Remazol Brilliant Blue R Research Articles

Investigation of Remazol Brilliant Blue R removal in batch and fixed bed column reactor systems by MnOx: Non-linear isotherm and kinetic modelling

Investigation of Remazol Brilliant Blue R removal in batch and fixed bed column reactor systems by MnOx: Non-linear isotherm and kinetic modelling

Isolation of marine-derived filamentous fungi and their potential application for bioremediation process.

We evaluated the bioremediation potential of petroleum-derived compounds using fungal strains isolated from marine samples collected on the coast of the states of Paraná, Brazil. About 75 isolated filamentous fungi were subjected to assays including decolorization of the synthetic dye Remazol Brilliant Blue R (RBBR), tolerance to diesel oil, production of bioemulsifying and degradation of pyrene. Nine isolates could decolorize RBBR between 3.4% and 88.16%. Ten were able to tolerate diesel oil and/or pyrene. One isolate was able to produce compounds with emulsifying properties. Three strains, Trichoderma sp. FM14 (Penicillium spp. FM02 and FM16, and FM14) were able to degrade pyrene between 33.0 and 42.4%, after 8 days. The results of the present work encourage future studies to optimize enzymatic conditions using isolates with biotechnological potential in bioremediation studies of marine environments contaminated with industrial pollutants including hydrocarbons derived from petroleum such as diesel oil and PAHs and synthetic dyes.

Dependence of photocatalytic efficiency of titania-carbon nanotube nanocomposites on optoelectrical properties and colloidal stability

The correlation of photocatalytic efficiency of titania–amorphous (nitrogen doped) carbon nanotubes (TiO2–a(N)CNT) nanocomposites with colloidal and optoelectrical properties of the photocatalysts was investigated. TiO2–aNCNT and TiO2–aCNT exhibited narrow zeta potential variation, high polydispersity index, and large agglomerate size across the pH range 1–8. Despite the poor colloidal stability, TiO2–aNCNT exhibited superior degradation for high molecular weight reactive dyes, RR 120 and Remazol brilliant blue (RBB) with 55 mg.L−1 of RR 120 mineralized under solar irradiation. The photocatalytic performance for TiO2–aNCNT and TiO2–aCNT correlated with the respective energy band gaps 3.01 and 3.14 eV, Ubarch tailing energies. Cyclic voltammetry showed a narrow peak-to-peak separation (ΔEp) of 200.7 V (vs Ag/AgCl) for TiO2–aNCNT thus confirming enhanced electron transfer kinetics. Electron impedance spectroscopy confirmed low charge transfer resistance for TiO2–aNCNT. Herein it is demonstrated that optoelectrical properties are superior in driving photocatalytic reactions.

Anti-biofouling membrane coated with polyvinyl alcohol/sodium carboxymethylcellulose/tannic acid hydrogel for efficient dye/salt separation

Biofouling is the most severe challenge for separation membranes. In this study, a metal-organic framework (MOF)-based mixed-matrix membranes (MMMs) with polyvinyl alcohol (PVA)/sodium carboxymethylcellulose (CMC)/tannic acid (TA) hydrogel coating exhibited a comprehensive anti-biofouling property and high efficient for dye/salt separation. For the hydrogel layer, ethanol inhibited the cross-linking of the hydrogen bond between the PVA, CMC and TA, forming a uniform “hydrogel paint” applied to the membrane surface using the coating method. Subsequently, the hydrogen bond was re-established by evaporating the ethanol. The hydrogel coating could form a dense hydrated layer, endowing the membrane with excellent anti-fouling properties, including oil, proteins, and bacteria. For the MOF-based MMMs layer, the skeleton structure of polyvinylidene fluoride anchored the bimetallic MOF crystals to mitigate the phenomenon of “trade-off”. The hydrogel-coated MOF-based MMMs showed excellent properties, such as the water permeability was ~200 Lm−2 h−1, the rejection for Reactive Blue 19 was 100 %, the rejection for NaCl was 10.9 %, and it showed excellent stability for long-term service. Furthermore, the hydrogel-coated MOF-based MMMs presented a significant inhibitory effect on surface bacteria growth. In brief, this paper provided a new insight into preparing hydrogel-coated MOF-based MMMs, which had potential applications in separating dye/salt.

