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1.
Water Res ; 253: 121315, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38382289

RESUMO

The microalgal-bacterial granular sludge (MBGS) based enhanced biological phosphorus removal (EBPR) (MBGS-EBPR) was recently proposed as a sustainable wastewater treatment process. Previous work showed the possibility of obtaining an MBGS-EBPR process starting from mature MBGS and phosphate-accumulating organisms (PAOs) enriched aerobic granular sludge (AGS) and validated the effectiveness of removing carbon/nitrogen/phosphorus with mechanical aeration. The present work evaluated whether the same could be achieved starting from conventional activated sludge and operating under aeration-free conditions in an alternating dark/light photo-sequencing batch reactor (PSBR). We successfully cultivated filamentous MBGS with a high settling rate (34.5 m/h) and fast solid-liquid separation performance, which could be attributed to the proliferation of filamentous cyanobacteria and stimulation of extracellular polymeric substances (EPS) production. The process achieved near-complete steady-state removal of carbon (97.2 ± 1.9 %), nitrogen (93.9 ± 0.7 %), and phosphorus (97.7 ± 1.7 %). Moreover, improved phosphorus release/uptake driven by photosynthetic oxygenation under dark/light cycles suggests the enrichment of PAOs and the establishment of MBGS-EBPR. Batch tests showed similar phosphorus release rates in the dark but significantly lower phosphorus uptake rates in the presence of light when the filamentous granules were disrupted. This indicates that the filamentous structure of MBGS has minor limitations on substrate mass transfer while exerting protective effects on PAOs, thus playing an important role in sustaining the function of aeration-free EBPR. Microbial assays further indicated that the enrichment of filamentous cyanobacteria (Synechocystis, Leptoolybya, and Nodosilinea), putative PAOs and EPS producers (Hydrogenophaga, Thauera, Flavobacterium, and Bdellovibrio) promoted the development of filamentous MBGS and enabled the high-efficient pollutant removal. This work provides a feasible and cost-effective strategy for the startup and operation of this innovative process.


Assuntos
Microalgas , Esgotos , Esgotos/química , Fósforo , Reatores Biológicos/microbiologia , Fosfatos , Bactérias , Nitrogênio , Carbono
2.
iScience ; 26(7): 107195, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37456844

RESUMO

The manuscript reviews the research on economic and environmental benefits of second-life electric vehicle batteries (EVBs) use for energy storage in households, utilities, and EV charging stations. Economic benefits depend heavily on electricity costs, battery costs, and battery performance; carbon benefits depend largely on the electricity mix charging the batteries. Environmental performance is greatest when used to store renewable energy such as wind and solar power. Inconsistent system boundaries make it challenging to compare the life cycle carbon footprint across different studies. The future growth of second-life EVB utilization faces several challenges, including the chemical and electrical properties and states of health of retired EVBs, the rapidly decreasing costs of new batteries, and different operational requirements. Measures to mitigate these challenges include the development of efficient diagnostic technologies, comprehensive test standards, and battery designs suitable for remanufacturing. Further research is needed based on real-world operational data and harmonized approaches.

3.
Membranes (Basel) ; 13(4)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37103877

RESUMO

Mixtures of silica nanoparticles (SiO2 NPs) and natural organic matter (NOM) are ubiquitous in natural aquatic environments and pose risks to organisms. Ultrafiltration (UF) membranes can effectively remove SiO2 NP-NOM mixtures. However, the corresponding membrane fouling mechanisms, particularly under different solution conditions, have not yet been studied. In this work, the effect of solution chemistry on polyethersulfone (PES) UF membrane fouling caused by a SiO2 NP-NOM mixture was investigated at different pH levels, ionic strengths, and calcium concentrations. The corresponding membrane fouling mechanisms, i.e., Lifshitz-van der Waals (LW), electrostatic (EL), and acid-base (AB) interactions, were quantitatively evaluated using the extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) theory. It was found that the extent of membrane fouling increased with decreasing pH, increasing ionic strength, and increasing calcium concentration. The attractive AB interaction between the clean/fouled membrane and foulant was the major fouling mechanism in both the initial adhesion and later cohesion stages, while the attractive LW and repulsive EL interactions were less important. The change of fouling potential with solution chemistry was negatively correlated with the calculated interaction energy, indicating that the UF membrane fouling behavior under different solution conditions can be effectively explained and predicted using the xDLVO theory.

