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This study aimed to evaluate the removal of harmful cationic dyes, namely brilliant green and safranin-O, from wastewater produced by industries like textile, pigment, and pharmaceutical, which pose a direct threat to human health and the environment. An emulsion liquid membrane (ELM) was employed to eliminate these dyes, and the efficiency of the membrane was measured by calculating the percentage of dye removal and the breaking rate. The study successfully optimized the ELM process to remove the dyes within an hour and demonstrated the membrane's stability for more than 60 minutes. The results showed that the prepared ELM could remove 100% of the brilliant green dye and 99.6% of the safranin-O dye. A maximum breaking rate of 0.029% was obtained for brilliant green and 0.008% for safranin-O. Furthermore, the study resulted in the maximum removal of 99.36% and 99.15% for brilliant green and safranin-O dyes, respectively, in the binary system. When both dyes were present simultaneously, the maximum breakage observed was only 0.16%. The experimental results were analyzed using a UV–visible spectrophotometer and an optical microscope, and the optimization and analysis of the variance of means and signal-to-noise (S/N) ratio were carried out using the Taguchi L16 orthogonal array. [ABSTRACT FROM AUTHOR]

The current study aims to use a facile and novel method to remove Congo red (CR) and Methyl Orange (MO) dyes from contaminated water with Maize offal biomass (MOB) and its nanocomposite with magnetic nanoparticles (MOB/MNPs). The MOB and MOB/MNPs were characterized with Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), BET, XRD and point of zero charge (pHPZC). The influence of initial CR and MO levels (20–320 mg/L), adsorbent dosage (1-3 g/L), pH (3-9), co-exiting ions, temperature (25–45 °C) and time (15–180 min) was estimated. The findings demonstrated that MOB/MNPs exhibited excellent adsorption of 114.75 and 29.0 mg/g for CR and MO dyes, respectively while MOB exhibited 81.35 and 23.02 mg/g adsorption for CR and MO dyes, respectively at optimum pH-5, and dose 2 g/L. Initially, there was rapid dye removal which slowed down until equilibrium was reached. The interfering/competing ions in contaminated water and elevated temperature favored the dyes sequestration. The MOB/MNPs exhibited tremendous reusability and stability. The dyes adsorption was spontaneous, and exothermic with enhanced randomness. The adsorption effects were well explained with Freundlich model, pseudo second order and Elovich models. It is concluded that MOB/MNPs showed excellent, eco-friendly, and cost-effective potential to decontaminate the water. Nanocomposite of Maize offal biomass demonstrated higher dyes removal. FTIR, SEM, BET, XRD and pHPZC provided vital evidence for dyes adsorption. MOB/MNPs displayed excellent stability and reusability for dyes adsorption. Groundwater samples exposed a higher dyes removal. Results were validated with equilibrium and kinetic adsorption models. [ABSTRACT FROM AUTHOR]

This study presents the synthesis and characterization of a copper-based layered double hydroxide (Cu-LDH) composite via the coprecipitation method. The composite material aimed to effectively remove the anionic dye "Coomassie Brilliant Blue" (CBB) and exhibit antibacterial properties against both gram-positive and gram-negative bacteria. The synthesized nanocomposites were characterized using various techniques. The adsorption of CBB dye was investigated by studying various physicochemical variables, including contact time, pH of the dye solution, and initial dye concentration. The optimal dosage and contact time for efficient CBB dye removal were determined as 0.07 g and 10 min, respectively. The results showed that Cu-LDHs exhibited a high adsorption capacity for CBB dye, with a maximum removal efficiency of 85% which could be achieved within 10 min, and the Cu-LDHs improved an experimental adsorption capacity at equilibrium qmax = 80 mg/g. The adsorption process followed a pseudo-second-order kinetic model. The Langmuir isotherm model provided a good fit to the equilibrium data, indicating monolayer adsorption. Furthermore, the antibacterial activity of Cu-LDHs was assessed against various bacterial strains using a diffusion method. The results demonstrated the inhibitory effects of Cu-LDHs and CBB-Cu-LDHs on bacterial growth at a dosage of 10 mg, indicating the potential of Cu-LDHs as antibacterial agents. The underlying mechanisms responsible for dye adsorption and antibacterial activity were discussed. [ABSTRACT FROM AUTHOR]

Human visual recognition is remarkably robust to chromatic changes. In this work, we provide a potential account of the roots of this resilience based on observations with 10 congenitally blind children who gained sight late in life. Several months or years following their sight-restoring surgeries, the removal of color cues markedly reduced their recognition performance, whereas age-matched normally sighted children showed no such decrement. This finding may be explained by the greater-than-neonatal maturity of the late-sighted childrenÕs color system at sight onset, inducing overly strong reliance on chromatic cues. Simulations with deep neural networks corroborate this hypothesis. These findings highlight the adaptive significance of typical developmental trajectories and provide guidelines for enhancing machine vision systems. [ABSTRACT FROM AUTHOR]

Food grade dyes pose severe health hazards when consumed in excessive amounts or enter body via contaminated water. Despite its harmful effects, Allura Red (AR) is very less explored dye for its removal, especially using agricultural/fruit waste. This study presents efficient removal of an important and unsafe food grade dye, AR via adsorption. Waste watermelon peel waste has been used for the first time for treatmenting wastewater contaminated with AR. Waste was converted to two types of adsorbents, with and without subjecting it to pyrolysis. Both the adsorbents were characterized for functionality and crystallinity and used for conducting adsorption studies. Removal of dye was evaluated by intrinsic strategy of monitoring the model solutions under pre‐ and post‐adsorption conditions. Removal percentage of dye was determined by calculating its initial (Co) and final (Cf) concentrations in solution using the formula (see Eq. (1)). Various reaction parameters important for adsorption, viz. pH, adsorbent dose, residence time, reaction temperature and particle size were optimized. Results indicate that ~80 % and >92 % dye could be removed using 0.5 g/L adsorbent before and after pyrolysis respectively in 3.5 h from its 2 ppm concentration in modelled water. [ABSTRACT FROM AUTHOR]

The degradability of an azo dye, Basic Blue 9 (BB9), by heterogeneous sonocatalytic, photocatalytic, and sonophotocatalytic oxidation process was examined using simultaneous irradiation of UV‐C at 254 nm and power ultrasound at 20 kHz accompanied with a heterogeneous catalyst zinc oxide (ZnO) in the study. The effect of ZnO dose and initial dye concentration was investigated on the dye degradation in sonocatalytic, photocatalytic, and sonophotocatalytic processes at pH 5.5 (natural pH). The results obtained from the experimental studies were evaluated with the parameters of color removal, pseudo‐first‐order rate constant, and half‐life time. It was observed that the degradation of BB9 dye by the sonophotocatalytic process was higher compared to both sonocatalytic and photocatalytic degradation. as follows: 97.46, 48.64 and 56.88 %. The combination of sono and photocatalytic showed a remarkable synergistic effect in BB9 degradation. The kinetics of sonophotocatalytic oxidations, depending on the initial BB9 dye concentration, were found to follow the Langmuir‐Hinshelwood model. In addition, the effect of ZnO on the sonophotocatalytic oxidation process was higher compared to titanium dioxide and zero‐valent iron as follows: 97.47, 80.77 and 80.62 %. [ABSTRACT FROM AUTHOR]