Photocatalytic degradation of reactive blue-4 dye from wastewater with α-Bi2O3 microrods under natural sunlight

Photocatalytic degradation of reactive blue-4 dye from wastewater with α-Bi2O3 microrods under natural sunlight

Toxicological assessment of reactive blue 19 dye aqueous solutions under UV-LED light

Abstract The dye-contaminated industrial effluent causes serious health issues when it gets mixed with underground water without primary treatment. The current project was designed to treat reactive blue-19 dye aqueous solutions in the presence of hydrogen peroxide (H2O2) and titanium dioxide (TiO2) under UV-LED light. The characterization of the photocatalyst was carried out via X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) for structure, purity, and surface study. The effect of various factors such as pH, TiO2 dose, UV-LED light exposure time, H2O2, and dye concentration, on the degradation rate and cytotoxicity reduction was evaluated and optimized through the Response Surface Methodology (RSM). The maximum degradation of dye solution and chemical oxygen demand (COD) reduction was achieved at 98.81 and 86.22 %, respectively for 50 ppm solution, using UV-LED/H2O2(3 %)/TiO2(6 g/L) hybrid process. The toxicity evaluation through the Allium cepa test demonstrated a 62.40, 65.2, and 56.97 % increase in root length (RL), root count (RC), and mitotic index (MI), respectively, following treatment with the UV-LED/H₂O₂/TiO₂ combined process for 150 min. The hemolytic and brine shrimp tests revealed a reduction in toxicity up to 92.18 and 84.08 %, respectively, after applying the same treatment. Additionally, the Ames test indicated up to 80.94 % reduction in mutagenicity for TA98 and an 84.04 % reduction for TA100 strain when dye samples were treated with UV-LED light in the presence of H₂O₂ and TiO₂ for 150 min. The findings suggested that UV-LED light in conjunction with H2O2 and TiO2 can be a useful tool for the degradation and detoxification of toxic pollutants found in textile wastewater.

Reactive Blue MEBF 222 dye and textile wastewater treatment using metal-doped cobalt and nickel perovskites by batch and column adsorption process.

Water contamination is a serious issue that has an impact on the whole globe. In the current work, adsorption technique was used to remove synthetic Reactive Blue MEBF 222 textile dye utilizing Cd-doped Co (Co1-xCd1.5xFeO3), Zn-doped Co (Co1-xZn1.5xFeO3), Cr-doped Co (Co1-xCr1.5xFeO3), Zn-doped Ni (Ni1-xZn1.5xFeO3), and Cr-doped Ni (Ni1-xCr1.5xFeO3) perovskites, synthesized by sol-gel auto-combustion approach. According to the findings of batch adsorption studies, maximum adsorption was observed at pH 3 (45.62mg/g), 0.01g/50ml dosage (36.67mg/g), 60min (14.31mg/g), 100ppm dye concentration (47.41mg/g), and 308K (35.96mg/g) for Co1-xCd1.5xFeO3; at 3 pH (42.94mg/g), 0.01g/50ml dosage (35.33mg/g), 60min (12.88mg/g), 100ppm dye concentration (40.52mg/g), and 308K (31.31mg/g) for Co1-xZn1.5xFeO3; at 2 pH (38.82mg/g), 0.01g/50ml dosage (32.20mg/g), 60min (11.98mg/g), 100ppm dye concentration (33.54mg/g), and 308K (29.34mg/g) for Co1-xCr1.5xFeO3; at 2 pH (34.97mg/g), 0.01g/50ml dosage (30.41mg/g), 60min (10.46mg/g), 100ppm dye concentration (27.19mg/g), and 308K (26.12mg/g) for Ni1-xZn1.5xFeO3; and at 2 pH (31.22mg/g), 0.01g/50ml dosage (25.04mg/g), 60min (9.48mg/g), 100ppm dye concentration (21.73mg/g), and 308K (23.61mg/g) for Ni1-xCr1.5xFeO3. The pseudo-second-order model showed good fitness for adsorption kinetic data. Electrolytes, detergents/surfactants, and heavy metal ions had a substantial impact on the adsorption potential. The column adsorption experiments demonstrated optimal bed height, flow rate, and intake dye concentration to be 3cm, 1.8ml/min, and 70mg/l, respectively, in the column experiment. With an adsorption capacity of 44.1mg/g, reactive blue (RB) 222 dye was able to achieve its maximum adsorption. Detailed desorption of RB 222 dye was also achieved. The novelty of this adsorption method lies in its eco-friendliness, ease of handling, and cost-effectiveness.

