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1.
Artigo em Inglês | MEDLINE | ID: mdl-31669278

RESUMO

Application of traditional bait in aquaculture caused environment pollution and disease frequent occurrence. Residual papaya could be re-utilized to culture Tilapia mossambica as dietary supplement. Therefore, a novel integrated system of the improvement of yield, antioxidant and nonspecific immunity of Tilapia mossambica by dietary residual papaya was proposed and investigated. Tilapia mossambica could grow well in all supplement residual papaya groups. Survival rate, yield, whole fish body composition under 15-45% groups were increased compared with control group (CK). Bioactive substances (polyphenols and vitamin) in residual papaya enhanced ALP, ACP, phagocytic, SOD, CAT activities through up-regulating ALP, ACP, SOD, CAT genes expression levels. Theoretical analysis showed bioactive substances regulated these genes expressions and enzyme activities as stimulus signal, component, active center. Moreover, residual papaya improved mTOR and NF-kB signaling pathway. Furthermore, residual papaya inhibited Aeromonas hydrophila that increased resistance to diseases. This technology completed the solid waste recovery and the Tilapia mossambica growth performance simultaneously.

2.
Water Res ; 164: 114915, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31421511

RESUMO

This paper focused on the performance of an up-flow bio-electrochemical system (UBES) for treating the ß-lactams pharmaceutical wastewater under different hydraulic retention time (HRT). UBES is added a bio-electrochemical system below the three-phase separator based on up-flow anaerobic sludge blanket (UASB). Comparisons of chemical oxygen demand (COD) removal, accumulation of volatile fatty acid (VFA) and biogas production were investigated during the 316-day operation time, which was divided into five parts with HRT of 96 h, 72 h, 48 h, 36 h and 20 h, respectively. The average COD removal efficiency of UBES could reach 45.3 ±â€¯7.5%, 72.2 ±â€¯3.5%, 86.2 ±â€¯1.4%, 75.9 ±â€¯1.8% and 64.9 ±â€¯2.0%, which were 2.4%, 6.1%, 6.4%, 10.2%, 8.7% more than those of UASB under different HRTs, respectively. Biogas production as well as methane production of UBES were significantly higher than UASB during the whole changing HRT process, the maximum methane yield of UBES was 0.31 ±â€¯0.07 L/gCODremoved. Accumulation of VFA in UBES was discovered to be lighter than UASB, the minimum average VFA in UBES was 131.9 ±â€¯18.5 mg/L, which was obtained at HRT of 48 h. These results proved that UBES can slow down the inhibition of VFA on methanogens to make sure a good performance on COD removal and biogas production than UASB. Moreover, the relationships between methane production and VFA, biogas production and COD consumption were analyzed. A cost and benefit were analyzed for evaluating the potential of UBES in practical applications compared with UASB. Finally, radial basis function neural network (RBFNN) model was developed and fitted well with the experimental data, which can be employed to predict the effluent quality of the UBES and UASB.

3.
Fish Shellfish Immunol ; 93: 726-731, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31265912

RESUMO

Application of traditional bait in aquaculture caused environment pollution and disease frequent occurrence. Residual coconut could be re-utilized to culture Spinibarbus sinensis as dietary supplement. Therefore, a novel integrated system of the improvement of yield, antioxidant and nonspecific immunity of Spinibarbus sinensis by dietary residual coconut was proposed and investigated. Spinibarbus sinensis could grow well in all supplement residual coconut groups. Survival rate, yield, whole fish body composition under 15-45% groups were increased compared with control group (CK). Bioactive substances (polyphenols and vitamin) in residual coconut enhanced AKP, ACP, phagocytic, SOD, CAT activities through up-regulating AKP, ACP, SOD, CAT genes expression levels. Theoretical analysis showed bioactive substances regulated these genes expressions and enzyme activities as stimulus signal, component, active center. Moreover, residual coconut improved mTOR and NF-kB signaling pathway. Furthermore, residual coconut inhibited Aeromonas hydrophila that increased resistance to diseases. This technology completed the solid waste recovery and the Spinibarbus sinensis culture simultaneously.

