Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Jing Su, Jennifer Noro, Jiajia Fu et al.
Journal of Cleaner Production · 2018
Laccase from Myceliophthora thermophila was used to catalyze the polymerization of catechol under high-pressure homogenization for the green coloration of textile substrates. The oxidation reactions were conducted using different forms of laccase, namely native laccase, PEGylated laccase and PEGylated laccase immobilized onto an epoxy resin. The three enzyme forms were deposited inside a polyester fabric bag during the experiments. The amount of polymer obtained was similar when using the three enzyme forms and its dispersion in water/DMSO mixture lead to powder particles of about 30–60 nm. The immobilized and PEGylated enzymes lead to poly(catechol) with 13 and 10 units, respectively, while the native form gave rise to shorter polymers (DP = 8). We have shown that the oxidation of catechol conducted under high-pressure homogenization can be an efficient methodology for the in situ coloration of textiles. The polymers produced by this methodology stained strongly the textile container, revealing this experimental set-up as a promising greener coloration/coating methodology involving milder conditions than the normally used in textile processes.
Ribika Etana, Kenatu Angassa, Tolesa Getu
Scientific Reports · 2025
Textile wastewater poses significant risks if discharged untreated, especially due to the presence of synthetic dyes, salts, and heavy metals. As a result, constructed wetlands have emerged as a promising solution for sustainable textile wastewater management. In this context, this study evaluates a micro-scale vertical subsurface flow constructed wetland (VSSFCW) for treating textile wastewater. Specifically, the experimental setup consisted of two microcosm units, each with a depth of 32 cm and a diameter of 24 cm, which were filled with scoria media. One unit was planted with Vetiver grass, while the other was left unplanted. Furthermore, the experiment was conducted with a hydraulic retention time of 3 days. Additionally, the scoria media was characterized using FTIR, SEM, XRD, CEC, and pH analyses, which revealed notable changes in both functional groups and surface morphology. The scoria was found to have a CEC of 12 meq/100 g and a pH of 8.86, both of which facilitated pollutant removal. Moreover, the textile wastewater that was fed into the VSSFCW systems contained dye concentrations ranging from 39.41 to 45.29 mg/L throughout the study period. As a result of this setup, the dye removal efficiency in both wetland cells increased over time. Notably, the VSSFCW planted with Vetiver grass achieved a higher dye removal efficiency (84%) compared to the unplanted system (80%). These findings, therefore, demonstrate that the VSSFCW consistently meets wastewater standards, representing a low-cost, decentralized solution to address textile pollution, especially in developing countries like Ethiopia. In conclusion, the synergy between the scoria media and Vetiver grass proved highly effective in treating textile wastewater.
Maryam Keykhaee, Maryam Razaghi, Arash Dalvand et al.
Journal of Environmental Health Science and Engineering · 2020
Sanjay Nagarajan, Vivek V. Ranade
Industrial & Engineering Chemistry Research · 2019
Lignocellulosic biomass (LCB) is an abundant renewable resource that can be used to produce fuels and chemicals. Valorization of LCB is, however, a challenge due to its recalcitrant nature posed by the strongly interlinked cellulose–lignin–hemicellulose structures. A range of physicochemical and biological LCB pretreatment methods has been reported in the literature for enhancing its bioutilization. In this work, we used hydrodynamic cavitation (HC) based on vortex devices as a chemical-free, environmentally friendly LCB pretreatment method to enhance biomethane production. A bench scale pretreatment setup using a vortex-based cavitation device was established for the pretreatment of two common LCBs: grass silage (GS) and sugar cane bagasse (SCB). Dried and powdered feedstocks were used in all the experiments. HC was carried out by operating the cavitation device at a flow rate of ∼1.5 m3/h. The feedstocks before and after pretreatment were characterized for morphological and compositional differences using a range of analytical techniques. Liquid phase products produced upon cavitation were also analyzed using an HPLC-RI. Biomethane potential (BMP) was measured for GS and SCB with and without pretreatment, and a first order model was used to describe the kinetics. Up to 40% enhancement was observed in BMP after cavitation pretreatment using vortex-based devices. A brief discussion on preliminary cost considerations based on the experimentally observed enhancement in BMP is included. The results indicate significant promise of harnessing hydrodynamic cavitation-based pretreatment using vortex-based devices for enhancing biomethane production from LCB.
S. Lakshmi, G. M. Shashidhara, G. M. Madhu et al.
Applied Water Science · 2018
Phenol is one of the greatest menaces among the industrial pollutants. A treatment method which utilizes agricultural wastes in a simple manner has become the need of the hour. In this investigation, details on the extraction, optimization of parameters and study of detoxification potential of the peroxidase enzyme obtained from baby corn waste have been elaborated. The enzyme has been extracted from both corn silk and husk, and studies have been conducted on both the samples. Estimation of amount of protein and enzyme activity has shown promising results, and the conditions optimized are easily attainable at larger scales, making this work feasible for scale-up.
Saman Sargazi, Mohammad Reza Hajinezhad, Abbas Rahdar et al.
Applied Physics A · 2021
Abstract Nanomaterials are attracting increasing interest in many biomedical fields, including the fight against cancer. In this context, we successfully synthesized CoNi alloy nanoparticles (NPs) by a simple polyol process. The magnetic characteristics of the products were measured by vibration sample magnometry, which revealed that the samples have soft ferromagnetic behavior. The microstructure and morphology were inspected by X-ray diffraction and scanning electron microscopy, respectively. Human cancer cells derived from the breast (MCF7) and oral cavity (C152) and normal cells derived from human umbilical vein endothelial cells (HUVECs) were treated with increasing concentrations of CoNi NPs, and their cytotoxic effect was measured via MTT and lactate dehydrogenase (LDH) leakage assays. We found that treatments by using 12.5 to 400 µg/mL of Co0.5Ni0.5, Co0.6Ni0.4, and Co0.4Ni0.6 NPs were associated with significant concentration-dependent toxicity toward such cell lines and profoundly enhanced LDH leakage following 48 h of exposure ( P < 0.05 compared with untreated cells). Besides, a NP dose of 6.25 µg/mL did not affect the survival of HUVECs while leading to marked cell death in MCF7 and C152 cells. In vivo experiments in rats were done to investigate the biochemical and histopathological changes over three weeks, following intraperitoneal administration of Co0.5Ni0.5, Co0.6Ni0.4, and Co0.4Ni0.6 NPs (100 mg/kg). As compared with the controls, the exposure to NPs caused significant elevations in aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, serum creatinine, serum catalase activity, serum superoxide dismutase, and liver malondialdehyde levels. Also, rats treated with Co0.6Ni0.4 NPs showed more severe histopathological changes of the liver and kidney. Our findings represent an essential step toward developing theranostic nanoplatforms for selective cancer treatment.