Degradation of Remazol Brilliant Blue Dye Using Persulfate Activated by Fe3O4@PDA Nanoparticles: Kinetic Studies, Radical Determination, and Phytotoxicity Test.

In the current research work, an advanced oxidation process was applied to the degradation of Remazol brilliant blue dye (RBBD) using a sulfate radical. Fe3O4@PDA nanoparticles were synthesized using coprecipitation and self-polymerization techniques. Nanoparticle formation was confirmed by XRD, FTIR, FESEM-EDX, VSM, and XPS analyses. The crystalline nature of the material showed that it possessed a spherical shape with an Ms value of 58 emu/g. The elemental composition and binding energy from EDX and XPS analyses showed successful doping. Batch studies were conducted, and experimental studies showed that the optimum condition for degradation of 90 ppm of RBBD was 0.3 g/L of nanomaterial, 20 mM PS at pH 3, achieving 91.35% degradation. The kinetic model suitable for this study was a pseudo-second-order kinetic model with R2 value >0.9. From the radical identification tests, sulfate radicals played a dominant role in degradation, and to confirm it, EPR analysis was conducted using DMPO. A stability test was performed for 5 cycles in which the degradation efficiency was reduced appreciably. From XPS, XRD, and EDX analyses, the elemental composition and oxidation state of the recycled material used in the fifth cycle showed variation in a negligible manner when compared to the fresh catalyst used in the first cycle of the degradation experiment. Intermediate identification was done by GCMS analysis, and it disclosed the formation of aliphatic products from the degradation of RBBD with less toxicity. Phytotoxicity analysis was conducted using green grams for 10 days, and it proved that intermediates formed in the solution were nontoxic to the plants. Additionally, TOC and COD removal % were attained to be 80.021 and 80.903%, respectively, which confirm the mineralization efficacy. Hence, this research work proved the efficient performance of the catalyst for RBBD degradation with less formation of intermediates, and therefore, this technique is most suitable for the reduction of water pollution.

Fabrication of charged and zwitterionic nanofiltration membranes and anti-adhesion analysis using quartz crystal microbalance with dissipation and atomic force microscopy

