Percentage Of Dye Removal Research Articles

Fabrication and assessment of performance of clay based ceramic membranes impregnated with CNTs in dye removal

In this research, flat disk clay-based ceramic membranes were fabricated and optimized for use in the treatment of wastewater contaminated with dye. The properties of the fabricated membranes were assessed to optimize the fabrication conditions, namely, the firing temperature (1150 °C, 1200 °C, and 1250 °C), soaking time (30 min and 60 min) and zeolite percentage (0%, 10%, and 20%). On the other hand, the rejection of methylene blue dye (MB) and acid fuchsin dye (AF) was studied. The surface of the optimal membrane support was modified using functionalized COOH-carbon nanotubes to increase the dye removal percentage. The fabricated membranes were characterized using FTIR, XRD, and XRF. The optimum membrane support was fabricated at 1150 °C, after 30 min of soaking and with 0% zeolite. The most suitable membrane support was found to be AF, as its rejection percentages reached 42% and 95% without and after surface modification, respectively. The surface of the membrane was examined via SEM, which revealed normally distributed pores. The average pore size of the final membrane was found to be 0.076 micrometers using a mercury porosimeter; thus, the produced membranes can be used in ultrafiltration applications. Finally, the fouling properties showed that the total fouling reached 72.8%, of which only 2.1% was irreversible.

Oxidative degradation of anionic dyes in wastewater by magnetic lignin micro-nano spheres catalyzed peroxymonosulfate

Lignin has gained significant attention in wastewater treatment due to its abundant resources and good adsorbability. In this work, magnetic lignin micro-nano spheres (Fe3O4@SiO2-LNS) was prepared using alkali lignin as the raw material, and was used as the adsorbent and catalyst to activate peroxymonosulfate (PMS) to build an inhomogeneous catalytic oxidation system (Fe3O4@SiO2-LNS/PMS). The system was then used to remove the stubborn acid blue 9 (AB9) dye in wastewater, and the effects of pH, catalyst dosage, PMS dosage of the system on the removal percentage of AB9 dye and the corresponding degradation mechanism were explored. The results showed that Fe3O4@SiO2-LNS/PMS system had good removal efficiency for AB9 in wastewater, and AB9 dye was completely oxidized and finally degraded into CO2 and H2O. The maximum removal percentage of AB9 was observed when the pH and temperature of the system were 6.0 and 313 K, and the removal percentage of AB9 achieved 100 % when the optimal dosage of Fe3O4@SiO2-LNS and PMS were 3.44 g/L and 53.15 mM, respectively. In addition, Fe3O4@SiO2-LNS had good stability and reusability. This work provides a promising approach for abatement of dyeing wastewater pollution and a new direction for high-value utilization of alkali lignin.

A Sustainable Solution for the Adsorption of C.I. Direct Black 80, an Azoic Textile Dye with Plant Stems: Zygophyllum gaetulum in an Aqueous Solution.

The presence of pollutants in water sources, particularly dyes coming by way of the textile industry, represents a major challenge with far-reaching environmental consequences, including increased scarcity. This phenomenon endangers the health of living organisms and the natural system. Numerous biosorbents have been utilized for the removal of dyes from the textile industry. The aim of this study was to optimize discarded Zygophyllum gaetulum stems as constituting an untreated natural biosorbent for the efficient removal of C.I. Direct Black 80, an azo textile dye, from an aqueous solution, thus offering an ecological and low-cost alternative while recovering the waste for reuse. The biosorbent was subjected to a series of characterization analyses: scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) method, X-ray diffraction (XRD), and infrared spectroscopy (IR) were employed to characterize the biosorbent. Additionally, the moisture and ash content of the plant stem were also examined. The absorption phenomenon was studied for several different parameters including the effect of the absorption time (0 to 360 min), the sorbent mass (3 to 40 g/L), the pH of the solution (3 to 11), the dye concentration (5 to 300 mg/L), and the pH of the zero-charge point (2-12). Thermodynamic studies and desorption studies were also carried out. The results showed that an increase in plant mass from 3 to 40 g/L resulted in a notable enhancement in dye adsorption rates, with an observed rise from 63.96% to 97.08%. The pH at the zero-charge point (pHpzc) was determined to be 7.12. The percentage of dye removal was found to be highest for pH values ≤ 7, with a subsequent decline in removal efficiency as the pH increased. Following an initial increase in the amount of adsorbed dye, equilibrium was reached within 2 h of contact. The kinetic parameters of adsorption were investigated using the pseudo-first-order, pseudo-second-order and Elovich models. The results indicated that the pseudo-first-order kinetic model was the most appropriate for the plant adsorbent. The isotherm parameters were determined using the Langmuir, Frendlich, Temkin, and Dubinin-Radushkevich models. The experimental data were more satisfactory and better fitted using the Langmuir model for the adsorption of dye on the plant. This study demonstrated that Zygophyllum gaetulum stems could be employed as an effective adsorbent for the removal of our organic dye from an aqueous solution.

