Adsorption Of Eriochrome Black T Research Articles

Comparative analysis of EBT dye removal using Spartium junceum and derived activated carbon: experimental and DFT insights

ABSTRACT This study explores the use of Spartium junceum biomass (SJ) to create activated carbon (SJAC) through a one-step activation with phosphoric acid. Characterisation of SJ and SJAC was conducted using FTIR spectroscopy, pHpzc measurement, nitrogen adsorption/desorption isotherms, and SEM to analyse their surface chemical groups, morphology, and texture. Results showed that SJAC has a well-developed mesoporous structure, high pore volume, and a significantly enhanced specific surface area (325.759 m2 g−1) compared to raw SJ (1.647 m2 g−1). The adsorptive performance of SJ and SJAC was tested by removing the anionic dye Eriochrome Black T (EBT). Using central composite design under response surface methodology, batch experiments were optimised for factors like pH, adsorbent dosage, initial EBT concentration, and contact time. Optimal conditions were determined using a desirability function. Adsorption data were analysed with various isothermal models, showing that the Freundlich model best described SJ, while the Langmuir model was more suitable for SJAC. SJAC exhibited an exceptional adsorption capacity of 261.36 mg g−1, about five times higher than SJ. Thermodynamic analysis indicated that the adsorption process for both sorbents was spontaneous and endothermic. Density functional theory was used to investigate the adsorption mechanism of EBT on SJ and SJAC, identifying multiple mechanisms such as electrostatic interactions, pore filling, hydrogen bonding, and π-π stacking, with pore filling being the primary mechanism for SJAC. SJAC maintained over 77% EBT adsorption efficiency across four reuse cycles, highlighting its potential for EBT remediation applications.

Optimizing Eriochrome Black T adsorption through In-Situ polymerization of Poly(aniline-co-formaldehyde) on biochar: Multivariate approach using full factorial Design, Box-Behnken, Artificial intelligence, and DFT

Over the past few years, using organic–inorganic composites in wastewater treatment through adsorption has become increasingly widespread. The combination of activated carbon and polyaniline (AC@PANI) has garnered significant interest in these composites. This study introduces a novel type of coating known as poly(aniline-co-formaldehyde) (PAF), which is classified as a copolymer and exhibits crosslinking properties. Compared to polyaniline, PAF forms a three-dimensional network structure, a rapid process for the synthesis of AC@PAF. Moreover, PAF demonstrates a notable enhancement in adsorption capacity for the anionic Eriochrome Black T (EBT) dye. In this study, we coated activated carbon, previously activated using H3PO4 (ACNgG-P), with PANI and PAF. Our findings reveal that the PAF coating exhibits an exceptional adsorption capacity of 700.01 mg/g for EBT, surpassing ACNgG-P and ACNgG-P@PANI.Furthermore, the adsorption of EBT onto the surface of ACNgG-P@PAF was optimized and modeled using artificial intelligence (AI), specifically an artificial neural network (ANN). The ANN was employed to predict and maximize adsorption by analyzing the complex relationships between various parameters. Finally, the Density Functional Theory calculations were used to elucidate the adsorption mechanism by identifying the active sites on the surface of ACNgG-P@PAF and analyzing the molecular structure of EBT.

Removal of Eriochrome black-T from wastewater by utilizing the commercial DF-120 anion exchange membrane

This work describes the batch adsorption of Eriochrome black-T (EBT) an anionic dye onto the DF-120 commercial anion exchange membrane (AEM) from wastewater at 25 °C. The effect membrane dosage, temperature, ionic strength, contact time, pH and initail concentration on EBT adsorption was illustrated. Adsorption capacity (qe) was enhanced from 7.32 to 12.71, 1.77 to 12.71, 6.71 to 12.71, and 16.16 to 17.39 mg/g with membrane dosage (mass), initial concentration, contact time, and ionic strength respectively while decreased from 12.71 to 3.77 and 12.71 to 3.65 mg/g with temperature and pH of medium respectively. Adsorption of EBT was subjected to various adsorption isotherms including Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) models. It was noticed that EBT adsorption obeyed Freundlich isotherm because the value of correlation coefficient (R2 = 0.991) was close to unity. Several kinetics models were utilized to demonstrate EBT adsorption. Results showed that EBT adsorption fitted to pseudo-second order (PSO) model because the value of correlation coefficient (R2 = 0.997) was close to unity. Adsorption thermodynamics study represented that EBT adsorption onto the DF-120 commercial AEM was an exothermic process (ΔH°= −79.78 KJ/mol). In addition, the regeneration of DF-120 commercial AEM was also studied.