Three nanofiltration (NF) membranes (positive charge, negative charge and near charge neutrality) were fabricated to investigate the anti-adhesion mechanism. Among them, the NF membrane with positive charge was synthesized through an electrophilic substitution reaction between the amino group of polyethyleneimine (PEI) and the chloromethyl groups of chloromethyl polysulfone (CMPSf) on a supporting polysulfone (PSf)/CMPSf blend membrane. The NF membrane with negative charge was fabricated through polycondensation using 1, 3, 5-benzenetricarbonyl trichloride (TMC) as a reactive monomer on the positive charge NF membrane. Subsequently, the near charge neutral zwitterion NF membrane (ZNF) was prepared by grafting 3-((2-aminoethyl) dimethylammonio) propane-1-sulfonate (sulfobetaine) (ADSS) onto the negative charge NF membrane. The anti-adhesion behaviors of the NF membranes during the dye selective separation were analyzed by Atomic force microscopy (AFM) and quartz crystal microbalance with dissipation (QCM-D). The results demonstrated that the near charge neutral ZNF membrane displayed a higher dyes rejection (>94.4 %) and higher flux recovery rates (>88.1 %) than charged NF membranes. Meanwhile, the near charge neutral ZNF membrane demonstrated the lowest amounts of dye deposition compared with charged NF membranes, such as reactive blue 4 (R4) for 509.9 ng/cm2, basic blue 24 (BB 24) for 269.0 ng/cm2, rhodamine B (RB) for 197.4 ng/cm2). Additionally, the near charge neutral ZNF membrane with the thicker hydration layer (121.7 nm) displayed weaker interaction forces (−4.8 nN to −7.4 nN) with the dyes than the charged membranes (−10.4 nN to −28.6 nN). Finally, an anti-adhesion mechanism involved charged shielding effect and hydration layer formation was proposed. These observations provide comprehensive insights into the anti-adhesion mechanism of ZNF membrane.

Biodegradation and Detoxification of Some Dyes by Crude Lignin Peroxidase Complex Produced by Escherichia coli Accession No: LR0250096.1 and Pseudomonas aeruginosa Accession No: CP031449.2

Synthetic and untreated dyes discharged in wastewater effluents are a threat to an ecosystem. This study investigated dye degradation and detoxification efficiency of crude lignin peroxidase separately obtained from the cultures of Escherichia coli (LR0250096.1) and Pseudomonas aeruginosa (CP031449.2). The ability of the crude lignin peroxidase to degrade Malachite Green (MG), Remazol Brilliant Blue R (RBBR), Congo Red (CR), and Azure B (AZ) was evaluated at different operating conditions (enzyme, dye, and hydrogen peroxide concentrations; pH; temperature; and contact time). The ability of the degraded dyes to support the growth of bacteria was also investigated. The observed optimum operating conditions for lignin peroxidase extracts of the Escherichia coli on AZ were 20 mg/mL enzyme concentration, 50 mg/L dye, pH 7.0, temperature 50 °C, and 1.5 mM hydrogen peroxide within 20–50 min of incubation time and on MG were 20 mg/mL, 50 mg/L, 9.0, 30 °C, 0.1 mM, and 20 min, respectively. The enzyme extract from Pseudomonas aeruginosa on AZ demonstrated optimum operation conditions of 20 mg/mL, 50 mg/L, pH 9.0, 40 °C, 1.5 mM, and 50 min, respectively and on MG, they were 20 mg/mL, 50 mg/L, 6.0, 30 °C, 1.0 mM, and 20 min, respectively). The prepared enzyme showed an appreciable degradative effect on CR and RBBR compared with commercial lignin peroxidase. The degraded dyes were able to support the growth of two Gram-positive (Bacillus cereus and Staphylococcus aureus), and two Gram-negative (Proteus mirabilis and Escherichia coli) bacteria, indicating the efficiency and the potential use of the enzyme complexes in the clean-up of industrial dyes’ waste.

Sorption interactions and behavior of bentonite-lignite based composite toward immobilization of dyes, pharmaceuticals and surfactants