Regeneration and Single Stage Batch Adsorber Design for Efficient Basic Blue-41 Dye Removal by Porous Clay Heterostructures Prepared from Al13 Montmorillonite and Pillared Derivatives.

Porous clay heterostructures are a hybrid precursor between the pillaring process and organoclays. In this study, the organoclay was substituted by an aluminium intercalated species clay or pillared alumina clays. A porous clay heterostructure was successfully achieved from an aluminium intercalated species clay, due to the easy exchange of the aluminium species by the cosurfactant and silica species. However, using alumina pillared clays, the porous clay heterostructures were not formed; the alumina species were strongly attached to clay sheets which made difficult their exchange with cosurfactant molecules. In this case, the silica species were polymerized and decorated the surface of the used materials as indicated by different characterization techniques. The specific surface area of the porous clay heterostructure material reached 880 m2/g, and total pore volume of 0.258 cc/g, while the decorated silica alumina pillared clays exhibited lower specific surface area values of 244-440 m2/g and total pore volume of 0.315 to 0.157 cc/g. The potential of the synthesized materials was evaluated as a basic blue-41 dye removal agent. Porous clay heterostructure material has a removal capacity of 279 mg/g; while the other materials exhibited lower removal capacities between 75 mg/g and 165 mg/g. The used regeneration method was related to the acidity of the studied materials. The acidity of the materials possessed an impact on the adopted regeneration procedure in this study, the removal efficiency was maintained at 80% of the original performance after three successive regeneration cycles for the porous clay heterostructure. The Langmuir isotherm characteristics were used to propose a single-stage batch design. Porous clay heterostructures with a higher removal capacity resulted in a decrease in the quantities needed to achieve the target removal percentage of the BB-41 dye from an aqueous solution.

Synthesis of Cu-SnO<sub>3</sub> NCs by Photo Irradiation Method for Removal Tartrazine Dye Yellow in Aqueous Solutions

Background: Copper tin oxide (Cu-SnO3) is a cheap and easily accessible tunable that has a 2.5-5 eV bandgap. It is a desirable semi-conductor because of these components for a number of applications, including transparent conducting oxides, transistors, solar cells and photocatalytic. Objective: The aim of this research is to increase the rate of yellow dye removal percentage efficiency by using Photo Irradiation Method that rate was determined between (59 to 76) % by the simple chemical method. Methods: Photo irradiation method used to synthesis Cu-SnO3 from precursor materials, the solution is irradiated by photocell for 30min with cooling (5°C) then drop sodium hydroxide (4 g in 100 ml) then washed, isolated by centrifugation for 20 minutes, grinding the dried powder and calcinated at (450 °C). Results: The crystallite size and the crystal structure of Cu-SnO3 NPs are (43-8.2) nm with a tetragonal structure. Field Emission-Scanning Electron Microscopy (FESEM) results displayed the formation of spherical and semispherical and an average size of (35.97 - 74.43) nm. The optical energy gap value (Eg) is 5 eV. It is clear from the disappearance of tartrazine’s yellow hue in an aqueous solution that the combination was shaken at 298 K and 185 rpm. Conclusions: Prove that the removal percentage process by a photo-irradiation method is more effective than other used methods.

