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1.
Chemosphere ; 362: 142860, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39019174

RESUMO

The application of artificial neural networks (ANNs) in the treatment of wastewater has achieved increasing attention, as it enhances the efficiency and sustainability of wastewater treatment plants (WWTPs). This paper explores the application of ANN-based models in WWTPs, focusing on the latest published research work, by presenting the effectiveness of ANNs in predicting, estimating, and treatment of diverse types of wastewater. Furthermore, this review comprehensively examines the applicability of the ANNs in various processes and methods used for wastewater treatment, including membrane and membrane bioreactors, coagulation/flocculation, UV-disinfection processes, and biological treatment systems. Additionally, it provides a detailed analysis of pollutants viz organic and inorganic substances, nutrients, pharmaceuticals, drugs, pesticides, dyes, etc., from wastewater, utilizing both ANN and ANN-based models. Moreover, it assesses the techno-economic value of ANNs, provides cost estimation and energy analysis, and outlines promising future research directions of ANNs in wastewater treatment. AI-based techniques are used to predict parameters such as chemical oxygen demand (COD) and biological oxygen demand (BOD) in WWTP influent. ANNs have been formed for the estimation of the removal efficiency of pollutants such as total nitrogen (TN), total phosphorus (TP), BOD, and total suspended solids (TSS) in the effluent of WWTPs. The literature also discloses the use of AI techniques in WWT is an economical and energy-effective method. AI enhances the efficiency of the pumping system, leading to energy conservation with an impressive average savings of approximately 10%. The system can achieve a maximum energy savings state of 25%, accompanied by a notable reduction in costs of up to 30%.


Assuntos
Redes Neurais de Computação , Eliminação de Resíduos Líquidos , Águas Residuárias , Poluentes Químicos da Água , Águas Residuárias/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Reatores Biológicos , Fósforo/análise , Análise da Demanda Biológica de Oxigênio , Nitrogênio/análise , Purificação da Água/métodos
2.
Environ Pollut ; 346: 123648, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38408504

RESUMO

Municipal wastewater is ubiquitously laden with myriad pollutants discharged primarily from a combination of domestic and industrial activities. These heterogeneous pollutants are threating the natural environments when the traditional activated sludge system fails sporadically to reduce the pollutants' toxicities. Besides, the activated sludge system is very energy intensive, bringing conundrums for decarbonization. This research endeavoured to employ Chlorella vulgaris sp. In converting pollutants from municipal wastewater into hydrogen via alternate light and dark fermentative process. The microalgae in attached form onto 1 cm3 of polyurethane foam cubes were adopted in optimizing light intensity and photoperiod during the light exposure duration. The highest hydrogen production was recorded at 52 mL amidst the synergistic light intensity and photoperiod of 200 µmolm-2s-1 and 12:12 h (light:dark h), respectively. At this lighting condition, the removals of chemical oxygen demand (COD) and ammoniacal nitrogen were both achieved at about 80%. The sustainability of microalgal fermentative performances was verified in recyclability study using similar immobilization support material. There were negligible diminishments of hydrogen production as well as both COD and ammoniacal nitrogen removals after five cycles, heralding inconsequential microalgal cells' washout from the polyurethane support when replacing the municipal wastewater medium at each cycle. The collected dataset was finally modelled into enhanced Monod equation aided by Python software tool of machine learning. The derived model was capable to predict the performances of microalgae to execute the fermentative process in producing hydrogen while subsisting municipal wastewater at arbitrary photoperiod. The enhanced model had a best fitting of R2 of 0.9857 as validated using an independent dataset. Concisely, the outcomes had contributed towards the advancement of municipal wastewater treatment via microalgal fermentative process in producing green hydrogen as a clean energy source to decarbonize the wastewater treatment facilities.