The presence of dyes, pharmaceuticals, and surfactants in the environment results from extensive industrial and societal progress, prompting the need to explore efficient and safe techniques for their removal. Common concentrations in wastewater can range from micrograms to milligrams per liter, which is concerning due to their persistence and potential health impacts. The sustainable approach of using a nonconventional, eco-friendly mineral-organic composite might address this environmental issue. This study focuses on utilizing a composite of bentonite (BEN) and lignite (LIG) as a sorbent for dyes: Rhodamine b (RB), Remazol brilliant blue r (RBBR), pharmaceuticals: ibuprofen (IB), sulfamethoxazole (STX), and surfactant: sodium dodecylbenzenesulfonate (SDBS) from both synthetic solutions and real wastewater. BEN was chosen for its high cation exchange capacity, while LIG was selected for its ability to adsorb both anionic and cationic formsdiverse functional groups. The composite with BEN to LIG ratio of 20:80 (BL 20:80) demonstrated superior sorption capacity. The adsorption performance is quantified, showing removal efficiencies of up to 18.9 mg RBBR/g, 22.8 mg RB/g, 1.77 mg IB/g, 1.47 mg STX/g, and 4.7 mg SDBS/g. Sorption efficiency is influenced by factors such as the initial sorbate concentration, the pH of the solution, the form of sorbates, and the adsorbents textural, physicochemical (point of zero charge pHZPC), ion-exchange capacity, hydrophobicity/hydrophilicity) properties. Generally, STX and RB is favored by slightly acidic conditions (pH 4–7), while RBBR and IB are favored by alkaline conditions (pH > 7). The complex physical sorption mechanism includes hydrogen bonding, electrostatic and dispersion forces, as well as π-π interactions. Nuclear magnetic resonance spectroscopy (NMR) suggests that a significant portion of the hydrogen bonding interactions contributes to RB adsorption. The sorption results indicate that the specially-designed mineral composite can effectively remove various chemically distinct organic compounds from real wastewater. Subsequent investigations will focus on the granulated BL 20:80 composite and its applicability in dynamic column systems. This aligns with the ongoing development of purification technologies.

ZnO nanostructures grown from spent batteries: Ambient catalytic aspects and novel mechanistic insights

The present work includes a facile and economic microwave assisted hydrothermal synthesis of Zinc Oxide (ZnO), Diethylene Triamine Pentaacetic Acid (DTPA) stabilized Zinc Oxide (ZD) and DTPA stabilized Silver doped Zinc Oxide (ZAD) nanostructures using Zn from spent alkaline batteries. The synthesised nanostructures were well characterised using electronic, vibrational and X-Ray spectroscopic techniques as well as thermal and microscopic techniques revealing the successful stabilisation of DTPA in ZD and doping of Ag in ZAD. The Fourier Transform Infrared Spectroscopy (FTIR) spectra showed peaks characteristic to the presence of ZnO in the fingerprint region and those to the presence of DTPA. The X-Ray Diffraction Spectroscopy (XRD) pattern of ZnO, ZD and ZAD indicated the hexagonal wurtzite structure of ZnO and face centred cubic metallic Ag in ZAD. The Transmission Electron Microscopy (TEM) images revealed rod shaped morphology for ZnO and spherical morphologies for ZD and ZAD. The nanostructures proved to be efficient catalysts to achieve 100 % degradation of Malachite Green, Crystal Violet and Reactive Blue-21 and their binary mixtures under ambient conditions in presence of Hydrogen peroxide (H2O2). ZAD exhibited relatively rapid degradation with rate constants 0.754 min−1, 0.187 min−1 and 0.0150 min−1 for MG, CV, and RB-21 respectively as well as 99 % reduction in Chemical Oxygen Demand (COD) value of the dye solutions. Scavenging studies and Electron Paramagnetic Resonance (EPR) studies using different spin trapping agents revealed the involvement of singlet oxygen species, hydroxyl radicals (OH.) and superoxide radicals (O2.-) in the degradation process. This work aligns with Sustainable Development Goals 6, 12 and 13.

