonas sp. in the biomass that are able to efficiently accumulate metals by both extracellular adsorption and intracellular uptake. Biogas production was not affected by the increased metal concentrations. In conclusion, bioaugmentation increased the concentration of metals in dry sludge, which means that it could potentially have negative effects on the environment.


Assuntos
Metais/metabolismo , Esgotos/química , Adsorção , Anaerobiose , Archaea/genética , Archaea/crescimento & desenvolvimento , Archaea/metabolismo , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Biomassa , Cádmio/análise , Cádmio/metabolismo , Cobalto/análise , Cobalto/metabolismo , Metais/química , Pseudomonas/genética , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/metabolismo , Esgotos/microbiologia , Eliminação de Resíduos Líquidos
6.
Chemosphere ; 259: 127474, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32603962

RESUMO

Anaerobic digestion (AD) is the biological preferred treatment applied to Slaughterhouse wastewaters (SWW) due to its effectiveness. The aim of the study is to investigate the effect of different percentages of fats, oil and grease (FOG) on biomethane production in anaerobic co-digestion with slaughterhouse wastewater using BMP tests under mesophilic conditions (35 °C). For this purpose, three percentages of FOG from 1% to 10% were tested. Biodegradability, biomethane production and the microbial population were studied. In addition, settling capacity has been evaluated at different conditions: i) before and after anaerobic co-digestion; ii) at different temperature 25 °C and 35 °C. The settling rates as well as the characterization of the digestate were recorded. Experimental results showed that all the co-digestion mixtures (FOG percentages = 1-10%) enhanced biomethane production and biodegradability compared to AD of sole SWW. The best conditions were achieved at 5-10% of FOG, showing biodegradability of 66-70% CODtremoval and specific biomethane productions of 562 and 777 mLCH4·g-1CODsremoved, respectively. Regarding microbial dynamics, Eubacteria was reduced with the increase in %FOG but Acetate utilizing methanogens was increased. Regarding settling capacity, mesophilic temperatures (35 °C) increased the settling rate of digestate in 1.76 times and reduced the lag-phase to 0.92 min; obtaining a more concentrated sludge and leaving a clarified whose TSS represent only 8% of TS.


Assuntos
Matadouros , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias , Anaerobiose , Bactérias , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Gorduras , Hidrocarbonetos , Metano , Esgotos/química
7.
Chemosphere ; 260: 127617, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32683031

RESUMO

In this study, poly dimethyl diallyl ammonium chloride (PDADMAC) and polyacrylamide (PAM) were applied to substitute ferric trichloride (FeCl3) and lime conditioning for advanced dewatering of landfill sludge (LS). Four response surface methodology (RSM) models were constructed for FeCl3-lime, FeCl3-PAM, PDADMAC-lime and PDADMAC-PAM, and identical dosages, namely 29.86, 57.91, 5.73 and 2.99 mg/g dry solids (DS) for FeCl3, lime, PDADMAC and PAM, were obtained by solving the system of four RSM equations at water content of 60% to investigate conditioning mechanisms. Compared to FeCl3-lime, PDADMAC-PAM conditioning had strong charge neutralization and bridging performance, and obtained conditioned LS with large flocs size, strong network structure and rapid dewatering rate. By integrating RSM with nonlinear programming for optimization, the total cost of PDADMAC-PAM route was saved by 7.9% and close to FeCl3-lime, and the optimized condition with dosages of 1.93 and 3.47 kg/t DS was further confirmed by pilot-scale experiments. The results indicated that PDADMAC-PAM was a feasible substitute for FeCl3-lime in sludge conditioning, and showed more advantage if dewatered sludge was further treated by incineration.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Resinas Acrílicas , Compostos de Cálcio , Floculação , Ferro/química , Óxidos , Polímeros , Esgotos/química , Instalações de Eliminação de Resíduos , Água
8.
Chemosphere ; 260: 127659, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32698118