Michelle Michelle, Rachel Arvy Nabasa Siregar, Astia Sanjaya et al.
Biodiversitas Journal of Biological Diversity · 2020
Abstract. Michelle, Siregar RAN, Sanjaya A, Jap L, Pinontoan R. 2020. Methylene blue decolorizing bacteria isolated from water sewage in Yogyakarta, Indonesia. Biodiversitas 21: 1136-1141. The textile industry contributes to water pollution issues all over the world. One of the most commonly applied cationic dye in the textile industry is methylene blue. This study aimed to isolate bacteria with the potential to decolorize methylene blue from dye contaminated sewage water located in Kulon Progo District, Yogyakarta, where several textile industries within the proximity, are located. Characterizations of bacterial candidates were done morphologically and biochemically. Molecular identification was conducted by 16S rRNA sequencing. The ability of isolates to decolorize methylene blue was observed by the reduction of methylene blue’s maximum absorption at the wavelength of 665 nm. The results showed that isolates were identified as Comamonas aquatica and Ralstonia mannitolilytica. C. aquatica PMB-1 and R. mannitolilytica PMB-2 isolates were able to decolorize methylene blue with decolorization percentage of 67.9% and 60.3%, respectively when incubated for 96 hours at 37°C. These findings present information on the capability of the genus Ralstonia and Comamonas to decolorize methylene blue cationic dye.
Zakira Naureen, Zainab Ali Rashid Al Matani, Miyassa Nasser Al Jabri et al.
Advances in Bioscience and Biotechnology · 2016
The present study aimed at isolation characterization and evaluation of electrogenic bacteria for electricity generation using waste water. In this context, waste water samples were collected from University of Nizwa waste water treatment plant. A total of eight distinct bacterial isolates were isolated from these samples by serial dilution and plating on LB Agar medium. The bacterial isolates were than grown at different temperatures and pH. DNA from bacterial samples was isolated and 16S rRNA gene amplification was carried out. The 16S rRNA gene PCR products were directly sequenced and the resulting sequence was blasted using BLASTn. Based on BLAST results, the bacterial strains were identified. The bacteria were used in different combinations to generate electricity from waste water in microbial fuel cells constructed using plastic bottles. The microbial isolates were found to produce varying levels of currents and their electrogenic potential in waste water was observed to increase with the passage of time.
Nandita Das, Ankita Das, Sandeep Das et al.
Fermentation · 2023
Anthropogenic activities and industrial effluents are the major sources of petroleum hydrocarbon contamination in different environments. Microbe-based remediation techniques are known to be effective, inexpensive, and environmentally safe. In this review, the metabolic-target-specific pathway engineering processes used for improving the bioremediation of hydrocarbon-contaminated environments have been described. The microbiomes are characterised using environmental genomics approaches that can provide a means to determine the unique structural, functional, and metabolic pathways used by the microbial community for the degradation of contaminants. The bacterial metabolism of aromatic hydrocarbons has been explained via peripheral pathways by the catabolic actions of enzymes, such as dehydrogenases, hydrolases, oxygenases, and isomerases. We proposed that by using microbiome engineering techniques, specific pathways in an environment can be detected and manipulated as targets. Using the combination of metabolic engineering with synthetic biology, systemic biology, and evolutionary engineering approaches, highly efficient microbial strains may be utilised to facilitate the target-dependent bioprocessing and degradation of petroleum hydrocarbons. Moreover, the use of CRISPR-cas and genetic engineering methods for editing metabolic genes and modifying degradation pathways leads to the selection of recombinants that have improved degradation abilities. The idea of growing metabolically engineered microbial communities, which play a crucial role in breaking down a range of pollutants, has also been explained. However, the limitations of the in-situ implementation of genetically modified organisms pose a challenge that needs to be addressed in future research.
Pasquale Iovino, Angelo Fenti, Simona Galoppo et al.
Molecules · 2023
In the last few years, many industrial sectors have generated and discharged large volumes of saline wastewater into the environment. In the present work, the electrochemical removal of nitrogen compounds from synthetic saline wastewater was investigated through a lab-scale experimental reactor. Experiments were carried out to examine the impacts of the operational parameters, such as electrolyte composition and concentration, applied current intensity, and initial ammoniacal nitrogen concentration, on the total nitrogen removal efficiency. Using NaCl as an electrolyte, the N TOT removal was higher than Na 2 SO 4 and NaClO 4 ; however, increasing the initial NaCl concentration over 250 mg·L -1 resulted in no benefits for the N TOT removal efficiency. A rise in the current intensity from 0.05 A to 0.15 A resulted in an improvement in N TOT removal. Nevertheless, a further increase to 0.25 A led to basically no enhancement of the efficiency. A lower initial ammoniacal nitrogen concentration resulted in higher removal efficiency. The highest N TOT removal (about 75%) was achieved after 90 min of treatment operating with a NaCl concentration of 250 mg·L -1 at an applied current intensity of 0.15 A and with an initial ammoniacal nitrogen concentration of 13 mg·L -1 . The nitrogen degradation mechanism proposed assumes a series-parallel reaction system, with a first step in which NH 4 + is in equilibrium with NH 3 . Moreover, the nitrogen molar balance showed that the main product of nitrogen oxidation was N 2 , but NO 3 - was also detected. Collectively, electrochemical treatment is a promising approach for the removal of nitrogen compounds from impacted saline wastewater.
Jingyi Xie, Haixiao Li, Shiyu Wang et al.