4.
J Environ Manage ; 245: 168-172, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31152960

RESUMO

The biorestoration of cyhalofop-butyl and fertility in soil using Rhodopseudanonas palustris (R. palustris) in the treated wastewater were investigated in this research. Cyhalofop-butyl was not degraded under control group. The treated wastewater containing R. palustris degraded cyhalofop-butyl and remediated fertility. Interestingly, the cyhalofop-butyl-hydrolyzing carboxylesterase gene was expressed after inoculation 24 h. Subsequently, the cyhalofop-butyl-hydrolyzing carboxylesterase were synthesized to degrade cyhalofop-butyl. The cyhalofop-butyl started to be degraded after inoculation 24 h. The cyhalofop-butyl as stimulus signal induced cyhalofop-butyl-hydrolyzing carboxylesterase gene expression through signal transduction pathway. This process took 24 h for R. palustris as they were ancient bacteria. The residual organics in the wastewater provided sufficient carbon sources and energy for R. palustris under three dosage groups. The new method completed the remediation of cyhalofop-butyl pollution, the improvement of soil fertility and soybean processing wastewater treatment simultaneously, and realized the resource reutilization of wastewater and R. palustris as sludge.


Assuntos
Herbicidas , Águas Residuárias , Butanos , Nitrilos , Solo
5.
Bioprocess Biosyst Eng ; 42(8): 1375-1384, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31172262

RESUMO

Simultaneous (SPW and propyzamide) wastewater treatment and the production of biochemicals by Rhodopseudomonas capsulata (R. capsulata) were investigated with supplement of soybean processing wastewater (SPW). Compared to control group, propyzamide was removed and biochemicals production were enhanced with the supplement of SPW. Propyzamide induced camH gene expression through activating MAPKKKs gene in MAPK signal transduction pathway. The induction of camH gene and CamH occurs after 1 day for R. capsulata. However, lack of organics in original wastewater did not maintain R. capsulata growth for over 1 day. The supplement of SPW provided sufficient carbon source for R. capsulata under three addition dosages. This new method resulted in the mixed (SPW and propyzamide) wastewater treatment and improvement of biochemicals simultaneously, as well as the realization of reutilization of wastewater and R. capsulata as sludge. Meanwhile, high-order nonlinear mathematical model of the relationship between propyzamide removal rate, Xt and Xt/r, was established.

6.
Sci Total Environ ; 671: 443-451, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-30933800

RESUMO

Sludge treatment wetlands (STWs) have recently been used to treat surplus sludge. However, the distribution of antibiotics involved in the process has not been comprehensively investigated. This study aimed to evaluate the fate of two antibiotics, i.e., ciprofloxacin (CIP) and azithromycin (AZM) in STWs during the treatment of surplus sludge. Three pilot-scale STWs units-S1 with aeration tubes, S2 with aeration tubes and reed planting, and S3 with reed planting-were constructed and operated under feeding followed by resting periods. The results showed that antibiotic content in residual sludge decreased over time and unit S2 performed the best in terms of antibiotic removal. Planting reed considerably improved the antibiotic removal performance of the STWs. Biodegradation and absorption resulted in removal of most of the antibiotics in the test units. Less than 2% of the antibiotics was taken up by plants, whereas <5% of the influent antibiotics left the STW units through the drainage discharge. Overall, STW units contributed to effectively decrease CIP and AZM to 41-72% and 49-84%, respectively.


Assuntos
Antibacterianos/análise , Azitromicina/análise , Ciprofloxacino/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Áreas Alagadas , Biodegradação Ambiental , Monitoramento Ambiental , Esgotos/análise
7.
J Environ Manage ; 240: 231-237, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30952043

RESUMO

In this study, antibiotics removal, sludge stabilization and the change in the bacterial community in sludge treatment wetlands (STWs) were investigated in different seasons. Pilot-scale STWs were characterized for sludge stabilization and the fate of antibiotics in surplus sludge applied during different seasons in three different configurations. The three configurations were unit S1 with ventilation, unit S2 with ventilation and reed plantings and unit S3 with reed plantings. The antibiotics used were ciprofloxacin, azithromycin and oxytetracycline and their degradation, degree of sludge stabilization and bacterial community dynamics were monitored. The results showed that the removal of antibiotics and reduction in the amount of organics in the planted units S2 and S3 were higher than those in the unplanted unit S1, especially in summer. The antibiotic removal efficiency in the planted unit S2, which was equipped with aeration tubes, was the highest over the entire test period. Bacterial community was analyzed by IlluminaMiSeq sequencing of the 16SrRNA gene, showed that the presence of plants in STWs enhanced microbial diversity and richness which promote the removal of antibiotics and sludge stabilization. Proteobacteria, Bacteroidetes and Firmicutes were dominant in the bacterial communities, with Thiobacillus, Dechloromonas and Pseudomonas occurring as dominant genera.


