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Advanced materials for the efficient treatment of textile wastewater need to be developed for the sustainable growth of the textile industry. In this study, graphene oxide (GO) was modified by the incorporation of natural clay (bentonite) and mixed metal oxide (copper-cobalt oxide) to produce GO-based binary and ternary composites. Two binary composites, GO/bentonite and GO/Cu–Co Ox (oxide), and one ternary composite, GO/bentonite/Cu–Co Ox, were characterized by Fourier transform-infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and Brunauer-Emmett-Teller (BET) analysis. The adsorption efficiency of these composites was evaluated against a cationic dye, Basic Blue 41 (BB41). The composites had several surface functional groups, and the ternary composite had tubular porous structures formed by the cross-linking of the bentonite and GO planes. The BET surface area of the ternary composite was 50% higher than that of the GO. The BB41 removals were 92, 89, 80, and 69% for GO/bentonite/Cu–Co oxide, GO/bentonite, GO and GO/Cu–Co oxide, respectively. The pseudo-2nd-order and intraparticle diffusion models best describe the kinetics results, indicating chemisorption and slow pore diffusion-controlled adsorption processes. The Langmuir isotherm-derived adsorption capacity of GO/bentonite/Cu–Co oxide was 351.1 mg/g, which was very close to the measured value. After five consecutive cycles, the ternary composite retained 90% BB41 removal efficiency compared to its 1st cycle. Electrostatic interaction and pore diffusion were predicted to be the controlling mechanisms for the adsorption of the BB41. The GO-based ternary composite can be a feasible and scalable adsorbent for BB41 in wastewater treatment. [Display omitted] • Graphene oxide (GO) was intercalated into bentonite layers, with crumpled and tubular pore structures. • Carboxylic, hydroxyl, epoxide, and carbonyl groups were present on GO/bentonite/Cu–Co oxide (Ox). • GO/bentonite/Cu–Co Ox has 40 and 50% greater surface area and adsorption capacity than GO. • GO/bentonite/Cu–Co Ox retained ∼90% efficiency after 5 consecutive cycles compared to the 1st cycle. • Kinetics studies: chemical interaction dominated the adsorption process for basic blue 41 (BB41). [ABSTRACT FROM AUTHOR]

This study represents the morphometric and meristic characters of the least concern, Trichogaster fasciata (Bloch & Schneider, 1801) including length-weight relationships (LWRs) and length-length relationships (LLRs) using a total of six linear dimensions and various meristic counts from the Gajner Beel, a large wetland ecosystem of northwestern Bangladesh. Sums of 324 specimens of T. fasciata were occasionally collected from the Gajner Beel during the period from July 2017 to June 2018, using different traditional fishing gears. Fin rays were counted with the help of a magnifying glass. Moreover, a total of seven different lengths (e.g., TL, SL, PrDL etc.) were measured using digital slide calipers, and the total body weight (BW) was weighed by an electronic balance with a 0.01 g accuracy for each individual, respectively. Minimum and maximum sizes were 3.1-8.8 cm (Mean ± SD = 5.78 ± 1.50) in total length (TL) and 0.81- 13.15 g (Mean ± SD = 4.90 ± 3.30) in body weight (BW). All LWRs were highly significant (p< 0.001) with r² values ≥ 0.960. Based on the r² value, the LWRs by BW vs. TL constitute the finest fitted model among seven equations. In addition, the LLRs also had significance with r² values ≥ 0.993. Based on the r² values, the LLRs by TL vs. SL was the best fitted model among six equations. The fin formula of T. fasciata is: dorsal, D. XV-XVII/10-14; pectoral, Pc. 9-10; pelvic, Pv. 1; anal, A. XVXVIII/15-19 and caudal, C. 18-20. This study will contribute to species identification and stock assessment of Gajner Beel and the adjacent ecosystems. [ABSTRACT FROM AUTHOR]

Biochar is a promising material for facilitating the reclamation of oil sands process water (OSPW); however, how biochar properties can be optimized for metal removal from OSPW is not well studied. This study was conducted to determine relationships among feedstock type, pyrolysis condition, biochar property, and lead(II) adsorption capacity to demonstrate the potential use of biochar for metal removal from a synthetic OSPW. Sawdust, canola and wheat straw, and manure pellet were pyrolyzed at 300, 500, and 700 °C, with or without steam activation. Increasing pyrolysis temperature increased, with a few exceptions, biochar pH, surface area, and carbon content, but decreased hydrogen and oxygen contents and surface functional groups. Steam activation increased surface area but did not affect other properties. For non-steam-activated biochars, canola and wheat straw biochars produced at 700 °C had the highest lead(II) adsorption capacity (Q max_Pb), at 108 and 109 mg g−1, respectively. Increasing the pyrolysis temperature increased Q max_Pb due to increased biochar pH, ash content, and surface area by increasing precipitation, ion exchange, and inner-sphere complexation of lead(II). Steam activation increased lead(II) adsorption capacity for most biochars mainly due to the increased surface area, with the highest Q max_Pb at 195 mg g−1 for canola straw biochar pyrolyzed at 700 °C with steam activation. The adsorption with time followed a pseudo-second order kinetic model. The results of this study will help select most effective biochars that can be produced from locally available agricultural or forestry byproducts that are optimized for metal removal from synthetic OSPW. • Relationships among feedstock type, pyrolysis conditions, biochar properties, and Q max of lead(II) (Q max_Pb) were tested • Biochar properties and Q max_Pb depended on feedstock type, pyrolysis temperature, and steam activation • Canola straw biochar had highest and sawdust biochar had lowest Q max_Pb • Increases in pyrolysis temperature and steam activation increased Q max_Pb • Lead(II) adsorption followed the pseudo-second order kinetic model [ABSTRACT FROM AUTHOR]