4.
Artigo em Inglês | MEDLINE | ID: mdl-36901520

RESUMO

Green credit is an indispensable funding source through which China can achieve its carbon neutrality goal. This paper quantifies the influences of different green credit scales on energy structures, carbon reduction, the industrial economy, and the macroeconomy. It creates a green credit mechanism related to green technology innovation in a Chinese carbon neutrality computable general equilibrium (CGE) model and integrates energy, environmental, economic, and financial (3EF) systems. The green credit scale can influence green technology innovation and hence CO2 emissions. The results show that (1) green credit can accelerate China's achievement of its carbon neutrality goal, and the larger the green credit scale, the less time it takes to achieve goals; (2) the influence of green credit scales confers marginal decreasing effects with realistic policy considerations; (3) using a cost-benefit perspective, 60% is the most appropriate green credit scale to use to achieve dual carbon goals in China; (4) the different green credit scales have a heterogeneous impact on the industry output, and high-carbon-emission producers from nonenergy industries need to pay attention to their green credit risk. This research provides a scientific reference for the policy design of China's future green financial market development.


Assuntos
Poluição do Ar , Objetivos , Carbono , Dióxido de Carbono , China , Desenvolvimento Econômico , Políticas , Poluição do Ar/prevenção & controle
5.
Environ Pollut ; 313: 120190, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36122658

RESUMO

Black carbon (BC) exposure in China continues to be relatively high, prompting researchers to assess BC exposure levels using data from monitoring sites, satellite remote sensing, and models. However, data regarding the application of a combined strategy comprising the analysis of monitoring data and various types of data to simulate BC exposure levels are lacking. Hence, the current study seeks to estimate short- and long-term BC exposure levels by combining national monitoring data with data from the second Modern-Era Retrospective analysis for Research and Applications (MERRA-2). Furthermore, this study attempts to improve the spatio-temporal resolution of BC exposure levels using Bayesian maximum entropy (BME). The BME model performed well in terms of estimating short- (R2 = 0.74 and RMSE = 1.76 µg/m3) and long-term (R2 = 0.76 and RMSE = 1.3 µg/m3) exposure. Premature mortalities and economic losses were also assessed by applying localised concentration-response coefficients simulated in China. A total of 74,500 (95% confidence interval (CI): 23,900-124,500) and 538,400 (95% CI: 495,000-581,300) all-cause premature mortality cases were found to be associated with short- and long-term BC exposure, respectively. Meanwhile, short-term BC exposure was associated with economic losses ranging from 7.5 to 13.2 billion US dollars (USD) (1 USD = 6.36 RMB on January 19, 2022) based on amended human capital (AHC) and willingness to pay (WTP), accounting for 0.06%-0.1% of China's total gross domestic product (GDP) in 2017 (1.2 × 104 billion USD), respectively. The economic losses for long-term exposure varied from 53 to 93.2 billion USD based on AHC and WTP, accounting for 0.4%-0.8% of China's total GDP in 2017, respectively.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Teorema de Bayes , Carbono/análise , China , Humanos , Material Particulado/análise , Saúde Pública , Estudos Retrospectivos , Fuligem/análise
6.
Artigo em Inglês | MEDLINE | ID: mdl-35627787

RESUMO

Global warming resulting from greenhouse gas emissions has been a worldwide issue facing humanity. Simultaneously, governments have the challenging task of striking a judicious balance between increased economic growth and decreased carbon emissions. Based on the energy-environment-economy triple coupling (3E-CGE) model, we endogenously integrate climate-friendly technologies into the model's analysis framework through logic curves and refine and modify the CGE model's energy use and carbon emission modules. We conduct a scenario simulation and sensitivity analysis on carbon tax, carbon-trading, and climate-friendly technological progress, respectively. The results reveal that carbon tax and carbon trading contribute to reducing carbon emissions in the short-term but achieving the goals of peak carbon and carbon neutrality will cause the collapse of the economic system. In the long-term, climate-friendly technologies are key to achieving the dual carbon goal; the development of such technologies can also stimulate economic development. The best path for China to achieve its dual carbon goals and economic development in the next 40 years involves effectively combining the carbon tax, carbon trading, and a climate-friendly technological progress. Specifically, China can begin trading carbon in high-emissions industries then impose industry-wide carbon taxes.


