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1.
Water Res ; 174: 115600, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32088385

RESUMO

A hierarchically assembled superomniphobic membrane with three levels of reentrant structure was designed and fabricated to enable effective treatment of low surface tension, hypersaline oily wastewaters using direct contact membrane distillation (DCMD). The overall structure is a combination of macro corrugations obtained by surface imprinting, with the micro spherulites morphology achieved through the applied phase inversion method and nano patterns obtained by fluorinated Silica nanoparticles (SiNPs) coating. This resulted in a superomniphobic membrane surface with remarkable anti-wetting properties repelling both high surface tension water and low surface tension oils. Measurements of contact angle (CA) with DI water, an anionic surfactant, oil, and ethanol demonstrated a robust wetting resistance against low surface tension liquids showing both superhydrophobicity and superoleophobicity. CA values of 160.8 ± 2.3° and 154.3 ± 1.9° for water and oil were obtained, respectively. Calculations revealed a high liquid-vapor interface for the fabricated membrane with more than 89% of the water droplet contact area being with air pockets entrapped between adjacent SiNPs and only 11% come into contact with the solid membrane surface. Moreover, the high liquid-vapor interface imparts the membrane with high liquid repellency, self-cleaning and slippery effects, characterized by a minimum droplet-membrane interaction and complete water droplet bouncing on the surface within only 18 ms. When tested in DCMD with synthetic hypersaline oily wastewaters, the fabricated superomniphobic membrane demonstrated stable, non-wetting MD operation over 24 h, even at high concentrations of low surface tension 1.0 mM Sodium dodecyl sulfate and 400 ppm oil, potentially offering a sustainable option for treatment of low surface tension oily industrial wastewater.


Assuntos
Destilação , Purificação da Água , Membranas Artificiais , Óleos , Tensão Superficial , Águas Residuárias
2.
ACS Appl Mater Interfaces ; 12(1): 1617-1627, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31834764

RESUMO

In this work, a new protocol was developed for creating charge-tuned, hydrophilic hybrid ultrafiltration (UF) membranes with high flux, rejection rate, and fouling resistance. The membranes were fabricated using a combination of sulfonated poly(ether sulfone) (SPES) and aminated graphene (GO-SiO2-NH2) nanohybrid via the non-solvent-induced phase separation (NIPS) method. The GO-SiO2-NH2 nanohybrid was first synthesized using GO nanosheets and 3-aminopropyl triethoxysilane (APTES) through the covalent condensation reaction at 80 °C and was thoroughly characterized. Then, 2-8 wt% of the nanohybrid was incorporated into the matrix of SPES for the fabrication of the hybrid membranes. The resulting membranes were characterized using an electrokinetic analyzer, a contact angle goniometer, and Raman, field emission scanning electron microscopy-energy-dispersive X-ray spectrometry (FESEM-EDX), and atomic force microscopy experiments. The porosity, charge density, and surface morphology were altered, and the hybrid membranes became more hydrophilic after the incorporation of the nanohybrid. The pure water flux of the hybrid membranes systematically increased with the loading amount of the nanohybrid. The pure water flux of the hybrid membrane containing 6 wt% GO-SiO2-NH2 nanohybrid at a 2 bar feed pressure was 537 L m-2 h-1, about 3-fold that of pristine membrane (186 L m-2 h-1). The fouling resistance of the hybrid membranes was evaluated and confirmed using several representative foulants, including bovine serum albumin, humic acid, sodium alginate, and a synthetic solution of natural organic matter (NOM). The fabricated membranes were capable of removing more than 97% of NOM, without a compromise of their rejection rate.

3.
Sci Total Environ ; 691: 1251-1261, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31466205

RESUMO

Pore wetting phenomenon plays a critical role in a porous media and is critical in various processes. For instance, liquid entry pressure (LEP) is one of the critical characteristics of hydrophobic membranes used in membrane distillation (MD) processes. In this study, pore-scale models were developed to assess the accuracy of two multiphase flow computational fluid dynamics (CFD) methods, as modeling tools for predicting two-phase flow in microporous MD membranes. Finite element method (FEM)-based phase field (PF) method (which was applied in the COMSOL package) and finite volume method (FVM)-based volume of fluid (VOF) method (which was applied in Star-CCM+) were the selected CFD tools for the implementation. The boundary conditions of the models were first set based on the experimental procedure for measuring the LEP, as given in the literature. Then, the models were used to capture the LEP under the gradually increased water pressure. Critical tuning of CFD parameters of each tool (such as mesh size, mesh type, and interface thickness) was conducted to investigate their influence on the LEP prediction accuracy and the water/air interface representation at the pore entrance. CFD model results were presented and compared with both experimental LEP data and the calculated value using the Young-Laplace equation (YLE). Both CFD tools were capable of capturing the water/air interface. LEP result from the VOF model showed good agreement with the experimental data, but the PF model overestimated the LEP value closer to the theoretical YLE value. For both approaches, the adjustment of the interface thickness was critical. In the VOF method, a realistic interface thickness could be achieved by adjusting both mesh size and time step simultaneously. In contrast, PF simulations were less mesh sensitive. The accuracy of the VOF model was better due to its mass conservation condition at the interface.