Assuntos
Compostos de Amônio , Chlorella vulgaris , Microalgas , Águas Residuárias , Esgotos , Fotoperíodo , Nitrogênio , Hidrogênio , Biomassa
3.
Chemosphere ; 346: 140591, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37918531

RESUMO

Current study had made a significant progress in microalgal wastewater treatment through the implementation of an economically viable polyethylene terephthalate (PET) membrane derived from plastic bottle waste. The membrane exhibited an exceptional pure water flux of 156.5 ± 0.25 L/m2h and a wastewater flux of 15.37 ± 0.02 L/m2h. Moreover, the membrane demonstrated remarkable efficiency in selectively removing a wide range of residual parameters, achieving rejection rates up to 99%. The reutilization of treated wastewater to grow microalgae had resulted in a marginal decrease in microalgal density, from 10.01 ± 0.48 to 9.26 ± 0.66 g/g. However, this decline was overshadowed by a notable enhancement in lipid production with level rising from 181.35 ± 0.42 to 225.01 ± 0.11 mg/g. These findings signified the membrane's capacity to preserve nutrients availability within the wastewater; thus, positively influencing the lipid synthesis and accumulation within microalgal cells. Moreover, the membrane's comprehensive analysis of cross-sectional and surface topographies revealed the presence of macropores with a highly interconnected framework, significantly amplifying the available surface area for fluid flow. This exceptional structural attribute had substantially contributed to the membrane's efficacy by facilitating superior filtration and separation process. Additionally, the identified functional groups within the membrane aligned consistently with those commonly found in PET polymer, confirming the membrane's compatibility and efficacy in microalgal wastewater treatment.


Assuntos
Microalgas , Águas Residuárias , Polietilenotereftalatos , Ultrafiltração , Estudos Transversais , Biomassa , Lipídeos
4.
Mol Biotechnol ; 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37964101

RESUMO

Conventionally, increasing the yield of microalgal biomass has been the primary focus of research, while the significant protein reserve within this biomass has remained largely unexplored. This protein reserve possesses substantial value and versatility, offering a wide range of prospective applications and presenting an enticing chance for innovation and value enhancement for various sectors. Current study employed an innovative research approach that focused solely on the LCA of protein production potential from microalgal biomass, a lesser-explored aspects within this domain. Most environmental impact categories were shown to be significantly affected by cultivation phase because of the electrical obligation, followed by the harvesting and protein extraction phase. Still, the environmental aspect was seen to yield a minimal impact on global warming potential, i.e., 4 × 10-3 kg CO2, underscoring the ecologically favorable nature of the process. Conversely, the overall energy impact was seen to intensify with NEB of - 39.33 MJ and NER of 0.49, drawing attention to the importance of addressing the energy aspect to harness the full potential of microalgal protein production.

5.
Environ Res ; 233: 116533, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37394167

RESUMO

Changing the growth environment for microalgae can overall lead to the fundamental alteration in cellular biochemicals whilst attaching onto palm kernel expeller (PKE) waste to form adhesion complex in easing harvesting at stationary growth phase. This study had initially optimized the PKE dosage, light intensity and photoperiod in maximizing the attached microalgal productivity being attained at 0.72 g/g day. Lipid content increased progressively from pH 3 to pH 11, with the highest value observed at pH 11. Meanwhile, in terms of protein and carbohydrate contents, the highest values were obtained by cultivation medium of pH 5 with 9.92 g and 17.72 g, respectively followed by pH 7 with 9.16 g and 16.36 g, respectively. Moreover, the findings also suggested that the low pH mediums utilized polar interactions in the formation of complexes between PKE and microalgae, whereas at higher pH levels, the non-polar interactions became more significant. The work of attachment was thermodynamically favourable towards the attachment formation with values greater than zero which was also aligned with the microscopic surface topography, i.e., revealing a clustering pattern of microalgae colonizing the PKE surface. These findings contribute to comprehensive understanding of optimizing growth condition and harvesting strategy of attached microalgae in attaining the cellular biochemical components, facilitating the development of efficient and sustainable bioresource utilization.


Assuntos
Microalgas , Biomassa
6.
Brain Sci ; 13(5)2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37239189

RESUMO

Stroke is the fourth leading cause of mortality and is estimated to be one of the major reasons for long-lasting disability worldwide. There are limited studies that describe the application of physical therapy interventions to prevent disabilities in stroke survivors and promote recovery after a stroke. In this review, we have described a wide range of interventions based on impairments, activity limitations, and goals in recovery during different stages of a stroke. This article mainly focuses on stroke rehabilitation tactics, including those for sensory function impairments, motor learning programs, hemianopia and unilateral neglect, flexibility and joint integrity, strength training, hypertonicity, postural control, and gait training. We conclude that, aside from medicine, stroke rehabilitation must address specific functional limitations to allow for group activities and superior use of a hemiparetic extremity. Medical doctors are often surprised by the variety of physiotherapeutic techniques available; they are unfamiliar with the approaches of researchers such as Bobath, Coulter, and Brunnstrom, among others, as well as the scientific reasoning behind these techniques.