Assuntos
Carbono , Gases de Efeito Estufa , Carbono/análise , Desenvolvimento Econômico , Indústrias , Tecnologia
7.
Sci Total Environ ; 833: 155066, 2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-35398433

RESUMO

A high-resolution soil moisture prediction method has recently gained its importance in various fields such as forestry, agricultural and land management. However, accurate, robust and non- cost prohibitive spatially monitoring of soil moisture is challenging. In this research, a new approach involving the use of advance machine learning (ML) models, and multi-sensor data fusion including Sentinel-1(S1) C-band dual polarimetric synthetic aperture radar (SAR), Sentinel-2 (S2) multispectral data, and ALOS Global Digital Surface Model (ALOS DSM) to predict precisely soil moisture at 10 m spatial resolution across research areas in Australia. The total of 52 predictor variables generated from S1, S2 and ALOS DSM data fusion, including vegetation indices, soil indices, water index, SAR transformation indices, ALOS DSM derived indices like digital model elevation (DEM), slope, and topographic wetness index (TWI). The field soil data from Western Australia was employed. The performance capability of extreme gradient boosting regression (XGBR) together with the genetic algorithm (GA) optimizer for features selection and optimization for soil moisture prediction in bare lands was examined and compared with various scenarios and ML models. The proposed model (the XGBR-GA model) with 21 optimal features obtained from GA was yielded the highest performance (R2 = 0. 891; RMSE = 0.875%) compared to random forest regression (RFR), support vector machine (SVM), and CatBoost gradient boosting regression (CBR). Conclusively, the new approach using the XGBR-GA with features from combination of reliable free-of-charge remotely sensed data from Sentinel and ALOS imagery can effectively estimate the spatial variability of soil moisture. The described framework can further support precision agriculture and drought resilience programs via water use efficiency and smart irrigation management for crop production.


Assuntos
Aprendizado de Máquina , Solo , Algoritmos , Radar , Água/análise
8.
Integr Med Res ; 11(2): 100804, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35145853

RESUMO

BACKGROUND: Some Western medicine schools in China established standardized patient (SP) programs for medical education. However, SP programs are rarely applied to the education of traditional Chinese medicine (TCM). In this study, we evaluated the effectiveness of using standardized patient traditional Chinese medicine (SP-TCM) to improve clinical competency among TCM medical students. METHODS: This study was a prospective, 2-group, parallel-training randomized trial over the course of 5 years. Data were collected from September 2016 to December 2020. Participants in each year were randomly allocated into the traditional-method training group or the SP-TCM training group (1:1) for a 3-month curriculum. Measurement of clinical competency among all trainees was based on a standardized examination composed of scores of medical record documentation, scores of TCM syndrome differentiation and therapeutic regimen, and checklist assessment from both SP-TCMs and TCM professionals. Feedback was collected using semi-constructive questionnaires from both groups. RESULTS: Compared with those assigned to traditional-method training, those assigned to SP-TCM training demonstrated significantly greater post-training improvement in medical record documentation and TCM syndrome differentiation and therapeutic regimen. Moreover, SP-TCM trainees outscored those assigned to traditional training in the assessment for encounter performance given by independent SP-TCMs and TCM professionals. The SP-TCM method gained higher satisfaction of training efficacy and test performance than the traditional method. CONCLUSION: This SP-TCM program demonstrated great benefits for improving clinical competency among TCM medical students.

9.
Food Addit Contam Part B Surveill ; 14(3): 177-183, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34362289

RESUMO

Although the Chinese diet has become very abundant in the past 30 years, few people know that traditional Chinese diet is exposed to aluminium (Al). A total of 1232 samples were purchased during 2017-2019 and analysed for Al content with an inductively coupled plasma-mass spectrometry (ICP-MS) method. High Al levels were found in deep-fried dough sticks (mean 219 mg/kg), starch products (mean 84.5 mg/kg), and steam bread (mean 28.6 mg/kg). The average dietary Al exposure of residents in North China was 1.82 mg/kg bw/week, lower than the PTWI (provisional tolerable weekly intake). Deep-fried dough sticks (DFDS) are the main Al contributor in North China, providing 28.2% of the daily intake. The P95 dietary exposure to Al from DFDS was 2.3 mg/kg bw/week, exceeding the PTWI. Therefore, more attention should be paid to the health risk of exposure to Al from DFDS and starch products. Over-use of Al associated with food additives should be effectively controlled.