The production of oil from oil sands in northern Alberta has led to the generation of large volumes of oil sands process-affected water (OSPW) that was reported to be toxic to aquatic and other living organisms. The toxicity of OSPW has been attributed to the complex nature of OSPW matrix including the inorganic and organic compounds primarily naphthenic acids (NAs: C n H 2n+Z O x ). In the present study, granular activated carbon (GAC) adsorption was investigated for its potential use to treat raw and ozonated OSPW. The results indicated that NA species removal increased with carbon number (n) for a fixed Z number; however, the NA species removal decreased with Z number for a fixed carbon number. The maximum adsorption capacities obtained from Langmuir adsorption isotherm based on acid-extractable fraction (AEF) and NAs were 98.5 mg and 60.9 mg AEF/g GAC and 60 mg and 37 mg NA/g GAC for raw and ozonated OSPW, respectively. It was found that the Freundlich isotherm model best fits the AEF and NA equilibrium data (r 2  ≥ 0.88). The adsorption kinetics showed that the pseudo-second order and intraparticle diffusion models were both appropriate in modeling the adsorption kinetics of AEF and NAs to GAC (r 2  ≥ 0.97). Although pore diffusion was the rate limiting step, film diffusion was still significant for assessing the rate of diffusion of NAs. This study could be helpful to model, design and optimize the adsorption treatment technologies of OSPW and to assess the performance of other adsorbents. [ABSTRACT FROM AUTHOR]

Biological phosphorous (P) and nitrogen (N) removal from municipal wastewater was studied using an innovative anoxic-aerobic-anaerobic side-stream treatment system. The impact of influent water quality including chemical oxygen demand (COD), ammonium and orthophosphate concentrations on the reactor performance was evaluated. The results showed the system was very effective at removing both COD (>88%) and NH 4 + -N (>96%) despite varying influent concentrations of COD, NH 4 + -N, and total PO 4 3- -P. In contrast, it was found that the removal of P was sensitive to influent NH 4 + -N and PO 4 3- -P concentrations. The maximum PO 4 3- -P removal of 79% was achieved with the lowest influent NH 4 + -N and PO 4 3- -P concentration. Quantitative PCR (qPCR) assays showed a high abundance and diversity of phosphate accumulating organisms (PAO), nitrifiers and denitrifiers. The MiSeq microbial community structure analysis showed that the Proteobacteria (especially β-Proteobacteria , and γ-Proteobacteria ) were the dominant in all reactors. Further analysis of the bacteria indicated the presence of diverse PAO genera including Candidatus Accumulibacter phosphatis, Tetrasphaera , and Rhodocyclus , and the denitrifying PAO (DPAO) genus Dechloromonas . Interestingly, no glycogen accumulating organisms (GAOs) were detected in any of the reactors, suggesting the advantage of proposed process in term of PAO selection for enhanced P removal compared with conventional main-stream processes. [ABSTRACT FROM AUTHOR]

Naphthenic acids (NAs) found in oil sands process-affected waters (OSPW) have known environmental toxicity and are resistant to conventional wastewater treatments. The granular activated carbon (GAC) biofilm treatment process has been shown to effectively treat OSPW NAs via combined adsorption/biodegradation processes despite the lack of research investigating their individual contributions. Presently, the NAs removals due to the individual processes of adsorption and biodegradation in OSPW bioreactors were determined using sodium azide to inhibit biodegradation. For raw OSPW, after 28 days biodegradation and adsorption contributed 14% and 63% of NA removal, respectively. For ozonated OSPW, biodegradation removed 18% of NAs while adsorption reduced NAs by 73%. Microbial community 454-pyrosequencing of bioreactor matrices indicated the importance of biodegradation given the diverse carbon degrading families including Acidobacteriaceae , Ectothiorhodospiraceae , and Comamonadaceae . Overall, results highlight the ability to determine specific processes of NAs removals in the combined treatment process in the presence of diverse bacteria metabolic groups found in GAC bioreactors. [ABSTRACT FROM AUTHOR]