Environmental Engineering Research · 2021
Carbamazepine (CBZ), which is difficult to remove in the wastewater treatment system and easily forms toxic transformation products during the treatment process, is one of the priority pollutants of pharmaceuticals and personal care products (PPCPs). Increasing attention has been paid to explore their treatment technology without side effects from the treatment products. This study aims to reveal the removal and transformation of CBZ in the microbial fuel cell coupled constructed wetland (CW-MFC) system. The CW-MFC system was operated continuously at room temperature for nearly 80 days. The results show that CW-MFC system can effectively remove CBZ with an average removal rate of 97%. Three transformation products were identified by liquid chromatography−high-resolution mass spectrometry: 2-(2-oxoquinazolin-1(2H)-yl) benzoic acid (TP267), methyl 2-(2-oxoquinazolin-1(2H)-yl) benzoate (TP281), 2-(2,4-dioxo-3,4-dihydroquinazolin-1(2H)-yl) benzoic acid (TP283). Except TP281 in the influent, the other transformation products were formed in the system, which indicated that TP267 and TP283 were the main transformation products of CBZ. The formation pathway of transformation products could be explained by reactions including oxidation, hydrolysis, bond rupture and intramolecular reaction. The results also indicate that the CW-MFC system might be a promising technology for PPCPs treatment.
Fazlur Rashid, Mohammad U. H. Joardder
Engineering Reports · 2022
Abstract Electricity is an important part of our daily life. It is mainly generated from conventional energy sources. Conventional energy sources are diminishing day by day; whereas, energy demand increases significantly. Moreover, less land availability, low budget for energy, and weather‐dependent renewable sources result in poor energy management all over the world. Therefore, proper management of conventional energy and simultaneous finding of potential alternative energy sources are the prime concerns of energy‐related researchers. In this article, literature relating to less‐implemented energy sources is reviewed to demonstrate their current status and future prospects. This review shows that along with current renewable and conventional sources of energy, these less‐implemented energy sources can contribute substantially to overcome the energy scarcity in electricity production. Proper planning and improvement are required to get sufficient benefits from these less‐implement energy sources. In order to clarify the electricity generation from less‐applied energy sources, many figures are adapted using the concept and information of reviewed literature. In those figures and related text, several possible ways of electricity generation using these energy sources and their potential implementation techniques with related challenges have been outlined. The electricity generation rate and their corresponding applications are also depicted. Proper steps to popularize these less‐focused sources of energy would mitigate high energy demand all over the world and offers a cleaner environment for livelihood.
P Pasquet, M. Villain-Gambier, Dominique Trébouet
Sustainability · 2024
Beer production consumes significant amounts of water, energy, and raw materials, and results in the production of various by-products, including wastewater, brewers’ spent grain, yeast and hop. To lower its environmental footprint, by-products may be reclaimed or valorized in agro-food, cosmetic, material, chemical industries, etc. According to most recent research, breweries have the potential to become biorefineries, as they can extract diverse valuable plant-based compounds such as carbohydrates, proteins, lipids, phenolic compounds, platform chemicals, and biopolymers. These biomolecules possess bioactive and physicochemical properties, which can be enhanced through recovery processes. Brewery by-products may be utilized in various industries within the bioeconomy frame. In agro-food systems, extracts can increase final products’ techno-functionalities. Such additives can also help in creating marketing labels such as clean-label healthy, which can further attract potential customers. Businesses can gain economic and socio-environmental benefits by implementing sustainable practices, which can also improve their corporate image. This article outlines recent advancements in the processing and valorization of brewery by-products, ultimately defining an up-to-date, sustainable strategy for clean beer production.
Jumma Shaikh, Niranjan Patil, Vikas Shinde et al.
Journal of Microbial & Biochemical Technology · 2016
This study examined azo dye methyl red decolorization in a 2 chambered microbial fuel cell (MFC). The primary objectives of the study were to construct MFC and evaluate methyl red decolorizing and degrading bacterium Bacillus circulans potential in simultaneous decolorization and electricity generation process.
Helanka J. Perera
International Journal of Waste Resources · 2019
The most recent removal methods for the removal of Acid Orange 7 (AO7) dye from wastewater are complied. Microbial bio-degradation, chemical decomposition by oxidation, photo-degradation and adsorption by various adsorbents are various methods used in removal of AO7. The advantages and disadvantages of the various methods are discussed and there efficiencies are compared.
Bryan Tsai, Omar García‐Valdez, Pascale Champagne et al.
Processes · 2017
As the demand for textile products and synthetic dyes increases with the growing global population, textile dye wastewater is becoming one of the most significant water pollution contributors. Azo dyes represent 70% of dyes used worldwide, and are hence a significant contributor to textile waste. In this work, the removal of a reactive azo dye (Reactive Orange 16) from water by adsorption with chitosan grafted poly(poly(ethylene glycol) methyl ether methacrylate) (CTS-GMA-g-PPEGMA) was investigated. The chitosan (CTS) was first functionalized with glycidyl methacrylate and then grafted with poly(poly(ethylene glycol) methyl ether methacrylate) using a nitroxide-mediated polymerization grafting to approach. Equilibrium adsorption experiments were carried out at different initial dye concentrations and were successfully fitted to the Langmuir and Freundlich adsorption isotherm models. Adsorption isotherms showed maximum adsorption capacities of CTS-g-GMA-PPEGMA and chitosan of 200 mg/g and 150 mg/g, respectively, while the Langmuir equations estimated 232 mg/g and 194 mg/g, respectively. The fundamental assumptions underlying the Langmuir model may not be applicable for azo dye adsorption, which could explain the difference. The Freundlich isotherm parameters, n and K, were determined to be 2.18 and 17.7 for CTS-g-GMA-PPEGMA and 0.14 and 2.11 for chitosan, respectively. An “n” value between one and ten generally indicates favorable adsorption. The adsorption capacities of a chitosan-PPEGMA 50/50 physical mixture and pure PPEGMA were also investigated, and both exhibited significantly lower adsorption capacities than pure chitosan. In this work, CTS-g-GMA-PPEGMA proved to be more effective than its parent chitosan, with a 33% increase in adsorption capacity.
Ahmed A. Afify, Gamal K. Hassan, Hussein E. Al‐Hazmi et al.
