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1.
Environ Sci Pollut Res Int ; 27(1): 315-333, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31786757

RESUMO

Municipal wastewater treatment facilities produce a lot of sludge which is concentrated with different pollutants. The sustainable design of the sludge disposal alternatives is of crucial importance for touristic cities like Mashhad in Iran. Increasing sludge generation and its accumulation in the city and more stringent legislations highlight the challenge of sludge disposal, recently. This study compares different alternatives to reach maximum possible environmental benefits as well as the most cost-effective technologies. In this study, life cycle analysis (LCA) assesses different scenarios for disposal of sewage sludge which is aerobically treated and dewatered for two real case studies. Alteymore and KhinArab are wastewater treatment units in the city. The scenarios include incineration, composting, and landfilling alternatives. The incineration and landfill scenarios are the least interesting solutions according to different life cycle impact categories. The heavy metals' emission to the soil worsens their impacts. Also, lifecycle cost analysis reveals that composting scenario is more cost-saving than others. However, main disadvantage of the composting scenario is its contribution in freshwater eutrophication. To move towards sustainability, the composting scenario is here determined as the best scenario for sludge disposal in Mashhad.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Cidades , Compostagem , Poluentes Ambientais/análise , Eutrofização , Incineração , Irã (Geográfico) , Metais Pesados/análise , Eliminação de Resíduos , Esgotos , Solo , Instalações de Eliminação de Resíduos , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias
2.
Sci Total Environ ; 659: 1567-1576, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096366

RESUMO

A Life Cycle Assessment was carried out in order to assess the environmental performance of constructed wetland systems for winery wastewater treatment. In particular, six scenarios which included the most common winery wastewater treatment and management options in South-Western Europe, namely third-party management and activated sludge systems, were compared. Results showed that the constructed wetland scenarios were the most environmentally friendly alternatives, while the third-party management was the worst scenario followed by the activated sludge systems. Specifically, the potential environmental impacts of the constructed wetlands scenarios were 1.5-180 and 1-10 times lower compared to those generated by the third-party and activated sludge scenarios, respectively. Thus, under the considered circumstances, constructed wetlands showed to be an environmentally friendly technology which helps reducing environmental impacts associated with winery wastewater treatment by treating winery waste on-site with low energy and chemicals consumption.


Assuntos
Monitoramento Ambiental , Eliminação de Resíduos Líquidos/métodos , Áreas Alagadas , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/química , Águas Residuárias/estatística & dados numéricos
3.
Water Sci Technol ; 79(6): 1113-1122, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31070591

RESUMO

Sediment deposition in sewers and urban drainage systems has great effect on the hydraulic capacity of the channel. In this respect, the self-cleansing concept has been widely used for sewers and urban drainage systems design. This study investigates the bed load sediment transport in sewer pipes with particular reference to the non-deposition condition in clean bed channels. Four data sets available in the literature covering wide ranges of pipe size, sediment size and sediment volumetric concentration have been utilized through applying decision tree (DT), generalized regression neural network (GR) and multivariate adaptive regression splines (MARS) techniques for modeling. The developed models have been compared with conventional regression models available in the literature. The model performance indicators, showed that DT, GR and MARS models outperform conventional regression models. Result shows that GR and MARS models are comparable in terms of calculating particle Froude number and performing better than DT. It is concluded that conventional regression models generally overestimate particle Froude number for the non-deposition condition of sediment transport, while DT, GR and MARS outputs are close to their measured counterparts.


Assuntos
Árvores de Decisões , Drenagem Sanitária/estatística & dados numéricos , Sedimentos Geológicos/análise , Modelos Estatísticos , Redes Neurais de Computação , Poluição da Água/estatística & dados numéricos , Análise Multivariada , Eliminação de Resíduos Líquidos/estatística & dados numéricos
4.
Water Sci Technol ; 79(2): 314-322, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30865602