Simultaneous removal of acidic dyes on binary mixture from aqueous solutions by magnetic basic resin

AbstractThis study, magnetic basic resin (MBR) was synthesized by radical polymerization and modification. Its functional groups, surface morphology, elemental composition, and magnetic value were determined by ATR‐FTIR FE‐ESEM, EDX, and VSM techniques. Subsequently, the usability of MBR as an adsorbent in the simultaneous adsorption of Tartrazine (Tart) and Reactive Blue‐4 (RB4) dye binary mixtures were examined. Maximum adsorption for both dyes, (170 mg/g for Tart and 184 mg/g for RB4), was observed under acidic conditions at a pH range of 1.5–2. It was determined that the adsorption of both dyes onto MBR occurred in a monolayer, and the saturation time was 90 min for Tart and 60 min for RB4. The adsorption of both dyes fitted the pseudo‐second‐order kinetic model. It was also concluded that intra‐particle diffusion was effective. Based on the thermodynamic parameters, it was concluded that the adsorption proceeded spontaneously and endothermically, additionally, the calculated E values led to the conclusion that electrostatic interactions dominated the adsorption of Tart and RB4. The MBR exhibited a notable affinity for Tart and RB4, even within a dense matrix containing both anions and cations. Furthermore, it maintained this high removal affinity across four consecutive uses, involving adsorption and desorption processes.

Decolorization of anthraquinone dye (Reactive Blue 4) in the microbial fuel cell by Baker’s yeast: process optimization

The release of anthraquinone dyes in aquatic sources has a huge impact on the environment because of their turbidity, toxicity, mutagenicity, and carcinogenicity effects. Microbial Fuel Cell (MFC) is a hopeful technology for the decolorization of dyes. The goal of the present study is the decolorization of Reactive Blue 4 (RB4) as an anthraquinone dye from an aqueous solution by Baker’s yeast in MFC. The selection of three parameters (dye concentration, glucose concentration, and airflow rate) and optimization of dye decolorization and chemical oxygen demand (COD) removal are performed using response surface methodology (RSM). The results demonstrated that the interaction between parameters does not affect the dye decolorization efficiency, whereas the interaction between dye concentration and glucose concentration was found to be significant for COD removal. Accordingly, the optimum conditions for maximum dye decolorization and COD removal were obtained at a dye concentration of 50 mgL−1, a glucose concentration of 1 gL−1, and an airflow rate of 10 mLmin−1.

Amphoteric chitosan derivatives for the removal of basic and reactive dyes from aqueous solutions

The present study describes the use of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide and 2-acrylamido-2-methyl-1-propanesulfonic acid as grafting agents to chitosan (CS) natural polymer were examined. Two chitosan derivatives were synthesized in this study, and then added in single-component aqueous solutions in order to study the removal of Methylene Blue (MB) and Remazol Brilliant Blue R (RBBR) dyes, by adsorption, in a more innovative way. The characterization of the chitosan derivatives was achieved via X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Adsorption efficiency of the chitosan derivatives was tested at several pH values (2–12) and for adsorbent’s dosage between 10 and 50 mg per 30 mL effluent. The rising of temperature from 25 to 65 °C led to increased adsorption capacity. Equilibrium data were fitted to both the more common Langmuir and Freundlich isotherm models, as well as the Sips isotherm model. Pseudo 1st and 2nd kinetic order equations and a relatively simple phenomenological kinetic model for adsorption kinetics, were studied as well as the thermodynamic parameters were calculated. The adsorption capacity for CS grafted with [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide (CS-SBMA) was 238.1 and 244.5 mg/g for MB and RBBR removal, respectively, at 25 °C, while for CS grafted with 2-acrylamido-2-methyl-1-propanesulfonic acid (CS-AMPS) the adsorption capacity was 219.5 and 203.9 mg/g for MB and RBBR removal, respectively, at 25 °C.