Energies · 2023
The production of sodium hypochlorite (NaOCl) from salty wastewater using an electrochemical cell has several advantages over other methods that often require hazardous chemicals and generate toxic waste, being more sustainable and environmentally friendly. However, the process of producing sodium hypochlorite using an electrochemical cell requires careful control of the operating conditions, such as the current density, flow rate, inert electrode spacing, and electrolyte concentration, to optimize the conversion efficiency and prevent electrode fouling and degradation. In this study, NaOCl was produced via a bench-scale electrochemical cell using a flowing porous graphite electrode in a continuous flow system from salty wastewater collected from the Suez Canal in Egypt. The aim of the investigation was to examine the factors that affect the concentration of NaOCl and energy consumption, such as anodic current density, salinity, inert electrode spacing, and influent feed flow rate. A lab-scale reactor with two electrodes was used to conduct the experiments. The highest NaOCl yield of 20.6% was achieved with a graphite electrode, which had high current efficiency and rigidity at a flow rate of 4.5 mL/min, a current density of 3.183 mA/cm2, an electrode space of 0.5 cm, salinity of 40,000 ppm, and a pH of 6.4. The power consumption under these conditions was 0.0137 kwh. Additionally, a statistical and least square multivariate regression technique was employed to establish a correlation for predicting the % NaOCl production. The obtained correlation had an R2 value of 98.4%. Overall, this investigation provides valuable insights into the production of NaOCl using a continuous flow system from salty wastewater, which could have potential for industrial applications in various sectors such as textiles, detergents, paper, and pulp.
Sayed M. Saleh, Abuzar E. A. E. Albadri, Mohamed Ali Ben Aissa et al.
Crystals · 2022
This study investigated the photocatalytic degradation of RB dye by V2O5@g-C3N4 nano-catalysts. The sonication method was utilized to create V2O5@g-C3N4 nano-catalysts. V2O5@g-C3N4 nano-catalysts were characterized using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), high-resolution electron microscopy (TEM), BET-surface area analyzer, X-ray photoelectron spectroscopy (XPS), and ultraviolet spectroscopy. In the meantime, the photocatalytic activity, pH, and photocatalyst dosage are investigated in depth to account for RB dye decolorization. The rate constant for RB dye photodegradation was 0.0517 (min−1) and the decolorization rate was 93.4%. The degrading efficiency of RB dye by V2O5@g-C3N4 nanocatalysts is consistent with pseudo-first-order kinetics. The results of this study demonstrated that V2O5@g-C3N4 nanocatalysts are particularly effective at destroying dyes in water.
Ana Rotter, Michèle Barbier, Francesco Bertoni et al.
Frontiers in Marine Science · 2021
Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better health and well-being, new biomedicines, natural cosmeceuticals, environmental conservation, and sustainable energy sources. These societal needs stimulated the interest of researchers on the diverse and underexplored marine environments as promising and sustainable sources of biomolecules and biomass, and they are addressed by the emerging field of marine (blue) biotechnology. Blue biotechnology provides opportunities for a wide range of initiatives of commercial interest for the pharmaceutical, biomedical, cosmetic, nutraceutical, food, feed, agricultural, and related industries. This article synthesizes the essence, opportunities, responsibilities, and challenges encountered in marine biotechnology and outlines the attainment and valorization of directly derived or bio-inspired products from marine organisms. First, the concept of bioeconomy is introduced. Then, the diversity of marine bioresources including an overview of the most prominent marine organisms and their potential for biotechnological uses are described. This is followed by introducing methodologies for exploration of these resources and the main use case scenarios in energy, food and feed, agronomy, bioremediation and climate change, cosmeceuticals, bio-inspired materials, healthcare, and well-being sectors. The key aspects in the fields of legislation and funding are provided, with the emphasis on the importance of communication and stakeholder engagement at all levels of biotechnology development. Finally, vital overarching concepts, such as the quadruple helix and Responsible Research and Innovation principle are highlighted as important to follow within the marine biotechnology field. The authors of this review are collaborating under the European Commission-funded Cooperation in Science and Technology (COST) Action Ocean4Biotech – European transdisciplinary networking platform for marine biotechnology and focus the study on the European state of affairs.
Yonggang Yang, Guannan Kong, Xingjuan Chen et al.
Frontiers in Microbiology · 2017
Bacterial extracellular electron transfer (EET) plays a key role in various natural and engineering processes. Outer membrane c -type cytochromes (OMCs) are considered to be essential in bacterial EET. However, most bacteria do not have OMCs but have redox proteins other than OMCs in their extracellular polymeric substances of biofilms. We hypothesized that these extracellular non-cytochrome c proteins (ENCP) could contribute to EET, especially with the facilitation of electron mediators. This study compared the electrode respiring capacity of wild type Shewanella decolorationis S12 and an OMC-deficient mutant. Although the OMC-deficient mutant was incapable in direct electricity generation in normal cultivation, it regained electricity generation capacity (26% of the wide type) with the aid of extracellular electron mediator (riboflavin). Further bioelectrochemistry and X-ray photoelectron spectroscopy analysis suggested that the ENCP, such as proteins with Fe-S cluster, may participate in the falvin-mediated EET. The results highlighted an important and direct role of the ENCP, generated by either electricigens or other microbes, in natural microbial EET process with the facilitation of electron mediators.
Laila S. Alqarni, Maha D. Alghamdi, Aisha A. Alshahrani et al.
Journal of Chemistry · 2022
In the last decades, the idea of green nanotechnology has been expanding, and researchers are developing greener and more sustainable techniques for synthesizing nanoparticles (NPs). The major objectives are to fabricate NPs using simple, sustainable, and cost-effective procedures while avoiding the use of hazardous materials that are usually utilized as reducing or capping agents. Many biosources, including plants, bacteria, fungus, yeasts, and algae, have been used to fabricate NPs of various shapes and sizes. The authors of this study emphasized the most current studies for fabricating NPs from biosources and their applications in a wide range of fields. This review addressed studies that cover green techniques for synthesizing nanoparticles of Ag, Au, ZnO, CuO, Co3O4, Fe3O4, TiO2, NiO, Al2O3, Cr2O3, Sm2O3, CeO2, La2O3, and Y2O3. Also, their applications were taken under consideration and discussed.
Vahid Razaviarani, Golnaz Arab, N. Lerdwanawattana et al.