4.
Adv Mater ; 29(2)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28066987

RESUMO

Thermoplasmonic effects notably improve the efficiency of vacuum membrane distillation, an economically sustainable tool for high-quality seawater desalination. Poly(vinylidene fluoride) (PVDF) membranes filled with spherical silver nanoparticles are used, whose size is tuned for the aim. With the addition of plasmonic nanoparticles in the membrane, the transmembrane flux increases by 11 times, and, moreover, the temperature at the membrane interface is higher than bulk temperature.

5.
Prog Polym Sci ; 81: 209-237, 2016 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-29937599

RESUMO

Conventional water resources in many regions are insufficient to meet the water needs of growing populations, thus reuse is gaining acceptance as a method of water supply augmentation. Recent advancements in membrane technology have allowed for the reclamation of municipal wastewater for the production of drinking water, i.e., potable reuse. Although public perception can be a challenge, potable reuse is often the least energy-intensive method of providing additional drinking water to water stressed regions. A variety of membranes have been developed that can remove water contaminants ranging from particles and pathogens to dissolved organic compounds and salts. Typically, potable reuse treatment plants use polymeric membranes for microfiltration or ultrafiltration in conjunction with reverse osmosis and, in some cases, nanofiltration. Membrane properties, including pore size, wettability, surface charge, roughness, thermal resistance, chemical stability, permeability, thickness and mechanical strength, vary between membranes and applications. Advancements in membrane technology including new membrane materials, coatings, and manufacturing methods, as well as emerging membrane processes such as membrane bioreactors, electrodialysis, and forward osmosis have been developed to improve selectivity, energy consumption, fouling resistance, and/or capital cost. The purpose of this review is to provide a comprehensive summary of the role of polymeric membranes in the treatment of wastewater to potable water quality and highlight recent advancements in separation processes. Beyond membranes themselves, this review covers the background and history of potable reuse, and commonly used potable reuse process chains, pretreatment steps, and advanced oxidation processes. Key trends in membrane technology include novel configurations, materials and fouling prevention techniques. Challenges still facing membrane-based potable reuse applications, including chemical and biological contaminant removal, membrane fouling, and public perception, are highlighted as areas in need of further research and development.

6.
Ecotoxicol Environ Saf ; 121: 57-62, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26117278

RESUMO

Presence of heavy metals as well as different metal ions in treated wastewater is a problem for the environment as well as human health. This paper aims to investigate the possibility to combine an MBR (membrane biological reactor) with an adsorption process onto powdered eggshell and eggshell membrane in order to improve metal removal from wastewater. The first step of the experimental analysis consists of the evaluation of the compatibility between the two processes. Then, a study about sorbent concentration and size effect on fouling was conducted, because the use of this kind of sorbent could affect membrane performance. The second step of the work concerns the check up of eggshell removal capacity as a function of sorbent size, achieved treating an aqueous solution containing Al(3+), Fe(2+) and Zn(2+) as water pollutants. Finally, synthetic wastewater, containing the metal species, was treated by two alternative process schemes: one of them performs the metal uptake in a dedicated adsorption unit, before the MBR. In the second, the two processes take place in the same unit. Results demonstrate that the optimization of the first option could be a solution to MBR upgrading.


Assuntos
Reatores Biológicos , Casca de Ovo/química , Metais Pesados/isolamento & purificação , Adsorção , Animais , Análise da Demanda Biológica de Oxigênio , Águas Residuárias/química
7.
J Environ Manage ; 146: 320-336, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25194519

RESUMO

Solid waste management is a key aspect of the environmental management of establishments belonging to the hospitality sector. In this study, we reviewed literature in this area, examining the current status of waste management for the hospitality sector, in general, with a focus on food waste management in particular. We specifically examined the for-profit subdivision of the hospitality sector, comprising primarily of hotels and restaurants. An account is given of the causes of the different types of waste encountered in this sector and what strategies may be used to reduce them. These strategies are further highlighted in terms of initiatives and practices which are already being implemented around the world to facilitate sustainable waste management. We also recommended a general waste management procedure to be followed by properties of the hospitality sector and described how waste mapping, an innovative yet simple strategy, can significantly reduce the waste generation of a hotel. Generally, we found that not many scholarly publications are available in this area of research. More studies need to be carried out on the implementation of sustainable waste management for the hospitality industry in different parts of the world and the challenges and opportunities involved.