Assuntos
Alumínio , Exposição Dietética , Alumínio/análise , Pão/análise , China , Dieta/efeitos adversos , Contaminação de Alimentos/análise , Humanos
10.
Am J Transl Res ; 13(3): 1764-1771, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33841700

RESUMO

OBJECTIVE: To investigate the efficacy of ibandronate sodium and zoledronate sodium in the treatment of senile osteoporosis and their impact on quality of life, and to analyze the cost-effectiveness. METHODS: A retrospective study was conducted on 215 patients with senile osteoporosis, who were admitted to our hospital from January 2017 to June 2019. Among them, 115 cases treated with ibandronate sodium were set to group A and 100 cases treated with zoledronate sodium were set to group B. The clinical efficacy, bone mineral density (BMD) before and after treatment, bone metabolic markers (alkaline phosphatase (ALP), blood phosphorus (P), blood calcium ion (Ca2+)), quality of life, adverse reactions, cost-effectiveness indicators (length of hospitalization, cost) and complications were compared between the two groups. RESULTS: Total therapeutic response rate in group A was 96.52% (111/115), which was not statistically different from that of 93.00% (93/100) in group B (P=0.242). After treatment, the BMD, ALP, BGP and Ca2+ levels of the lumbar spine L1-L4, left femoral neck and right femoral neck, as well as quality of life scores in the two groups increased (P < 0.05), while serum ALP levels decreased (P < 0.05), however, there was no statistically significant difference between the two groups (P > 0.05). The incidence of adverse reactions in group A was 3.48% (4/115), which showed no statistical significance with that of 5.00% (5/100) in group B (P=0.830). The length of hospitalization, annual treatment expense, medical insurance expense and out-of-pocket payments in group A were all lower than those in group B (P < 0.05). CONCLUSION: In the treatment of senile osteoporosis, the efficacy and adverse reactions of ibandronate sodium and zoledronate sodium are similar, both of them can effectively improve the quality of life. However, the cost-effectiveness of ibandronate sodium is better than that of zoledronate sodium.

11.
Ann Transl Med ; 8(19): 1242, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33178774

RESUMO

BACKGROUND: The Kidd (JK) blood group is critical for clinical blood transfusion. Various methods for Jk typing have been commonly used, including urea hemolysis, serological test, and genotyping. However, the application of molecular methods has so far been restricted to selected samples and not been applied to the population-scale analysis. METHODS: One hundred eighty-three blood samples, containing 174 samples collected from voluntary blood donors of Chinese Han individuals, together with 3 Jk (aw+b-) and 6 Jk (a-b-) samples, were investigated by standard serology urea hemolysis test and Sanger-sequencing. Complete coverage of exons 4-11 and intron-exon borders have been sequenced. RESULTS: We report the frequencies of three SNPs in exon 4, 7, and intron 9. Besides, sequence analysis revealed the simultaneous DNA variants of intron 7 (-68) and exon 9 (838) found in all samples, suggesting the co-inheritance of these SNPs-taking the observed SNPs frequencies into account. Further, we discuss the potential of the sequencing technique for high-resolution genotyping. CONCLUSIONS: The described sequencing method for Jk exons delivers a genotyping technique for Jk molecular characterization. According to the co-inheritance of these DNA variants in intron 7 (-68) and exon 9 (838), and their regularity linkage with Jk phenotypes, these two sites offer a potential sequencing target for rapid and far more simplified Jk typing that can supplement routine serology and urea hemolysis tests.