International Journal of Environmental Science and Technology · 2022
Abstract Algal biomass has been gaining attention over the last decades as it is versatile and can be used in different industries, such as wastewater treatment and bioenergy industries. Microalgae are mixotrophic microorganisms that have potential to utilize nitrogen and phosphate (nutrients) and remove organic matters from wastewater streams. Phycoremediation is an intriguing and cost-efficient technique to simultaneously remove heavy metals from wastewater while removing nutrients and organic matters. The cultivated and produced algal biomass can be a promising candidate and a sustainable feedstock to produce biofuels (e.g., biodiesel, bio-alcohol, and bio-oil) and value-added products such as biochar, glycerol, functional food, and pigments. The algae suspended cultivation systems, WSP and HRAP, are efficient methods for the wastewater treatment in shallow ponds with no mechanical aeration and less required energy consumption, but when a short HRT and minimum evaporation losses are key points in the algal cultivation the PBRs are recommended. It was reported that biosorption and bioaccumulation are the two promising techniques of phycoremediation. Studies showed that among the current processes of algal biomass conversion to biofuels, transesterification of algal lipids and pyrolysis of algal biomass were found to be the most efficient techniques. This review paper investigates the applications of algal biomass in the phycoremediation of wastewater, productions of bioenergy and value-added products by reviewing articles mainly published over the last five years. Graphical abstract
Yaxuan Wang, Ting Xu, Kun Liu et al.
Aggregate · 2023
Abstract Supercapacitors exhibit considerable potential as energy storage devices due to their high power density, fast charging and discharging abilities, long cycle life, and eco‐friendliness. With the increasing environmental concerns associated with synthetic compounds, the use of environment friendly biopolymers to replace conventional petroleum‐based materials has been widely studied. Biomass‐based materials are biodegradable, renewable, environment friendly and non‐toxic. The unique hierarchical nanostructure, excellent mechanical properties and hydrophilicity allow them to be used to create functional conductive materials with precisely controlled structures and different properties. In this review, the latest development of biomass‐based supercapacitor materials is reviewed and discussed. This paper describes the physical and chemical properties of various biopolymers and their impact on supercapacitors, as well as the classification and basic principles of supercapacitors. Then, a comprehensive discussion is presented on the utilization of biomass‐based materials in supercapacitors and their recent applications across a range of supercapacitor devices. Finally, an overview of the future prospects and challenges pertaining to the utilization of biomass‐based materials in supercapacitors is provided.
Naveen Kumar Chaturvedi
Applied Water Science · 2022
Abstract The growing contamination of various freshwater resources due to industrial effluent is a serious concern among the scientific community. Several organic compounds are essentially used as chemical intermediate in variety of industrial processes. These organic compounds are hazardous chemicals which are already considered dangerous to global public health and other forms of life due to their high toxicity, carcinogenicity. These organic contaminants are found present in the industrial effluents. Several treatment methods were applied in the literature for their elimination from wastewater to make their final disposal safe for environment. In this article, different kinds of physical, biological and advanced oxidation methods (AOPs) applied for the treatment of various important organic compounds were compared for their advantages and disadvantages. The results showed that the conventional treatment methods are not effective to treat these kinds of toxic and refractory chemical compounds. Therefore, AOPs were found to be the most promising treatment methods.
Bor‐Yann Chen
American Journal of Chemical Engineering · 2016
Electron shuttles (or redox mediators) are organic chemical(s) that can be reversibly oxidized and reduced to drive electron transport phenomena for energy extraction to support myriads of lives. Efficient energy recycling would provide economically-feasible route(s) to environmental remediation and cost-effective energy shuttling could optimize activities to sustain human health. Thus, using microbial fuel cells (MFCs) as operation strategy is economically-competitive for pollutant bioremediation. Considering reductive decolorization, accumulation of decolorized metabolites (DM) could significantly stimulate electron-transfer (ET) capabilities for dye degradation. In addition, model intermediate(s) with auxochromes (e.g., amino and hydroxyl substituent(s)-containing chemicals) could act as electron shuttles (ESs) to feedback stimulate MFC-assisted degradation. Moreover, quantitative assessment of simultaneous reductive decolorization and bioelectricity generation (SRD&BG) via MFCs indicated that ET capabilities of SRD&BG could be augmented more than 40-70% due to autocatalysis of DM. Apparently, MFC-aided bioremediation was promising to wastewater decolorization due to redox-mediating characteristics of DM. In addition, impedance method in bioelectrochemistry was technically plausible due to specific fingerprints of different genus-related microalgae or microorganisms. As several edible flora (EF) contained crucial compositions to human health (e.g., antioxidants- polyphenolic compounds, flavonoids), extracts of EF were very likely to show promising ET capabilities to augment performance of RD and/or BG. That is, such stimulating capabilities were possibly associated to antioxidant characteristics of chemical species in EF. Evaluation of ET-stimulating characteristics of EF could thus be an indicator to prescreen whether candidate species of EF could be feasible antioxidant(s) or ESs for human health. As all lives utilize energy as driving force for sustaining diverse metabolic functioning, bioelectrochemistry is evidently vital to the biological world. As UN report mentioned, bioenergy will be a major portion of renewable energy for the planet’s energy supply by 2050. Therefore, ESs would play a significant role of energy extraction not only for environmental remediation, but also human health.
Rania Hamed, Ruwa Z. Obeid, Rana Abu‐Huwaij
Nanotechnology Reviews · 2023
Abstract Green synthesis of zinc oxide (ZnO) nanoparticles (NPs) using various plant extracts as reducing and capping agents has gained attention in recent research. The green synthesis of ZnO NPs offers several advantages such as being simple, eco-friendly, safe, cost-effective, and reproducible approach with high stability. Hence, this article provides an overview of zinc metal and ZnO compounds, and traditional chemical and physical synthesis of ZnO NPs with primary focuses on the green synthesis of ZnO NPs. This study discusses various plant extracts used and the proposed mechanisms in the green synthesis of ZnO NPs. Additionally, it explores the cytotoxic mechanisms of the green-synthesized ZnO NPs and addresses the various biomedical applications of ZnO NPs, including antibacterial, anticancer, antidiabetic, antioxidant, antifungal, antiviral, antiparasitic, anti-inflammatory, and wound healing. Moreover, the review critically discusses the toxicity of ZnO NPs and emphasizes the need for more toxicological studies to ensure the safety and facilitate the risk assessments and risk management of ZnO NPs. Furthermore, this review underlines the challenges associated with the translation process of ZnO NPs from bench to market, including the complex and time-consuming regulatory approval process for ZnO NPs, which requires a multidisciplinary approach involving scientists, regulators, and manufacturers.