This study aims to reduce the band gap by doping wide band‐gap TiO2 with CoFe2O4 and PANI to improve the photocatalytic efficiency and examine the decolorization kinetic of Rhodamine B (RhB). The characteristics of the nanocomposites were thoroughly assessed through the utilization of SEM‐EDS, TEM, XRD, FTIR, VSM, UV‐Vis, PL, and XPS analyses. The SEM and TEM analyses revealed that CoFe2O4/TiO2/PANI has a homogeneously porous structure. XRD analysis results were found to show good agreement with the standard diffraction data cards. The band structures obtained by FTIR analyses were compatible with literature studies. The band gap energies determined by UV‐Vis analyses were determined as 2.86 eV for CoFe2O4/TiO2/PANI. The decrease of CoFe2O4/TiO2/PANI recombination rate was proven with PL results. The different initial dye concentrations, temperature, and light intensity parameters were used to determine the decolorization kinetics of RhB over CoFe2O4/TiO2/PANI. The photodegradation rates of RhB in reactions catalyzed by PANI, CoFe2O4, commercial‐TiO2, CoFe2O4/TiO2, and CoFe2O4/TiO2/PANI were determined as 7.6 %, 20.7 %, 26.6 %, 32.4 %, and 48.8 %, respectively. According to data obtained from the decolorization of RhB on CoFe2O4/TiO2/PANI nanocomposite, the appropriate kinetic model was determined Network kinetic. The adsorption equilibrium constant (KB) and activation energy (Ea) were calculated as 0.007 and 7.9 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

One of the major environmental problems we have today is dye pollution, primarily caused by the textile industry. This pollution has detrimental effects on aquatic life, soil fertility, and human health. Many microbial biosorbents have been documented in the literature for the removal of a wide range of azo dyes commonly employed in the textile industry. However, Yarrowia lipolytica NBRC1658 is firstly used as both free and immobilized sorbents for the removal of Reactive yellow 18 (RY18), acid red 18 (AR18) and basic blue 41 (BB41) in this study. The effect of experimental conditions such as pH, biosorbent quantity, dye concentration, contact time, and temperature on dye removal capacity are examined. The research findings demonstrate that the adsorption capacity is higher in biomass compared to immobilized cells. The highest adsorption capacities are observed at pH 2 for RY18 and AR18, while pH 9 is optimal for BB41. Increasing the adsorbent dosage and initial concentration significantly improves the adsorption capacity. The Langmuir model best describes the adsorption process, indicating that the dye attaches to the biosorbent in a single layer, with a uniform biosorbent surface. The removal of the dye occurs through a chemical process on the biosorbent surface, as evidenced by the pseudo-second-order kinetic model. According to thermodynamic analysis, higher temperatures promote greater adsorption of dyes. Our study shows the effectiveness of Yarrowia lipolyica NBRC1658 as a biosorbent in the removal of a wide range of industrial dyes. [ABSTRACT FROM AUTHOR]

This work aimed to describe the adsorption behavior of Congo red (CR) onto activated biochar material prepared from Haematoxylum campechianum waste (ABHC). The carbon precursor was soaked with phosphoric acid, followed by pyrolysis to convert the precursor into activated biochar. The surface morphology of the adsorbent (before and after dye adsorption) was characterized by scanning electron microscopy (SEM/EDS), BET method, X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) and, lastly, pHpzc was also determined. Batch studies were carried out in the following intervals of pH = 4–10, temperature = 300.15–330.15 K, the dose of adsorbent = 1–10 g/L, and isotherms evaluated the adsorption process to determine the maximum adsorption capacity (Qmax, mg/g). Kinetic studies were performed starting from two different initial concentrations (25 and 50 mg/L) and at a maximum contact time of 48 h. The reusability potential of activated biochar was evaluated by adsorption–desorption cycles. The maximum adsorption capacity obtained with the Langmuir adsorption isotherm model was 114.8 mg/g at 300.15 K, pH = 5.4, and a dose of activated biochar of 1.0 g/L. This study also highlights the application of advanced machine learning techniques to optimize a chemical removal process. Leveraging a comprehensive dataset, a Gradient Boosting regression model was developed and fine-tuned using Bayesian optimization within a Python programming environment. The optimization algorithm efficiently navigated the input space to maximize the removal percentage, resulting in a predicted efficiency of approximately 90.47% under optimal conditions. These findings offer promising insights for enhancing efficiency in similar removal processes, showcasing the potential of machine learning in process optimization and environmental remediation. [ABSTRACT FROM AUTHOR]

The design of light‐responsive color switching systems (LCSs) is essential to the implementation of rewritable paper and oxygen detection. Previous LCSs rely on metal‐based semiconductor photocatalysts which are expensive and pose metal‐leaking risk. To solve the issue, for the first time, nitrogen‐doped carbon quantum dots (N‐CQDs) are reported as metal‐free photocatalyst for visible photoprinting and oxygen sensing. On N‐CQD surface, the decorated amino and hydroxyl groups act as hole scavengers and thus realize visible‐light‐responsive single and multiple color switching, after mixing with redox‐sensitive dyes. Combined with polymeric substrates, LCS rewritable papers can be fabricated and exhibit rapid decoloration performances under 420 nm light irradiation, due to the reduction of dye by photogenerated electrons from N‐CQDs. After the decoloration, efficient color reversion can be realized by the oxidization of dye in ambient air (O2). By taking advantage of the controlled recoloration kinetics, an oxygen sensor can be attained for visual quantitative analysis of atmospheric conditions with color variations. These results assist the future development of nonmetal color switching systems for superior functional design of photoprintable papers and colorimetric oxygen sensors. [ABSTRACT FROM AUTHOR]

In the former section of the present paper, the prospective application of B. mojavensis BI2 derived lipopeptides for dyes biodecolorization was demonstrated. The lipopeptide was mainly composed of linear and cyclic Fengycin and Surfactin isoforms. When using 100 mg/L, we are able to remove about 98% of 100 and 200 mg/L Malachite Green (MG). For the Crystal Violet (CV), the % of biodecolorization does not exceed 85% in the presence of 100 and 400 mg/L BI2 lipopeptide. In the second part of the paper, we proved the efficiency of dyes biosorption by palm waste floor, optimized by a Taguichi design. The bio-treatment efficiency was evaluated by color removal and the enhancement of germination index. Optimum treatments were obtained with 10 g/L and 6 g/L palm waste for 200 mg/L MG and CV respectively during 1 hour. Nevertheless, BI2 lipopeptide addition has no significant effect on color biosorption by date palm waste flour. [ABSTRACT FROM AUTHOR]

Emissive ionic supramolecular frameworks are designed by associating tetraphenylethylene‐based tetra‐cationic units and di‐anionic molybdenum or tetra‐anionic rhenium octahedral clusters. Obtained structures were characterized by single‐crystal X‐ray diffraction. The emission properties of the hybrids were investigated as dry powders or in various solvents by one photon and two photon absorption leading to a O2 concentration dependent luminescence color for the Mo based hybrid. [ABSTRACT FROM AUTHOR]