RESUMO

This study aims at defining a methodology to evaluate Ks reductions of gravel material constituting constructed wetland (CW) bed matrices. Several schemes and equations for the Lefranc's test were compared by using different gravel sizes and at multiple spatial scales. The falling-head test method was implemented by using two steel permeameters: one impervious (IMP) and one pervious (P) on one side. At laboratory scale, mean K values for a small size gravel (8-15 × 10-2 m) measured by the IMP and the P permeameters were equal to 19,466 m/d and 30,662 m/d, respectively. Mean Ks values for a big size gravel (10-25 × 10-2 m) measured by the IMP and the P permeameters were equal to 12,135 m/d and 20,866 m/d, respectively. Comparison of Ks values obtained by the two permeameters at laboratory scale as well as a sensitivity analysis and a calibration, lead to the modification of the standpipe equation, to evaluate also the temporal variation of the horizontal Ks. In particular, both permeameters allow the evaluation of the Ks decreasing after 4 years-operation and 1-1.5 years' operation of the plants at full scale (filled with the small size gravel) and at pilot scale (filled with the big size gravel), respectively.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Áreas Alagadas , Condutividade Elétrica , Hidrologia , Eliminação de Resíduos Líquidos/estatística & dados numéricos
5.
Water Sci Technol ; 79(2): 334-341, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30865604

RESUMO

China has achieved significant progress on wastewater treatment and aquatic environmental protection. However, leakage (in- and exfiltration) of sewer systems is still an issue. By using the statistical data of water and wastewater in 2016 in China, and the person loads (PLs) of water and wastewater in Singapore, the leakage fractions of hydraulic flow, organic carbon (COD), nitrogen (N) and phosphorus (P) mass loading, and in-sewer COD biological removal in the sewer systems of China (except Hong Kong, Macau and Taiwan), Shanghai, Guangzhou and Beijing were reported for the first time. The fractions of hydraulic flow infiltration (13%, Shanghai and Guangzhou) and exfiltration (39%, China) were calculated. Except Beijing, whose sewer networks are under appropriate management with small leakage fractions, the exfiltration fractions of COD (including in-sewer biological COD removal) ranged from 41% (Shanghai) to 66% (China) and averaged 55%; N ranged from 18% (Shanghai) to 48% (China) and averaged 33%; and P ranged from 23% (Shanghai and Guangzhou) to 44% (China) and averaged 30%. The exfiltrated sewage, COD, N and P not only wastes resources, but also contaminates the aquatic environment (especially groundwater) and contributes to 'black and odorous water bodies'. In- and exfiltration in the sewer network leads to low influent COD concentration, C/N ratio and high inorganic solids and inert particulate COD concentrations of many municipal wastewater treatment plants (WWTPs) causing high cost for nutrient removal, poor resource recovery, additional reactor/settler volume requirement and other operational problems. Therefore, tackling sewer leakage is of primary importance to today's environment in China. Recommendations for the inspection of sewer systems and the rehabilitation of damaged sewers as well as the development of design and operation guidelines of municipal WWTPs tailored to the specific local sewage characteristics and other conditions are proposed.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos/métodos , Poluição Química da Água/estatística & dados numéricos , China , Drenagem Sanitária , Odorantes , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/análise , Águas Residuárias/química , Poluição Química da Água/análise , Poluição Química da Água/economia
6.
Environ Sci Pollut Res Int ; 26(1): 544-558, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30406596

RESUMO

The study presented the occurrence of antibiotics in 16 different hospital effluents, the removal of antibiotics in urban wastewater treatment plant (WWTP), and the potential ecotoxicological risks of the effluent discharge on the aquatic ecosystem. The total concentration of antibiotics in hospital effluents was ranged from 21.2 ± 0.13 to 4886 ± 3.80 ng/L in summer and from 497 ± 3.66 to 322,735 ± 4.58 ng/L in winter. Azithromycin, clarithromycin, and ciprofloxacin were detected the highest concentrations among the investigated antibiotics. The total antibiotic load to the influent of the WWTP from hospitals was 3.46 g/day in summer and 303.2 g/day in winter. The total antibiotic contribution of hospitals to the influent of the WWTP was determined as 13% in summer and 28% in winter. The remaining 87% in summer and 72% in winter stems from the households. The total antibiotic removal by conventional physical and biological treatment processes was determined as 79% in summer, whereas it decreased to 36% in winter. When the environmental risk assessment was performed, azithromycin and clarithromycin in the effluent from the treatment plant in winter posed a high risk (RQ > 10) for the aquatic organisms (algae and fish) in the receiving environment. According to these results, the removal efficiency of antibiotics at the WWTP is inadequate and plant should be improved to remove antibiotics by advanced treatment processes.