Naphthenic acids (NAs) released into oil sands process-affected water (OSPW) during bitumen processing in Northern Alberta are problematic for oil sands industries due to their toxicity in the environment and resistance to degradation during conventional wastewater treatment processes. Granular activated carbon (GAC) has shown to be an effective media in removing biopersistent organics from wastewater using a combination of adsorption and biodegradation removal mechanisms. A simultaneous GAC (0.4 g GAC/L) adsorption and biodegradation (combined treatment) study was used for the treatment of raw and ozonated OSPW. After 28 days of batch treatment, classical and oxidized NAs removals for raw OSPW were 93.3% and 73.7%, and for ozonated OSPW were 96.2% and 77.1%, respectively. Synergetic effects of the combined treatment process were observed in removals of COD, the acid extractable fraction, and oxidized NAs, which indicated enhanced biodegradation and bioregeneration in GAC biofilms. A bacteria copy number >10 8 copies/g GAC on GAC surfaces was found using quantitative real time polymerase chain reaction after treatment for both raw and ozonated OSPW. A Microtox ® acute toxicity test ( Vibrio fischeri ) showed effective toxicity removal (>95.3%) for the combined treatments. Therefore, the simultaneous GAC adsorption and biodegradation treatment process is a promising technology for the elimination of toxic OSPW NAs. [ABSTRACT FROM AUTHOR]

Literature published during the year 2013 regarding the use of biofilms and bioreactors to treat water and wastewater is reviewed herein. The review is organized into the following sections: biofilm fornl.ation and factors Ulat impact biofilm fom13tion; xtracellular polymeric substance and its e rtraction from biofihns; biofilm consortia and quorum sensing; biofilm imaging teclmiques; biofilm carriers and biofilm reactors. [ABSTRACT FROM AUTHOR]

Oil sands process-affected water (OSPW) is a complex mixture of organic and inorganic contaminants, and suspended solids, generated by the oil sands industry during the bitumen extraction process. OSPW contains a large number of structurally diverse organic compounds, and due to variability of the water quality of different OSPW matrices, there is a need to select a group of easily measured surrogate parameters for monitoring and treatment process control. In this study, kinetic and surrogate correlation models were developed to predict the degradation of naphthenic acids (NAs) species during the ozonation of OSPW. Additionally, the speciation and distribution of classical and oxidized NA species in raw and ozonated OSPW were also examined. The structure-reactivity of NA species indicated that the reactivity of individual NA species increased as the carbon and hydrogen deficiency numbers increased. The kinetic parameters obtained in this study allowed calculating the evolution of the concentrations of the acid-extractable fraction (AEF), chemical oxygen demand (COD), and NA distributions for a given ozonation process. High correlations between the AEF and COD and NA species were found, suggesting that AEF and COD can be used as surrogate parameters to predict the degradation of NAs during the ozonation of OSPW. [ABSTRACT FROM AUTHOR]

Abstract: This study evaluated the treatment of oil sands process-affected water (OSPW) using a fluidized bed biofilm reactor (FBBR) with granular activated carbon (GAC) as support media. The bioreactor was operated for 120 days at different organic and hydraulic loading rates. The combined GAC adsorption and biodegradation process removed 51% of chemical oxygen demand (COD), 56% of acid-extractable fraction (AEF) and 96% of classical naphthenic acids (NAs) under optimized operational conditions. Bioreactor treatment efficiencies were dependent on the organic loading rate (OLR), and to a lower degree, on the hydraulic loading rate (HLR). Further ultra performance liquid chromatography/high resolution mass spectroscopy (UPLC/HRMS) analysis showed that the removal of classical NAs increased as the carbon number increased. Compared with planktonic bacterial community in OSPW, more diverse microbial structures were found in biofilms colonized on the surface of GAC after 120-day treatment, with various carbon degraders namely Polaromonas jejuensis, Algoriphagus sp., Chelatococcus sp. and Methylobacterium fujisawaense in the GAC-biofilm reactor. The results of this study, therefore, showed that the GAC-biofilm seems to be a promising biological treatment method for OSPW remediation. [Copyright &y& Elsevier]

RATIONALE Surface mining of bitumen in Northern Alberta, Canada, results in large volumes of toxic oil sands process-affected water (OSPW) that must be contained in tailings ponds. Ozonation has shown great promise as an OSPW treatment process, by decreasing its toxicity and increasing its biodegradability, but the effect of ozonation on the thousands of dissolved organic chemical groups has not yet been examined. METHODS Reversed-phase liquid chromatography with ultrahigh-resolution linear ion trap-orbitrap mass spectrometry was applied to the characterization of treated (utilized ozone doses of 20 and 50 mg O3/L) and untreated OSPW. The analysis was performed in positive and negative electrospray ionization modes for each sample (ESI+/ESI-). RESULTS Semi-quantitative analysis of ozonated and unozonated samples allowed degradation to be monitored for naphthenic acids (i.e. O2 species in ESI- mode) and >2000 other organic species belonging to various heteroatom-containing classes: O x (where x = 1 to 6), NO x (where x = 1 to 4), SO x (where x = 1 to 4), NO2S, N, and S. No chlorinated byproducts were detected in any treated sample, but at the low dose (20 mg O3/L) some compound classes increased in abundance (e.g. the O5 class), indicating that they were formed as byproducts at faster rates than they were degraded. Nevertheless, all organic compound classes subsequently diminished at the higher dose (50 mg O3/L). For several O x and SO x classes, species observed in ESI+ mode (e.g. O2+ species) were often more recalcitrant to ozonation than the corresponding species detected in ESI- mode (e.g. O2- species; naphthenic acids). CONCLUSIONS Ozonation appears to be a very suitable treatment option for OSPW, but the more recalcitrant groups of compounds may help to explain the residual toxicity of ozonated OSPW. Analysis of OSPW constituents in both ionization modes is warranted in all future OSPW fate studies. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The review includes literature published during the year 2012 regarding the use of biofilms and bioreactors to treat wastewater. Topics considered are: biofilm formation and factors that impact biofilm formation; extracellular polymeric substance and its extraction from biofilms; biofilm consortia and quorum sensing; biofilm imaging techniques; biofilm reactors and modeling. [ABSTRACT FROM AUTHOR]