RESUMO

Per- and polyfluoroalkyl substances (PFAS), highly stable and persistent chemicals used in numerous industrial applications and consumer goods, pose an exceptionally difficult challenge for disposal. Three approaches are currently available for PFAS wastes: landfilling, wastewater treatment and incineration. Each disposal approach can return either the original PFAS or their degradation products back to the environment, illustrating that the PFAS problem is cyclical. Landfilling and wastewater treatment do not destroy PFAS and simply move PFAS loads between sites. Consumer products and various materials discarded in landfills leach PFAS over time, and landfill leachate is commonly sent to wastewater treatment plants. From wastewater treatment plants, PFAS are carried over to sludge and effluent. Sewage sludge can be landfilled, incinerated, or applied on agricultural fields, and PFAS from treated sludge (biosolids) can contaminate soil, water, and crops. Incineration of PFAS-containing wastes can emit harmful air pollutants, such as fluorinated greenhouse gases and products of incomplete combustion, and some PFAS may remain in the incinerator ash. Volatile PFAS are emitted into the air from landfills and wastewater treatment plants, and research is urgently needed on the potential presence of PFAS compounds in air emissions from commercially run incinerators. Monitoring of waste streams for PFAS, stopping PFAS discharges into water, soil and air and protecting the health of fence-line communities close to the waste disposal sites are essential to mitigate the impacts of PFAS pollution on human health.


Assuntos
Fluorcarbonetos/química , Poluentes Atmosféricos , Materiais de Construção , Humanos , Incineração , Eliminação de Resíduos , Esgotos/química , Solo , Instalações de Eliminação de Resíduos , Águas Residuárias , Poluentes Químicos da Água/análise
9.
PLoS One ; 15(6): e0234136, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520947

RESUMO

Groundwater treatment sludge is a Fe/Mn-bearing waste that is mass produced in groundwater treatment plant. In this study, sludge was converted to a magnetic adsorbent (MA) by adding ascorbate. The sludge was weakly magnetised in the amorphous form with Fe and Mn contents of 28.8% and 8.1%, respectively. After hydrothermal treatment, Fe/Mn oxides in the sludge was recrystallised to siderite and rhodochrosite, with jacobsite as the intermediate in the presence of ascorbate. With an increment in ascorbate dosage, the obtained magnetic adsorbent had a significant increase in chromate adsorption but a decrease in magnetisation. When the Mascorbate/MFe molar ratio was 10, the produced MA-10 was a dumbbell-shaped nanorod with a length of 2-5 µm and a diameter of 0.5-1 µm. This MA-10 showed 183.2 mg/g of chromate adsorption capacity and 2.81 emu/g of magnetisation. The mechanism of chromate adsorption was surface coprecipitation of the generated Cr3+ and Fe3+/Mn4+ from redox reaction between chromate and siderite/rhodochrosite on MA-10, separately. This study demonstrated an efficient recycling route of waste sludge from groundwater treatment to produce MA for treating chromate-bearing wastewater.


Assuntos
Cromatos/química , Magnetismo , Nanotubos/química , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Adsorção , Carbonatos/química , Compostos Férricos/química , Ferro/química , Cinética , Manganês/química , Oxirredução , Óxidos/química
10.
PLoS One ; 15(6): e0234248, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32559201

RESUMO

When clothes are worn and washed, they emit fibres into the ecosystem via discharges of sewage that have been linked to the global dispersion of clothing fibres. Facilities that treat sewage divert some fibres from sewage effluent to sludge, but no current methods of filtration eliminate their environmental release. While filters for washing-machines are sold to consumers with the argument they will reduce the emissions of fibres from clothes to the environment, there is insufficient scientific peer-reviewed evidence assessing their ability to retain fibres from washed clothes and reduce environmental contamination. To improve our understanding and develop more realistic methods to assess the efficiency of filters, we washed replicate cotton and polyester garments in replicate domestic front-loaded washing-machines with and without replicate filters (micro- and milli-meter-sized pores), and then quantified the masses of the fibres retained by the filters and those released in the effluent. Here we show micrometer-sized filters significantly reduced the mass of cotton by 67% (F2,6 = 11.69, P<0.01) compared to effluent from appliances with no filters, whilst filters in general reduced polyester fibres in their effluent by more than 65% (micrometer-sized pores) and 74% (millimeter-sized pores) compared to effluent from appliances with no filters (F2,12 = 5.20, P<0.05). While filters with micrometer-sized pores caught larger masses and total proportions of fibres than filters with millimeter-sized pores, the differences were only significant for the total proportions of cotton (t = 4.799 df = 4, P<0.01). For tests with garments of either types of polymer, the filtered effluent still contained up to a third of the original masses of fibres released from the garments. Given the diversity of clothes, polymers, appliances and filters currently sold to consumers, our work shows the value of increasing the rigour (e.g. more levels of replication) when testing filters and the need for further studies that test an even greater diversity of materials and methods in order to meet the growing demand for knowledge from governments, industry and the public.