The Adsorption of Eriochrome Black T onto the Activated Carbon Produced from Pepper Stalks

The aim of this paper is to present the evaluation of the adsorption of Eriochrome Black T (EBT) on the activated carbon (trH-BS) produced from pepper stalk by activating with 50% phosphoric acid solution (H3PO4) and then by carbonizing at 650 oC for 30 min. in atmosphere of nitrogen (N2) was presented. The isotherm of trH-BS was Type IV, representing micro, meso and macroporous structures. The micropore volume and micropore surface area values of trH-BS were 0.39 cc/g and 1107.294 m2/g, respectively. Also, its meso and macropores had a volume of about 15-17 cc/g and an average surface area of 400 m2/g. The adsorption energy was 18.156 kJ/mol and the BET surface area was 756.257 m2/g. Depending on Langmuir parameters, monolayer capacity was determined as 55,56 mg/g. the enthalpy change was calculated as 30.78 kJ/mol. The structure of trH-BS was clarified structurally and morphologically and the formations like nano rod were seen at Scanning Electron Microscopy (SEM) images. By using trH-BS, the adsorption of EBT from the aqueous medium was investigated using 5 different parameters. As a result, it was found that the adsorbents obtained from pepper stalks are suitable for use in EBT adsorption with a ratio of about 50% under suitable conditions.

Adsorption of anionic and cationic dyes from aqueous solutions on fly ash-based porous geopolymer

<p>Fly ash, solid waste from coal-fired power plant, had been utilized as raw material for porous geopolymer by alkaline activation and addition of hydrogen peroxide (H2O2) blowing agent. Porous geopolymer had higher surface area and total pore volume compared to fly ash and geopolymer without blowing agent, namely 45.511 m2 g-1 and 0.05131 cc g-1, respectively. Porous geopolymer was applied as adsorbent for anionic dyes Eriochrome Black T (EBT) and cationic dyes Methyl Violet (MV) from aqueous solutions. In this paper, factors affecting adsorption process such as adsorbent dosage, pH, time, and initial concentration were studied, in addition to adsorption kinetics and isotherm studies. Adsorbent dosage, time, and initial concentration factors had the same effect on the adsorption process for both EBT and MV dyes. The optimum removal efficiency was obtained at adsorbent dosage of 2 g L-1 and adsorption time of 90 minutes. The increase of the initial concentration of dyes would decrease the removal efficiency. For pH factor, adsorption of EBT dyes was better at pH of 2, while adsorption of MV dyes was better at pH of 10. Both adsorption of EBT and MV dyes by porous geopolymer followed pseudo-second-order kinetics model and Langmuir isotherm model with maximum adsorption capacity of 45.454 mg g-1 and 49.261 mg g-1, respectively.</p>

Mono and binary mixture removal of eriochrome black T and Cr(VI) from water by SiO2/polyaniline composite

The combined uptake of heavy metals and dyes from wastewater discharged by different sectors is a challenging concept. For this reason, this study investigated the uptake of hexavalent chromium Cr(VI) and eriochrome black T (EBT) dye over SiO2/polyaniline composite in a single and binary mixture. The prepared composite was examined by FTIR, XRD, and SEM-EDX to provide evidence of the successful synthesis and the enhanced properties compared to the polyaniline polymer (PAni). In a batch system, various factors affecting the adsorption were studied. Kinetic investigations revealed that Cr(VI) and EBT adsorption in both systems suited the pseudo second order kinetic model. The hybrid Langmuir-Freundlich isotherm correlated with the obtained findings in the mono and binary systems. The prepared composite showed a higher affinity toward Cr(VI), with a monolayer capacity of 285.5 mg g−1, than EBT dye with a capacity of 90.23 mg g−1. However, Cr(VI) capacity decreased to 149 mg g−1 in the binary mixture, indicating the antagonist effect between the adsorbate and the inhibitory impact of EBT dye. However, the EBT adsorption capacity in the mixture was 89.23 mg g−1, which is almost equivalent to the single system. The calculated thermodynamic parameters indicated that Cr(VI) and EBT uptake in the mono and binary systems was endothermic, favorable, and spontaneous, with physical adsorption as the governing mechanism.