The review includes literature published during the year 2011 regarding the use of biofilm and bioreactors to treat wastewater. Topics considered are: biofilm formation and factors that impact biofilm formation; extracellular polymeric substance and its extraction from biofilms; biofilm consortia and quorum sensing; biofilm imaging techniques; biofilm reactors and modeling. [ABSTRACT FROM AUTHOR]

Promoting green hydrogen has emerged as a pivotal discourse in the contemporary energy landscape, driven by pressing environmental concerns and the quest for sustainable energy solutions. This paper delves into the multifaceted domain of C -Suite issues about green hydrogen, encompassing both technological advancements and policy considerations. The question of whether green hydrogen is poised to become the focal point of the upcoming energy race is explored through an extensive analysis of its potential as a clean and versatile energy carrier. The transition from conventional fossil fuels to green hydrogen is considered a fundamental shift in energy paradigms, with far-reaching implications for global energy markets. The paper provides a comprehensive overview of state-of-the-art green hydrogen technologies, including fuel cells, photocatalysts, photo electrocatalysts, and hydrogen panels. In tandem with technological advancements, the role of policy and strategy in fostering the development of green hydrogen energy assumes paramount significance. The paper elucidates the critical interplay between government policies, market dynamics, and corporate strategies in shaping the green hydrogen landscape. It delves into policy mechanisms such as subsidies, carbon pricing, and renewable energy mandates, shedding light on their potential to incentivize the production and adoption of green hydrogen. This paper offers a nuanced exploration of C -Suite issues surrounding green hydrogen, painting a comprehensive picture of the technological and policy considerations that underpin its emergence as a transformative energy source. As the global community grapples with the imperatives of climate change mitigation and the pursuit of sustainable energy solutions, understanding these issues becomes imperative for executives, policymakers, and stakeholders alike. [Display omitted] • The latest advancements in photo electrocatalysts and fuel cell technologies are reviewed. • The storage and transportation within the realm of green hydrogen energy were discussed. • Policy and strategy for fostering the development of green energy are proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Recent advances in solar water heating (SWH) systems have been systematically reviewed. • The design criteria of the major components of the SWH system were discussed elaborately. • The potential applications based on thermal performance were studied thoroughly. • Nanofluids selection criteria for a specific SWH system were reviewed extensively. The solar water-heating (SWH) system is one of the most convenient applications of solar energy, which is considered an available, economical, and environmentally friendly energy source to fulfill the energy demands of the world. In this review, existing SWH systems and design aspects of major components e.g., solar thermal collector, storage tank, heat exchanger, heat transferring fluid, absorber plate, etc. were extensively studied. Recent research to further improve SWH systems and potential practical applications are critically reviewed. Moreover, a relatively new concept in SWH systems, which is using nanofluids in solar collectors as heat transfer fluid has been studied in terms of design criteria for the development of SWH systems. Stationary flat plate collector (FPC) and single-axis tracking compound parabolic collector (CPC) exhibit thermal efficiencies of 45–60 % (operating range: 25–100 °C) and 30–50 % (operating range: 60–300 °C), respectively. The use of thermal stratification structures e.g., diffusers, baffles, membranes, fabrics, etc. is an effective tool to reduce heat losses from the storage tank as well as to harvest the highest energy from the solar collector. Coating of nanomaterials e.g., nickel, copper, etc. was found to reduce the backside heat loss in SWJ systems which eventually increases the thermal performance of the system. Nanofluids consisting of multiwall carbon nanotubes (MWCNTs) and Al 2 O 3 increased the effectiveness of FPC by 28.3 and 35 %, respectively. Moreover, using CuO nanofluids, the collector efficiency of a typical evacuated tube collector (ETC) was increased by up to 12.4 %. Several potential future recommendations for improving the performance of the SWH system were stated. [ABSTRACT FROM AUTHOR]