Heba A. El-Gawad, Gamal K. Hassan, K.M. Aboelghait et al.
Scientific Reports · 2023
Chromium is a hazardous compound from industrial processes, known for its toxicity, mutagenicity, teratogenicity, and carcinogenicity. Chemical methods are efficient but cost-effective alternatives with reduced sludge are sought. Electro-coagulation, utilizing low-cost iron plate electrodes, was explored for factual tannery wastewater treatment in this manuscript. Operating parameters such as initial chromium concentration, voltage, electrode number, operating time, agitation speed and current density has been studied to evaluate the treatment effeciency. Under optimal conditions (15 V, 0.4 mA/cm 2 , 200 rpm, 330 ppm chromium, 8 iron electrodes with a total surface area of 0.1188 m 2 , 3 h), chromium elimination was 98.76%. Iron anode consumption, power use, and operating cost were 0.99 gm/L, 0.0143 kW-h/L, and 160 EGP/kg of chromium eliminated, respectively. Kinetics studies were pursued first-order reaction (97.99% correlation), and Langmuir isotherms exhibited strong conformity (Langmuir R 2 : 99.99%). A predictive correlation for chromium elimination (R 2 : 97.97%) was developed via statistical regression. At HARBY TANNERY factory in Egypt, industrial sewage treatment achieved a final chromium disposal rate of 98.8% under optimized conditions.
Fikradis Habtamu, Sintayehu Berhanu, Teshome Mender
Journal of Chemistry · 2021
Ag-ZnO/PANI nanocomposite was prepared via the sol-gel technique following in situ oxidative polymerization of polyaniline (PANI). XRD, UV-Vis, and FT-IR spectroscopy were employed to study the crystal size, bandgap energy, and bond structure of as-synthesized nanocomposites. The mean crystallite size of the nanocomposite determined from XRD was 35.68 nm. Photocatalytic degradation of malachite green (MG) dye using as-synthesized photocatalysts was studied under visible light irradiation. The highest degradation efficiency was recorded for Ag-ZnO/PANI nanocomposites (98.58%) than Ag-ZnO nanoparticles (88.23%) in 120 min. The kinetics of photocatalytic degradation of MG follows pseudo-first-order reaction with rate order of 1.16 10−2 min−1. Moreover, the photocatalytic activity of Ag-ZnO/PANI nanocomposites was evaluated and compared with Ce-Cd oxide, electrospun P(3HB)-TiO2, and with other catalysts in the literature. The optimal conditions for photocatalytic degradation are as follows: the concentration of malachite green (0.2 g/l), pH (8), and the concentration of catalyst load (0.2 g/l) under visible light with an irradiation time of 120 min.
Kah Chun Ho, Yeit Haan Teow, Wei Lun Ang et al.
Journal of Engineering Science and Technology Review · 2017
Membrane fouling is the major challenges that hinders the widespread application of membrane bioreactor (MBR). Recently, application of electricity in electrically-enhanced MBR (EMBR) to suppress membrane fouling has gained much attention among research communities. This paper presents an overview of developments on EMBR for fouling suppression in wastewater treatment. The flow of electricity has stimulated several electrokinetic processes including electrophoresis/electrochemical process, and electrocoagulation which are the major fouling suppression mechanisms employed in EMBR. In electrophoresis, the membrane fouling is suppressed by the increased electrorepulsive force between negatively-charged foulants and cathode membrane under the influence of an electric field. Besides, electric field also induces simultaneous electrochemical oxidation and reduction which generate chemicals to degrade pollutant in wastewater. On top of that, use of active anode is reminiscent of electrocoagulation which produces cation coagulants in EMBR that capable to neutralize charge of the foulants and promotes flocs formation. This increases flocs size and sedimentation rate thereafter reduces adhesion of foulants on the membrane surface. Lastly, bioelectricity generation of microbial fuel cell (MFC) integrated with MBR to attain self-sustained EMBR has been studied. Self-sustained EMBR combines the advantages of MFC and MBR in treating wastewater and energy recovery simultaneously. Overall, it is evidenced that MBR and electrokinetic processes have a synergetic enhancement effect in EMBR system.
Çağrı Akyol, Alessia Foglia, E. Gözde Özbayram et al.
Critical Reviews in Environmental Science and Technology · 2019
The development of innovative technologies in wastewater treatment create the concept of biorefinery in wastewater treatment plants (WWTPs), placing anaerobic processes in the highlight. Starting from the conventional anaerobic treatment processes to ‘closing the loop’ scheme, next generation WWTPs are ready to serve for water, energy and materials mining. While bioenergy is still dominating the resource recovery, recovery of value-added materials (i.e. struvite, biopolymers, cellulose) are receiving significant attention in recent years. So, what are the state-of-the-art approaches for energy-efficient resource recovery and re-use from municipal wastewater? This paper follows a critical review on the validated technologies in operational environment available and further suggests possible market routes for the recovered materials in WWTPs. Considering the development and verification of a novel technology together with the valorization of the obtained products, biorefinery and resource recovery approaches were gathered in this review paper from a circular economy point of view. General currently-faced barriers were briefly addressed to pave the way to create to-the-point establishments of resource recovery facilities in the future.
Anna Kulis-Kapuscinska, Monika Kwoka, Michał A. Borysiewicz et al.