Comparison of the natural and surfactant-modified zeolites in the adsorption efficiency of sunset yellow food dye from aqueous solutions

The removal of Sunset Yellow (E110) on natural zeolite and zeolite modified with the cationic surfactant cetyl pyridinium chloride (CPC) was studied using the adsorption method. The structural characteristics of the surfactant-modified zeolite (SMZ-CPC) were investigated using X-ray diffraction(XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) analysis, and the scanning electron microscopy (SEM) images. The effect of different parameters on the adsorption process, such as equilibration time and amount of adsorbent at 298 K, were determined using UV–Vis spectroscopy. The maximum dye removal percentage on SMZ-CPC was obtained with 0.08 g of adsorbent in 30 min. The results show that the zeolite modified with CPC surfactant (SMZ) has a higher adsorption capacity for Sunset Yellow than the unmodified zeolite (natural form). The experimental adsorption data were nonlinearly analyzed using isotherm equations such as Langmuir, Freundlich, Temkin, Langmuir-Freundlich (or Sips), and Extended Langmuir (EL). The experimental data were better fitted with the Sips isotherm. The adsorption kinetic data were analyzed using eight models in nonlinear forms: the pseudo-first-order (PFO), pseudo-second-order (PSO), integrated kinetic Langmuir (IKL), Elovich, intraparticle diffusion (IPD), mixed order rate equation (MOE), fractal-like pseudo-first-order (FL-PFO) and fractal-like pseudo-second-order (FL-PSO). According to the results of the coefficient of determination (R2), Elovich kinetic model well expressed E110 adsorption onto SMZ-CPC. Most of the dye removal takes place in less than 5 min and the maximum adsorption capacity is 5.06 mg/g. The results of this study show that zeolite modified with cationic surfactant is an effective adsorbent for removal anionic dyes from an aqueous solution.

ECO-FRIENDLY BIONANOCOMPOSITE BASED ON BIOSYNTHESIZED POLY(3-HYDROXYBUTYRATE-CO-3-HYDROXYVALERATE) REINFORCED WITH Ni-CuO NANOPARTICLES FOR REMOVAL OF BRILLIANT GREEN

Ni-doped Copper oxide (Ni-CuO) nanoparticles have been synthesized from Arabic Gum. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) polyester was biosynthesized by the microorganism Haloferax mediterranei utilizing date waste as carbon source. The produced Ni-doped copper oxide (Ni-CuO) nanoparticles have been incorporated with different percentages into the PHBV matrix. The produced bionanocomposites were achieved with different percentages of the nanoparticles: 1%, 3%, 5% and 10%, and were referred to as PHBV/Ni-CuO(1,3,5,10%). FTIR, TGA, XRD, SEM and EDX techniques have been used to study and characterize the synthesized bionanocoposites. In addition, the prepared nanocomposites were studied for their efficiency as solid phase adsorbents for Brilliant Green (B.G.) dye from water resources under different conditions. The prepared nanocomposites were found to be very efficient and promising solid phase adsorbent materials to treat water samples for the purpose of dye removal. The percentage of the removed dye increased from 45.6% to 97.7% as the PHBV/Ni-CuO(10%) nanocomposite amount increased from 10 mg to 70 mg per 25 mL of water sample. The dye removal percentage reached an equilibrium in 90 min. Natural water samples from three different sources have been tested against the Ni-CuO/PHBV(3%) nanocomposite as solid adsorbent for the B.G. removal, and the results showed >90% dye removal in all cases under the optimum experimental conditions.