A major worldwide challenge that presents significant economic, environmental, and social concerns is the rising generation of food waste. The current work used chicken bones (CB) and rice (R) food waste as alternate precursors for the production of activated carbon (CBRAC) by microwave radiation-assisted ZnCl2 activation. The adsorption characteristics of CBRAC were investigated in depth by removing an organic dye (crystal violet, CV) from an aquatic environment. To establish ideal conditions from the significant adsorption factors (A: CBRAC dosage (0.02–0.12 g/100 mL); B: pH (4–10); and C: duration (30–420), a numerical desirability function of Box-Behnken design (BBD) was utilized. The highest CV decolorization by CBRAC was reported to be 90.06% when the following conditions were met: dose = 0.118 g/100 mL, pH = 9.0, and time = 408 min. Adsorption kinetics revealed that the pseudo-first order (PFO) model best matches the data, whereas the Langmuir model was characterized by equilibrium adsorption, where the adsorption capacity of CBRAC for CV dye was calculated to be 57.9 mg/g. CV adsorption is accomplished by several processes, including electrostatic forces, pore diffusion, π-π stacking, and H-bonding. This study demonstrates the use of CB and R as biomass precursors for the efficient creation of CBRAC and their use in wastewater treatment, resulting in a greener environment. The novelty of this research work relates to converting food wastes (mixture of chicken bones and rice waste) into activated carbon via microwave assisted ZnCl2 activation. Moreover, the produced activated carbon was successfully applied as a potential adsorbent for removal of a toxic cationic dye; namely, crystal violet (CV) from aqueous environment. [ABSTRACT FROM AUTHOR]

Recently a large number of extensive studies have amassed that describe the removal of dyes from water and wastewater using natural adsorbents and modified materials. Methyl orange dye is found in wastewater streams from various industries that include textiles, plastics, printing and paper among other sources. This article reviews methyl orange adsorption onto natural and modified materials. Despite many techniques available, adsorption stands out for efficient water and wastewater treatment for its ease of operation, flexibility and large-scale removal of colorants. It also has a significant potential for regeneration recovery and recycling of adsorbents in comparison to other water treatment methods. The adsorbents described herein were classified into five categories based on their chemical composition: bio-sorbents, activated carbon, biochar, clays and minerals, and composites. In this review article, we want to demonstrate the capacity of natural and modified materials for dye adsorption which can yield significant improvements to the adsorption capacity of dyes such as methyl orange. In addition, the effect of critical variables including contact time, initial methyl orange concentration, dosage of adsorbent, pH, temperature and mechanism on the adsorption efficiency will be covered as part of this literature review. The novelty of this review article describes the utility of various natural and modified materials employed to remove methyl orange (MO) from water, wastewater and aqueous solutions. Natural sorbents are very popular adsorbents because the majority of them are affordable and readily accessible in terms of addressing key challenges concerning water security that are relevant to MO adsorption processes. This review is significant since it will be useful in guiding researchers on the selection of an adsorbent that would be suitable for MO adsorption. Furthermore, our findings provide a basis for researchers interested in the design of composite adsorbents based on the selection of constituent components. [ABSTRACT FROM AUTHOR]

Stenotrophomonas koreensis, was isolated from a textile effluent and employed to biologically degrade 98.8% of the recalcitrant toxic dye malachite green in 4 h in the absence of any supplements or media. Chromatographic and Spectroscopic analysis confirmed the degradation of the dye. According to Response Surface Methodology, the optimum conditions for biodegradation were pH 6, inoculum size 6 mL (initial concentration Log10CFU/mL = 6.2), and temperature 45 °C. More than 98% decolorization was achieved within 2.5 h of the addition of soymeal extract or peptone. One of the most promising features of this strain is that even in the presence of heavy metals, S. koreensis actively degraded the dye. The bacteria biodegraded malachite green following the first-order reaction kinetics. LC-MS analysis of the degradation product yielded several intermediates like Michler's ketone (m/z 269), 4-N,N-dimethylaminophenol (m/z 137), Benzophenone (m/z 182), N,N-dimethylaniline (m/z 121), 4-(N-methylamino)-benzophenone (m/z 211), 4-aminobenzaldehyde (m/z 121), anionic canonical form of 4-aminobenzaldehyde (m/z 120), 4-(N,N-dimethylamino)benzoic acid (m/z 165), 4-(N-methylamino) benzoic acid (m/z 152). The enzymes responsible for the malachite green degradation were tyrosinase, Malachite Green reductase, and NADH-DCIP reductase. The present work is the first to report the degradation of malachite green by S. koreensis. [ABSTRACT FROM AUTHOR]

Adsorption and photocatalytic decolorization methods were used to remove Reactive Orange 16 dye from textile wastewater by using ethyleneglycoldimethacrylate and 1-vinyl-1,2,4-triazole, m-poly(EGDMA-VTA)-TiO2 polymer composite particles with magnetic synthesized by suspension polymerization. The characterization of the synthesized m-poly(EGDMA-VTA)-TiO2 particules were carried out by using XRD, FTIR, SEM–EDS-elemental mapping, ESR, and BET analyses. Both adsorption and photocatalytic decolorization processes of RO16 dye were applied to the polymer particles. The effects of solution pH, amount of adsorbent, initial dye concentration, temperature, and time on the adsorption capacity were investigated. The removal of R016 dye reached a maximum at pH 3. Dye substance removal decreased due to increasing temperature and adsorbent amount. As a result of experimental studies, the adsorption of RO16 dye was explained by the Langmuir isotherm, while its kinetics was stated by a pseudo-second-order mechanism. Additionally, thermodynamic functions (ΔHo, ΔGo, and ΔSo) have been determined. At the end of adsorption, the decolorization kinetics were elucidated by examining the adsorbent amount, time, and dye concentration parameters for the photocatalytic decolorization of non-adsorbed dyes. It was determined that the photocatalytic activity was highest at low dye concentration and high photocatalyst content. Additionally, it was determined that decolorization kinetics studies were compatible with the Langmuir–Hinshelwood model. [ABSTRACT FROM AUTHOR]

It is established that anthryltricyanoethylene reacts with cysteine and glutathione. The addition of biothiols to an anthryltricyanoethylene solution leads to a strong change in the color of the latter compound, which potentially opens up the possibility of using this dye for quantitative determination of the concentration of biothiols in living cells. The study of the model reaction of anthryltricyanoethylene with benzyl mercaptan and the isolation of a new compound, 5-amino-4-(anthracen-9-yl)-2-(benzylthio)-1H-pyrrole-3-carbonitrile, made it possible to propose the mechanism for the reaction of anthryltricyanoethylene with biothiols. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicle (UAV)-based geological mapping is significant for understanding the geological structure in the high-steep slopes, but the images obtained in these areas are inevitably influenced by the backlit effect because of the undulating terrain and the viewpoint change of the camera mounted on the UAV. To handle this concern, a novel backlit image restoration method is proposed that takes the real-world application into account and addresses the color distortion issue existing in backlit images captured in high-steep slope scenes. Specifically, there are two main steps in the proposed method, which consist of the backlit removal and the color and detail enhancement. The backlit removal first eliminates the backlit effect using the Retinex strategy, and then the color and detail enhancement step improves the image color and sharpness. The author designs extensive comparison experiments from multiple angles and applies the proposed method to different engineering applications. The experimental results show that the proposed method has potential compared to other main-stream methods both in qualitative visual effects and universal quantitative evaluation metrics. The backlit images processed by the proposed method are significantly improved by the process of feature key point matching, which is very conducive to the fine construction of 3D geological models of the high-steep slope. [ABSTRACT FROM AUTHOR]