Nanotechnology · 2022
The photocatalytic degradation of the wastewater dye pollutant methylene blue (MB) at ZnO nanostructured porous thin films, deposited by direct current reactive magnetron sputtering on Si substrates, was studied. It was observed that over 4 photocatalytic cycles (0.3 mg · l -1 MB solution, 540 minUV irradiation), the rate constant k of MB degradation decreased by ∼50%, varying in the range (1.54 ÷ 0.78) · 10 -9 (mol·l -1 ·min -1 ). For a deeper analysis of the photodegradation mechanism, detailed information on the nanostructured ZnO surface morphology and local surface and subsurface chemistry (nonstoichiometry) were obtained by using scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) as complementary analytical methods. The SEM studies revealed that at the surface of the nanostructured ZnO thin films a coral reef structure containing polycrystalline coral dendrites is present, and that, after the photocatalytic experiments, the sizes of individual crystallites increased, varying in the range 43 ÷ 76 nm for the longer axis, and in the range 28 ÷ 58 nm for the shorter axis. In turn, the XPS studies showed a slight non-stoichiometry, mainly defined by the relative [O]/[Zn] concentration of ca. 1.4, whereas [C]/[Zn] was ca. 1.2, both before and after the photocatalytic experiments. This phenomenon was directly related to the presence of superficial ZnO lattice oxygen atoms that can participate in the oxidation of the adsorbed MB molecules, as well as to the presence of surface hydroxyl groups acting as hole-acceptors to produce OH· radicals, which can be responsible for the generation of superoxide ions. In addition, after experiments, the XPS measurements revealed the presence of carboxyl and carbonyl functional groups, ascribable to the oxidation by-products formed during the photodegradation of MB.
Laura Lomba, Ma Pilar Ribate, Estela Sangüesa et al.
Applied Sciences · 2021
Deep eutectic solvents (DESs) are a relatively new type of solvent that have attracted the attention of the scientific community due to their environmentally friendly properties and their versatility in many applications. Many possible DESs have been described and, thus, it is not easy to unequivocally characterize and generalize their properties. This is especially important in the case of the (eco)toxicity information that can be found for these mixtures. In this review, we collect data on the human and environmental toxicity of DESs, with the aim of gathering and exploring the behavioral patterns of DESs. The toxicity data found were analyzed attending to different factors: hydrogen bond donors or acceptors that form part of the eutectic mixture, pH, and the presence of organic acids in the DES molar ratio of the components, or interactions with natural compounds. In the case of ecotoxicity, results generally depend on the biomodel studied, along with other factors that have been also revised. Finally, we also carried out a revision of the biodegradation of DESs.
Cuicui Yang, Mengjie Chen, Yijun Qian et al.
Science China Materials · 2018
M.J. Salar-García, Xavier Alexis Walter, Jonas Gurauskis et al.
Electrochimica Acta · 2020
Ceramic materials based on naturally occurring clays are a low cost and environmentally friendly alternative to commercial polymer-based membranes in bioelectrochemical systems. In this work, ceramic membranes containing different amounts of iron oxide (1.06, 2.76 and 5.75 vol.%) and sintered at different temperatures (1100, 1200 and 1300 °C) have been elaborated and tested as separators in urine-fed microbial fuel cells (MFCs). The results reveal that the presence of iron oxide in the ceramic membrane composition increases the structural porosity and reduces the pore size for the three temperatures investigated. On the other hand, it was also observed that the iron content mitigates the negative effect of the high sintering temperature on the power performance of the MFCs. In the case of the ceramic membranes sintered at 1300 °C, power output improved ca. 10-fold when the iron oxide content in the membrane increased from 1.06 up to 5.75 vol.% (30.9 and 286.6 µW, respectively). Amongst the different combinations of iron phase content and sintering temperatures, the maximum power output was obtained by MFCs working with separators containing 5.75 vol. % of iron oxide and sintered at 1100 °C (1.045 mW). Finally, the system was stable for 65 days, which supports the long-term functionality of the different materials assessed.
M. Emran Khan, Agung Wibowo, Zoheb Karim et al.
Polymers · 2024
Huge amounts of noxious chemicals from coal and petrochemical refineries and pharmaceutical industries are released into water bodies. These chemicals are highly toxic and cause adverse effects on both aquatic and terrestrial life. The removal of hazardous contaminants from industrial effluents is expensive and environmentally driven. The majority of the technologies applied nowadays for the removal of phenols and other contaminants are based on physio-chemical processes such as solvent extraction, chemical precipitation, and adsorption. The removal efficiency of toxic chemicals, especially phenols, is low with these technologies when the concentrations are very low. Furthermore, the major drawbacks of these technologies are the high operation costs and inadequate selectivity. To overcome these limitations, researchers are applying biological and membrane technologies together, which are gaining more attention because of their ease of use, high selectivity, and effectiveness. In the present review, the microbial degradation of phenolics in combination with intensified membrane bioreactors (MBRs) has been discussed. Important factors, including the origin and mode of phenols' biodegradation as well as the characteristics of the membrane bioreactors for the optimal removal of phenolic contaminants from industrial effluents are considered. The modifications of MBRs for the removal of phenols from various wastewater sources have also been addressed in this review article. The economic analysis on the cost and benefits of MBR technology compared with conventional wastewater treatments is discussed extensively.
Tonoy Chowdhury, Lei Zhang, Junqing Zhang et al.
Nanomaterials · 2018
MIL-53(Al)-graphene oxide (GO) nanocomposites of different GO to MIL-53(Al) mass ratios (1% to 25% GO) were synthesized and tested for removal of arsenite (As(III)), which is a well-known groundwater contaminant. The properties of MIL-53(Al)-GO nanocomposites were characterized using X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) Spectroscopy, Brunauer-Emmett-Teller (BET) surface area measurements, and Scanning Electron Microscopy (SEM). Batch experiments were performed on MIL-53(Al)-GO nanocomposites for As(III) adsorption in aqueous solutions to investigate adsorption kinetics and isotherm behavior under varying environmental conditions. The effects of solution pH (2 to 11), initial As(III) concentrations (10⁻110 mg/L), adsorbent dosage (0.2⁻3.0 g/L), and temperature (298⁻318 K) on As(III) adsorption were investigated. MIL-53(Al)-GO nanocomposites showed higher adsorption of As(III) than pristine MIL-53(Al) and GO individually. As (III) removal was optimized at a ratio of 3% GO in the MIL-53(Al)-GO nanocomposite, with an adsorption capacity of 65 mg/g. The adsorption kinetics and isotherms followed pseudo-second-order and Langmuir isotherm models, respectively. Overall, these results suggest that MIL-53(Al)-GO nanocomposite holds a significant promise for use in the remediation of As (III) from groundwater and other aqueous solutions.