Assuntos
Esgotos , Áreas Alagadas , Antibacterianos , Bactérias , Estações do Ano
8.
Chemosphere ; 224: 502-508, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30831502

RESUMO

Antibiotics contamination and related antibiotics resistance genes (ARGs) in wastewater sludge have been a concern for environmental pollution and human health risk for years. This study investigated the fate of antibiotics and related ARGs in sludge from sludge treatment wetlands (STWs). We examined three sludge treatment beds i.e. unit No.1 was sludge drying bed with aeration tubes; unit No.2 was a ventilated sludge drying reed bed; and the unit No.3 was a sludge drying reed bed without aeration tubes. The targeted antibiotics included oxytetracycline, roxithromycin and azithromycin. The targeted ARGs included tetA, tetC, msrSA and ermB. The results indicated that in all three units antibiotics were removed significantly and related ARGs declined over one year period. The antibiotics concentrations in the surface layer were lower than those in the bottom layer. The highest removal efficiency of the targeted antibiotics was observed in the unit No.2. The removal efficiency of the targeted ARGs influenced by different parameters, especially reeds, aeration tubes and temperature. Correlation analysis between the concentrations of antibiotics and corresponding ARGs showed that in both the bottom and surface layer of all three units, a significant correlation (p < 0.05) was found between the concentrations of roxithromycin and azithromycin and the absolute abundances of msrSA. A significant correlation (p < 0.05) was also observed between the concentrations of oxytetracycline and the absolute abundances of tetA and tetC. The results demonstrated that STWs can effectively reduce the target antibiotics contents and related ARGs; and the STW with reed and aeration tubes performed better.


Assuntos
Antibacterianos/análise , Resistência Microbiana a Medicamentos/genética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Genes Bacterianos/efeitos dos fármacos , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Áreas Alagadas , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Águas Residuárias/análise
9.
Opt Lett ; 43(19): 4719-4722, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30272723

RESUMO

We demonstrate here an ultrafast, miniature, and high-performance fiber-tip Fabry-Perot (F-P) humidity sensor with ∼300 nm-thick graphene oxide (GO) diaphragm suspended onto the end face of a capillary tube with an inner diameter of 50 µm and a cavity length of ∼100 µm. The sensitivity to relative humidity (RH) spanning from ∼10%RH to ∼90%RH was examined based on the wavelength shift in the interference spectrum. Due to the intrinsic hydrophilicity of the porous GO membrane, the developed sensor exhibited an average wavelength variation of ∼0.2 nm/%RH, which indicated a relatively broad and readily detectable RH linear measurement range. More prominently, an ultrahigh response time of 60 ms was achieved over other alternative F-P humidity sensors previously reported, to our knowledge.

10.
Bioresour Technol ; 269: 319-328, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30195224

RESUMO

A pilot-scale anaerobic membrane bioreactor (AnMBR) was operated for 435 days in this study, aiming to treat pharmaceutical solvent wastewater containing m-Cresol (MC), isopropanol (IPA) and N,N-Dimethylformamide (DMF) pollutants at different temperatures of 35 ±â€¯3 °C, 25 ±â€¯3 °C, 15 ±â€¯3 °C and 25 ±â€¯3 °C, respectively. The reactor reached average total removal efficiencies of about 96%, 97.2% and 98% of MC, IPA and DMF at psychrophilic condition (15 ±â€¯3 °C). Higher physical removal rate was obtained at 15 ±â€¯3 °C due to the important contribution of membrane filtration. At this stage, the biogas production, methane content and specific methanogenic activity and extracellular polymeric substances of suspended sludge were observed with the lowest level. Moreover, the kinetic models for solvent degradation were established at different temperatures, results showed the smaller maximum specific substrate degradation rate of MC and IPA, besides, the lowest degradation rate of three solvents were obtained at 15 ±â€¯3 °C.