Fabrication of nano-biocomposite for the removal of Eriochrome Black T and malachite green from aqueous solution: isotherm and kinetic studies.

The increasing generation of toxic dye wastewater from various enterprises continues to be a serious public health issue and happens to be of environmental concern, posing a significant challenge to existing conventional water treatment facilities. Malachite green (MG) and Eriochrome Black T (EBT) are extremely hazardous and carcinogenic substances; hence it is crucial to remove them from water bodies. A well-known cleaner, more economical, and environmentally friendly treatment method is adsorption. The kind of adsorbent material employed determines how well the treatment procedure works. A physiologically compatible nanocomposite adsorbent (HAP@CT@MNP) was fabricated from laboratory synthesized hydroxyapatite (HAP) and magnetite (MNP) for its application in the wastewater remediation process. The ability of the fabricated nanocomposite to remove the harmful dyes EBT and MG from a simulated wastewater was evaluated. The impact of operational parameters including pH, adsorbate concentration, adsorbent dose, contact time, and temperature was examined to gauge the maximum adsorption capacity of the developed nanocomposite. The optimum pH for the eradication of EBT and MG were found to be 3 and 7.4, respectively. The maximum capacity evaluated was 222mg/g and 500mg/g at room temperature and at contact time of 50 and 40min respectively. The binding of either EBT or MG followed the monolayer Langmuir model and kinetic studies revealed the suitability of pseudo-second-order model. Studies using spectroscopy and isotherm modeling showed that the main mechanism controlling the adsorption of EBT and MG onto HAP@CT@MNP is physisorption. The efficacy of the adsorbent to be reused with 8% loss in its efficiency reveals the economic viability of HAP@CT@MNP. The current work showed that a biocompatible nanocomposite could be successfully fabricated and used as an enhanced adsorbent for the quick and effective removal of the toxic dyes EBT and MG from wastewater.

Kinetic, Thermodynamic and Adsorption Isotherm Studies of Detoxification of Eriochrome Black T Dye from Wastewater by Native and Washed Garlic Peel

Eriochrome Black T (EBT) is mutagenic and carcinogenic, and thus its presence in water may result in severe illnesses. This study was aimed at adsorbing EBT from simulated water samples by using a batch adsorption process, onto native (GP) and washed garlic peel (WGP). Surface and structural characterization of native and washed GP was performed using FTIR, SEM, BET, and BJH analysis. The effects of several parameters, affecting the process of adsorption, like pH, temperature, contact time, adsorbent dose, and initial dye concentration, were also examined. Freundlich and Langmuir isotherms were applied to the equilibrium data. Pseudo-first and pseudo-second order models were used to study the adsorption kinetics. The Langmuir isotherm and pseudo-second order model perfectly explained the equilibrium data. ΔG°, ΔH°, ΔS° studies indicated that adsorption of EBT onto GP and WGP was a favorable, spontaneous, and physical process. Maximum dye removal by GP (96%) and WGP (82%) was observed at pH 2. Similarly Maximum adsorption capacities were found to be 99.5 mg/g and 89.4 mg/g for GP and WGP, respectively. It is concluded from these results that garlic peel can be used as a cheaper and more efficient material for the adsorptive removal of EBT from contaminated water samples.