Assuntos
Antibacterianos/análise , Monitoramento Ambiental , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Azitromicina , Claritromicina , Hospitais , Medição de Risco , Estações do Ano , Águas Residuárias/análise , Águas Residuárias/estatística & dados numéricos
7.
Environ Health Perspect ; 126(6): 067008, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29957590

RESUMO

BACKGROUND: Hydraulically fractured wells produce 2-14 million liters of wastewater, which may contain toxic and radioactive compounds. The wastewater is predominantly disposed of using Class II injection wells. OBJECTIVE: Our objective was to evaluate the relationship between sociodemographic characteristics and injection well locations in Ohio. METHODS: Using state and federal data sources, we classified Ohio census block groups by presence of injection wells, number of hydraulically fractured wells, sociodemographic factors (median household income, % white, population density, % ≥high school education, median age, voter turnout), and geographic information (land area, water area, situated over shale). We modeled the odds of having at least one injection well within a block group with respect to all covariates using three multivariable models incorporating different spatial components to account for similarities in neighboring block groups. RESULTS: In bivariate analyses, block groups with injection wells (n=156) compared with those without (n=9,049) had lower population density (71 vs. 2,210 people/mi2 or 27 vs. 854 people/km2), larger median area (43.5 vs. 1.35 km2), higher median age (42.8 vs. 40.2 y), and higher % white (98.1% vs. 92.1%). After adjustment using a spatial logistic regression model, the odds of a block group containing an injection well were 16% lower per $10,000 increase in median income [odds ratio(OR)=0.837; 95% credible interval (CI): 0.719, 0.961] and 97% lower per 1,000 people/mi2 (or per 386 people/km2) increase (OR=0.030; 95% CI=0.008, 0.072). Block groups on shale and those containing fewer hydraulically fractured wells were more likely to include an injection well. Percentage white, median age, % ≥high school education, and % voter turnout were not significant predictors of injection well presence. CONCLUSION: In Ohio, injection wells were inversely associated with block groups' median incomes after adjusting for other sociodemographic and geographic variables. Research is needed to determine whether residents in census blocks with injection wells face increased risk of chemical exposures or adverse health outcomes. https://doi.org/10.1289/EHP2663.


Assuntos
Geografia/estatística & dados numéricos , Fraturamento Hidráulico , Fatores Socioeconômicos , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Ohio , Análise de Regressão , Águas Residuárias
8.
Sci Total Environ ; 636: 69-79, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-29704718

RESUMO

Discharges from pharmaceutical manufacturing facilities (PMFs) previously have been identified as important sources of pharmaceuticals to the environment. Yet few studies are available to establish the influence of PMFs on the pharmaceutical source contribution to wastewater treatment plants (WWTPs) and waterways at the national scale. Consequently, a national network of 13 WWTPs receiving PMF discharges, six WWTPs with no PMF input, and one WWTP that transitioned through a PMF closure were selected from across the United States to assess the influence of PMF inputs on pharmaceutical loading to WWTPs. Effluent samples were analyzed for 120 pharmaceuticals and pharmaceutical degradates. Of these, 33 pharmaceuticals had concentrations substantially higher in PMF-influenced effluent (maximum 555,000 ng/L) compared to effluent from control sites (maximum 175 ng/L). Concentrations in WWTP receiving PMF input are variable, as discharges from PMFs are episodic, indicating that production activities can vary substantially over relatively short (several months) periods and have the potential to rapidly transition to other pharmaceutical products. Results show that PMFs are an important, national-scale source of pharmaceuticals to the environment.