Assuntos
Reatores Biológicos , Águas Residuárias , Anaerobiose , Metano , Esgotos , Solventes , Eliminação de Resíduos Líquidos
11.
Chemosphere ; 206: 750-758, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29793067

RESUMO

In this study, a pilot scale anaerobic membrane bioreactor (AnMBR) was operated for 80 days to treat pharmaceutical wastewater containing m-cresol (MC) and iso-propyl alcohol (IPA). The aim of the study is to investigate the performance and methane fermentation characteristics of AnMBR at different hydraulic retention time (HRT) (48, 36, 24, 18 and 12 h). The average total removal efficiencies of MC and IPA were 95%, 96% during the 80 days, which demonstrated that the AnMBR system performed well in the MC and IPA removal. The major volatile fatty acid (VFA) was found to be acetic acid, propionic acid, butyric acid, besides, the VFA accumulated apparently when HRT decreased to 12 h. The decrease of HRT led to an increase of relative abundance of methanosarcina from 13 to 33% and a decrease in biogas yield from 0.19 to 0.05 L/gCODremoval. The biogas production was found to increase dramatically at HRT of 36 h. The trend of methane content kept stable at this stage with the average value of 78.5% which higher than other HRTs. The investigation of methanogen community showed that methanosarcinaceae was always dominant acetoclastic methanogens and methanomicrobiales was the dominant hydrogen utilizers throughout the operational period. When the HRT dropped to 12 h, the growth of the methanosarcinaceae and methanomicrobiales was observed, the amount of the methanosarcinaceae and methanomicrobiales sharply increased. After the overall research, HRT of 36 h was chosen as the most suitable operating condition due to the comprehensively preferable performance and more economical.


Assuntos
1-Propanol/química , Reatores Biológicos/normas , Cresóis/química , Metano/química , Águas Residuárias/química , Águas Residuárias/análise
12.
Chemosphere ; 198: 49-58, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29421760

RESUMO

This study focuses on the effects of organic loading rate (OLR) on the removal of N,N-Dimethylformamide(DMF), m-Cresol (MC) and isopropyl alcohol (IPA) by a pilot-scale anaerobic membrane bioreactor (AnMBR) for treating chemical synthesis-based antibiotic solvent wastewater at period of improved influent COD concentration with decreased HRT. The whole process was divided into five stages in terms of the variation of OLR ranging from 3.9 to 12.7 kg COD/(m3·d). During 249 days of operating time, the average DMF, MC, IPA removal efficiency were 96.9%,98.2% and 96.4%, respectively. Cake layer was accumulated on the membrane surface acted as a dynamic secondary biofilm which lead to the increase of physical removal rate. In addition, mathematical statistical models was built on the linear regression techniques for exploring the inner relationship between EPS and the performance of the AnMBR.


Assuntos
Antibacterianos , Reatores Biológicos/normas , Águas Residuárias/química , Purificação da Água/métodos , 2-Propanol/isolamento & purificação , Anaerobiose , Cresóis/isolamento & purificação , Dimetilformamida/isolamento & purificação , Membranas Artificiais , Projetos Piloto , Solventes
13.
J Hazard Mater ; 342: 383-391, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28850916

RESUMO

Tetrahydrofuran (THF) is one of the most representative characteristics of pollutant in pharmaceutical industry usually has high biological toxicity, making it difficult to treat. In this study, a pilot scale anaerobic membrane bioreactor (AnMBR) was employed to treat THF pharmaceutical wastewater under different hydraulic retention time (HRT). During the 80-day operating time, chemical oxygen demand (COD) and THF removal efficiencies reached 95.3% and 98.5% when HRT was above 24h. Mixed liquid suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS) in the attached sludge on membrane surface showed a trend of rising on first 28days (48h-36h) and then decreasing. Protein is the major component of extracellular polymeric substances (EPS) independent of changes in HRT. The study concludes that THF pharmaceutical wastewater can be effectively remedied in the AnMBR system at low HRT.