Central composite experimental design for Indigo Carmine dye removal from solutions by applying electro-coagulation and electro-oxidation processes

Textile and food industries produce toxic or harmfull dye-containing wastewaters that should be treated for safely discharge. The electro-coagulation (EC) and the electro-oxidation (EO) methods for removal of dyes from wastewaters are being investigated nowadays by researchers. In this study, the Indigo Carmine, a textile and food coloring agent, removal was investigated by applying the electro-coagulation and the electro-oxidation methods. For this purpose, aluminum electrodes for EC and graphite plates for EO were used. The central composite experimental design was applied as the optimization method for the EC and the EO processes. The optimization parameters were selected as time (10-30 minutes), current density (0.4-2 Ampere/500 mL) and concentration (50-250 mg/L), natural pH (5.78-6.90) and room temperature (20-25 °C). The EO process was determined to be effective than the EC process. Statistically important parameters were concentration and time-current density interaction for the EC, but all the parameters were statistically unimportant for the EO. Dye removal percentages by the EC were calculated between 82.75% and 98.38%, and dye removal percentages by the EO were calculated between 46.88% and 100% for the determined experimental matrix. Electrical consumptions were almost equal for the EO and the EO prosesses. A column ion exchange process (Selion SBA 2000 resin) was applied to the dye residue after the EO treatment. From the oxidation reduction measurements, the treated solutions were determined as dischargeable.

Evaluation of optimized conditions for the adsorption of malachite green by SnO2-modified sugarcane bagasse biochar nanocomposites.

This work deals with the synthesis of SnO2-modified sugarcane bagasse biochar (SnO2-SBB) nanocomposites using an impregnation method. XRD, FTIR, SEM, and EDX analyses were used to characterize the produced nanocomposites. Several factors influencing the removal of malachite green from wastewater via the adsorption process were explored to maximize the effectiveness of this process. These factors included the different doses of nanocomposites, pH, temperature, contact time, etc. Studies on batch adsorption were conducted to examine the impact of operational parameters, such as contact time (5 to 30 minutes), adsorbent dosage (5 to 40 mg), pH (2 to 10), and temperature (303, 323, and 353 K), on the percentage of MG dye removal. The adsorption kinetics of MG dye over SnO2-SBB nanocomposites were evaluated with the aid of the Langmuir adsorption isotherm, which provided a good fit (R 2 = 0.99) for pseudo-second-order kinetics. The thermodynamic parameters revealed spontaneous and exothermic adsorption of MG dye over SnO2-SBB nanocomposites. A maximum adsorption capacity (q max) of 52.64 ± 0.03 for 0.3 SnO2-SBB and 73.86 ± 0.05 for 0.5 SnO2-SBB nanocomposites was observed. The newly synthesized SnO2-SBB nanocomposites showed negative zeta potential, which facilitated the adsorption of hydrated cationic dye molecules due to the electrostatic force of attraction.

Efficient removal of Rhodamine-B dye using sulfonated/un-sulfonated three-dimensional mesoporous carbon nitride prepared from KIT-6 template: kinetics, modelling, thermodynamic analysis

Mesoporous carbon nitride (MCN-K) was prepared using mesoporous KIT-6 material as a template and ethylenediamine and carbon tetrachloride as N and C sources, respectively. The synthesized MCN-K was treated with sulfuric acid under different experimental conditions, thus obtaining sulfonated MCN-KS adsorbents. The effects of initial solution pH, initial dye concentration, adsorbent amount, and temperature on Rhodamine-B (Rh-B) dye removal were investigated. The XRD, FT-IR, and N2 adsorption–desorption analyses confirmed that the mesoporous carbon nitride structure was successfully synthesized. The high nitrogen content (C/N molar ratio: 4.0) of the MCN-K sample was confirmed by (carbon, hydrogen, nitrogen and sulfur) CHNS elemental analysis. The XPS analysis was used to characterize the chemical states of the C, N and S atoms in the MCN-K and MCN-KS sorbents. It was found that there was not much difference between the removal percentages (93.13–89.92%) obtained in the pH range (4–12) studied. This result was attributed to the zwitter-ion form of Rh-B. The exothermic nature of the adsorption process of Rh-B on the MCN-K sorbent was determined by adsorption experiments performed at different temperatures. Adsorption capacities obtained from the Langmuir model were 185.2–104.2 mg/g in the studied temperature range. The kinetic behavior of the adsorption process was explained by the pseudo-second-order kinetic model in terms of both correlation coefficients (R2 > 0.91) and qe (35.59–190.26 mg/g) values. When the percentages of dye removal of the un-sulfonated and sulfonated samples were compared, it was found that sulfonation increased the adsorption rate considerably but did not contribute positively to the dye removal percentage.