Assuntos
Filtração/instrumentação , Lavanderia/instrumentação , Polímeros/química , Esgotos/química , Porosidade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
11.
Ecotoxicol Environ Saf ; 201: 110858, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32563161

RESUMO

This work presents the research on the treatment of an anthraquinone derivatives of disperse dye Blue SI from aqueous solution using aluminium for the optimization of operational parameters like pH, current density, addition of electrolyte, contact time for the color removal efficiency (CRE) and the results are compared with the performance of copper electrodes in electrocoagulation (EC). The parameters for maximum CRE was found with Al at current density 40 Am-2, time 10 min at pH 7, and for Cu at 60 Am-2 15 min, at pH 6 were optimized. The characterization of the treated water using HPLC, MS studies revealed intermediate compounds. From the XPS analysis of the sludge obtained, the mechanism of EC was deduced. Treated aqueous solution was studied for its phytotoxicity with Vigna radiata and ecotoxicity studies were conducted on Artemia salina to study the toxicity effect of the intermediatory products in the treated dye solution. Blue SI dye aqueous solution treated with aluminium electrodes shows no or lesser toxicity in plants as well as in ecotoxic study compared with copper electrodes.


Assuntos
Alumínio/química , Antraquinonas/análise , Cobre/química , Técnicas Eletroquímicas/métodos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Animais , Antraquinonas/química , Antraquinonas/toxicidade , Artemia/efeitos dos fármacos , Eletrodos , Floculação , Concentração de Íons de Hidrogênio , Esgotos/química , Vigna/efeitos dos fármacos , Águas Residuárias/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
12.
Chemosphere ; 257: 127140, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32526467

RESUMO

The recent increase in municipal sludge worldwide has led to a great deal of interest in developing an efficient and environmentally friendly sludge treatment method. In the paper, the treatment of municipal sludge by hydrothermal oxidation (HTO) process with H2O2 as the oxidant was proposed. The impacts of HTO temperature and H2O2 mass fraction on the distribution of products, the moisture content, the migration behaviors of the heavy metals (HMs) of the resulted solid products, the concentration of volatile fatty acids (VFAs) and NH3-N contained in the resulted aqueous phase products and the pH value were investigated. The results indicated that the sludge reduction was achieved by HTO treatment, the increasing H2O2 mass fraction and HTO temperature can significantly improve the dewatering performance of the sludge. The potential toxicity fraction of Pb and Cd contained in the resulted solid residual increased with the increasing HTO severity and the potential toxicity fraction of solid residues was still lower than that of raw material. Acetic acid was the main VFAs produced from HTO treated sludge, and its concentration reached to the maximum value of 2923.41 mg/L at 230 °C under H2O2 mass fraction of 15%. The change in the pH of the resulted aqueous phase products was caused by the competition between the acidic (VFAs or CO2) or alkaline (NH3-N) substances derived from the sludge during HTO process. The HTO process was expected to be an efficient method for municipal sludge treatment due to its mild conditions and high heavy metal safety.