Assuntos
Reatores Biológicos , Furanos/química , Esgotos/química , Águas Residuárias/análise , Anaerobiose , Análise da Demanda Biológica de Oxigênio , Preparações Farmacêuticas , Polímeros , Águas Residuárias/química
14.
Bioresour Technol ; 243: 218-227, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28668560

RESUMO

This study aims at evaluating the performance and microbial community dynamics of anaerobic membrane bioreactor (AnMBR) treating antibiotic solvent wastewater at improved influent quality period. The whole process was divided into five phases according to the influent COD concentration with a fluctuated volume loading rate (VLR) ranging from 3.9 to 12.7kgCOD/(m3·d). After 249days of operation, the average COD and THF removal efficiency were 93.6% and 98.7%, respectively. The accumulation of VFA, relatively low pH, decline of biogas production and methane content were discovered at higher VLR (>10kgCOD/(m3·d)). Methanomicrobiales are the major population throughout the whole running period. Methanosaetaceae showed a minor relative abundance compared both of them, while Methanobacteriales remained a minimum value. Results showed that the reactor performed an excellent pollutants removal effect because of the function of membranes even at high VLR conditions.


Assuntos
Reatores Biológicos , Eliminação de Resíduos Líquidos , Anaerobiose , Antibacterianos , Solventes , Águas Residuárias
15.
Water Environ Res ; 87(10): 1515-50, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26420098

RESUMO

This review on stream, lake, and reservoir management covers selected 2014 publications on the focus of the following sections: • Biota • Climate effect • Models • Remediation and restoration • Reservoir operations • Stream, Lake, and Reservoir Management • Water quality.

16.
Water Sci Technol ; 71(12): 1823-30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26067502

RESUMO

Central composite design and response surface methodology (RSM) were implemented to optimize the operational parameters for a cross-flow aerobic sludge reactor (CFASR) in remedying mixed printing and dyeing wastewater (MPDW). The individual and interactive effects of three variables, hydraulic retention time (HRT), pH and sludge loading rate (SLR), on chemical oxygen demand (COD) and terephthalic acid (TA) removal rates were evaluated. For HRT of 15.3-19.8 hours, pH of 7.2-8.1 and SLR of 0.4-0.6 kg chemical oxygen demand (COD) per kg mixed liquor suspended solids per day, COD and TA removal rates of the CFASR exceeded 85% and 90%, respectively. The check experiment revealed that the effluent from the optimized CFASR was stable below the limitation of 100 mg COD/L and the TA concentration decreased by 6.0% compared to the usual CFASR. The results verified that the RSM was useful for optimizing the operation parameters of the CFASR in remedying MPDW.


Assuntos
Reatores Biológicos , Ácidos Ftálicos/química , Esgotos/química , Aerobiose , Análise da Demanda Biológica de Oxigênio , Corantes , Eliminação de Resíduos Líquidos , Águas Residuárias/química
17.
Water Sci Technol ; 71(7): 1011-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25860703

RESUMO

Sludge treatment reed bed systems (STRBs) are considered as an alternative technology for surplus sludge treatment. Organic matter is decomposed by various microbial reactions, resulting in gases such as CO2and CH4emitting into the atmosphere. The aim of this study is to investigate gas emission from STRBs. The static transparent chamber was adopted to measure gas emission; it allows sunlight to enter and plants to photosynthesise. The comparison of total solids and volatile solids showed STRBs have a higher efficiency in dewatering and mineralization than a conventional unplanted sludge drying bed (USDB). The CO2emission ranged from 28.68 to 100.42 g CO2m⁻² d(-1) in USDB, from 16.48 to 65.18 g CO2m⁻² d⁻¹ in STRBs; CH4emission ranged from 0.26 to 0.99 g CH4 m⁻² d⁻¹ in USDB, from 0.43 to 1.95 g CH4m⁻² d⁻¹ in STRBs. Both gas fluxes decreased towards the end of vegetation and reached the highest rates during the hot and dry summer. After the system was loaded by sludge, the fluxes of CO2and CH4significantly decreased in the USDB, whereas they increased in STRBs. In terms of CO2equivalent, the global warming potential of CH4was 13.13 g CO2eq m⁻² d⁻¹ and 15.02 g CO2eq m⁻² d⁻¹ in USDB and STRBs, respectively.