7.
Children (Basel) ; 10(5)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37238390

RESUMO

Spasticity is a common issue among children, especially those with bilateral spastic cerebral palsy (CP). Selective dorsal rhizotomy (SDR) is a surgical procedure that is often used to decrease lower limb rigidity, alongside other treatment options such as intrathecal medication, peripheral nerve surgery, and deep brain stimulation (DBS). The objective of these therapies is to improve the standard of living for young individuals. This article intends to explain the motor deficits observed in spastic diplegia and a rehabilitation program using physical therapy after SDR. The information can help with counseling parents about the prognosis and developing a clinical treatment plan. The article presents a case study of a 12-year-old girl who recently underwent L3, L4, and L5 nerve root rhizotomy in the physical therapy department. It highlights the importance of long-term physical therapy follow-up and orthotic usage in the management of spastic diplegia.

8.
Chemosphere ; 323: 138196, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36842558

RESUMO

World estimated municipal solid waste generating at an alarming rate and its disposal is a severe concern of today's world. It is equivalent to 0.79 kg/d per person footprint and causing climate change; health hazards and other environmental issues which need attention on an urgent basis. Waste to energy (WTE) considers as an alternative renewable energy potential to recover energy from waste and reduce the global waste problems. WTE reduced the burden on fossil fuels for energy generation, waste volumes, environmental, and greenhouse gases emissions. This critical review aims to evaluate the source of solid waste generation and the possible routes of waste management such as biological landfill and thermal treatment (Incineration, pyrolysis, and gasification). Moreover, a comparative evaluation of different technologies was reviewed in terms of economic and environmental aspects along with their limitations and advantages. Critical literature revealed that gasification seemed to be the efficient route and environmentally sustainable. In addition, a framework for the gasification process, gasifier types, and selection of gasifiers for MSW was presented. The country-wise solutions recommendation was proposed for solid waste management with the least impact on the environment. Furthermore, key issues and potential perspectives that require urgent attention to facilitate global penetration are highlighted. Finally, practical implications of membrane and comparison membrane-based separation technology with other conventional technologies to recover bioenergy and resources were discussed. It is expected that this study will lead towards practical solution for future advancement in terms of economic and environmental concerns, and also provide economic feasibility and practical implications for global penetration.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Humanos , Resíduos Sólidos/análise , Incineração , Conservação dos Recursos Naturais , Instalações de Eliminação de Resíduos
9.
Environ Res ; 222: 115352, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36716802

RESUMO

The capacity to maximize the proliferation of microalgal cells by means of topologically textured organic solid surfaces under various pH gave rise to the fundamental biophysical analysis of cell-surface attachment in this study. The substrate used in analysis was palm kernel expeller (PKE) in which the microalgal cells had adhered onto its surface. The findings elucidated the relevance of surface properties in terms of surface wettability and surface energy in relation to the attached microalgal growth with pH as the limiting factor. The increase in hydrophobicity of PKE-microalgae attachment was able to facilitate the formation of biofilm better. The pH 5 and pH 11 were found to be the conditions with highest and lowest microalgal growths, respectively, which were in tandem with the highest contact angle value at pH 5 and conversely for pH 11. The work of attachment (Wcs) had supported the derived model with positive values being attained for all the pH conditions, corroborating the thermodynamic feasibility. Finally, this study had unveiled the mechanism of microalgal attachment onto the surface of PKE using the aid of extracellular polymeric surfaces (EPS) from microalgae. Also, the hydrophobic nature of PKE enabled excellent attachment alongside with nutrients for microalgae to grow and from layer-by-layer (LbL) assembly. This assembly was then isolated using organosolv method by means of biphasic solvents, namely, methanol and chloroform, to induce detachment.