12.
Bull Environ Contam Toxicol ; 105(4): 602-606, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32978647

RESUMO

A method for simultaneous quantitation of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in potato plant, soil and potato tuber samples was established. The mean recoveries of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in different matrices spiked with them were 81.4%-101.1%, 76.1%-99.0% and 77.4%-106.4% with relative standard deviations (RSDs) of 2.7%-13.3%, 0.9%-5.5%, 1.7%-11.3%, respectively. The open-field trials in China were conducted in potato cultivation system of Changchun and Jinan. The results indicated that the half-lives of rimsulfuron and quizalofop-P-ethyl were 0.04-13.1 days. The residues of quizalofop-P during the harvest time in Jinan soil were < 0.01-0.044 mg kg-1, while there was no residue of target herbicides detected in all other samples. The risk assessment results demonstrated that the risk quotients (RQs) of rimsulfuron and quizalofop-P-ethyl were 7.857 × 10-5 and 8.730 × 10-3, respectively, which exhibited an acceptable dietary risk to Chinese consumers.


Assuntos
Resíduos de Praguicidas/análise , Propionatos/análise , Piridinas/análise , Quinoxalinas/análise , Poluentes do Solo/análise , Sulfonamidas/análise , China , Herbicidas/análise , Medição de Risco , Solo/química , Solanum tuberosum
13.
Environ Pollut ; 255(Pt 2): 113267, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31574391

RESUMO

In recent years, ozone pollution has become more and more serious in China. Several epidemiological studies have demonstrated the correlation between short-term ozone exposure and several health risks including all-cause mortality, cardiovascular mortality, and respiratory mortality. In this study, the daily ozone exposure levels with 10 km × 10 km resolution were estimated based on satellite data derived from Ozone Monitoring Instrument (OMI) and the monitoring data. The health impacts for potential decrease in the daily ozone concentration and the corresponding economic benefits in 2016 were estimated by applying the environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) model. By reducing the daily maximum 8-h average concentration of ozone to 100 µg/m3, the estimated avoided all-cause mortalities were 120 × 103 (95% confidence interval (CI): 67 × 103, 160 × 103) cases and the correspondingly economic benefits ranged from 36 to 64 billion CNY using amended human capital (AHC) and willingness to pay (WTP) method in 2016. If the daily maximum 8-h average concentration of ozone were rolled back to 70 µg/m3, the estimated avoided all-cause mortalities were 160 × 103 (95% CI: 98 × 103, 230 × 103) cases and economic benefits ranged from 54 to 95 billion CNY based on AHC and WTP methods.


Assuntos
Poluição do Ar/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Tecnologia de Sensoriamento Remoto , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Exposição Ambiental/análise , Humanos , Modelos Teóricos , Ozônio/análise , Astronave
14.
Bull Environ Contam Toxicol ; 94(4): 431-6, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25636438

RESUMO

Metal accumulation in fish is a global public health concern, because the consumption of contaminated fish accounts for the primary exposure of humans to toxic metals. In this study, the concentrations of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in Crucian carp (Carassius auratus),Yellow catfish (Pelteobagrus fulvidraco), and Bighead carp (Hypophthalmichthys nobilis) from Nansi Lake of China were evaluated, and compared with the corresponding historical values in 2001 when the government started to govern water environment effectively. Bioaccumulation of heavy metal was highest in P.fulvidraco, followed by C.auratus and H.nobilis. The concentrations of Pb, As, Cd were much lower than the historical values, but Hg concentration was higher, suggesting that heavy metal pollution problem in fish from Nansi Lake still exists. Health hazard assessment showed no health risk from exposure to Pb, As, Cd, and Hg by consuming fish from this lake.


Assuntos
Carpas/metabolismo , Peixes-Gato/metabolismo , Monitoramento Ambiental , Lagos/química , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Arsênio/metabolismo , Cádmio/metabolismo , China , Contaminação de Alimentos/análise , Humanos , Chumbo/metabolismo , Mercúrio/metabolismo , Medição de Risco
15.
Bioresour Technol ; 182: 353-363, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25690682

RESUMO

Specific organic pollutants (SOPs) such as phenolic compounds, PAHs, organic pesticides, and organic herbicides cause health and environmental problems due to their excessive toxic properties and poor biodegradability. Low-cost biosorbents are considered as a promising alternative for conventional adsorbents to remove SOPs from water. These materials have several advantages such as high sorption capacities, good modifiability and recoverability, insensitivity to toxic substances, simple operation in the treatment processes. However, previous reports on various types of biosorbents for removing SOPs are still moderately fragmented. Hence, this paper provides a comprehensive review on using typical low-cost biosorbents obtained from lignocellulose and chitin/chitosan for SOPs adsorption. Especially, their characteristics, biosorption mechanism together with utilization for eliminating SOPs are presented and discussed. The paper also gives a critical view regarding future applications of low-cost biosorbents in SOPs-contaminated water treatment.