Assuntos
Resíduos Sólidos , Gerenciamento de Resíduos/métodos , Humanos , Indústrias , Restaurantes
8.
Biotechnol Adv ; 32(7): 1283-1300, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25109678

RESUMO

Membrane processes have long been applied in different stages of microalgae cultivation and processing. These processes include microfiltration, ultrafiltration, dialysis, forward osmosis, membrane contactors and membrane spargers. They are implemented in many combinations, both as a standalone and as a coupled system (in membrane biomass retention photobioreactors (BR-MPBRs) or membrane carbonation photobioreactors (C-MPBRs). To provide sufficient background on these applications, an overview of membrane materials and membrane processes of interest in microalgae cultivation and processing is provided in this work first. Afterwards, discussion about specific aspects of membrane applications in microbial cultivation and harvesting is provided, including membrane fouling. Many of the membrane processes were shown to be promising options in microalgae cultivation. Yet, significant process optimizations are still required when they are applied to enable microalgae biomass bulk production to become competitive as a raw material for biofuel production. Recent developments of the coupled systems (BR-MPBR and C-MPBR) bring significant promises to improve the volumetric productivity of a cultivation system and the efficiency of inorganic carbon capture, respectively.


Assuntos
Técnicas de Cultura de Células , Membrana Celular , Microalgas , Fotobiorreatores , Membrana Celular/química , Membrana Celular/metabolismo , Microalgas/citologia , Microalgas/metabolismo
9.
Waste Manag ; 33(8): 1704-13, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23726119

RESUMO

Gasification is the thermochemical conversion of organic feedstocks mainly into combustible syngas (CO and H(2)) along with other constituents. It has been widely used to convert coal into gaseous energy carriers but only has been recently looked at as a process for producing energy from biomass. This study explores the potential of gasification for energy production and treatment of municipal solid waste (MSW). It relies on adapting the theory governing the chemistry and kinetics of the gasification process to the use of MSW as a feedstock to the process. It also relies on an equilibrium kinetics and thermodynamics solver tool (Gasify(®)) in the process of modeling gasification of MSW. The effect of process temperature variation on gasifying MSW was explored and the results were compared to incineration as an alternative to gasification of MSW. Also, the assessment was performed comparatively for gasification of MSW in the United Arab Emirates, USA, and Thailand, presenting a spectrum of socioeconomic settings with varying MSW compositions in order to explore the effect of MSW composition variance on the products of gasification. All in all, this study provides an insight into the potential of gasification for the treatment of MSW and as a waste to energy alternative to incineration.


Assuntos
Fontes Geradoras de Energia , Modelos Teóricos , Eliminação de Resíduos/métodos , Resíduos Sólidos , Gases , Cinética , Tailândia , Termodinâmica , Emirados Árabes Unidos , Estados Unidos
10.
Waste Manag Res ; 28(6): 481-8, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19942652

RESUMO

Solid waste is considered an urgent environmental health issue in the Palestinian Territory. The aim of this paper was to analyse the current status of residential solid waste (RSW) management in the Palestinian Territory, with the objective of identifying windows for improvement. The study is based on a national household sample survey in the Palestinian Territory, which was conducted by the Palestinian Central Bureau of Statistics (PCBS). The results of this study revealed various interesting trends. For example, while about 90% of households in the Palestinian Territory receive solid waste collection service, about 50% of the households receive this service three times per week or less, leaving a chance for waste pile-up and litter generation. Organic waste (including food waste) was found to account for more than 90% of RSW, providing an opportunity for waste utilization through composting or biogas generation. Additional efforts are required, and some were suggested in this paper, in order to improve the current situation of Palestinian residential solid waste management.