Assuntos
Chlorella vulgaris , Microalgas , Propriedades de Superfície , Interações Hidrofóbicas e Hidrofílicas , Biofilmes , Biomassa
10.
Sci Total Environ ; 862: 160800, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36493816

RESUMO

A bushfire is a spontaneous vegetation fire that can fundamentally affect lives, property, the environment, and even the global climate. Ash from fire carries hazardous pollutants like metal oxides/hydroxides, minerals, black carbons, and by-products of partial combustion, such as hydrocarbons and colloidal charcoal. Bushfire gases and residues can heavily pollute surface and groundwater resources. This paper focuses on the impact of bushfire residue on water quality and explores methods to remediate impacted water supplies. Soils burned in controlled furnace conditions between 150 °C, and 600 °C were characterised, suspended in water, and changes in water quality was measured following leaching from the burned residues. Results indicate that once the soil is burned at temperatures above 300 °C, there is little evidence of leached organic matter. At temperatures below 300 °C, the water discolouration was evident after 24 h leaching, and much higher quantities of leached organic matter were measured. Higher burning temperatures resulted in more alkaline residues. Leachate and charred sample characterisation data shows that the charcoal is highly porous and mainly consists of- amorphous material. The ash is a heterogeneous concoction of smaller particles and comprises significant mineral content. The results also indicate that the primary pollutant among the brushfire residuals is ash which increases pH, alkalinity, turbidity, and UV254. Coagulation experiments reveal that dual coagulation systems with metal salts- organic polyelectrolyte reduced the turbidity by 84 %, and dissolved organic carbon (DOC) reduced by 68 % of water containing ash residues. However, some other treatments are needed to reduce the alkalinity.


Assuntos
Carvão Vegetal , Incêndios , Carvão Vegetal/química , Metais , Qualidade da Água , Solo/química
11.
Membranes (Basel) ; 12(10)2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36295676

RESUMO

Scaling, or inorganic fouling, is a major factor limiting the performance of membrane-based water treatment processes in long-term operation. Over the past few decades, extensive studies have been conducted to control the scale growth found in membrane processes and to develop sustainable and greener processes. This study details the role of CO2 in scale inhibition in membrane processes. The core concept of CO2 utilization is to reduce the influent pH and to minimize the risk of scale formation from magnesium or calcium salts. Three reverse osmosis (RO) units were operated with a control (U1), CO2 (U2), and a commercial antiscalant, MDC-220 (U3). The performances of all the units were compared in terms of change in transmembrane pressure (TMP). The overall efficiency trend was found as U1 > U3 > U2. The membrane surfaces were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) for the morphological and elemental compositions, respectively. The surface analysis signified a significant increase in surface smoothness after scale deposition. The noticeable reduction in surface roughness can be described as a result of ionic deposition in the valley region. A sludge-like scale layer was found on the surface of the control membrane (U1) which could not be removed, even after an hour of chemical cleaning. After 20−30 min of cleaning, the U2 membrane was successfully restored to its original state. In brief, this study highlights the sustainable membrane process developed via CO2 utilization for scale inhibition, and the appropriate cleaning approaches.

12.
Adv Colloid Interface Sci ; 306: 102718, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35714572

RESUMO

This review discusses the classification, characteristics, and applications of biosurfactants. The biosynthesis pathways for different classes of biosurfactants are reviewed. An in-depth analysis of reported research is carried out emphasizing the synthetic pathways, culture media compositions, and influencing factors on production yield of biosurfactants. The environmental, pharmaceutical, industrial, and other applications of biosurfactants are discussed in detail. A special attention is given to the biosurfactants application in combating the pandemic COVID-19. It is found that biosurfactant production from waste materials can play a significant role in enhancing circular bioeconomy and environmental sustainability. This review also details the life cycle assessment methodologies for the production and applications of biosurfactants. Finally, the current status and limitations of biosurfactant research are discussed and the potential areas are highlighted for future research and development. This review will be helpful in selecting the best available technology for biosynthesis and application of particular biosurfactant under specific conditions.


Assuntos
COVID-19 , Tensoativos , Humanos , Tensoativos/metabolismo
13.
Membranes (Basel) ; 11(9)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34564505

RESUMO

CO2 capture and utilization (CCU) is a promising approach in controlling the global discharge of greenhouse gases (GHG). This study details the experimental investigation of CO2 utilization in membrane-based water treatment systems for lowering the potential of ionic precipitation on membrane surface and subsequent scale development. The CO2 utilization in feed water reduces the water pH that enables the dissociation of salts in their respective ions, which leave the system as a concentrate. This study compares the efficiency of CO2 and other antifouling agents (CA-1, CA-2, and CA-3) for fouling control in four different membrane-based wastewater reclamation operations. These systems include Schemes 1, 2, 3, and 4, which were operated with CA-1, CA-2, CA-3, and CO2 as antiscalants, respectively. The flux profile and percent salt rejection achieved in Scheme 4 confirmed the higher efficiency of CO2 utilization compared with other antifouling agents. This proficient role of CO2 in fouling inhibition is further endorsed by the surface analysis of used membranes. The SEM, EDS, and XRD examination confirmed the higher suitability of CO2 utilization in controlling scale deposition compared with other antiscalants. The cost estimation also supported the CO2 utilization for environmental friendly and safe operation.