In the modern world, as the population rises and fossil fuel supplies decline, energy demands continue to rise. Moreover, the use of fossil fuels harms the ecology, contributing to pollution and global warming. In order to overcome these difficulties, several approaches are revealed, such as the utilization of biomass as a renewable source of energy. Studies revealed that biomass can be converted into bioenergy via several thermal conversion processes, like pyrolysis, gasification, and torrefaction. Pyrolysis is the most convenient process to obtain three different types of biofuels (biochar as a solid, bio-oil as a liquid, and syngas as a gas). The biofuels produced in this process are normally lower in quality and cannot be used directly as fuel because they contain many undesirable components. Catalytic pyrolysis is one of the best processes to upgrade the quality of biofuels. Several varieties of catalysts are used in the catalytic pyrolysis process (ex situ and in situ). Due to stable operating conditions, both catalytic and non-catalytic pyrolysis procedures produce biochar that has a consistent output. Meanwhile, the effects of catalysts in the catalytic pyrolysis process considerably enhance the quality and quantity of bio-oils and syngas. By removing the unwanted oxygenated and nitrogenous components, the bio-oils produced through the catalytic pyrolysis method have a higher calorific value, reduced viscosity, and improved stability. Many researchers have looked at ways to increase the rate of pyrolysis, whereas a few have focused on maximizing the effects of the factors in order to improve the efficiency of catalytic pyrolysis. This review addresses the impact of catalysts on the catalytic pyrolysis of biomass to enhance the quality of the bio-oils in great detail. Machine learning and techno-economic analysis were investigated, as well as the future potential of the catalytic pyrolysis method for the generation of bio-oil. [ABSTRACT FROM AUTHOR]

Despite the widespread interest in electrospinning technology, very few simulation studies have been conducted. Thus, the current research produced a system for providing a sustainable and effective electrospinning process by combining the design of experiments with machine learning prediction models. Specifically, in order to estimate the diameter of the electrospun nanofiber membrane, we developed a locally weighted kernel partial least squares regression (LW-KPLSR) model based on a response surface methodology (RSM). The accuracy of the model's predictions was evaluated based on its root mean square error (RMSE), its mean absolute error (MAE), and its coefficient of determination (R2). In addition to principal component regression (PCR), locally weighted partial least squares regression (LW-PLSR), partial least square regression (PLSR), and least square support vector regression model (LSSVR), some of the other types of regression models used to verify and compare the results were fuzzy modelling and least square support vector regression model (LSSVR). According to the results of our research, the LW-KPLSR model performed far better than other competing models when attempting to forecast the membrane's diameter. This is made clear by the much lower RMSE and MAE values of the LW-KPLSR model. In addition, it offered the highest R2 values that could be achieved, reaching 0.9989. [ABSTRACT FROM AUTHOR]

Ozonation at high doses is a costly treatment for oil sands process-affected water (OSPW) naphthenic acids (NAs) degradation. To decrease costs and limit doses, different peroxone (hydrogen peroxide/ozone; H 2 O 2 :O 3 ) processes using mild-ozone doses of 30 and 50 mg/L were investigated. The degradation efficiency of O x -NAs (classical (O 2 -NAs) + oxidized NAs) improved from 58% at 30 mg/L ozone to 59%, 63% and 76% at peroxone (1:1), 50 mg/L ozone, and peroxone (1:2), respectively. Suppressing the hydroxyl radical (•OH) pathway by adding tert -butyl alcohol did significantly reduce the degradation in all treatments, while molecular ozone contribution was around 50% and 34% for O 2 -NAs and O x -NAs, respectively. Structure reactivity toward degradation was observed with degradation increase for both O 2 -NAs and O x -NAs with increase of both carbon (n) and hydrogen deficiency/or |-Z| numbers in all treatments. However, the combined effect of n and Z showed specific insights and differences between ozone and peroxone treatments. The degradation pathway for |-Z|≥10 isomers in ozone treatments through molecular ozone was significant compared to •OH. Though peroxone (1:2) highly reduced the fluorophore organics and toxicity to Vibrio fischeri, the best oxidant utilization in the degradation of O 2 -NAs (mg/L) per ozone dose (mg/L) was observed in the peroxone (1:1) (0.91) and 30 mg/L ozone treatments (0.92). At n = 9–11, peroxone (1:1) had similar or enhanced effect on the O 2 -NAs degradation compared to 50 mg/L ozone. Enhancing •OH pathway through peroxone versus ozone may be an effective OSPW treatment that will allow its safe release into receiving environments with marginal cost addition. [ABSTRACT FROM AUTHOR]

The effects of different ozone pretreatment doses on the performance of endogenous microbial populations in degrading naphthenic acids (NAs) for the treatment of oil sands process-affected water (OSPW) were evaluated in this study. Ozone pretreatment enhanced OSPW biodegradability and accelerated the growth of microbial populations in bioreactors. After ozone pretreatment, the maximum chemical oxygen demand (COD) removal through biodegradation occurred at an ozone dose of 50 mg/L. Although OSPW pretreated with a higher ozone concentration removed a higher COD concentration and acid extractable fraction (AEF), organics removal through biodegradation was not further improved. After pretreatment with an ozone dose of 200 mg/L and bioreactor operation for 73 days, the batch bioreactor removed more than 80% of the COD and more than 95% of AEF. High-resolution mass spectrometry analysis showed complete degradation of NAs with specific degrees of cyclization (Z = −2 and −4) after combined treatments of ozonation and biodegradation. At high pretreatment doses of ozone (116 and 200 mg/L), biodegradation completely eliminated the toxicity of OSPW toward Vibrio fischeri (IC 20 > 100% v/v). [ABSTRACT FROM AUTHOR]