Malachite green (MG) is a synthetic cationic dye extensively utilized in the textile industry for colouring purposes. It is a mutagenic agent and potentially carcinogenic for living organisms in nature. Therefore, it is necessary to treat and discharge the industrial effluents covering MG to avoid irreversible and serious effects on both living organisms and the environment. The photocatalyst SnO2 was synthesized by a new method by complexation of sodium diethyldithiocarbamate with tin dichloride pentahydrate, followed by calcination at 450, 600 and 750°C and utilized for photocatalytic degradation of MG dye. The better degradation was obtained at calcination temperature 600°C. The fluorescent light exposure resulted better degradation % of MG dye within 20 min, and the absorbance measurements were noted after every 5 min. The degradation of MG dye improved with an increase in the dose of SnO2 photocatalyst up to 20 mg. The highest decomposition of MG dye was found at 10 pH which may be due to deprotonation. The effects of Na+, HCO3−, Ca2+, Cl−, K+, SO42− and Mg2+ on dye degradation were examined and results showed that the salts had no effect on degradation. The kinetics and isothermic studies were carried out where the kinetic model pseudo-second-order and Langmuir isotherm were highly fitted. The factorial design was also drawn to checked the combined effects of variables, such as pH, dose, concentration and irradiation time on the degradation of MG dye. [ABSTRACT FROM AUTHOR]

Pollution of water is mainly due to industrial wastewater. In current research work, Blue-XGRRL dye removal using green hybrid materials was optimized via batch and column study. The characterization study of prepared materials was carried out via scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Fourier transform infra-red (FTIR) spectroscopy, and thermal analysis. The pH for maximum adsorption capacity of wheat straw (WS), wheat straw-zinc oxide-polythiophene (WS-ZnO-PTh), wheat straw-zinc oxide-polyaniline (WS-ZnO-PANI), and wheat straw-zinc oxide-polypyrrole (WS-ZnO-PPY) was determined to be 10 (14.6 mg g−1), 10 (31 mg g−1), 10 (37.8 mg g−1), and 11 (43.9 mg g−1) correspondingly and optimum dosage was determined to be 0.05 g/50 mL. The highest adsorption potential for all hybrid materials was achieved within a time duration of 60 min and highest adsorption potential for WS (30.7 mg g−1), WS-ZnO-PTh (43.8 mg g−1), WS-ZnO-PANI (55.8 mg g−1), and WS-ZnO-PPy (66.8 mg g−1) was obtained utilizing 100 mg L−1 dye at 30 °C. The data obtained through adsorption experiments presented the best fitness to pseudo-second-order kinetics and Langmuir sorption isotherm giving significant R2 values of 0.94–0.99 and 0.994–0.9994 respectively. Thermodynamic study showed exothermic nature of sorption. During column approach, optimal adsorbent bed height, dye flow rate, and inlet initial dye concentration to attain highest adsorption (30 mg g−1) were determined to be cm, 1.8 mL min−1, and 70 mg L−1 respectively indicating these materials a good alternative for dye removal. [ABSTRACT FROM AUTHOR]

Preformed flocs prepared by using coagulants, i.e. Fe2(SO4)3, MnSO4.4H2O, and MnCl2.4H2O, were applied as adsorbents for the decolorization of an aqueous C.I. Acid Red 1 dye solution. In order to determine the decolorizing efficiency of different adsorbents, kinetic and equilibrium studies were carried out at the optimum pH. Excellent color removal of 87 % was obtained with Fe2(SO4)3 at pH 4, good color removal of 65 % was achieved with manganese sulfate at pH 10, and moderate color removal of 58 % was obtained with manganese chloride at pH 10, at an optimum sorbent dose of 500 mg L−1 and an equilibrium contact time of 15 min. The sorption data of the equilibrium studies fitted well to the Langmuir isotherm, stating the occurrence of monolayer formation in the adsorption process of dye color removal. The maximum adsorption capacities of ferric sulfate and manganese sulfate are 47.619 and 23.474 mg g−1, respectively. The data of the kinetic studies fitted well to the pseudo‐second‐order equation, stating that chemisorption is the rate‐limiting step. [ABSTRACT FROM AUTHOR]

This study reports a simple and low-cost method for water purification using recyclable natural fibers (coarse wool fibers) as column-filling media for adsorption in the dynamic mode. As an instance of a dissolved organic pollutant, a cationic dye (basic blue 9, BB9) was assayed. According to the Langmuir isotherm (recorded at 300 K), the calculated maximum adsorption capacity of the fibrous material was found to be 24.86 mg/g for the retention of BB9. Response surface methodology (RSM) was employed for the design of experiments and the model-based optimization of the adsorption process performed in the dynamic regime (fixed-bed column). The optimal conditions provided by RSM indicated an adsorbent column height of H = 13.5 cm and a feed flow rate of Fv = 3 mL/min; these operating parameters ensured a color removal efficiency of 92.56% after 240 min of contact time. The recorded breakthrough curve under the optimal conditions was further interpolated using five quantitative mathematical models (Adams–Bohart, Thomas, Yoon–Nelson, Yan, and Clark) to assess the dynamic behaviors in the fixed-bed column. The best goodness-of-fit was achieved for the Thomas and Yoon–Nelson models. Thus, the coarse wool fibers used in a fixed bed demonstrated a relevant efficiency in the removal of cationic organic pollutants from contaminated water. [ABSTRACT FROM AUTHOR]

Three titanium dioxide quantum dots (TQDs) samples were successfully synthesized at low calcination temperatures via a modified precipitation method at T1 = 330, T2 = 360, and T3 = 400 °C. The synthesized TQDs samples were characterized by: XRD, FE-SEM, HRTEM, and EDX to analyze the crystallinity, purity, and existence of asymmetric circle forms for the TQDs catalysts. Also, the surface area, band gap energy, and crystallite size at different calcination temperatures are 322.32 m2/g, 3.20 eV, and 4.9 nm at 300 °C, 292.39 m2/g, 3.14 eV, and 5.4 nm at 360 °C, and 254.66 m2/g, 3.07 eV, and 6.2 nm at 400 °C, respectively. A xenon photoreactor (70 W/cm2) was used to evaluate the photodegradation process of Blue Dianix dye and sunlight for real industrial effluent treatment. The photocatalytic activity decreases as the crystallite size increases in the TQD samples. Photocatalytic activity of TQDs due to their distinguishable crystalline domain size of less than 10 nm and their high surface area. The photodegradation rate of real industrial effluents was evaluated according to the COD limits permitted by Egyptian environmental law. Also, TOC and COD analyses evaluated 12 recycled samples of TQDs. [ABSTRACT FROM AUTHOR]