Assuntos
Eliminação de Resíduos Líquidos , Ácidos , Peróxido de Hidrogênio , Governo Local , Metais Pesados/química , Oxidantes , Oxirredução , Esgotos/química , Temperatura
13.
Ecotoxicol Environ Saf ; 201: 110807, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32505762

RESUMO

In order to investigate the decrease in total metal contents and to mitigate the availability and toxicity of metals from farmland near a lead mining area, a combination of two effective soil washing and eco-friendly stabilization technologies was applied in current research. The pre-treatment was performed with three types of agents including Ethylenediaminetetraacetic acid (EDTA), citric acid (CA), and mixture of hydroxylamine hydrochloride and citric acid (HA)) and the post-treatment stabilization was adopted using four rich-carbon organic waste amendments (cow manure compost (CMC), vermicompost (VC), urban sewage sludge (SS), and sludge-derived biochar (BIO)). Furthermore, the fate of residual metals (leachability, plant-availability, bioaccessibility, and chemical distribution), soil quality indicators (phytotoxicity and enzyme activities), and some soil physicochemical properties were examined before and after the two-steps remediation. The soil washing, especially using HA and CA agents, dramatically increased the labile metals and negatively changed the soil microbial activity. The two-month stabilization with SS, BIO, and VC resulted in a significant control of the leachability and plant-availability of residual Zn and Pb. However, the post-treatment was only slightly immobilized of Cd. The amendments affected the restoration of soil pH and organic carbon as well as the improvement of available nutrients. Compared to the other amendments that caused restrictions, the SS significantly restored the enzyme activities. With the exception of CMC, the SS, VC, and BIO, indicated higher germination rate and growth of wheat were also obtained. This study reveal the ability of the complementary role of stabilization with soil washing to reduce metal toxicity and confirm the usefulness of municipal and animal wastes in enhancing soil and environmental qualities.


Assuntos
Recuperação e Remediação Ambiental/métodos , Fertilizantes/análise , Metais Pesados/análise , Mineração , Poluentes do Solo/análise , Solo/química , Animais , Bovinos , Carvão Vegetal/química , Ácido Cítrico/química , Compostagem , Ácido Edético/química , Esterco/análise , Metais Pesados/metabolismo , Plantas/metabolismo , Esgotos/química
14.
Chemosphere ; 258: 127275, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32535445

RESUMO

Clay minerals are widely used to treat sewage containing heavy metals such as zinc and cadmium. In this study, the chemical reactivity of natural serpentine was signally improved through mechanochemical activation, achieving the efficient separation of Zn(Ⅱ) and Cd(Ⅱ) ions in a mixed solution. The activated serpentine would release a large amount of Mg2+ and OH- and thereby selectively precipitate Zn(Ⅱ) ions as an uncommon metamorphic zinc mineral, bechererite, in the presence of SO42-. By adjusting the parameters including grinding intensity, reaction temperature, serpentine dosage and salt species, the optimum conditions were determined and a 92% separation rate of Zn(Ⅱ) and Cd(Ⅱ) ions was achieved. The mechanochemical activation of natural clay minerals expresses a great potential for purification of heavy metal contaminated sewage, as well as the simultaneous separation and recovery of multi-metal secondary resources.


Assuntos
Asbestos Serpentinas/química , Cádmio/isolamento & purificação , Zinco/isolamento & purificação , Precipitação Química , Esgotos/química , Soluções , Sulfatos/química
15.
Ecotoxicol Environ Saf ; 201: 110739, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32505047

RESUMO

In the study, antibiotic resistance genes (ARGs) were examined in wastewater and sludge samples to explore the effect of cephalexin (CFX) on the spreading and removal of ARGs in the Expanded Granular Sludge Bed (EGSB) reactor treating antibiotics wastewater. The result showed that the addition of CFX in the wastewater affected the removal amount of ß-lactam ARGs and other types ARGs. Besides, the addition of CFX in the wastewater had no obviously effect on total concentration of targeted ARGs in the sludge, but it was related to the accumulation of some typical ARGs. Based on gene cassette array libraries analysis, the diversity of gene cassettes carried by intI1 gene was increased by the addition of CFX in the wastewater. Furthermore, the co-occurrence patterns between ARGs and bacterial genus were also investigated. The results showed the CFX in the wastewater not only affected the number of potential host bacteria of ARGs, but also changed the types of potential host bacteria of ARGs. The correlation analysis of ARG in influent, effluent and sludge showed that, for blaCTX-M, sul2, qnrS and AmpC genes, their removal amount in EGSB reactor treating antibiotic wastewater system might be enhanced by reducing their concentration in the sludge.