Assuntos
Gerenciamento de Resíduos/métodos , Habitação/estatística & dados numéricos , Oriente Médio , Eliminação de Resíduos/métodos , Eliminação de Resíduos/estatística & dados numéricos , Gerenciamento de Resíduos/estatística & dados numéricos , Resíduos/estatística & dados numéricos
11.
Waste Manag ; 29(1): 449-55, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18397822

RESUMO

Litter is recognized as a form of street pollution and a key issue for solid waste managers. Nablus district (West Bank, Palestinian Territory), which has an established network of urban and rural roads, suffers from a wide-spread litter problem that is associated with these roads and is growing steadily with a well-felt negative impact on public health and the environment. The purpose of this research was to study the effects of four socio-economic characteristics (gender, income, marital status, and religious convictions) of district residents on their attitudes, practices, and behavior regarding street litter generation and to suggest possible remedial actions. All four characteristics were found to have strong correlations, not only with littering behavior and practices, but also with potential litter prevention strategies. In particular, the impact of religious convictions of the respondents on their littering habits and attitudes was very clear and interesting to observe.


Assuntos
Poluição Ambiental/prevenção & controle , Renda , Estado Civil , Eliminação de Resíduos/métodos , Religião , Caracteres Sexuais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Oriente Médio
12.
Waste Manag Res ; 25(4): 363-70, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17874663

RESUMO

Street littering is considered an important environmental health issue in the Middle East. This problem is growing steadily and is attracting great concerns within the communities. The purpose of this paper, which focuses on Nablus district (Palestinian Territory), is to measure the perception and opinion of residents toward littering, in addition to studying prevailing attitudes and practices on littering. This was achieved using an interview survey approach. The influence of three socio-economic factors; level of education, age, and type of residence, on the littering behaviour of individuals was studied. As a result, possible remedial actions have been suggested. The data presented in this work can be considered as one piece of information, which can be compiled with other future data to design an effective litter control programrhe for Middle Eastern countries.


Assuntos
Comportamento , Poluição Ambiental , Fatores Socioeconômicos , Fatores Etários , Educação , Habitação , Humanos , Entrevistas como Assunto , Oriente Médio , Percepção , Mudança Social
13.
Waste Manag ; 27(12): 1910-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17224264

RESUMO

There is a great interest in solving problems related to municipal solid waste (MSW) management in the Palestinian territory. However, few studies have been done to assess the extent of these problems and suggest the best alternative solutions. This study aims at assessing MSW conditions in the seven major districts in northern West Bank, Palestinian territory. The study focuses on comparing several MSW management elements (such as collection, budget, and disposal) in municipalities, village councils, and refugee camps in the studied districts and the problems faced by these institutions in handling the waste. It also provides information on MSW collection service availability and waste disposal practices in the districts studied. It was found that, although MSW collection service was available for 98% of the residents in the areas surveyed, no proper treatment or landfill procedure was followed for the collected waste in most of these areas. Instead, waste burning in open dumpsites was the most common practice. Moreover, due to inefficient collection of waste disposal fees from the residents, municipalities were forced to sometimes cut the collection service and reduce its labor force, especially in villages. The budget for MSW management was between 2% and 8% of the total budget of the municipalities studied, indicating a low priority for this issue.


Assuntos
Países em Desenvolvimento , Eliminação de Resíduos/economia , Eliminação de Resíduos/métodos , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodos , Oriente Médio
14.
Int J Environ Health Res ; 16(4): 281-7, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16854673

RESUMO

Since the start of the second Palestinian uprising (Al-Aqsa Intifada), and due to the Israeli activities, curfews, closures, and military checkpoints imposed since 2000, the quality of social services rendered by Nablus city has been gradually deteriorating. Solid waste management in Nablus city was badly affected by these conditions, and this situation is negatively affecting health and damaging the environment. Most of these cases were due to reasons beyond the capability of the municipality with its limited resources. This study revealed that some of the important municipal solid waste (MSW) equipment had been damaged during the uprising. The workforce in the MSW system was reduced and certain MSW-related development projects and activities have been frozen due to the current conditions. The city's medical waste incinerator had been phased out and the number of special medical containers had been reduced from 16 to 10. Some MSW compressing trucks had been out of use with no substitute. Another important figure is the number of waste collection workers which decreased from 420 to 301, although the city is growing in premises as well as population. The created unsanitary solid waste transfer station is now a pollution source on its own, causing an ugly scene at the eastern entrance of Nablus city. There should be a comprehensive and urgent solution for this problem and the needed resources should be invested.


Assuntos
Árabes , Exposição Ambiental , Resíduos Industriais , Eliminação de Resíduos , Esgotos/química , Violência , Gerenciamento de Resíduos/métodos , Cidades , Estudos Transversais , Humanos , Israel , Fatores de Risco , Gerenciamento de Resíduos/normas
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