Remediation of different dyes from textile effluent using activated carbon synthesized from Buxus Wallichiana

In this project, eriochrome black T (EBT) and methylene blue (MB) which are well known textile and other industries effluents pollutants were removed by activated carbon prepared from the plant, having no medicinal or other importance (stem of Buxus Wallichiana) by pyrolysis method. Initially, different analytical techniques were applied to describe the composition and morphology of the prepared activated carbon (ACs). Different structural analysis found that pyrolysis at 600 °C brought a significant change in chemical composition of the prepared ACs. EDX elucidated high carbon contents ACs was formed which is highly desires for adsorption process. For optimization of different conditions for adsorption of both the dyes, different parameters which include initial concentration of both the dyes, pH of dye solutions, contact time and temperature were investigated in batch mode. It was found from adsorption of dyes on the prepared ACs that maximum amount of MB and EBT adsorption were 866.15 mg/g and 383 mg/g respectively. Also, adsorption of MB on the prepared ACs was higher than commercial ACs while in case of EBT commercial ACs has higher adsorption value than the prepared ACs. Due to physisorption nature, maximum adsorption of both the dyes took place at low temperature. The pH at PZC for ACs was around 5.9. The adsorptions of the EBT and MB on the prepared ACs were exothermic in nature due to the -ve value of enthalpy. The reusability of the prepared ACs was checked, with the adsorption capacity dropping from 126 mg/g to 103 mg/g over the course of five cycles in the real sample. These findings suggest that Buxus Wallichiana stem is a suitable biosorption substitute for the remediation of cationic (MB) and anionic (EBT) dyes from textile industrial effluents . • Activated carbon prepared from Buxus Wallichiana by pyrolysis method. • Efficient adsorbent for the removal of MB and EBT dyes. • Adsorption capacity for MB reached to 866.15 mg/g while 383 mg/g for EBT. • Highly stable and recyclable adsorbent up to five cycles.

Removal of anionic dye from aqueous solution by chitosan - magnetite nanocomposite

ABSTRACT Chitosan-magnetite nanocomposite (CM) was synthesised using the one-step procedure, reducing the synthesis time and the complexity of the process. The synthesized CM was characterised by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM). The nanocomposite was used to remove eriochrome black T (EBT) from the aqueous solution. The effects of pH, adsorption time, initial concentration of EBT, dose, and temperatures were studied. The experiment data were analysed by pseudo-first-order, pseudo-second-order, Elovich, and intra-particle-diffusion kinetic models. Among these models, the pseudo-second-order was the best fit model and the adsorption rate constant of EBT was 0.007 g/mg.min. The adsorption isotherms were studied by fitting the experimental data to the Langmuir, Freundlich, and Temkin models. The results indicated that the Langmuir model was the fittest model for describing the isotherms of the EBT adsorption on CM. When the temperature increased from 293 to 313K, the maximum adsorption capacity of EBT decreased from 291.2 to 83.5 mg/g. The thermodynamic study showed that the ETB adsorption process onto CM was a spontaneous and exothermic process with ∆G0, ∆H0 negative. The EBT dye adsorption mechanism was discussed, involved interactions, such as electrostatic attraction and H-bonding. CM could be regenerated and reused to adsorb anionic dye.

Efficient Removal of Eriochrome Black T (EBT) Dye and Chromium (Cr) by Hydrotalcite-Derived Mg-Ca-Al Mixed Metal Oxide Composite

Eriochrome Black T (EBT) and chromium (Cr) are considered to be potential pollutants due to their toxicity and severe impact on the environment. In the current study, hydrotalcite-derived Mg-Ca-Al-LDO mixed metal oxide composite was prepared using a conventional co-precipitation method and explored in terms of the removal of Cr and EBT dye from aqueous solution in a batch mode adsorption process. The prepared Mg-Ca-Al-LDH, Mg-Ca-Al-LDO and spent Mg-Ca-Al-LDO adsorbents were characterized to propose the adsorption mechanism. Different adsorption parameters were examined, such as adsorbent dosage, initial concentration, pH, reaction temperature and contact time. The EBT adsorption kinetic results matched strongly with the pseudo-second-order model for both Cr (R2 = 0.991) and EBT (R2 = 0.999). The Langmuir isotherm model exhibited a maximum adsorption capacity of 65.5 mg/g and 150.3 mg/g for Cr and EBT, respectively. The structure and morphology results obtained after Cr and EBT dye adsorption reveal that the adsorption mechanism is associated with electrostatic interactions and surface complexation of Cr and EBT dye with Mg-Ca-Al-LDO surface functional groups. Moreover, more than 84% of the initial adsorption capacity of EBT and Cr can be achieved on the Mg-Ca-Al-LDO surface after five adsorption/desorption cycles. Finally, the Mg-Ca-Al-LDO mixed metal oxide composite can be potentially used as a cost-effective adsorbent for wastewater treatment processes.