A statistical optimization for almost-complete methylene blue biosorption by Gracilariabursa-pastoris

In this study, the dried biomass of four marine algae, namely Porphyra sp., Gracilaria bursa-pastoris, Undaria pinnatifida and Laminaria sp., were screened for their ability to remove methylene blue (MB) dye from aqueous solutions. Statistical approaches of the Plackett-Burman Design (PBD) and Box-Behnken Design (BBD) were applied to optimize different environmental conditions in order to achieve the maximum MB removal percentage by Gracilaria bursa-pastoris. The biosorbent was characterized before and after adsorption process using FTIR, XRD and SEM analysis. Additionally, isotherms, kinetics and thermodynamics studies were conducted to investigate the adsorption behavior of the adsorbent. The results showed that Gracilaria bursa-pastoris achieved the highest dye removal efficiency (98.5 %) compared to 96.5 %, 93.5 % and 93.9 % for Undaria pinnatifida, Porphyra sp. and Laminaria sp., respectively. PBD analysis revealed that the agitation speed, pH, and biomass dose were found to be the significant parameters affecting MB removal onto Gracilaria dried biomass. According to the BBD results, the maximum dye removal percentage (99.68 %) was obtained at agitation speed of 132 rpm, pH 7 and biomass dose of 7.5 g/L. FTIR, XRD and SEM analysis demonstrated the participation of several functional groups in the adsorption process and changes in the cell surface morphology of the adsorbent following the dye adsorption. The adsorption isotherms showed better fit to Freundlich model (R2 = 0.9891) than the Langmuir, Temkin, and Dubinin-Radushkevich models. The adsorption kinetics were best described by the pseudo-second-order model (R2 = 0.9999), suggesting the chemical interactions between dye ions and the algal biomass. The thermodynamic parameters indicated that the adsorption of MB onto Gracilaria dried biomass was spontaneous, feasible, endothermic and random. These results indicate that dried biomass of Gracilaria bursa-pastoris is an attractive, environmentally friendly, cheap and effective agent for MB dye removal from environmental discharges.

Postindustrial Jute Waste as a Support for Nano-Carbon Nitride Photocatalyst: Influence of Chemical Pretreatment.

Non-woven jute (NWJ) produced from carpet industry waste was oxidized by H2O2 or alkali-treated by NaOH and compared with water-washed samples. Changes in the structure of the NWJ, tracked by X-ray diffraction (XRD), showed that both chemical treatments disrupt hydrogen bond networks between cellulose Iβ chains of the NWJ fibers. Thereafter, nano-carbon nitride (nCN) was impregnated, using a layer-by-layer technique, onto water-washed jute samples (nCN-Jw), NaOH-treated samples (nCN-Ja) and-H2O2 treated samples (nCN-Jo). Analysis of the Fourier transform infrared spectroscopy (FTIR) spectra of the impregnated samples revealed that nCN anchors to the water-washed NWJ surface through hemicellulose and secondary hydroxyl groups of the cellulose. In the case of chemically treated samples, nCN is preferentially bonded to the hydroxymethyl groups of cellulose. The stability and reusability of prepared nCN-jute (nCN-J) samples were assessed by tracking the photocatalytic degradation of Acid Orange 7 (AO7) dye under simulated solar light irradiation. Results from up to ten consecutive photocatalytic cycles demonstrated varying degrees of effectiveness across different samples. nCN-Jo and nCN-Ja samples exhibited declining effectiveness over cycles, attributed to bond instability between nCN and jute. In contrast, the nCN-Jw sample consistently maintained high degradation rates over ten cycles, with a dye removal percentage constantly above 90%.