Assuntos
Antibacterianos/farmacologia , Cefalexina/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Antibacterianos/análise , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Cefalexina/análise , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/efeitos dos fármacos , Esgotos/química , Esgotos/microbiologia , Águas Residuárias/química
16.
Artigo em Inglês | MEDLINE | ID: mdl-32475216

RESUMO

Zinc oxide nanoparticles (ZnO NPs) production and usage might lead to a large discharge of ZnO NPs into the natural environment, raising concerns of pollution and ecological security. The effects of ZnO NPs on waste activated sludge hydrolytic acidification and microbial communities were studied in semi-continuous fermentation systems. The fermentation performance of eight ZnO NPs concentrations including ZnO NPs normal [0.01, 0.1, 1 and 10 mg/g mixed liquor suspended solids (MLSS)] and ZnO NPs shock (10, 1000, 1000 and 10,000 mg/g MLSS) were discussed, and their biodegradability was also analyzed. The experimental results showed that proteins, polysaccharides and short-chain fatty acids were enhanced by ZnO NPs, particularly by ZnO NPs shock. Low ZnO NPs concentrations inhibited coenzyme 420 (F420) and dehydrogenase activities but enhanced α-glucosidase and protease activities. Illumina MiSeq sequencing revealed that ZnO NPs addition enriched Azospira, Ottowia and Hyphomicrobium but not Anaerolineaceae.


Assuntos
Fermentação , Microbiota/efeitos dos fármacos , Nanopartículas/toxicidade , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Anaerobiose , Biodegradação Ambiental , Hidrólise , Nanopartículas/análise , Esgotos/química , Poluentes Químicos da Água/análise , Óxido de Zinco/análise
17.
Chemosphere ; 258: 127273, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32554005

RESUMO

This work describes the design, optimization and validation of an analytical method for the simultaneous determination of 14 pharmaceuticals and personal care products (PPCPs) in sewage sludge. A thorough optimization of the sample pre-treatment was carried out. As a result, microwave-assisted extraction (MAE) was combined with an in-situ clean-up stage and a filtration step. A combination of MilliQ® water/MeOH 95:5 (v/v) adjusted to pH 9 turned out to be the optimal solvent mixture for extraction. The instrumental part of the method presents a significant novelty based on a fully automated sample preparation for the analysis of PPCPs. It consisted of a direct immersion solid phase microextraction followed by on-fiber derivatization, online coupled to gas chromatography - mass spectrometry (DI-SPME-On-fiber derivatization - GC-MS). An isotope dilution approach was used for quantifying, which conferred high reliability to the method. This methodology was validated for 10 compounds with good analytical performance, limit of detection below 20 ng g-1 and absolute recovery in the range of 30-70% for most of the compounds. It supposes an ecological analytical alternative for many routine analysis laboratories around the world. The developed method was applied to different real samples generated in both a pilot-scale thermal hydrolysis treatment plant and an anaerobic digester operated in mesophilic conditions. Salicylic acid and naproxen were found at concentrations above 1000 ng g-1.


Assuntos
Cosméticos/análise , Micro-Ondas , Preparações Farmacêuticas/análise , Esgotos/química , Solventes/química , Poluentes Químicos da Água/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Metanol/química , Reprodutibilidade dos Testes , Microextração em Fase Sólida/métodos , Água/química
18.
Artigo em Inglês | MEDLINE | ID: mdl-32552322

RESUMO

This study proposed a method for analysis of 10 phthalate esters compounds from wastewater treatment plant sludges. The analytical efficiency of GC-MS for of target compounds was verified by a standard mixture of phthalate esters. The response factors related to the respective internal standards from a five-point calibration curve quantified the phthalate esters in individual compounds. Based on the literature compiled by environmental agencies, new generation phthalate compounds have been developed, such as di-iso-nonyl phthalate (DiNP), di-iso-decyl phthalate (DiDP), as alternative to conventional phthalates. The analytical results showed that the total PAEs concentration was in the range from 7.4 to 138.6 mg kg-1 dw in these seven analyzed sludge samples. More, di-iso-nonyl phthalate (DiNP), di-iso-decyl phthalate (DiDP) and bis(2-ethylhexyl) phthalate (DEHP) contributed to over 99% of PAEs in the sludge. The correlation between total PAEs concentration in household and sewage flow treated at seven WWTPs and concentrations of DEHP, DiNP and DiDP was significant.