Efficient Removal of Eriochrome Black T Dye Using Activated Carbon of Waste Hemp (Cannabis sativa L.) Grown in Northern Morocco Enhanced by New Mathematical Models

In the present work, the adsorption behavior of Eriochrome Black T (EBT) on waste hemp activated carbon (WHAC) was examined. The surface of the WHAC was modified by H3PO4 acid treatment. The surface and structural characterization of the adsorbents was carried out using Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analysis. The effect of influential adsorption parameters (pH, contact time, dosage, and initial concentration) on the adsorption of EBT onto WHAC was examined in batch experiments; some adsorption parameters such as pH, concentration and dose were improved by new mathematical models. The adsorption behavior of EBT on the surfaces of WHAC was evaluated by applying different isotherm models (Langmuir, Freundlich, Temkin and Dubinin–Radushkevich) to equilibrium data. The adsorption kinetics was studied by using pseudo-first-order, pseudo-second-order, Elovich and intraparticle models on the model. Adsorption followed the pseudo-second-order rate kinetics. The maximum removal of EBT was found to be 44–62.08% by WHAC at pH = 7, adsorbent dose of 10–70 mg, contact time of 3 h and initial dye concentration of 10 mg.L−1. The maximum adsorption capacities were 14.025 mg.g−1 obtained by calculating according to the Langmuir model, while the maximum removal efficiency was obtained at 70 mg equal to 62.08% for the WHAC. The adsorption process is physical in the monolayer and multilayer.

Study on Adsorption of Alizarin Red S and Eriochrome Black T Dyes by Untreated Typha Grass as a Low Cost Adsorbent

The purpose of this investigation was to study the adsorptive potential of untreated typha grass (UTG) using a batch system under control conditions to decolorize Alizarin Red S (ARS) and Eriochrome Black T (EBT) anionic toxic dyes from synthetic aqueous solution. In this regard, the impact of various experimental parameters namely, contact time, adsorbent dose, initial dye concentration, pH, and temperature were assessed and optimized. The adsorbent was characterized using Fourier transformed infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and point of zero charge (PZC) analysis. The maximum adsorption rates of ARS and EBT onto UTG were determined to be 49.92 mg/g and 47.43 mg/g, respectively, at equilibrium. In comparison to previous models evaluated, removal of both ARS and EBT by the UTG demonstrated that the data had a strong fit with pseudo-second-order kinetic and Freundlich adsorption isotherms. The contact time for both dyes was optimised at 15 minutes, while the pH for ARS and EBT were attained at 8 and 2 respectively. However, based on the established results of various parameters in this study, the adsorptive removal of ARS and EBT by UTG was a favourable process. The Van't Hoff plot was used to calculate the thermodynamic quantities of the adsorption process, including ΔG, ΔH and ΔS. The outcomes showed that the process was both spontaneous and thermodynamically possible. From the parameters tested, EBT was found to be better adsorbed onto UTG than ARS. Even though both dyes are anionic in nature, but EBT has additional diazo and nitro functional groups than the hydroxyl and sulphate functional groups present in ARS. This might be the reason for the better adsorption of EBT onto UTG than ARS. Results from this investigation supported the efficiency of UTG as a low-cost and environmentally friendly solution for the adsorption of ARS and EBT from contaminated wastewater.