Gouranga Dutta, Santosh kumar Chinnaiyan, Abimanyu Sugumaran et al.
RSC Advances · 2023
Cancer, microbial infections, and water pollution are significant challenges the modern human population faces. Traditional treatments for cancer and infections often have adverse effects and ecological consequences, while chemical methods for water decontamination can produce harmful byproducts. Metal nanoparticles, particularly zinc oxide (ZnO) and silver (Ag) nanoparticles, show promise in addressing these issues. However, doping Ag on ZnO NPs may synergistically enhance biomedical and therapeutic effects with fewer adverse consequences and improved photocatalytic properties for wastewater treatment. This study aimed to create ZnO and ZnO-Ag nanoparticles through green synthesis and compare their anticancer, antimicrobial, and photocatalytic activity mechanisms. XRD studies determined the crystal diameters of ZnO NPs and ZnO-Ag NPs to be 12.8 nm and 15.7 nm, respectively, with a hexagonal wurtzite structure. The XPS and EDS analyses confirmed the presence of Ag on the ZnO NPs. ZnO NPs and ZnO-Ag NPs exhibited low aggregation in aqueous suspensions, with zeta potentials of -20.5 mV and -22.7 mV, respectively. Evaluating antimicrobial and antibiofilm activity demonstrates that ZnO-Ag NPs have superior potential to ZnO NPs and standard antibiotic drugs against E. coli , S. typhi , B. subtilis , S. aureus , C. albicans , and A. niger . The results of the in vitro cytotoxicity test indicated that on the NCI-H460 lung cancer cell line, ZnO NPs and ZnO-Ag NPs demonstrated IC 50 values of 40 μg mL -1 and 30 μg mL -1 , respectively. The photocatalytic degradation of methylene blue under direct sunlight revealed that ZnO and ZnO-Ag NPs degraded MB by 98% and 70% in 105 min, respectively. These results show that these nanomaterials may have great potential for treating the aforementioned issues.
Musarat Amina, Nawal M. Al Musayeib, Nawal A. Alarfaj et al.
PLoS ONE · 2020
Distinct morphological MgO nanoparticles (MgONPs) were synthesized using biomasses of Saussurea costus roots. The biomass of two varieties of Saussurea costus (Qustal hindi and Qustal bahri) were used in the green synthesis of MgONPs. The physical and chemical features of nanoparticles were confirmed by spectroscopic and microscopic techniques. The surface morphology of the obtained nanoparticles was detected at different magnifications by SEM and TEM microscopy and the size of nanoparticles were found to be 30 and 34 nm for Qustal hindi and Qustal bahri, respectively. The antimicrobial activity of the prepared MgONPs was screened against six pathogenic strains. The synthesized nanoparticles by Qustal bahri biomass exerted significant inhibition zones 15, 16, 18, 17, 14, and 10 mm against E. coli, P. aeruginosa, C. tropicalis and C. glabrata, S. aureus and B. subtilis as compared to those from Qustal hindi 12, 8 and 17 mm against B. subtilis, E. coli and C. tropicalis, respectively. MgONPs showed a potential cytotoxicity effect against MCF-7 breast cancer cell lines. Cellular investigations of MgONPs revealed that the prepared nanoparticles by Qustal bahri exhibited high cytotoxicity against MCF-7 cancer cell lines. IC50 values in MCF-7 cells were found to be 67.3% and 52.1% for MgONPs of Saussurea costus biomasses, respectively. Also, the photocatalytic activity of MgONPs of each Saussurea costus variety was comparatively studied. They exhibited an enhanced photocatalytic degradation of methylene blue after UV irradiation for 1 h as 92% and 59% for those prepared by Qustal bahri and Qustal hindi, respectively. Outcome of results revealed that the biosynthesized MgONPs showed promising biomedical potentials.
Eric Mutegoa
Discover Water · 2024
The rise in the world's population has led to an amplified need for fundamental requirements such as healthcare, shelter, and water. At the same time, human practices like agriculture, mining, and deforestation have resulted in challenges related to environmental sustainability and the contamination of water resources. As a result, access to safe drinking water has become a major challenge worldwide, and controlling water pollution is crucial. Several water treatment methods, including adsorption, nanotechnology, and membrane technology, have been developed to mitigate health and environmental impacts. However, many of these methods are too expensive, especially for people living in low-income countries. Additionally, some of the technologies are not very effective at removing pollutants, which exacerbates the problem. The physical, chemical, and biological approaches for treating water are categorized in this review, along with the benefits and drawbacks of each approach. Given that the adsorption method is thought to be one of the more economical and environmentally friendly techniques to treat water, this review recommends that in order to increase the efficacy of the adsorbents, a comprehensive investigation into the exact operation of the adsorbents at the cellular and molecular levels be conducted.
Neha Tavker, Virendra Kumar Yadav, Krishna Kumar Yadav et al.
Polymers · 2021
Nano-fibrillated cellulose (NFC) was extracted by a chemical method involving alkali and acid hydrolysis. The characterisation of the citrus sinensis fruit peel bran and nano-fibrillated cellulose was performed by XRD, FTIR, TEM, and FESEM. XRD confirmed the phase of NFC which showed monoclinic crystal with spherical to rod shape morphology with a size of 44-50 nm. The crystallinity index of treated NFC increased from 39% to 75%. FTIR showed the removal of lignin and hemicellulose from waste peels due to the alkaline treatment. Silver nanoparticles were also synthesised by utilizing extract of citrus sinensis skins as a reducing agent. Pharmaceutical effluent samples from an industrial area were tested by Atomic Absorption Spectrometry. Out of the four metals obtained, cadmium and chromium were remediated by silver nanoparticles with nano-fibrillated cellulose via simulated method in 100 mg/L metal-salt concentrations over a time period of 160 min. The highest removal efficiency was found for cadmium, i.e., 83%, by using silver and NFC together as adsorbents. The second highest was for chromium, i.e., 47%, but by using only NFC. The Langmuir and Freundlich isotherms were well fitted for the sorption of Cd (II) and Cr (II) with suitable high R 2 values during kinetic simulation. Thus, the isolation of NFC and synthesis of silver nanoparticles proved efficient for heavy metal sorption by the reuse of waste skins.