Assuntos
Monitoramento Ambiental , Preparações Farmacêuticas/análise , Águas Residuárias/estatística & dados numéricos , Poluentes Químicos da Água/análise , Indústria Farmacêutica/estatística & dados numéricos , Humanos , Instalações Industriais e de Manufatura , Estados Unidos , Eliminação de Resíduos Líquidos/estatística & dados numéricos
9.
Integr Environ Assess Manag ; 14(4): 447-462, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29603595

RESUMO

Mediterranean-African countries (MACs) face a major water crisis. The annual renewable water resources are close to the 500 m3 /capita threshold of absolute water scarcity, and water withdrawals exceed total renewable water resources by 30%. Such a low water availability curbs economic development in agriculture, which accounts for 86% of freshwater consumption. The analysis of the current situation of wastewater treatment, irrigation, and water management in MACs and of the research projects targeted to these countries indicates the need for 1) an enhanced capacity to analyze water stress, 2) the development of water management strategies capable of including wastewater reuse, and 3) development of locally adapted water treatment and irrigation technologies. This analysis shaped the MADFORWATER project (www.madforwater.eu), whose goal is to develop a set of integrated technological and management solutions to enhance wastewater treatment, wastewater reuse for irrigation, and water efficiency in agriculture in Egypt, Morocco, and Tunisia. MADFORWATER develops and adapts technologies for the production of irrigation-quality water from drainage canals and municipal, agro-industrial, and industrial wastewaters and technologies for water efficiency and reuse in agriculture, initially validated at laboratory scale, to 3 hydrological basins in the selected MACs. Selected technologies will be further adapted and validated in 4 demonstration plants of integrated wastewater treatment and reuse. Integrated strategies for wastewater treatment and reuse targeted to the selected basins are developed, and guidelines for the development of integrated water management strategies in other basins of the 3 target MACs will be produced. The social and technical suitability of the developed technologies and nontechnological tools in relation to the local context is evaluated with the participation of MAC stakeholders and partners. Guidelines on economic instruments and policies for the effective implementation of the proposed water management solutions in the target MACs will be developed. Integr Environ Assess Manag 2018;14:447-462. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).


Assuntos
Agricultura , Reciclagem , Eliminação de Resíduos Líquidos/métodos , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Purificação da Água/métodos , Purificação da Água/estatística & dados numéricos , Egito , Marrocos , Tunísia
10.
Sci Total Environ ; 628-629: 74-84, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29428862

RESUMO

This study explored the feasibility and estimated the environmental impacts of two novel wastewater treatment configurations. Both include combined bioflocculation and anaerobic digestion but apply different nutrient removal technologies, i.e. partial nitritation/Anammox or microalgae treatment. The feasibility of such configurations was investigated for 16 locations worldwide with respect to environmental impacts, such as net energy yield, nutrient recovery and effluent quality, CO2 emission, and area requirements. The results quantitatively support the applicability of partial nitritation/Anammox in tropical regions and some locations in temperate regions, whereas microalgae treatment is only applicable the whole year round in tropical regions that are close to the equator line. Microalgae treatment has an advantage over the configuration with partial nitritation/Anammox with respect to aeration energy and nutrient recovery, but not with area requirements. Differential sensitivity analysis points out the dominant influence of microalgal biomass yield and wastewater nutrient concentrations on area requirements and effluent quality. This study provides initial selection criteria for worldwide feasibility and corresponding environmental impacts of these novel municipal wastewater treatment plant configurations.


Assuntos
Nitrogênio/metabolismo , Eliminação de Resíduos Líquidos/métodos , Biomassa , Reatores Biológicos , Microalgas , Nitrificação , Nitrogênio/análise , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/química , Microbiologia da Água
11.
Sci Total Environ ; 627: 869-879, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29426212