This research work demonstrates a highly efficient photocatalytic destruction of rhodamine B dye and tetracycline drug on the surface of S-scheme AgI/g-C3N4 heterojunctions under simulated solar radiations. The thermal decomposition of urea fabricates g-C3N4 nanosheets with auspicious physicochemical and photocatalytic properties. However, brilliant yellow AgI nanoparticles are synthesized by combined precipitation-ultrasonic routes. AgI/g-C3N4 heterojunctions containing different compositions of g-C3N4 and AgI nanoparticles are constructed sonochemically. The physicochemical properties of the heterojunctions are investigated by DRS, PL, HRTEM, Zeta potential measurements, BET, XPS and XRD analysis. The photocatalytic experiments have pointed out that g-C3N4 sheets decomposes 12% of RhB dye due to the poor separation efficiency of the electron-hole pairs and low surface area of solid specimen. With introducing AgI nanoparticles on g-C3N4 sheets, the surface properties of the photocatalyst improved and the ultra-fast recombination rate of the electron-hole pairs is inhibited. The decomposition of RhB dye approaches 67, 92 and 85% of initial dye concentration for heterojunctions containing 5, 10 and 15 wt% AgI, respectively. Superoxide, positive holes and hydroxyl radicals are the main reactive species for expelling RhB as elucidated from scrubber experiments. S-scheme charge transportation mechanism records a plausible explanation for production of charge carriers with auspicious redox power. Hopefully, this research study inspire the rational design of the photocatalysts for efficient destruction of organic pollutants. [ABSTRACT FROM AUTHOR]

This study reports the treatment of synthetic dye wastewater in a sono-electrochemical reactor. The influence of three different supporting electrolytes (Na2SO4, NaCl, and Na2NO3) on % decolorisation was studied and higher decolorisation was observed with NaCl. The increase in applied current density (0.25, 0.5, 0.75, 1, 1.25 A/dm2) enhanced the color removal and the optimum current density arrived was 1.25 A/dm2. The % decolorisation was studied at three different pH (3, 7 & 11), and about 95.7% decolorisation was observed at pH 3. The inter electrode distance of 1 cm gave highest decolorisation. The addition of Na2SO4 and Na2NO3 in the sonolyzer bath did not influence the % decolorisation significantly. The sono-electrochemical process gave 99.16% decolorisation and 91.15% COD reduction while the electrochemical process gave 94.79% decolorisation and 76.82% COD reduction. The optimum electrolyte concentration, current density, pH and electrode distance of 0.5 g/L, 1.25 A/dm2, 3, and 1 cm, respectively gave highest decolorisation. The reaction kinetics of the sono-electrochemical oxidation treatment was also investigated. The higher mineralisation rate at a lower residence time indicates that the combined treatment is promising for degrading recalcitrant compounds present in wastewater. [ABSTRACT FROM AUTHOR]

The oxyhydrogen flame (OHF) can generate temperatures as high as 2800 K and a jet flow of highly reactive free radicals including H, OH, HO 2 and O. Therefore, it could serve as an effective means for treating various chemical wastes, particularly organic wastes. Building upon our previous research on metal chlorides, we present here a study on the degradation mechanism of aqueous methyl orange (MO) solution under OHF. Although the decolorization of MO solution is rapid, complete degradation is a slow and intricate process. Initially, MO solution undergoes decolorization by breaking the azo bond followed by oxidation processes that convert aminobenzene compounds to benzoquinone and break down the benzene ring until ultimately being fully converted into CO 2 and H 2 O. [Display omitted] • Oxyhydrogen flame (OHF) produces only water and highly reactive radicals. • MO eventually degraded to simplest stable molecules such as CO 2 , H 2 O and N 2 by OHF. • OHF is promising for treatment of organic wastewater without any more waste. [ABSTRACT FROM AUTHOR]

Constructing crystalline covalent organic frameworks (COF) robust 3D reusable macroscopic objects exposing more adsorption sites with high water flux for use as a filter is an unresolved challenge. A simple scalable procedure is shown for making a robust, highly compressible 3D crystalline COF nanowire interconnected porous open‐cell sponge. The compressive strength and Young's modulus (80% strain) of the sponge are 175 and 238 kPa, respectively. The sponge can withstand multiple compression‐release cycles and a load of 2800 times its weight without collapsing. As an exemplary application, the use of a COF sponge in the selective removal and separation of cationic model dye from a mixture of dyes in water by adsorption and filtration with >99% efficiency is shown. Depending on the dye concentration, the dye removal time can be as short as 2 min, and dye adsorption efficiency can be as high as 653 mg g−1 (COF in the sponge). During filtration, the sponges as filters show a high water flux of 2355 L h−1 m−2 under ambient conditions and maintain their performance for many cycles. The lightweight, reusability, and efficiency make present sponges sustainable materials as adsorbents and filters. [ABSTRACT FROM AUTHOR]

Magnetic core–shell Fe3O4@SiO2 nanoparticles were synthesized by sol–gel method. Based on the characterization and experimental results, the adsorbent was found to have an average particle size of approximately 120 nm, a pore size range of 2–5 nm and superparamagnetic properties. It exhibited electrostatic and hydrogen bonding interactions during adsorption of methyl orange (MO). The adsorption of MO on the magnetic Fe3O4@SiO2 nanoparticles exhibited pseudo-second-order kinetics, the adsorption process is a spontaneous endothermic adsorption process, which conforms to the Langmuir adsorption isotherm model. he maximum amount of MO was adsorbed at pH = 2, T = 45 °C and t = 30 min, and the highest adsorption capacity was 182.503 mg/g; The unit adsorption capacity of the Fe3O4@SiO2 nanoparticles still reached 83% of the original capacity after 5 cycles, so the material was reusable and met the requirements of environmental protection. This study reveals the great potential of magnetic mesoporous nanoparticles for removal of dyes from wastewater. [ABSTRACT FROM AUTHOR]

Piezocatalysis technology emerges as a promising solution for environmental protection and wastewater pollution treatment. This study focuses on the synthesis of Pb(Zr 0.50 Ti 0.50)O 3 (PZT) ferroelectric thin films as piezocatalysts through a sol-gel method. The piezocatalytic performance of these PZT films under vibration is also evaluated through utilizing Rhodamine B(RhB) dye as a model pollutant. When vibrations are applied to the RhB solution for 3 h, the RhB dye decomposition ratio reaches 90.22 %. The influence of pH values, vibration power and dye concentration condition on the decomposition ratio of RhB dye wastewater during the piezocatalytic process. Furtherly, these inhibitor experiments indicate that these middlle active species in piezocatalysis of PZT film are mainly the ·O 2 − and ·OH radicals. The study demonstrates the tremendous potential of PZT film's piezoelectric effect in treating dye wastewater through harvesting mechanical vibration energy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three-dimensional electrochemical technology (3DET) toward concentrate treatment. • Waste aluminum scraps were recycled as particle electrodes in 3DET for the first time. • 3DET showed an excellent performance for color and organic removal. • Main mechanisms involved in Al 3DET for organic removal were proposed. • Fe EC post treatment provided good neutralization and enhancement effects for Al 3DET. Landfill leachate nanofiltration concentrate is a kind of wastewater containing high concentrations of color and refractory organics. Herein, we proposed a novel three-dimensional electrochemical technology (3DET) with waste aluminum scraps as particle electrodes for its treatment. The planar and particle electrodes were first optimized. Ti/RuO 2 and graphite were used as anodes in the two-dimensional electrochemical technology (2DET). In the light of contaminant removal (color, UV 254 , COD, and TOC), chlorine reduction, and energy consumption, graphite was selected as planar anodes and cathodes. Moreover, 3DET with Al particle electrodes (Al 3DET) outperformed that with conventional granular activated carbon electrodes, 2DET, and Al particles. At 120 min, the removal efficiencies of color, UV 254 , COD, and TOC using Al 3DET were 98.94 %, 84.72 %, 51.93 %, and 67.46 %, respectively. UV–vis and EEM spectroscopy, and GC–MS analyses indicate that macromolecular organic matter such as humic-like substances could be effectively degraded and simultaneously removed. Reactive species identification tests including free radical quenching and EPR spectra were conducted. The results indicate that in addition to anodic direct oxidation, indirect oxidation by oxidative species (H 2 O 2 , •OH, and RCS) and flocculation by Al species also played a vital role in contaminant removal. Continuous-flow experiments show that Fe EC as a post-treatment step of Al 3DET could effectively provide a neutralization effect for the 3DET effluent and enhance the removal efficiency of contaminants. The total operating cost of combined process was 1.307 USD/m3. This study shows that the Al 3DET-Fe EC process is a promising technology for the treatment of nanofiltration concentrate. [ABSTRACT FROM AUTHOR]