Biochar is a promising material for efficient removal of toxic metals from wastewater to meet standards for discharge into surface water. We characterized adsorption behaviour of willow (Salix alba) wood (WW) and cattle manure (CM) and their biochars, willow wood biochar (WWB) and cattle manure biochar (CMB), and elucidated the mechanisms for the removal of Ni(II), Cu(II) and Cd(II) from aqueous solutions. The kinetic adsorption suggests that the adsorption of Ni(II), Cu(II) and Cd(II) by feedstock and their biochars was controlled by mass transport, and chemisorption also played a role in the adsorption process. The Elovich model also well described the adsorption kinetics for WW and CM (R2 > 0.92), indicating that heterogeneous diffusion was the mechanism. The Sips isotherm model fitted best (R2 > 0.98) for Ni(II), Cu(II) and Cd(II) adsorption by the feedstocks and their biochars, indicating that both monolayer and multilayer adsorption played roles on the heterogeneous surfaces of the four adsorbents. The WWB had a higher while the CMB had a lower adsorption capacity than their respective feedstock due to the presence of abundant –COOH functional group on WWB surface to interact with Ni(II), Cu(II) and Cd(II) to form surface complexes. The higher specific surface area and lower pH of point of zero charge (PZC) of WWB were other contributing factors for its greater removal capacity. Therefore, we conclude that proper feedstocks need to be selected to produce biochars that are efficient for the removal of toxic metals from wastewater. Unlabelled Image • Biochar adsorbed heavy metals dominated by chemisorption. • Feedstock adsorbed heavy metals through heterogeneous diffusion. • Willow wood biochar (WWB) binds metals through surface complexation with –OH and C O. • Cattle manure biochar exhibited lower adsorption capacity than its feedstock. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnO and Chitosan-modified TiO 2 nanocomposites were synthesized by the sol–gel method. • TiO 2 /ZnO/Chitosan exhibited high photodegradation efficiency for MB and MO dye. • TiO 2 /ZnO/Chitosan exhibited excellent reusability and followed 1st order kinetics. TiO 2 and ZnO-embedded chitosan-based nanocomposites were prepared, immobilized on borosilicate glass, and applied for the degradation of the binary dye mixture of methylene blue and methyl orange under solar irradiation. XRD of the nanocomposites showed the existence of the anatase phase of TiO 2 in the nanocomposites with crystalline sizes ranging from 13.92 nm to 17.82 nm. The FESEM results showed disintegration of the agglomerated TiO 2 due to Chitosan resulting in the reduction of particle size (20.6 ± 4.6 µm to 2.9 ± 0.9 µm). BET specific surface area of TiO 2 /ZnO/Chitosan was 2.29 times that of pure TiO 2 in addition to the reduction of bandgap energy from 3.17 eV to 2.84 eV. The photocatalytic experiment for TiO 2 , TiO 2 /Chitosan, TiO 2 /ZnO, and TiO 2 /ZnO/Chitosan showed the degradation of Methylene Blue to be 78.48%, 83.65%, 86.06%, and 91.22%, respectively and 72.53%, 80.18%, 84.3%, and 88.9%, respectively for methyl orange under solar irradiation for 5 h. The formation of heterojunction with ZnO and the enhanced adsorption capacity of Chitosan resulted in enhanced photocatalytic degradation. The reusability test of the nanocomposites showed no substantial reduction in the degradation percentage after 5 cycles of use. The reaction kinetic study suggested that the first-order model was the best-fitted kinetic model. The first order rate constant for TiO 2 /ZnO/Chitosan was found to be 7.88 × 10−3 min−1 and 7.10 × 10−3 min−1 for degradation MB and MO, respectively. Thus, the outcome of the experiment suggests that the application of TiO 2 doped with ZnO and Chitosan results in enhanced degradation of persistent organic contaminants in textile wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Visible light irradiated enhanced photocatalytic biodiesel production was evaluated. • A visible light irradiated biodiesel yield of 96% was attained after 3.5 h of reaction. • Light-molecule interactions at plasmonic-metal/support heterojunctions were performed. • The photocatalytic transesterification mechanism of Si/MgO heterojunction was proposed. Renewable energy sources offer greater reliability and resilience compared to traditional sources. Biodiesel, derived from renewable resources that absorb carbon dioxide during growth and production, boasts a significantly lower carbon footprint than petroleum-based diesel fuel. Heterojunction photocatalysts have emerged as a promising solution for environmental challenges. This study focused on efficient biodiesel production using visible light-irradiated Si/MgO heterojunctions. The XPS analysis confirmed the crucial role of surface functionality in achieving high photocatalytic efficiency. Transesterification occurs through SiH and SiOH bond formation on the catalyst. Finite-difference time-domain (FDTD) predicts the structure–activity relationship, showing stronger plasmonic nearfields in Si/MgO due to distinct dielectric constants. The Si/MgO photocatalyst exhibited superior photocatalytic activity under visible light, consistent with FDTD results. Biodiesel production was attained to 96% yield using 2 wt% catalysts, a 12:1 M ratio of methanol to Jatropha curcas oil, and a 3.5 hrs reaction time. Therefore, the work provided valuable insights into the mechanism of efficient plasmonic photocatalysis, paving the way for future advancements in novel high-performance photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plasma-based doping of composite materials was an efficient way to reduce the band gap. • Plasma-based doping promoted substitutional doping. • Different methods for plasma discharge for doping were discussed. • Limited studies were performed on the real-life applications of plasma-based materials. • An in-depth understanding of the mechanisms was required for computational modelling. In recent years, solar energy-driven photocatalysis materials have drawn significant attention to addressing the global energy and environmental crisis. However, many of the semiconductor photocatalysts are unable to absorb the visible light of the solar spectra due to their wide band gap. The incorporation of a foreign element such as a dopant in the lattice of these photocatalysts was shown to reduce their band gap and enhance visible light absorption. The doping of semiconductors can be performed using several techniques such as sol–gel, hydrothermal, solvothermal, and plasma-based doping. However, plasma-based doping has been considered a highly efficient approach due to the reduction of the band gap to a large extent, enhancement of visible light absorption, and remarkable photocatalytic activities under visible light illumination. The plasma-based doping approach offered many advantages such as high reactivity, process simplicity, scalability, energy efficiency, homogeneous doping, no chemical inventory, low pressure, and low-temperature operation, and flexibility of operation under gas and liquid phase media. Further advancement of plasma-based doping can be achieved through more theoretical studies allowing an in-depth understanding of the mechanisms and interactions of the species involved. This will facilitate the synthesis and application of doped photocatalysts in a cost-effective manner. This review surveyed recent advances in a wide range of semiconductor photocatalysts doped with various dopants using plasma treatment. Various plasma methods for doping semiconductor photocatalysts and their fundamental mechanisms were discussed. The performance characteristics of the plasma-doped photocatalysts were compared to other methods in terms of energy and environmental applications including degradation of environmental contaminants and solar fuel production such as hydrogen production from water splitting using visible light-driven solar energy. Finally, potential future research directions were recommended for the applications of the efficient photocatalysts developed by plasma treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The functional ligand-based conjugate materials were prepared for Eu(III) adsorption. • The materials exhibited high selectivity even in the presence of diverse foreign ions. • A high adsorption capacity (176.31 mg/g) was found in the Langmuir model. The hybrid donor chemical ligand of 5- tert -butyl-2-hydroxybenzaldehyde thiosemicarbazone (THTB) was prepared and then embedded onto inorganic porous silica as hybrid conjugate materials (HCM). The Europium (Eu(III)) ion was selected from the lanthanides (Ln(III)) series for green and robust adsorption and recovery based on the adsorption, complexation, and selectivity tendency from the standpoint of the pH-dependent factor. The chemical compound of THTB consisted of O-, N-, and S-donor atoms and was able to make stable complexation with Ln(III) ions in optimum conditions due to the open functionality of the HCM. A surface complexation with a good complexation fitting to the experimentally collected data was used to describe the adsorption mechanism. The Eu(III) ion adsorption performance was measured with batch equilibrium methods. The affecting experimental protocols including solution pH, contact time, initial Eu(III) ion concentration, foreign ions effect, and recovery were carried out and evaluated consistently. The Eu(III) ion adsorption by the HCM was at pH 5.0 and this pH was selected to avoid the precipitation problem to ensure the adsorption mechanism. The co-existing several metal ions were not interfered with Eu(III) ion adsorption by the HCM due to the high affinity between Eu(III) ion and the functional groups of HCM. The bonding mechanism suggested that O-, N-, and S-donor atoms of THTB were strongly coordinated to Eu(III) with 2:1 ratio complexation. The Langmuir adsorption isotherm model was plotted due to the HCM morphology and applied to validate the adsorption isotherms according to the homogeneous ordered frameworks. The Eu(III) ion adsorption capacity by the HCM was 176.31 mg/g as expected because of the high surface area of the HCM. The adsorbed Eu(III) ion was completely eluted from HCM with the eluent of 0.20 M HNO 3 and simultaneously regenerated into its initial form without significant deterioration. This study could be of great applicative utility for Eu(III) ions from waste aqueous solutions as green technology. [ABSTRACT FROM AUTHOR]