Assuntos
Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Metano/análise , Poaceae/metabolismo , Esgotos/análise , Eliminação de Resíduos Líquidos/métodos , China , Dessecação , Gases , Efeito Estufa , Rios , Áreas Alagadas
18.
Bioresour Technol ; 167: 241-50, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24994681

RESUMO

In this study, three novel multi-sparger multi-stage airlift loop membrane bioreactors (Ms(2)ALMBRs) were set up in parallel for treating synthetic high-strength 7-ACA pharmaceutical wastewater under different HRTs, temperatures and pHs, respectively. During the 200-day operating time, average COD removal efficiencies were 94.96%, 96.05% and 93.9%. While average 7-ACA removal efficiencies were 66.44%, 59.04% and 59.60%, respectively. The optimal conditions were 10h, 15-35°C and 7-9 for HRT, temperature and pH, respectively. Moreover, the sludge characteristics and microorganism drug-resistances were explored. Results showed that different temperatures and pHs influenced contaminant removals by affecting MLSS concentration and ß-lactamase activity significantly. In addition, mathematical statistical models, built on the polynomial and linear regression techniques, were developed for exploring the inner relationships between HRT, temperature and pH changes and MLSS concentrations, ß-lactamase activities and contaminant removals of the Ms(2)ALMBR system.


Assuntos
Reatores Biológicos , Cefalosporinas/isolamento & purificação , Membranas Artificiais , Modelos Teóricos , Temperatura Ambiente , Águas Residuárias/química , Purificação da Água/instrumentação , Purificação da Água/métodos , Biodegradação Ambiental , Concentração de Íons de Hidrogênio , Preparações Farmacêuticas/isolamento & purificação , Fatores de Tempo
19.
Tetrahedron ; 69(36): 7618-7626, 2013 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-23913987

RESUMO

Chromenes, isochromenes, and benzoxathioles react with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone to form stable aromatic cations that react with a range of nucleophiles. These oxidative fragment coupling reactions provide rapid access to structurally diverse heterocycles. Conducting the reactions in the presence of a chiral Brønsted acid results in the formation of an asymmetric ion pair that can provide enantiomerically enriched products in a rare example of a stereoselective process resulting from the generation of a chiral electrophile through oxidative carbon-hydrogen bond cleavage.

20.
Huan Jing Ke Xue ; 34(3): 1161-5, 2013 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-23745429

RESUMO

The difference in the removal efficiencies of polycyclic aromatic hydrocarbons (PAHs) in planted and unplanted sludge drying bed was investigated. Pilot-scale sludge drying bed and reed bed had the same size of 3.0 m x 1.0 m x 1.3 m (L x W x H), and the bed height consisted of a 65 cm media layer and a 65 cm super height. Both beds had a ventilation pipe which was mounted on the drainage pipes. The experiment lasted for three years, and the first two years was the sludge loading period, and the third year was the natural stabilization period. In the first two years, a total thickness of 8.4 m of sludge was loaded and the average sludge loading rate was 41.3 kg x (m2 x a)(-1). After the three-year stabilization, the contents of the sixteen PAHs decreased with time in both the sludge drying bed and the reed bed. The total PAHs contents in the surface, middle and bottom sludge layers in the sludge drying bed were 4.161, 3.543 and 3.118 mg x kg(-1) (DW), corresponding to 26.91%, 37.77% and 45.23% of removal; and the values in the reed bed were 2.722, 1.648 and 1.218 mg x kg(-1) (DW), corresponding to 52.18%, 71.05% and 78.60% of removal. The average PAHs removal in the reed bed was 29.86% higher than that in the sludge drying bed. In the stabilized sludge, the removal of low-molecular-weight PAHs predominated. The results suggested that reed played a positive role in the removal of PAHs.


Assuntos
Poluentes Ambientais/análise , Poaceae/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Esgotos/química , Áreas Alagadas , Biodegradação Ambiental , Poluentes Ambientais/isolamento & purificação , Poaceae/crescimento & desenvolvimento , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos
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