Robust peroxidase from Bacillus mojavensis TH309: Immobilization on walnut shell hydrochar and evaluation of its potential in dye decolorization

Peroxidases have received considerable attention as a cost-effective and environmentally friendly catalyst for bioremediation. Their rapid activity loss under harsh environmental conditions and inability to be used repetitively limit their exploitation in real-world wastewater treatment. First, a peroxidase was produced extracellularly by Bacillus mojavensis TH309 and purified 8.12-fold with a final yield of 47.10 % using Sephadex G-100 superfine resin. The pure peroxidase (BmPer) possessed a relatively low molecular weight of ∼21 kDa and was active against L-DOPA on acrylamide gel after electrophoresis. BmPer was immobilized by adsorption functionalized walnut shell hydrochar (WsH) with 61.99 ± 1.34 % efficiency and 37.07 ± 4.16 % activity loss. BmPer and its immobilized form (WsH-BmPer) exhibited maximum activity at 50 °C and pH 9. WsH-BmPer exhibited 3.23-, 2.37-, 1.65-, and 2.25-fold longer half-life than BmPer at 50, 60, 70, and 80 °C, respectively. Immobilization significantly enhanced the stability of the enzyme under acidic conditions. BmPer and WsH-BmPer showed maximal activity in the presence of 1 % salt and retained more than 85 % of their activity even after pre-incubation with 2.5 M salt for 60 min at 50 °C. Their catalytic efficiency was significantly stimulated by pre-incubation with Triton X-100 (1 mM), Tween20 (1 mM), and Mg2+ (1 and 10 mM). Immobilization strongly reduced the loss of activity caused by inhibitors including Ba2+, Hg2+, and Cu2+. Moreover, both forms of the enzyme were compatible with solvents. The Michaelis constant (Km) values of BmPer and WsH-BmPer were 0.88 and 2.66 mM for 2,4 DCP, respectively. WsH-BmPer peroxidase maintained about 82 % and 85 % of its activity when stored at 4 °C for 30 days and reused for up to 10 cycles, respectively. Furthermore, it decolorized Cibacron red (CR), Poly R-478 (PR), Remazol Brilliant Blue R (RBBR), and Methyl red (MR) dyes by 60.13 %, 91.34 %, 86.41 %, and 50.51 % within 60 min, respectively.

Efficient adsorption removal of anionic dyes by waste PET-derived MIL-101(Cr)

Adsorption can be used as a pollutant removal method to solve the increasingly serious problem of synthetic dye pollution and metal organic framework (MOF) is considered as a novel adsorbent for its unique structure. However, the high cost and high toxicity during the synthesis procedure of MOFs like MIL-101(Cr) limited their potential on the large-scale production and application. In this paper, waste PET plastic was depolymerized to prepare terephthalic acid (TPA) as an organic linker to synthesize MIL-101(Cr). Besides, Hydrofluoric acid (HF) was not added during the synthesis to avoid poisonous pollution. MIL-101(Cr) was applied to the adsorption of anionic dyes reactive red 2 (RR2) and reactive blue 19 (RB19). The batch experiments exhibited kinetic data best fitted the pseudo-first-order model (PFO) with the adsorption capacity of 662.87 (RR2) and 863.67 mg g-1 (RB19). The isotherm adsorption data fitted well with the Freundlich isotherm, indicating formation of multilayer coverage over the surface of MIL-101(Cr). The highest regeneration rate of MIL-101(Cr) at the fourth cycle was 91.18 and 91.44 % after RR2 and RB19 adsorption. X-ray photoelectron spectroscopy (XPS) technique and Fourier Transform Infrared (FTIR) spectroscopy both indicated the possible adsorption mechanism of MIL-101(Cr) toward RR2 and RB19 could be attributed to electrostatic interactions, hydrogen bonding, and the π-π stacking. This work proposed a novel method using waste plastics as raw materials to synthesize eco-friendly pollutant adsorbent, which had an enlightening effect on pollutant treatment.

Eco-Friendly g-C3N4/Carboxymethyl Cellulose/Alginate Composite Hydrogels for Simultaneous Photocatalytic Degradation of Organic Dye Pollutants.