RESUMO

The presence of pharmaceutical and personal care products and drugs of abuse (PPCPs) in wastewater treatment plants (WWTPs) indicates discharge of the effluent may not be suitable for the ecological balance of water ecosystems, such as wetlands. These PPCPs degrade water quality, considered as an ecosystem service (ES), provoking serious environmental impacts. Assessing the monetary value of PPCPs can be used as a proxy for environmental status of the ES of water quality (ESWQ). Considering PPCPs as non-desirable outputs of WWTPs, the shadow prices methodology has been implemented using directional distance function to measure the environmental avoided cost of removing salicylic acid (SA), methylparaben (MP), and THCOOH from WWTPs effluents discharged to Albufera Natural Park (Spain). The SA shows the highest shadow price (138.16 €/µg), followed by THCOOH (48.15 €/µg), and MP (30.66 €/µg). These values are interpreted as the environmental cost that would be avoided if SA, MP, and THCOOH were removed from WWTPs effluents. The non-parametric tests show that wastewater treatment technology, together with population equivalent (as a proxy of the size of urban areas) and seasonality are factors that influence shadow prices obtained. The approach used in this study highlights the use of PPCPs as status indicators of ESWQ quantified in monetary units. As a way to synthesize the essential concepts to implement the shadow prices approach, this study proposes a flow diagram to represent the relationship between all the factors involved in this work. The use of shadow prices methodology proves that removing SA, MP, and THCOOH is associated with a measurable improvement in the ESWQ of Albufera Natural Park. The findings of this study will be useful for plant managers in order to make decisions about the removal of PPCPs in WWTPs effluents.


Assuntos
Monitoramento Ambiental , Parabenos/análise , Ácido Salicílico/análise , Eliminação de Resíduos Líquidos/economia , Poluentes Químicos da Água/análise , Poluição Química da Água/economia , Áreas Alagadas , Cosméticos , Preparações Farmacêuticas , Espanha , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias , Poluição Química da Água/estatística & dados numéricos
12.
Environ Sci Pollut Res Int ; 24(25): 20291-20299, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28702917

RESUMO

Antidepressants are gaining public attention because of increasing reports of their occurrence in environment and their potential impact on ecosystems and human health. Continuous input of pharmaceuticals into rivers, through psychiatric hospital or wastewater treatment plant (WWTPs) effluent, may cause adverse effects on the aquatic ecosystems of the receiving water bodies. This work investigates the occurrence and sources of 8 antidepressants in main stream and tributaries of Huangpu River in Shanghai. The detected concentrations of the selected antidepressants ranged from low nanogram per liter to 42.9 ng L-1 (fluoxetine) in main stream and ranged from low nanogram per liter to 33.7 ng L-1 (fluoxetine) in tributaries. To study the effect of hospital or wastewater treatment plants (WWTPs) on environment, the upstream and downstream samples were analyzed. Generally, antidepressants had greater concentrations in downstream than that in upstream of the WWTPs or hospitals. It is suggesting that WWTPs and hospitals may introduce pollution into water environment. A preliminary risk assessment was conducted: none of the eight target compounds yielded risk quotient (RQ) values more than 0.1, thus indicating that no adverse effect is expected in water environment. These results will provide background data for future antidepressants pollution control and management in Shanghai, China.


Assuntos
Antidepressivos/análise , Monitoramento Ambiental , Rios/química , Poluentes Químicos da Água/análise , China , Humanos , Medição de Risco , Instalações de Eliminação de Resíduos/estatística & dados numéricos , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/química
13.
Water Sci Technol ; 75(12): 2952-2963, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28659535

RESUMO

Monitoring and fault detection methods are increasingly important to achieve a robust and resource efficient operation of wastewater treatment plants (WWTPs). The purpose of this paper was to evaluate a promising machine learning method, Gaussian process regression (GPR), for WWTP monitoring applications. We evaluated GPR at two WWTP monitoring problems: estimate missing data in a flow rate signal (simulated data), and detect a drift in an ammonium sensor (real data). We showed that GPR with the standard estimation method, maximum likelihood estimation (GPR-MLE), suffered from local optima during estimation of kernel parameters, and did not give satisfactory results in a simulated case study. However, GPR with a state-of-the-art estimation method based on sequential Monte Carlo estimation (GPR-SMC) gave good predictions and did not suffer from local optima. Comparisons with simple standard methods revealed that GPR-SMC performed better than linear interpolation in estimating missing data in a noisy flow rate signal. We conclude that GPR-SMC is both a general and powerful method for monitoring full-scale WWTPs. However, this paper also shows that it does not always pay off to use more sophisticated methods. New methods should be critically compared against simpler methods, which might be good enough for some scenarios.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/estatística & dados numéricos , Monitoramento Ambiental/métodos , Método de Monte Carlo , Distribuição Normal , Eliminação de Resíduos Líquidos/estatística & dados numéricos
14.
Sci Total Environ ; 543(Pt A): 547-569, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26613513