14.
Sci Total Environ ; 796: 148753, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34274668

RESUMO

An investigation into the effect of stepwise saline introduction (3-20 g·L-1 NaCl) on the anaerobic ammonium oxidation (anammox) process in a lab-scale sequencing batch reactor was carried out for 252 days by evaluating the changes in influent and effluent nitrogen concentrations, conductivity, microbial extracellular polymeric substances' (EPS) ionic content, as well as stresses due to salinity, via microbial ATP analysis. It was observed that, effluent nitrogen concentrations remained stable at low saline levels of 3 g·L-1 to 10 g·L-1. Nonetheless, midway through 10 g·L-1 and the preliminary phase of 15 g·L-1 salinity presented a very unstable, highly fluctuating as well as deteriorating effluent nitrogen concentrations. A more satisfactory nitrogen removal efficiency of 83.7 ± 5.9% was obtained at higher saline concentrations implying that, the adaptation mechanism to tolerate increasing salinity was taking place. Saline induced stress, which measures the variation in viable anammox bacteria, was correlative to the formation of EPS and changes in its cationic contents along the increasing salinity. Although the specific anammox activity (SAA) dropped by approximately 15% from the beginning of the process to the midpoint, the drop in SAA after the midpoint was not as drastic as the initial phase. A change in microbial aggregation and dominance proved the existence of new saline-dependent species that can withstand high saline stresses. Recovery from abrupt high saline shocks in batch experiment was seen to be almost impossible.


Assuntos
Reatores Biológicos , Salinidade , Aclimatação , Bactérias , Água Doce , Oxirredução
15.
J Environ Manage ; 297: 113268, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34280865

RESUMO

The fossil fuel utilization adversely affected the environmental health due to the rising emission levels of greenhouse gases. Consequently, the challenges of climate change loaded great stress on renewable energy sources. It is noted that extreme consumption of fossil fuels increased the earth temperature by 1.9 °C that adversely influenced the life and biodiversity. Biorefinery is the sustainable process for the production of biofuels and other bio-products from biomass feedstock using different conversion technologies. Biofuel is an important component of renewable energy sources contributing to overall carbon-neutral energy system. Studies reported that on global scale, over 90% of petroleum goods could be produced from renewable resources by 2023, whereas, 33% chemicals, and 50% of the pharmaceutical market share is also expected to be bio-based. This study details the brief review of operation, development, application, limitations, future perspectives, circular bioeconomy, and life cycle assessment of biorefinery. The economic and environmental aspects of biofuels and biorefineries are briefly discussed. Lastly, considering the present challenges, the future perspectives of biofuels and biorefineries are highlighted.


Assuntos
Biocombustíveis , Carbono , Biomassa , Combustíveis Fósseis
16.
J Environ Manage ; 296: 113246, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34271353

RESUMO

Nitrogen and phosphorous are indispensable for growth and vitality of living beings, hence termed as nutrients. However, discharge of nutrient rich waste streams to aquatic ecosystems results in eutrophication. Therefore, nutrient removal from wastewater is crucial to meet the strict nutrient discharge standards. Similarly, nutrient recovery from waste streams is vital for the realization of a circular economy by avoiding the depletion of finite resources. This manuscript presents analysis of existing information on different conventional as well as advanced treatment technologies that are commonly practiced for the removal of nutrient from domestic wastewater. First, the information pertaining to the biological nutrient removal technologies are discussed. Second, onsite passive nutrient removal technologies are reviewed comprehensively. Third, advanced nutrient removal technologies are summarized briefly. The mechanisms, advantages, and disadvantages of these technologies along with their efficiencies and limitations are discussed. An integrated approach for simultaneous nutrient removal and recovery is recommended. The fifth section of the review highlights bottlenecks and potential solutions for successful implementation of the nutrient removal technologies. It is anticipated that the review will offer an instructive overview of the progress in nutrient removal and recovery technologies and will illustrate necessity of further investigations for development of efficient nutrient removal and recovery processes.