Engineered biochar supported layered double hydroxide-cellulose nanocrystals composite-: Synthesis, characterization and azo dye removal performance

In this work, engineered biochar decorated layered double hydroxides and cellulose nanocrystals (B–CuFe–CNC) biocomposites were synthesized by the facile ultrasonicated-co-precipitation technique. The biocomposite was investigated for purification of Eriochrome Black T (EBT) dye from water. The characterization results showed that the presence of CNC in biochar-layered double hydroxides resulted in a two-dimensional rod-like structure with excellent crystallinity, improved surface functionalities, and provides an attractive platform for the enhanced adsorption of azo anionic dye molecules. The adsorption system was appropriately demonstrated by the BBD-RSM (R2 > 0.994). The biocomposite exhibited higher EBT adsorption in the acidic pH range (2–5) due to strong electrostatic and chemical interactions. The kinetic and isotherm results were well demonstrated by pseudo-second order, Freundlich, and Redlich Peterson models. The maximum adsorption capacity of biocomposite was 876.2 mg/g achieved within 45 min. The spectroscopic analyses imply that the high removal of EBT by biocomposite is mainly governed by electrostatic attraction, hydrogen bonding, and chemical/metal complexation mechanisms. The biocomposite maintained high EBT removal after six successive adsorption cycles and excellent dye adsorption in the different water matrices. The results suggest that tailoring biochar properties with layered double hydroxide and CNC is a promising way for the enhanced removal of dye contaminants from wastewater.

Comparative adsorption of Eriochrome black T onto recyclable steel dust wastes: Isotherm, kinetics and thermodynamic studies

In this study, low-cost steel dust wastes from two different steel-manufacturing plants were investigated for the decontamination of water containing an anionic dye, Eriochrome black T (EBT). The characterization results indicated that the steel dust particles are mesoporous material with heterogenous structure and exhibit different surface functionalities that, mainly, included metal oxides and C-O groups. The steel dust particles showed high affinity towards EBT dye (100% removal) at pH 2, and dye concentration 20 mg/L. The kinetic data was better described by pseudo-second order model indicating chemisorption interactions. The isotherm results showed good fitting to the Langmuir isotherm model implying monolayer EBT adsorption onto steel dust particles. The maximum adsorption capacity of Q-Steel and L-Steel was 100.20 mg/g and 94.18 mg/g, respectively. The thermodynamic study demonstrated endothermic nature of EBT adsorption process. The steel dust particles showed excellent removal performance of EBT dye (i.e., less than 10% reduction) after five regeneration cycles. This demonstrated that steel dust particles can be directly, used as potential low cost and recyclable adsorbent material for treating dye contaminated water streams.

A new biosource for synthesis of activated carbon and its potential use for removal of methylene blue and eriochrome black T from aqueous solutions

Flora is a cheap, eco-friendly and recycling source of activated carbon. In this study, activated carbon (AC) was prepared from Datura metel seeds (D. M. seeds). The prepared AC was then used as a bioadsorbent for the removal of cationic and anionic dyes. Initially, the AC was prepared by pyrolysis method and then characterized by using different techniques such as FTIR, BET, SEM, EDX and XRD. From the EDX analysis, it was found that the carbon contents was drastically increased from 65 to 85.5 by atomic%, while XRD analysis concluded the formation of graphitic carbon due to the presence of peak at 25° 2theta position. Different parameters were tested to assess the effectiveness of biomass and the prepared AC toward adsorption of two dyes i.e. methylene blue (MB) and Eriochrome black T (EBT). The results demonstrated that adsorption of MB and EBT were remarkably boosted with rising concentration of the dyes and the agitation speed. In contrast, it significantly decreased with rising the temperature, and the highest adsorption was observed at 10 °C. From contact time, it was found that equilibrium position was achieved in 60 min for both MB and EBT. The study of alteration of pH indicated that the optimum pH for adsorption of MB and EBT was 6 and 2, respectively. The current data for both the dyes well follow Langmuir isotherm compared to the Freundlich isotherm. Additionally, the adsorption process dynamics was measured in terms of rate constant and it was found that data well follow pseudo-2nd kinetic model. Generally, the adsorption of EBT was higher than MB on the prepared AC. These findings proposed that AC prepared from D. M. seeds is a promising alternative adsorbent that could be utilized as an efficacious adsorbent for the removal of cationic and anionic dyes.