Synthesis of nano calcium silicates from waste calcite and aragonite phases for efficient adsorptive removal of industrial organic pollutants

The present study focuses on the adsorption efficacy of solid-state synthesized calcium silicate for removing congo red dye. Three different sources were used as calcium precursors; one was calcium carbonate, and the other two were natural waste sources, aragonite (P. globosa) and calcite (Eggshells). Structural analysis and functional groups of the samples were carried out by X-ray diffractometer (XRD), and a Fourier Transform Infrared Spectrometer (FTIR). Various well-known models/equations models such as the Liner Straight Line method of Scherrer’s equation (LSLMSE), Sahadat-Scherrer Model (SSM), Monshi-Scherrer model (MSM), Williamson-Hall model (WHM), Size-Strain plot method (SSP), and Halder-Wagner Model (HWM) were applied to compute the crystallite size of the synthesized calcium silicates; the estimated crystallite size range was 8–77 nm. The adsorption efficacy of the synthesized E-CaSiO3, S-CaSiO3, and C-CaSiO3 was assessed under various provisos for eradicating Congo red dye from wastewater. Computed results revealed that the dye removal percentages were approximately 100 % at 120 min and 200 rpm for 0.2 g E-CaSiO3. The point of zero charge evaluation showed that the pH of the adsorbents during maximum dye removal was 7 and was less than the value of pHpzc. Thermodynamics studies confirmed that the adsorption process was spontaneous. The method of adsorption of dye by the adsorbent was more clearly comprehended by Langmuir, Freundlich, and Temkin adsorption isotherm. 151.28 mg/g was the maximum adsorption capacity for S- CaSiO3 depending on the Langmuir isotherm model’s linear form (R2 = 0.924).

Surfactant-modified coconut coir powder (SMCCP) as a low-cost adsorbent for the treatment of dye-contaminated wastewater: parameters and adsorption mechanism.

The dye-contaminated wastewater discharged from various industries such as dye manufacturing, paint, textile, paper, and cosmetic is a prime source of surface water pollution having serious detrimental effects on both the environment and human beings. These hazardous dyes when exposed to water obstruct the penetration of sunlight into the water and thus restrain aquatic plants from generating photosynthetic compounds. Moreover, some dyes are potential cancer-causing and also negatively impact the human nervous and respiratory systems. In this current study, modification of coconut coir powder (CCP) was carried out through cationic surfactant treatment and was successively utilized as the adsorbent for decoloring anionic dye (acid blue 185 (AB 185)) containing waste stream. Further, a comparative investigation of the dye removal efficiency of raw CCP and surfactant-modified coconut coir powder (SMCCP) as the adsorbent was studied. On surfactant treatment, using a very minimal SMCCP dosage of 8.3g/L, a very high percentage dye removal of 98.4% is possible, whereas with raw CCP, even after using a higher dosage of 14g/L, only 70.1% dye removal can be achieved. Characterization of SMCCP adsorbent was done by Fourier transform infrared, thermogravimetric, X-ray, and scanning electron microscope analyses. Furthermore, the optimization of critical operating parameters was investigated for the effective adsorption of AB 185 dye in batch mode. The adsorption of AB 185 onto SMCCP was a thermodynamically spontaneous endothermic process, following the Langmuir isotherm and pseudo-second-order kinetic model. Moreover, regeneration of exhausted SMCCP by 0.1 (M) NaOH was achieved with a satisfactorily high recovery of 97% in the first cycle. Subsequently, SMCCP can be successfully reutilized for five consecutive cycles with a loss of 17.6% in the total adsorption capacity. With all such advantages, the present study delivers a new paradigm to utilize the novel adsorbent SMCCP as a promising eco-friendly adsorbent aided by its advantage of regeneration and reusability for the treatment of dye-contaminated wastewater.