For several decades, water pollution has become a major threat to aquatic and non-aquatic species, including humans. Different treatment techniques have already been proposed and implemented depending on wastewater characteristics. But many of these treatment techniques are expensive and inefficient. Adsorption-based techniques have shown impressive performances as an inexpensive treatment method previously. Coconut-based resources have been considered as adsorbents for wastewater treatment because of their abundance, low cost, and favorable surface properties. However, over the last decade, no comprehensive study has been published regarding biochar from coconut-based materials for wastewater treatment and CO 2 capture. This review discusses biochar production technology for coconut-based materials, its modification and characterization, its utilization as an adsorbent for removing metals and organics from wastewater, and the associated removal mechanisms and the economic aspects of coconut-based biochar. Coconut-based materials are cheap and effective for removing various organic compounds such as pesticides, hormones, phenol, and phenolic compounds from solutions and capturing CO 2 from air mainly through the pore-filling mechanism. Utilizing coconut-based biochars in a hybrid system that combines adsorption and other techniques, such as biotechnology or chemical coagulation is a promising way to increase their performance as an adsorbent in wastewater treatment. [Display omitted] • Coconut biomass is abundant, cheap, and thermochemically modifiable to produce adsorbent. • Production methods and activation conditions have high impact on biochar characteristics. • Hybrid techniques can significantly improve the removal performance of metals and organics. • Coconut-based materials capture CO 2 from air mainly through the pore-filling mechanism. • CO 2 adsorption capacity is comparable to or higher than most studied adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ligand-based optical composite material was fabricated for effective Cd(II) capturing. • The proposed material was effective to capture the Cd(II) ion with high sensitivity. • The foreign metals did not compete with Cd(II) ions during detection & removal. The chemical ligand of N , N –bis(salicylidene)1,2–bis(2–aminophenylthio)ethane (BSBAE) was synthesized and then embedded indirectly on the mesoporous silica for the fabrication of optical composite materials (OCM) for toxic cadmium (Cd(II)) ion detection and removal from wastewater solutions. The variable parameters were measured including solution acidity, contact time, initial concentration, selectivity, and sensitivity, on the detection and removal of Cd(II) by the OCM. The solution pH played an important role in detection and removal but the present OCM worked well in the acidic pH region at 3.50. The data clarified that OCM formed distinguished color upon the addition of trace level of Cd(II) ions. The results also disclosed that the OCM was not affected by the existing diverse metal ions and the signal intensity was observed only toward the Cd(II) ion. The OCM was able to detect the low-level Cd(II) ion as the detection limit was 0.32 µg/L and the adsorption of the highest removal capacity was 179.65 mg/g. In addition, the diverse foreign ions were not reduced the Cd(II) ion adsorption significantly, and the OCM has approximately no adsorption capacity for other ions at this pH. The elution of Cd(II) ions from the saturated OCM was desorbed successfully with 0.25 M HCl. The regenerated OCM that remained maintained the high selectivity to Cd(II) ions and exhibited almost the same adsorption capacity as that of the original OCM. However, the adsorption efficiency slightly decreased after several cycles according to the experimental data observation. Therefore, the proposed OCM offered a cost-effective material and may be considered a viable alternative for effectively toxic Cd(II) ion detection and removal from wastewater as potential materials. [ABSTRACT FROM AUTHOR]