RESUMO

A comprehensive study, which contains the seasonal occurrence, removal, mass loading and environmental risk assessment of 55 multi-class pharmaceuticals and personal care products (PPCPs), took place in the wastewater treatment plant (WWTP) of Volos, Greece. A one year monitoring study was performed and the samples were collected from the influent and the effluent of the WWTP. Solid phase extraction was used for the pre-concentration of the samples followed by an LC-DAD-ESI/MS analysis. Positive samples were further confirmed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The maximum concentrations of the PPCPs varied between 21 ng/L and 15,320 ng/L in the influents and between 18 ng/L and 9965 ng/L in the effluents. The most commonly detected PPCPs were the diuretic furosemide, the beta-blockers atenolol and metoprolol, the analgesics paracetamol, nimesulide, salicylic acid and diclofenac and the psychomotor stimulant caffeine. The removal efficiencies ranged between negative and high removal rates, demonstrating that the WWTP is not able to efficiently remove the complex mixture of PPCPs. The estimated mass loads ranged between 5.1 and 3513 mg/day/1000 inhabitants for WWTP influent and between 4.1 to 2141 mg/day/1000 inhabitants for WWTP effluent. Finally, environmental risk assessment has been regarded a necessary part of the general research. According to the results produced from the calculation of the risk quotient on three trophic levels, the anti-inflammatory drug diclofenac and the antibiotics, trimethoprim and ciprofloxacin, identified to be of high potential environmental risk for acute toxicity, while diclofenac also for chronic toxicity.


Assuntos
Cosméticos/análise , Monitoramento Ambiental , Preparações Farmacêuticas/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Grécia , Medição de Risco , Estações do Ano , Eliminação de Resíduos Líquidos/estatística & dados numéricos
15.
Sci Total Environ ; 511: 535-43, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25585156

RESUMO

The use of nano-enabled materials in industry and consumer products is increasing rapidly and with it, the more imperative it becomes to understand the consequences of such materials entering the environment during production, use or disposal. The novel properties of engineered nanomaterials (ENMs) that make them desirable for commercial applications also present the possibility of impacting aquatic and terrestrial environments in ways that may differ from materials in bulk format. Modeling techniques are needed to proactively predict the environmental fate and transport of nanomaterials. A model for nanoparticle (NP) separation and transformation in water treatment was parameterized for three metal and metal-oxide NPs. Functional assays to determine NP specific distribution and transformation were used to parameterize the model and obtain environmentally relevant concentrations of NPs and transformation byproducts leaving WWTPs in effluent and biosolids. All three NPs were predicted to associate >90% with the solid phase indicating significant accumulation in the biosolids. High rates of transformation for ZnO and Ag NPs resulted in ~97% transformation of the NPs that enter the plant despite differences in transformation rate in aerobic versus anaerobic environments. Due to high insolubility and negligible redox transformation, the only process predicted to impact TiO2 NP fate and transport in WWTPs was distribution between the solid and liquid phases. Subsequent investigation of ZnO NP species fate and transport when land applied in biosolids indicated that steady state concentrations of ZnO phases would likely be achieved after approximately 150days under loading conditions of biosolids typical in current practice.