Yttria‐stabilized zirconia (YSZ), although well known for a lot of excellent engineering applications, has limited footprints in the field of adsorption/dye removal. Through this work, we demonstrate the remarkable efficacy (adsorption capacity ∼550 mg/g) of 8 mol.% YSZ nano‐adsorbents for toxic azo‐dye (e.g., Congo red) removal. The consistency of our adsorption experiments was validated with the help of a series of tests, such as regeneration (via thermal and chemical routes), in real‐life river water, with mixed ion solution, and under varied pH (3–11). Noteworthy is also that the commercial trademark composition (with the same dopant concentration) showed little/no adsorption. Our success of the adsorption experiments is credited to the multitude of factors, namely, size refinement ∼6 nm, retainment of phase‐pure cubicity, and enhanced surface area (155 m2/g), which eventually led to the generation of massive oxygen vacancies on our synthesized doped‐zirconia surfaces. [ABSTRACT FROM AUTHOR]

Piezocatalysis technology emerges as a promising solution for environmental protection and wastewater pollution treatment. This study focuses on the synthesis of Pb(Zr 0.50 Ti 0.50)O 3 (PZT) ferroelectric thin films as piezocatalysts through a sol-gel method. The piezocatalytic performance of these PZT films under vibration is also evaluated through utilizing Rhodamine B(RhB) dye as a model pollutant. When vibrations are applied to the RhB solution for 3 h, the RhB dye decomposition ratio reaches 90.22 %. The influence of pH values, vibration power and dye concentration condition on the decomposition ratio of RhB dye wastewater during the piezocatalytic process. Furtherly, these inhibitor experiments indicate that these middlle active species in piezocatalysis of PZT film are mainly the ·O 2 − and ·OH radicals. The study demonstrates the tremendous potential of PZT film's piezoelectric effect in treating dye wastewater through harvesting mechanical vibration energy. [ABSTRACT FROM AUTHOR]

The seed layers were deposited on the activated glass lamellas by dip-coating using zinc solutions with and without diethanolamine (DEA). ZnO nanorods were grown on these two types of seed layers by chemical bath deposition (CBD) method at 95 °C. The nanorods were then annealed in air at 300, 400 and 500 °C and in an oxygen atmosphere at 400 and 500 °C. The influences of seed solution chemistry, annealing temperature and atmosphere on the structural properties of the ZnO nanorods were investigated via X-ray diffraction (XRD) and scanning electron microscopy (SEM). An improved vertical alignment of the nanorods along the c-axis was observed on the DEA-containing seed layer. Their diameters decreased with the increasing annealing temperature, whereas their crystallinities increased. Optical properties of the samples were also studied by ultraviolet–visible (UV–vis) and photoluminescence (PL) spectroscopies. Their optical band edges shifted to lower energies as the annealing temperature increased up to 400 °C. The PL intensities decreased with annealing at 500 °C in an oxygen atmosphere, which was attributed to the decrease in defect concentration. Their photocatalytic tests using AR88 azo dye and UVA irradiation revealed that the annealing process is beneficial in achieving improved color removals from the aqueous dye solutions. The well-aligned nanorods were successfully grown on the DEA-supported seed layer. However, their photocatalytic efficiencies remained relatively low, which was attributed to poor light interactions with their lateral surfaces. [ABSTRACT FROM AUTHOR]

The magnetic biochar was prepared using Ulva fasciata marine algae and used to remove Methylene blue (MB) as model organic molecule. A comprehensive characterization was conducted on pristine Ulva fasciata biochar (UFBC) and UFBC modified by Fe 3 O 4 (UFBC-MIO) by using SEM, EDX, FTIR, TEM, BET, and XRD along with the PZC. The adsorption of MB was noted as 20.83 mg g−1 for UFBC and 50.12 mg g−1 for UFBC–MIO, at pH = 9, 2 g L−1 dosage and T = 298 K with approx. 85 mg L−1 MB concentration. The higher performance of UFBC-MIO was explained by formation of higher surface area and pore volume. The mechanism of adsorption depicted as pore-filling and electrostatic interaction was identified as physisorption. The adsorption model followed the Langmuir isotherm and the kinetic studies disclosed pseudo-second-order for both adsorbents. The thermodynamic study revealed that the process is non-spontaneous, decreased in randomness and was exothermic. The UFBC–MIO was easily recovered and regenerated through its magnetic property and exhibited 89% MB removal after 5 cycles at pH = 9, 2 g L−1 dosage and T = 298 K with 86.37 mg L−1 of MB. The magnetic biochar of algae Ulva fasciata is an excellent adsorbent recommended for the removal of cationic dyes from wastewaters. [Display omitted] • Preparation of magnetic biochar from Ulva fasciata macro algae. • Elucidation of methylene blue adsorption mechanism. • Adsorption capacity of about 50 mg g− 1. • Predominant Langmuir adsorption isotherm. [ABSTRACT FROM AUTHOR]

The present work reports the adsorption of crystal violet dye (CVD) onto magnetized bentonite clay particles (MBCP). The MBCP adsorbent was synthesized by the co-precipitation method, where magnetic particles of Fe3O4 precipitated the bentonite clay particles. The synthesized MBCP showed a high capacity for CVD adsorption, removing 93.97% of the dye at an equilibrium adsorption time of 80 min at an optimum temperature of 303 K. The effects of adsorbent dosage, dye concentration, and pH, on adsorption were also assessed. Adsorption data were best described by the Langmuir adsorption isotherm with a maximum monolayer adsorption capacity of 588.23 mg g−1, while the pseudo-second-order kinetic model best fitted the adsorption kinetics. Adsorption was found to be thermodynamically feasible and led to an increase in entropy. The HCl was the most effective desorbing agent for regenerating MBCP up to four cycles. This study of MBCP, therefore, ensures the sustainability and cost-effectiveness of dye treatment in industrial effluents. Further, the magnetization of bentonite mineral clay makes it more effective with enhanced adsorption characteristics along with easy separability. [ABSTRACT FROM AUTHOR]