UiO-66-NDC (1,4-naphthalenedicarboxylic acid): A versatile metal-organic framework-based catalyst for photocatalytic degradation of dye chemicals

Metal-organic frameworks (MOFs) have received significant attention for their use as photocatalysts and photocatalyst supports. These materials have several benefits, including stability, catalyst reusability, tunability, and the capacity for post-reaction separation. Here, the potential applications of UiO-66-NDC as a photocatalyst for the degradation of reactive orange 16 (RO16), methyl orange (MO), and rhodamine B (RhB) were investigated. UiO-66-NDC was chosen for photocatalytic dye degradation due to its large surface area, adjustable characteristics, stability, effective light absorption, capacity for charge separation, and adaptability in design. UiO-66-NDC was synthesized the solvothermal process and its solid-state structure was characterized by solid-state methods, including UV-DRS, FTIR, zeta potential, PXRD and SEM measurements. The photocatalytic studies were performed by subjecting dye solutions with certain concentrations to UVA light irradiation in the presence of UiO-66-NDC. UV–Vis. spectroscopy was used to monitor the degradation process, which made it possible to calculate the degradation rate constants and the percentage of dye removal. The removal efficiency of adsorption, which was also examined, was at a minimum (17 % for RO16, 48 % for MO, and 25 % for RhB). The degradation of the dyes by UiO-66-NDC showed excellent photocatalytic activity, with degradation rates for RO16, MO, and RhB of 91 %, 93 %, and 81 %, respectively (300 mg/L catalyt; 20 ppm dye conc.). It was determined that the optimal concentration of catalyst was 300 mg/L. The reusability of UiO-66-NDC was successfully demonstrated through five successive cycles. The •OH radical was identified as the active species in photocatalysis. It was possible to remove 97 % of RO16, 99 % of MO, and 95 % of RhB at a high starting dye concentration (15 mg/L).

Efficient degradation of methyl red dye from the aqueous solution by individual bacterial and their consortium in a sugarcane bagasse waste-based media

Dye is one of the major pollutions around the whole world which have adverse effects on the environment and human beings. There is a requirement for an efficient, reliable, sustainable, and eco-friendly approach to the removal of dyes. In the present research, three individual bacterial strains Enterobacter aerogenes (MBX6), Klebsiella pneumoniae (MBC34), and Micrococcus luteus (MBC23) and their consortium was used to remove Methyl Red (MR) dye. The dye removal was observed at different initial concentrations of dye, nutrient media, additives in the nutrient media and sugarcane bagasse extract as a bacterial growth medium. The outcomes of the study showed that the bacterial consortium exhibits better removal efficiencies (63.6%) than individual bacterial strains and the dye removal percentage (75.19%) enhanced with increasing concentration of sucrose (3%) which was used as media additive. The addition of the sugar in nutrient medium resulted in more effective dye removal. The maximum removal of MR dye (98.6%) was achieved when the consortium was grown in a media containing pure sugarcane bagasse extract. The use of sugarcane bagasse extract (agricultural waste product) as a novel growth medium for the cultivation of bacteria possessing dye removal capabilities can offer a sustainable and cost-effective solution for industrial wastewater treatment.

Bacteriogenic synthesis of morphologically diverse silver nanoparticles and their assessment for methyl orange dye removal and antimicrobial activity.

Nanotechnology and nanoparticles have gained massive attention in the scientific community in recent years due to their valuable properties. Among various AgNPs synthesis methods, microbial approaches offer distinct advantages in terms of cost-effectiveness, biocompatibility, and eco-friendliness. In the present research work, investigators have synthesized three different types of silver nanoparticles (AgNPs), namely AgNPs-K, AgNPs-M, and AgNPs-E, by using Klebsiella pneumoniae (MBC34), Micrococcus luteus (MBC23), and Enterobacter aerogenes (MBX6), respectively. The morphological, chemical, and elemental features of the synthesized AgNPs were analyzed by using UV-Vis spectroscopy (UV-Vis), Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy-dispersive spectroscopy (EDX). UV-Vis absorbance peaks were obtained at 475, 428, and 503 nm for AgNPs-K, AgNPs-M, and AgNPs-E, respectively. The XRD analysis confirmed the crystalline nature of the synthesized AgNPs, having peaks at 26.2°, 32.1°, and 47.2°. At the same time, the FTIR showed bands at 599, 963, 1,693, 2,299, 2,891, and 3,780 cm-1 for all the types of AgNPs indicating the presence of bacterial biomolecules with the developed AgNPs. The size and morphology of the AgNPs varied from 10 nm to several microns and exhibited spherical to porous sheets-like structures. The percentage of Ag varied from 37.8% (wt.%) to 61.6%, i.e., highest in AgNPs-K and lowest in AgNPs-M. Furthermore, the synthesized AgNPs exhibited potential for environmental remediation, with AgNPs-M exhibiting the highest removal efficiency (19.24% at 120 min) for methyl orange dye in simulated wastewater. Further, all three types of AgNPs were evaluated for the removal of methyl orange dye from the simulated wastewater, where the highest dye removal percentage was 19.24% at 120 min by AgNPs-M. Antibacterial potential of the synthesized AgNPs assessment against both Gram-positive (GPB) Bacillus subtilis (MBC23), B. cereus (MBC24), and Gram-negative bacteria Enterococcus faecalis (MBP13) revealed promising results, with AgNPs-M, exhibiting the largest zone of inhibition (12 mm) against GPB B. megaterium. Such investigation exhibits the potential of the bacteria for the synthesis of AgNPs with diverse morphology and potential applications in environmental remediation and antibacterial therapy-based synthesis of AgNPs.