Assuntos
Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/economia , Adsorção , Biodegradação Ambiental , Quitina/química , Quitosana/química , Custos e Análise de Custo , Lignina , Praguicidas/isolamento & purificação , Fenóis/isolamento & purificação , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Purificação da Água/métodos
16.
Bioresour Technol ; 175: 594-601, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25453440

RESUMO

Constructed wetlands (CWs) have been used as a green technology to treat various wastewaters for several decades. CWs offer a land-intensive, low-energy, and less-operational-requirements alternative to conventional treatment systems, especially for small communities and remote locations. However, the sustainable operation and successful application of these systems remains a challenge. Hence, this paper aims to provide and inspire sustainable solutions for the performance and application of CWs by giving a comprehensive review of CWs' application and the recent development on their sustainable design and operation for wastewater treatment. Firstly, a brief summary on the definition, classification and application of current CWs was presented. The design parameters and operational conditions of CWs including plant species, substrate types, water depth, hydraulic load, hydraulic retention time and feeding mode related to the sustainable operation for wastewater treatments were then discussed. Lastly, future research on improving the stability and sustainability of CWs were highlighted.


Assuntos
Plantas , Eliminação de Resíduos Líquidos/métodos , Áreas Alagadas , Análise Custo-Benefício , Desenho de Equipamento , Plantas/metabolismo , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/instrumentação , Águas Residuárias/análise , Águas Residuárias/química , Poluentes Químicos da Água/metabolismo
17.
Environ Sci Technol ; 43(9): 3272-7, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19534146

RESUMO

Driving pressure and recovery are two primary design variables of a reverse osmosis process that largely determine the total cost of seawater and brackish water desalination. A two-step optimization procedure was developed in this paper to determine the values of driving pressure and recovery that minimize the total cost of RO desalination. It was demonstrated that the optimal net driving pressure is solely determined by the electricity price and the membrane price index, which is a lumped parameter to collectively reflect membrane price, resistance, and service time. On the other hand, the optimal recovery is determined by the electricity price, initial osmotic pressure, and costs for pretreatment of raw water and handling of retentate. Concise equations were derived for the optimal net driving pressure and recovery. The dependences of the optimal net driving pressure and recovery on the electricity price, membrane price, and costs for raw water pretreatment and retentate handling were discussed.


Assuntos
Osmose , Água do Mar/química , Cloreto de Sódio/isolamento & purificação , Purificação da Água/métodos , Membranas Artificiais , Pressão Osmótica , Purificação da Água/economia
18.
Water Environ Res ; 78(8): 857-63, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17059140

RESUMO

Membrane fouling is a primary concern in membrane bioreactors (MBRs) in wastewater treatment because it strongly affects both system stability and economic feasibility. A mathematical model was developed in this study for membrane fouling in submerged MBR systems for wastewater treatment, in which both reversible and irreversible fouling were quantified. While mixed liquor suspended solids are the major components of the reversible fouling layer, dissolved organic matter is thought to be the key foulant, in particular, responsible for the long-term irreversible fouling of the filtration unit. The model was calibrated (parameter identification) with a set of operational data from a pilot MBR and then verified with other independent operational data from the MBR. The good agreement between theoretical predictions and operational data demonstrates that the outlined modeling concept can be successfully applied to describe membrane fouling in submerged MBR systems.


Assuntos
Reatores Biológicos , Análise de Falha de Equipamento/métodos , Modelos Teóricos , Eliminação de Resíduos Líquidos/instrumentação , Reatores Biológicos/economia , Simulação por Computador , Análise de Falha de Equipamento/economia , Filtração , Manutenção/métodos , Filtros Microporos/economia , Modelos Biológicos , Tamanho da Partícula , Material Particulado/efeitos adversos , Material Particulado/isolamento & purificação , Projetos Piloto , Fatores de Tempo
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