Assuntos
Dietilexilftalato/análise , Ácidos Ftálicos/análise , Esgotos/química , Águas Residuárias/química , Purificação da Água , Cromatografia Gasosa-Espectrometria de Massas , Taiwan
19.
Chemosphere ; 259: 127472, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32599378

RESUMO

In line with the Circular Economy approach, the production of polyhydroxyalkanoate (PHA) with organic waste as the feedstock may a biotechnological application to reduce waste and recover high-value materials. The potential contaminants that could transfer from bio-waste to a PHA include inorganic elements, such as heavy metals. Hence, the total content and migratability of certain elements were evaluated in several PHA samples produced from different origins and following different methods. The total content of certain elements in PHA ranged between 0.0001 (Be) and 49,500 mg kg-1 (Na). The concentrations of some alkaline (Na and K) and alkaline earth (Ca and Mg) metals were highest, which are of little environmental concern. The feedstock type and PHA stabilisation and extraction procedures affected the element contents. Several sets of experiments were conducted to evaluate the migration of elements from the PHA samples under different storage times, temperatures, and pH levels. The total contents of some heavy metals (As, Cd, Fe, Hg, Ni, Pb, and Zn) in PHA produced from fruit waste or crops (commercial PHA) were lower than those in the PHA samples produced from the mixture of the organic fraction of municipal waste and sludge from wastewater treatment. Both the PHA obtained by extraction from wet biomass (acid storage) with aqueous phase extraction reagents and commercial PHA were below the migration limits stipulated by the current Toy Safety Directive and by Commission Regulation (EU) October 2011 on plastic materials and articles intended to come into contact with food under frozen and refrigerated conditions.


Assuntos
Plásticos Biodegradáveis/análise , Plásticos/análise , Resíduos/análise , Biomassa , Biotecnologia , Alimentos , Metais Pesados/análise , Polímeros , Esgotos/química , Eliminação de Resíduos Líquidos , Águas Residuárias
20.
Chemosphere ; 251: 126405, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32443235

RESUMO

In this study, different numbers of baffles were arranged in settling zone of an activated primary sedimentation tank (APST) to adjust the flow regime of sewage, and the characteristics of flow regime adjustment enhancing carbon source recovery in the APST were explored. The results showed that, compared with the APST without baffles, setting one baffle at the front end of settling zone led to the lowest sedimentation loss of soluble chemical oxygen in the settling zone, and the SCOD and volatile fatty acid concentrations in the effluent increased by 52 mg/L and 4.49 mg/L, respectively, furthermore, the SCOD/total nitrogen (TN), and SCOD/total phosphorus (TP) in the effluent also increased by 22.47%, and 11.95%, respectively. To evaluate the mechanism of setting baffles for carbon source recovery, the numerical simulation of flow regime adjustment was utilized. The results showed that, under the condition of setting one baffle, three large recirculation zones were formed which increased the probability of collision and friction between particulates to avoid the dissolved carbon that had been desorbed in the mechanical agitation zone from being re-adsorbed and settling in the settling zone. Moreover, the baffle changed the streamlines of sewage, thereby resuspending more small carbon sources that had already settled and increasing the carbon source content of effluent. Thus, this study provided a new method of adjusting sewage flow regime in APST for enhancing the efficiency of carbon source recovery which could help improving biological nitrogen and phosphorus removal in wastewater treatment plants.


Assuntos
Eliminação de Resíduos Líquidos , Reatores Biológicos , Carbono , Ácidos Graxos Voláteis , Veículos Automotores , Nitrogênio/análise , Fósforo , Esgotos/química , Águas Residuárias
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