The presented study was focused on the simple, eco-friendly synthesis of composite hydrogels of crosslinked carboxymethyl cellulose (CMC)/alginate (SA) with encapsulated g-C3N4 nanoparticles. The structural, textural, morphological, optical, and mechanical properties were determined using different methods. The encapsulation of g-C3N4 into CMC/SA copolymer resulted in the formation of composite hydrogels with a coherent structure, enhanced porosity, excellent photostability, and good adhesion. The ability of composite hydrogels to eliminate structurally different dyes with the same or opposite charge properties (cationic Methylene Blue and anionic Orange G and Remazol Brilliant Blue R) in both single- and binary-dye systems was examined through adsorption and photocatalytic reactions. The interactions between the dyes and g-C3N4 and the negatively charged CMC/SA copolymers had a notable influence on both the adsorption capacity and photodegradation efficiency of the prepared composites. Scavenger studies and leaching tests were conducted to gain insights into the primary reactive species and to assess the stability and long-term performance of the g-C3N4/CMC/SA beads. The commendable photocatalytic activity and excellent recyclability, coupled with the elimination of costly catalyst separation requirements, render the g-C3N4/CMC/SA composite hydrogels cost-effective and environmentally friendly materials, and strongly support their selection for tackling environmental pollution issues.

Cellophane-Based Membranes for Purification of Aqueous Media from Various Pollutants

The process of nanofiltration purification of water from various organic pollutants was examined. Cellophane film made from cheap natural raw materials was used as a membrane. The model substances targeted for removal were dyes (Safranin O, Orange II, and Remazol Brilliant Blue R, each differing in molecular weight, chemical composition, and charge) and ceftriaxone. The obtained cellophane permeability to water was 0.145 kg/(m2∙h∙atm). Cellophane membranes were found to be effective in retaining dissolved anionic substances containing acid groups. When Orange II and Remazol Brilliant Blue R were removed from the water, the retention coefficients were 97 ± 2 and 99 ± 1%, respectively. For the cationic dye Safranin O, the retention coefficient values were negative, –7 ± 3%. At the same time, ceftriaxone had the retention coefficient of only 41 ± 5%, which can be attributed to a combination of factors, such as its high affinity for cellophane and steric restrictions.

Electrocoagulation treatment for Remazol Brilliant Blue R (Reactive Blue 19) removal of textile dye simulated wastewater using iron-aluminum electrodes

Abstract The presence of non-biodegradable dyes, such as Remazol Brilliant Blue R (Reactive Blue 19), in wastewater poses a significant environmental challenge. This study investigates the application of electrocoagulation using iron-aluminum (Fe-Al) electrodes to efficiently remove Reactive Blue 19 dye from simulated textile dye wastewater. It considers various parameters such as electrode material, current, stirring speed, as well as the influence of sodium chloride acting as a supporting electrolyte to enhance conductivity. Additionally, it evaluates the economic feasibility through electrode consumption analysis. The experimental setup involved a designed reactor with aluminum and iron electrodes arranged at bipolar parallel connection, along with a 30-minute electrocoagulation process conducted at ambient temperature and subsequent filtration of the treated wastewater for UV-VIS analysis. The optimal parameter combination obtained consists of Fe-Al electrode material, a 3 A current, and a 200-rpm stirring speed, achieving 96.87% dye removal. Furthermore, extending the operating time to 60 minutes improved the removal by 99.15%. Under these optimal conditions, the energy consumption measured was 36 kWh/m3. The high dye removal rate obtained shows the effectiveness of this electrocoagulation process in treating Reactive Blue 19 simulated wastewater. A t-test, employed as a hypothesis testing technique with a significance level of 0.05, confirmed the optimal levels of the factors and interactions within the treatment process. A remarkable coefficient of determination of 0.9794 in the dye removal sensitivity analysis signifies a strong goodness of fit, indicating that these three (3) parameters collectively explain how they affect the outcome while accounting for dye removal efficiency variation. These results showed that electrocoagulation is a promising technology for treatment of Reactive Blue 19 dye wastewater.