Assuntos
Nanopartículas Metálicas/análise , Modelos Químicos , Prata/análise , Titânio/análise , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Óxido de Zinco/análise , Agricultura/métodos , Método de Monte Carlo , Eliminação de Resíduos Líquidos/estatística & dados numéricos
16.
Chemosphere ; 140: 150-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25262948

RESUMO

A paradigm shift is currently underway from an attitude that considers wastewater streams as a waste to be treated, to a proactive interest in recovering materials and energy from these streams. This paper is concerned with the development and application of a systematic, model-based methodology for the development of wastewater resource recovery systems that are both economically attractive and sustainable. With the array of available treatment and recovery options growing steadily, a superstructure modeling approach based on rigorous mathematical optimization appears to be a natural approach for tackling these problems. The development of reliable, yet simple, performance and cost models is a key issue with this approach in order to allow for a reliable solution based on global optimization. We argue that commercial wastewater simulators can be used to derive such models, and we illustrate this approach with a simple resource recovery system. The results show that the proposed methodology is computationally tractable, thereby supporting its application as a decision support system for selection of promising resource recovery systems whose development is worth pursuing.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/estatística & dados numéricos , Conservação dos Recursos Naturais/métodos , Modelos Teóricos , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/economia
17.
Chemosphere ; 140: 2-11, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25455679

RESUMO

Alternative domestic wastewater treatment processes that recover energy and nutrients while achieving acceptable nutrient limits (<5mgNL(-1)) are a key challenge. Major drivers are value and availability of phosphorous, nitrogen, and potassium, and increasing energy costs. The two major platforms that can achieve this are (a) low energy mainline (LEM), with low strength anaerobic treatment, followed by mainline anaerobic nitrogen removal and chemical or adsorptive phosphorous removal and (b) partition-release-recover (PRR), in which carbon and nutrients are partitioned to solids through either heterotrophic or phototrophic microbes, followed by anaerobic digestion of these solids and recovery from the digestate. This paper reviews practical application of these processes, with a focus on energy costs. Compared to conventional processes which require 0.5kWhkL(-1) electricity (500mgCODL(-1) influent concentration), PRR requires only 0.05kWhkL(-1) electricity. LEM offers the possibility to recover 0.1kWhkL(-1) as electricity with net energy generation above 400mgCODL(-1)influent, while PRR becomes energy generating at >650mgCODL(-1). PRR offers the possibility for recovery of nitrogen and other nutrients (including potassium) through assimilative recovery. However, the energetic overhead of this is substantial, requiring 5kWhkgN(-1) as electricity, which compares to ammonia fixation costs. The lower energy costs, and near to market status of LEM treatment make it likely as a recovery platform in the shorter term, while ability to recover other elements such as nitrogen and potassium, as well as enhance favourability on concentrated wastewaters may enhance the desirability of partitioning in the longer term.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Amônia/análise , Carbono/análise , Conservação dos Recursos Naturais/métodos , Nitrogênio/análise , Fósforo/análise , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Poluição da Água/prevenção & controle
18.
Sci Total Environ ; 490: 342-50, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24867699

RESUMO

In this study, the concentration probability distributions of 82 pharmaceutical compounds detected in the effluents of 179 European wastewater treatment plants were computed and inserted into a multimedia fate model. The comparative ecotoxicological impact of the direct emission of these compounds from wastewater treatment plants on freshwater ecosystems, based on a potentially affected fraction (PAF) of species approach, was assessed to rank compounds based on priority. As many pharmaceuticals are acids or bases, the multimedia fate model accounts for regressions to estimate pH-dependent fate parameters. An uncertainty analysis was performed by means of Monte Carlo analysis, which included the uncertainty of fate and ecotoxicity model input variables, as well as the spatial variability of landscape characteristics on the European continental scale. Several pharmaceutical compounds were identified as being of greatest concern, including 7 analgesics/anti-inflammatories, 3 ß-blockers, 3 psychiatric drugs, and 1 each of 6 other therapeutic classes. The fate and impact modelling relied extensively on estimated data, given that most of these compounds have little or no experimental fate or ecotoxicity data available, as well as a limited reported occurrence in effluents. The contribution of estimated model input variables to the variance of freshwater ecotoxicity impact, as well as the lack of experimental abiotic degradation data for most compounds, helped in establishing priorities for further testing. Generally, the effluent concentration and the ecotoxicity effect factor were the model input variables with the most significant effect on the uncertainty of output results.