Assuntos
Ecossistema , Águas Residuárias , Reatores Biológicos , Desnitrificação , Nitrogênio , Nutrientes , Fósforo , Eliminação de Resíduos Líquidos
17.
J Environ Manage ; 270: 110909, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721343

RESUMO

This review summarizes the recent development and studies of anaerobic membrane bioreactor (AnMBR) to control fouling issues. AnMBR is an emerging waste water treatment technology mainly because of its low sludge residual, high volumetric organic removal rate, complete liquid-solid separation, better effluent quality, efficient resource recovery and the small footprint. This paper surveys the fundamental aspects of AnMBRs, including its applications, membrane configurations, and recent progress for enhanced reactor performance. Furthermore, the membrane fouling, a major restriction in the practical application of AnMBR, its mechanism and antifouling strategies like membrane cleaning, quorum quenching, ultrasonic treatment, membrane modifications, and antifouling agents are briefly discussed. Based on the review, the key issues that require urgent attention to facilitate large scale and integrated application of AnMBR technology are identified and future research perspectives relating to the prevalent issues are proposed.


Assuntos
Reatores Biológicos , Purificação da Água , Anaerobiose , Membranas Artificiais , Esgotos , Eliminação de Resíduos Líquidos , Águas Residuárias
18.
Environ Sci Pollut Res Int ; 26(2): 1094-1102, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28432627

RESUMO

Inorganic fouling on the membrane surface is one of the major prevalent issues affecting the performance and cost of reverse osmosis system. Chemical dosage is a widely adopted method for the inhibition of inorganic scale on the membrane surface. In this study, CO2 was used to control inorganic scale formation on surface of reverse osmosis (RO) membrane in wastewater reclamation. The pH of influent could be lowered by purging CO2. It caused an increase in solubility of inorganic salts in water resulting in discharge of principle ions in concentrate stream. A pilot plant study was conducted with four different RO modules including control, with dosage of antiscalant, with purging CO2 and with co-addition of antiscalant and CO2. The effectiveness of CO2 purging was assessed on the basis of operational analysis, in-line analysis and morphological results. Ryznar stability index was used to determine the scaling potential of system. The examined data indicated that CO2 purging was successful to inhibit scale formation on the membrane surface. Moreover, CO2 was found more eco-friendly than antiscalant, as no by-products were generated in concentrate stream.


Assuntos
Incrustação Biológica/prevenção & controle , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Dióxido de Carbono , Concentração de Íons de Hidrogênio , Membranas Artificiais , Osmose , Águas Residuárias
19.
Bioresour Technol ; 269: 452-464, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30145004

RESUMO

Biohydrogen as one of the most appealing energy vector for the future represents attractive avenue in alternative energy research. Recently, variety of biohydrogen production pathways has been suggested to improve the key features of the process. Nevertheless, researches are still needed to overcome remaining barriers to practical applications such as low yields and production rates. Considering practicality aspects, this review emphasized on anaerobic membrane bioreactors (AnMBRs) for biological hydrogen production. Recent advances and emerging issues associated with biohydrogen generation in AnMBR technology are critically discussed. Several techniques are highlighted that are aimed at overcoming these barriers. Moreover, environmental and economical potentials along with future research perspectives are addressed to drive biohydrogen technology towards practicality and economical-feasibility.


Assuntos
Reatores Biológicos , Fermentação , Hidrogênio , Membranas Artificiais
20.
Chemosphere ; 203: 90-95, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29614414

RESUMO

The magnetite particles were chemically synthesized from the waste of hot rolling steel industry. The characterization of the synthesized magnetite was done by using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The synthesized magnetite particles were used for the adsorptive removal of arsenate from the contaminated water. The maximum adsorption capacity of 7.69 mg was found on the surface of 1 g of the magnetite. The point of zero charge for magnetite is determined at the pH 6. The adsorption capacity of magnetite particles was successfully restored with alkali cleaning. Newly synthesized particles were found to be effective for arsenate removal up to 5 times with regeneration. The synthesis of magnetite from raw mill scale and its application for arsenate adsorption is a cost effective and ecofriendly process.


Assuntos
Arseniatos/isolamento & purificação , Óxido Ferroso-Férrico/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Arseniatos/química , Óxido Ferroso-Férrico/química , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/química
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