A Sustainable and Cost‐Effective Bioadsorbent for the Removal of Allura Red from Contaminated Water

AbstractFood 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.

Utilization of Eco‐friendly Copper Oxide Nanoparticles and Iron Oxide Nanorods in Dye Removal from Real Textile Industry Effluent

AbstractTextile industry wastewater contaminated with dye effluents poses a significant environmental challenge. Numerous nanoparticles are used as adsorbents to treat similarly stimulated wastewater, but particularly nanomaterials synthesized through green methods have gained prominence. To assess their practical applicability in addressing real‐world textile wastewater pollution, studies on dye removal from authentic textile industrial effluents are recommended. As a result, a study focused on the removal of dye from real textile industrial effluent is conducted, and biosynthesized copper oxide nanoparticles and iron oxide nanorods are chosen as adsorbents. The investigation scrutinized the influence of adsorbent dosage, adsorbent‐adsorbate contact time, and wastewater pH on the percentage of dye adsorption. These findings indicate that increasing the adsorbent dosage and contact time leads to a higher percentage of dye removal. Notably, copper oxide nanoparticles exhibit superior dye removal efficiency at pH levels 5 and 7, outperforming the maximum dye removal efficiency of iron oxide nanorods at pH 12. The study achieved an impressive process efficiency of 95.24% for copper oxide nanoparticles and 62.5% for iron oxide nanorods. Response surface methodology (RSM) is employed for statistical data analysis and optimization of dye removal process parameters to maximize efficiency. Overall, the results demonstrate that biosynthesized nanomaterials offer a promising and effective solution for removing dyes from textile industrial wastewater.

Integrating biosorption and machine learning for efficient remazol red removal by algae-bacteria co-culture and comparative analysis of predicted models

This research investigates into the efficacy of algae and algae-bacteria symbiosis (ABS) in efficiently decolorizing Remazol Red 5B, a prevalent dye pollutant. The investigation encompasses an exploration of the biosorption isotherm and kinetics governing the dye removal process. Additionally, various machine learning models are employed to predict the efficiency of dye removal within a co-culture system. The results demonstrate that both Desmodesmus abundans and a composite of Desmodesmus abundans and Rhodococcus pyridinivorans exhibit significant dye removal percentages of 75 ± 1% and 78 ± 1%, respectively, after 40 min. The biosorption isotherm analysis reveals a significant interaction between the adsorbate and the biosorbent, and it indicates that the Temkin model best matches the experimental data. Moreover, the Langmuir model indicates a relatively high biosorption capacity, further highlighting the potential of the algae-bacteria composite as an efficient adsorbent. Decision Trees, Random Forest, Support Vector Regression, and Artificial Neural Networks are evaluated for predicting dye removal efficiency. The Random Forest model emerges as the most accurate, exhibiting an R2 value of 0.98, while Support Vector Regression and Artificial Neural Networks also demonstrate robust predictive capabilities. This study contributes to the advancement of sustainable dye removal strategies and encourages future exploration of hybrid approaches to further enhance predictive accuracy and efficiency in wastewater treatment processes.