In this study, the removal of indigo dye, which is used in the denim industry, by using the electro-oxidation method was investigated. Experiments were carried out using Sn/Sb/Ni–Ti anode and Pt–Ti cathode electrodes of indigo dye aqueous solution with an initial concentration of 100 mg/L, which was prepared synthetically in the laboratory. In the first stage of the study, appropriate support electrolyte (NaCl, KCl, Na2SO4, K2SO4) detection investigations were carried out. As a result of the trials, NaCl electrolyte was chosen as the supporting electrolyte type because it is both affordable and has high removal efficiency compared to other electrolytes. Color and COD removal were established according to the effective factors (pH, current density, supporting electrolyte concentration and electro-oxidation time) for the electro-oxidation method using the central composite design (CCD) based response surface methodology (RSM). The design consists of four components and seven central experiments, each with three levels. According to the RSM result, ideal conditions were pH 11, current density 51.01 mA/cm2, supporting electrolyte concentration 1565.66 mg/L and duration 120 min. In ideal conditions, COD removal was determined as 97.43% and color removal as 98.93%, while energy consumption was determined as 17.49 kWh/kg COD. In the last stage of the study, pilot-scale tests were carried out in a spherical polyethylene (PE) tank with a bottom diameter of 65 cm and a height of 157 cm. Color and COD removal efficiencies obtained from the pilot scale under optimum conditions were calculated as 95.26% and 92.16%, respectively. [ABSTRACT FROM AUTHOR]

Today, the importance of materials produced by natural means or by synthesis is increasing in the prevention of increasing water pollution. Sophora Japonica fruit seeds (SJfs) were pyrolyzed at 450 °C to produce SJfs-biochar (SJfsB) in this study. Iron nanoparticles were immobilized to the SJfsB structure to form a more active biosorbent matrix. SJfsB and the resulting novel biosorbent (nanomagnetic-Sophora Japonica fruit seeds biochar (nM-SJfsB) were used to remove malachite green (MG) from an aqueous solution. Fourier transform infrared analysis (FTIR) and scanning electron microscopy were used to elucidate the details of the biosorbent properties. The effect on removal was investigated using various parameters. A combined strategy was used to define the adsorption parameters such as adsorbent amount, time, initial dye concentration, pH, and temperature. The maximum adsorption capacity determined by the Langmuir model was 51.020 mg/g for SJfsB-MG and 101.010 mg/g was found for nM-SJfsB-MG. The pseudo second order equation made the equilibrium data suitable. After regeneration, nM-SJfsB can be used for re-adsorption studies and reused for multiple cycles in adsorption and desorption applications without discharging nano-iron particles into aqueous medium. [ABSTRACT FROM AUTHOR]

Background and Aim: The production of lignocellulosic biomass waste in the agricultural sector of Indonesia is quite high annually. Utilization of lignocellulosic biomass waste through fermentation technology can be used as feed and biofuel. Fermentation technology requires the involvement of micro-organisms such as bacteria (lactic acid bacteria or LAB). LABs can be isolated from various sources, such as duck excreta. However, there have not been many reports of LAB from duck excreta. The present study aimed to characterize LAB enzymes isolated from duck excreta and obtain LAB enzymes with superior fermentation properties. Materials and Methods: A total of 11 LAB cultures obtained from duck excreta in Yogyakarta, Indonesia, were tested. Enzyme characterization of each LAB was performed using the API ZYM kit (BioMérieux, Marcy-I'Etoile, France). The bacterial cell suspension was dropped onto the API ZYMTM cupule using a pipette and incubated for 4 h at 37°C. After incubation, ZYM A and ZYM B were dripped onto the API ZYM cupule, and color changes were observed for approximately 10 s under a strong light source. Results: Esterase activity was moderate for all LABs. The activity of a-chymotrypsin, ß-glucuronidase, a-fucosidase, and a-mannosidase was not observed in a total of 10 LAB. The phosphohydrolase and amino peptidase enzyme activity of seven LABs was strong. Only six LAB samples showed protease activity. The glycosyl hydrolase (GH) activity was observed in a total of 8 LAB, while the activity of 2 LAB was strong (Lactococcus lactis subsp. lactis K5 and Lactobacillus brevis M4A). Conclusion: A total of 2 LABs have superior properties. L. lactis subsp. lactis K5 and L. brevis M4A have a high potential to be used in fermentation. They have the potential for further research, such as their effectiveness in fermentation, lignocellulose hydrolysis, feed additives, molecular characterization to detect specific enzymes, and their specific activities. [ABSTRACT FROM AUTHOR]

Wastewater contaminated with organic pollutants must be carefully treated before being discharged into the environment in order to reduce its negative effects on public health. Currently, much attention has been paid to the removal of dyes from industrial wastewater. The aim of this study is to investigate the removal of Acid Blue 113 (AB113) and Congo Red (CR) dyes by using Moroccan Prickly Pear Cactus Peel (MPPCP) from the binary system in a batch reactor. All the parameters influencing the adsorption of the dye in the binary system were studied namely the effect of mixture composition, contact time (20–210 min), initial dye concentration (20–300 mg/L), temperature (25–40 °C), and pH of the dye solution (2–12). The results showed that the uptake of both AB113 and CR dyes highly depends on initial dye concentration, solution composition dyes, and temperature. The kinetic study was performed by applying two kinetic models, the pseudo-first-order and the pseudo-second-order. The pseudo-second-order model better describes the adsorption of the dyes onto MPPCP adsorbent. The analysis of the obtained results shows that the correlation coefficients of the Freundlich model are higher which shows that the adsorption of AB113 and CR dyes in the binary mixture takes a multilayer form. The thermodynamic study showed that the adsorption of dyes in a binary system is spontaneous, physical, and exothermic. The obtained results in this work show that MPPCP can be considered a good material for the removal of anionic AB113 and CR dyes in the binary mixture and therefore used this material on an industrial scale. [ABSTRACT FROM AUTHOR]

In this study, kocho was prepared from pseudostem and corm of Ensete ventricosum (enset). The behaviors of kocho were examined by using FESEM, TGA, XRD and FTIR spectroscopy. The biosorption potential of kocho, a possible low-cost new biosorbent for the efficient removal of MB dye from wastewater was investigated. Biosorption experiments were carried out in batch mode to study the effects of biosorbent dosages (0.025-0.2 g), pH (2-10), initial concentrations of MB (10 to 100 mg/L) and contact time (10 to 120 min). The highest removal efficiency of methylene blue dye (94.2%) was recorded at optimum experimental conditions. Following the removal study, it was determined that the pseudo-second order kinetics (R² = 0.997) and Langmuir isothermal (R²= 0.996) models may well describe the MB dye biosorption process. Furthermore, this newly developed biosorbent was fairly recyclable up to five cycles without significant loss of re-adsorption efficiency (around 9.6% loss) between 1st and 5th cycle. Thus, the findings of this study revealed that a new kocho biosorbent derived from Ensete ventricosum can be used as a promising low-cost, environmentally friendly and efficient biosorbent for the rapid removal of MB from aqueous solutions. [ABSTRACT FROM AUTHOR]