Oil sands process-affected water (OSPW) is a toxic and poorly biodegradable mixture of sand, silt, heavy metals, and organics. In this study, qualitative and quantitative comparisons of naphthenic acids (NAs) were done using ultraperformance liquid chromatography time-of-flight mass spectrometry (UPLC TOF- MS), Fourier transform ion cyclotron resonance (FT-ICR) MS, and ion mobility spectrometry (IMS). The unique combination of these analyses allowed for the determination and correlation of NAs, oxidized NAs, and heteroatom (sulfur or nitrogen) NAs. Despite its lower resolution, UPLC-TOF MS was shown to offer a comparable level of reliability and precision as the high resolution FT-ICR MS. Additionally, the impacts of ozonation (35 mg/L utilized ozone dose) and subsequent NAs degradation on OSPW toxicity were assessed via a collection of organisms and toxicity end points using Vibrio fischeri (nonspecific), specific fish macrophage antimicrobial responses, and fish olfactory responses. Fish macrophages exposed to ozonated OSPW for 1 week showed higher production of reactive oxygen and nitrogen intermediates; however, after 12 weeks the responses were reduced significantly Fish olfactory tests suggested that OSPW interfered with their perception of odorants. Current results indicate that the quantification of NAs species,using novel analytical methods, can be combined with various toxicity methods to assess the efficiency of OSPW treatment processes. [ABSTRACT FROM AUTHOR]

Literature published during the year 2010 on the topic of biological fixed film including biofilm and bioreactors for the purpose of water and wastewater treatment has been reviewed herein. Literature published regarding microbial fuel cells has also been included. The review has been organized into the following sections: biofilm formation, adhesion, quorum sensing, and consortia; techniques and analytic methods; biofilm reactors and modeling; and microbial fuel cells. [ABSTRACT FROM AUTHOR]

This is a review of literature published in 2009 that covered issues related physico-chemical processes used to treat water and wastewaters. The review is divided into six sections, including coagulation/flocculation, sorption processes, filtration, sedimentation/flotation, oxidation, and air stripping. [ABSTRACT FROM AUTHOR]

• Wheat straw biochar was modified by FeCl 3 and HCl. • Large surface area contributed abundant adsorption sites on modified biochars. • Ammonium adsorption by biochar was controlled by chemisorption. • Fe3+/Fe2+ redox coupling contributed to ammonium adsorption. • O C O groups in FeCl 3 and HCl modified biochars enhanced ammonium adsorption. The effectiveness of the modification of wheat straw biochar using FeCl 3 and HCl, alone or combined, on ammonium adsorption was evaluated using kinetic and isotherm models. The adsorption mechanisms were studied by comparative analysis of the surface properties of the biochars before and after ammonium adsorption. The results indicate that the modification methods enhanced the ammonium adsorption capacity by at least 14%, due to the increased OH and O C O functional groups and specific surface area, and increased Fe3+/Fe2+ redox coupling serving as an electron shuttle. It can be concluded that chemical modification of wheat straw biochars using FeCl 3 and HCl increased the effectiveness of biochars for the treatment of ammonium-contaminated wastewater. [ABSTRACT FROM AUTHOR]