Assuntos
Monitoramento Ambiental/métodos , Preparações Farmacêuticas/análise , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Poluição da Água/estatística & dados numéricos , Ecossistema , Água Doce , Modelos Químicos , Método de Monte Carlo , Preparações Farmacêuticas/classificação , Probabilidade , Medição de Risco , Incerteza , Águas Residuárias/estatística & dados numéricos , Poluentes Químicos da Água/classificação
19.
Sci Total Environ ; 490: 279-87, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24858225

RESUMO

The occurrence, fate, seasonal influence and environmental risk assessment of four selective serotonin re-uptake inhibitors (SSRIs) antidepressants, citalopram, fluoxetine, paroxetine and sertraline, were studied in 15 different wastewater treatment plants (WWTPs) across Portugal. Influent and effluent samples from four sampling campaigns, in 2013, were extracted through Oasis HLB cartridges, and quantified through liquid chromatography with tandem mass spectrometry (LC-MSn).Results showed that citalopram was the SSRI most frequently found, both in influents and in effluents, with mean mass loads ranging between 14.56 and 9.51 mg/day/1000 inhabitants, respectively. Fluoxetine and sertraline were only detected in influent samples, in lower mean mass loads (14.60 and 1.36 mg/day/1000 inhab., respectively), whereas paroxetine was found in influent and effluent samples (12.61 and 18.90 mg/day/1000 inhab., respectively). WWTPs were not capable of completely removing these pharmaceuticals; nonetheless, the mean removal efficiency was 82.24%. Removal efficiency was lower in winter (74.21%), summer (72.02%), and autumn (81.19%), when compared to spring (100%). Our results translate the variations in SSRI prescription and use between the five Portuguese regions in study. Influent contaminated samples were found in WWTPs from Lisbon, Alentejo, Center and North (28.25, 19.01, 16.55 and 6.98 mg/day/1000 inhab., respectively). In the Algarve region no contaminated samples were found. A seasonal pattern in the presence of SSRIs in influent wastewaters was observed. The SSRIs mass loads in influent wastewaters were higher in autumn, followed by spring, winter, and summer. Finally, the potential ecotoxicological risk posed by SSRIs to different trophic levels of aquatic organisms, exposed to the effluent wastewaters studied was evaluated by means of risk quotients (RQ). Citalopram and paroxetine, the only SSRIs found in these samples, presented RQ lower than 1. According to the results, algae appeared to be the most sensitive followed by fish and daphnids.


Assuntos
Antidepressivos/análise , Monitoramento Ambiental , Águas Residuárias/química , Poluentes Químicos da Água/análise , Seguimentos , Portugal , Medição de Risco , Estações do Ano , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/estatística & dados numéricos
20.
J Environ Manage ; 132: 94-106, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24291582

RESUMO

The system of "Service Objectives", introduced by the Italian National Strategic Framework 2007-2013, is an innovative results-oriented programme concerning 4 thematic areas (education, care for the elderly and children, management of municipal solid wastes and integrated water service) in which the Ministry of Economic Development and eight Southern Italy districts are involved. The system was initially associated to an incentive mechanism which provided subsidies for a total amount of EUR 3 billion from the national Underdeveloped Areas Fund, according to the achievement of specific targets set for 11 service indicators in 2013. The indicators used for the integrated water service refer to the efficiency in water supply service as well as the coverage of wastewater treatment service. The aim of the study is to describe the activities carried out in Italy by the ENEA Agency in order to define a new performance indicator for wastewater treatment service taking into account the appropriateness and efficiency of existing plants equipment and, consequently, evaluating economic incentives. The proposed procedure takes into account both wastewater treatment demand and quality of wastewater treatment service offered to citizens. Input data, provided by the National Institute of Statistics (ISTAT), were elaborated in order to define appropriate parameters, with a multi-criteria analysis being used to define the new performance indicator. The applicability of the proposed procedure was verified considering all the 8 Southern Italy and Island districts (Abruzzo, Molise, Campania, Apulia, Basilicata, Calabria, Sicily and Sardinia) involved in the programme. The obtained results show that the quality of municipal wastewater may influence the calculation of the incentive amount. The performance indicators defined in this work might be conveniently extended to other contexts similar to the assessed geographical area (Southern Italy and Islands).


Assuntos
Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Participação da Comunidade , Itália , Motivação , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Abastecimento de Água/análise
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