Perovskite oxides are attractive in the catalytic application owing to their stability, tuning characteristics, and easy synthesis process. Here, ZnTi 1-x Zr x O 3 (x = 0.5) (abbreviated as ZZT0.5) is synthesized under the chemical precursor solution decomposition method and calcined at 700 °C for 3 h. The cubic phase nanosized material exhibits cubic shape morphology with the proper ratio of the existing elements as from observed structural and morphological characterizations. In the photocatalytic dye degradation under natural sunlight irradiation, the materials show >90% color degradation of congo red and murexide. The observed result in the presence of solar light irradiation highlights an elevated photocatalytic efficiency. The pseudo-first-order degradation process shows a high correlation coefficient with good stability of the material in the reusable study. This ZnTiO 3 -based perovskite material has not been used previously in electrocatalytic water splitting. During oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) conditions, the material deposited on NF substrate showed 335 mV and 165 mV overpotential at 10 mA cm−2 current density, respectively which is indicative of notable electrocatalytic water splitting activity of the perovskite material designed herein. The long-term chronoamperometry (CA) study confirms the material's stability during both HER and OER conditions with negligible loss in activity over a period of 12 h. The post-catalytic characterizations confirm the robust nature of the material possessing the same phase characteristics. As an earth-abundant, low-cost material, the material designed herein shows the significant activity of environmental sustainability in terms of water treatment as well as green hydrogen production via electrolysis. [Display omitted] • Zr-doped ZnTiO 3 -based materials for photocatalytic & electrocatalytic study. • >90% color degradation for congo red and murexide under solar light. • OER and HER showed 335 mV and 165 mV overpotential at 10 mA cm−2 current density respectively. • The post-catalytic characterizations confirm the robust nature of the material. [ABSTRACT FROM AUTHOR]

Carbon felt (CF) is frequently used as an electrode in various processes of oxygen reduction reactions (ORR) and water treatment. Therefore, it is critical to increasing the performance of this material in ORR. In this study, the effect of the thermal modification, which is a simple and low-cost process, was examined. For testing the hydrogen peroxide generation efficiencies and the mineralisation of Acid Orange 7 (AO7) dye, the modified CF electrodes (under 0–900°C and N2 atmosphere for 1 hour) were used as cathodes with Ti/RuO2-IrO2-TiO2 as anode and saturated calomel electrode (SCE) as a reference electrode. In addition, to find the optimum Electro-Fenton (EF) process parameters, the potential of the cathode (0.8–3.0 V), pH (3.0–9.0), Fe2+ concentration (0.2–1.0 mM) and electrolyte (sodium sulphate) concentration (10–500 mM) were investigated. The highest efficiencies in dye and TOC removal were achieved at 0.8 V, 50 mM of electrolyte concentration with 0.3 mM of Fe2+ by using CF modified at 900°C as 96.26% at 10 min and 91.83% at 120 min, respectively. Besides, the modification process was increased the electroactive surface area (41.70%) and crystallite size (22.69%) of the electrode. Thus, more effective treatment was achieved. Thanks to the modification, the electrical energy and electrochemical energy saving are approximately 23.87% and 70.22%, respectively. On the other hand, a kinetic study was conducted with a large number of data coming from the on-line analysis system, which is different from most systems in the literature. At the end of the kinetic study, it was revealed that EF systems could not be explained by a single kinetic equation. It was found that the EF system has two different rate equations (first order and pseudo first order) with high correlation coefficients (R2 = 0.9965 and 9920). [ABSTRACT FROM AUTHOR]

In recent years, the advanced oxidation processes have been used to treat wastewater containing various dye pollutants through various methods of purification. In this study, the removal of the Sunset Yellow (SY) dye from contaminated water was investigated by UV/TiO2/H2O2 process using a recirculating thin-film fixed-bed reactor (TFFBR). The experiments were designed by the response surface method (RSM) via Minitab software, in such a way that the effects of various parameters on the process are investigated. The effect of different parameters such as reaction time, pH of the solution, initial dye concentration and hydrogen peroxide concentration on the dye removal efficiency has been investigated. According to the results of the screening and optimisation test by the response surface method, the optimal conditions for performing the process were, time of 45 min, pH of 2, hydrogen peroxide concentration of 13.33 mM and initial dye concentration of 10 mg/L. Under optimal conditions, the efficiency of dye removal was more than 97%. Besides, the kinetics of SY dye removal followed the first-order equation. [ABSTRACT FROM AUTHOR]

In the present study, the removal of direct blue 86 dye was explored via cationic surfactant enhanced ultrafiltration from aqueous phase. The effects of various parameters such as initial dye concentration, contact time, pressure, solution pH and surfactant concentration were evaluated on the process. The RSM using R software was chosen to investigate the effect of input independent factors on the dependent response (removal efficiency). The p-value (2.071 × e−06), F-value (7.82), R2 (multiple R-squared: 0.6494, adjusted R-squared: 0.5663), insignificant lack of fit (0.06) indicated that the reduced full second order model was highly significant for dye removal. The maximum percentage of dye removal (92%) was obtained at the optimum conditions (initial dye concentrations (25.8 mg/L), contact time (15.8 min), pressure (1.58 bar), pH = 6.16, and surfactant concentration (0.93 mg/L)). The utmost elimination efficiency was calculated to be 100%, by means of regression coefficients achieved from the model and Solver 'Add-ins', respectively. The results showed that the MEUF process is very suitable for the removal of direct blue 86 dye from aqueous solutions. [ABSTRACT FROM AUTHOR]

This research illustrates the modification of multi-walled carbon nanotube (MWCNT) by ZrO2/Pb to construct a nanocomposite (MWCNT/ZrO2/Pb-NC) using a simple precipitation technique, as well as to examine the ability of this NC for the adsorption of two dyes, amido black (AB) and Eosin B (EB), in binary systems. FESEM, XRD, FTIR, and EDX were utilised to investigate the MWCNT/ZrO2/Pb-NC. The results suggested that MWCNT/ZrO2/Pb-NCs possessed as-synthesised crystalline nature with a cubic morphology and the average particle size of 30–50 nm. The nano-adsorbent represented herein showed high adsorption efficiency towards AB and EB. The influence of experimental parameters, i.e. pH, initial concentration of dyes, contact time, and MWCNT/ZrO2/Pb-NCs mass, were analysed by central composite design (CCD). The removal percentages more than 95% for AB and EB dyes were obtained by the adjustment of operational conditions at pH 6.0, 0.05 g of MWCNT/ZrO2/Pb-NCs, 15 min stirring, and 15 mg L−1 of each dye. The binding behaviour of the two dyes on the proposed NC was precisely modelled by the Langmuir isotherm. The adsorption capacities for AB and EB were 15.46 and 16.92 mg g−1, respectively. Pseudo-first order model, owing to its high correlation coefficient and closeness of experimental and theoretical data, well represented the behaviour of the corresponding adsorption system. Mechanism examination strongly affirmed the high contribution of external mass transference as the main rate-controlling step. The successful regeneration of MWCNT/ZrO2/Pb-NC signified the usefulness of the NC in wastewater treatment and its capability of environmental management. [ABSTRACT FROM AUTHOR]