Enhanced removal of Eriochrome Black T from water using biochar/layered double hydroxide/chitosan hybrid composite: Performance evaluation and optimization using BBD-RSM approach

In this research work, a novel hybrid composite consisting of biochar (B), layered double hydroxide (CuFe) and chitosan (CS) (B-CuFe-CS) was produced using an ultrasonication-assisted co-precipitation method. The resultant composite was employed for adsorptive removal of Eriochrome black T (EBT) from water. Physicochemical characterization indicated that the B-CuFe-CS containing 10 wt % CS exhibited a heterogeneous structure with better crystallographic and textural characteristics. The B-CuFe-CS with abundant surface functionalities (-CO, -C-O, –OH, –NO3, and MMO), facilitates faster and enhanced removal of the EBT. The kinetic results showed better fitting to the pseudo-second order model, and equilibrium was achieved within 30 min. Equilibrium data was well explained by Langmuir and Redlich Peterson isotherm models (R2 > 0.98), indicating the EBT removal onto B-CuFe-CS followed monolayer adsorption. The maximum adsorption capacity was 806.4 mg/g, which was higher than pristine B–CuFe (476.19 mg/g) and many other adsorbents. The spectroscopic analysis (FTIR and XPS) and experimental results suggested that EBT adsorption is mainly governed by electrostatic, chemical and anion-exchange interactions. It is evident from these results that coupling B–CuFe composite with bio-filler (chitosan) resulted in an efficient bio-adsorbent to effectively purify dye-contaminated water streams.

Ultrasonic-Assisted Removal of Eriochrome Black T onto Vermicompost: Characterization, Isotherm and Kinetic Modelling

Recently, utilization of biological adsorbents plays an important role in the removal of toxic dyes such as Eriochrome Black T (EBT) azo-dye as they are considered as being produced from natural renewable source, easy availability, low cost, and being environmentally friendly. In this study, vermicompost (VC) was utilized to remove Eriochrome Black T (EBT) azo-dye from aqueous solution along ultrasonic ultrasonic-assisted adsorption. The parameters such as pH, adsorbent amount, operating time, and initial EBT concentration were investigated. The highest adsorption capacity was obtained as 50.64 (mg-EBT g-1-VC) at the pH of value of 2 after 2 minutes of ultrasonic adsorption. Pseudo first order kinetic model fitted very well with the experimental data (R2=0.9824). The determination coefficient of Temkin isotherm model (R2=0.8659) revealed that suggested model was compatible to experimental results. The results suggested that ultrasonic assisted adsorption of EBT onto VC could be cost- and time-efficient. Besides, the Scanning Electron Microscopy (SEM) analysis of adsorbent identified the surface structure morphology of VC. Moreover, functional groups of VC were detected after and before the ultrasonic-assisted adsorption by using Fourier Transform Infrared Spectroscopy (FTIR). Thus, interaction mechanism between VC and EBT were determined.

Ultrasonic-assisted adsorption of eriochrome black T and celestine blue dyes onto Ipomoea batatas-derived biochar

ABSTRACT In a bid to develop efficient biochars, we prepared new biochar by the pyrolysis of Ipomoea batatas feedstock for the ultrasonic-aided adsorption of eriochrome black T (EBT) and celestine blue (CB) dyes. The characterisation of the Ipomoea batatas-derived biochar (IBBC) showed potent functional groups, good thermal stability, porous structure and a point of zero charge of 6.41. The pH of 2.0 and 7.0 was found to be optimum for the uptake of anionic EBT and cationic CB onto IBBC, respectively. A decrease in the surface area of IBBC from 96.35 m2/g to 48.43 m2/g and 32.11 m2/g was obtained after the adsorption of EBT and CB, respectively. Thermogravimetric analysis revealed high thermal stability of IBBC up to 350°C. The Energy dispersive X-ray (EDX) spectrum revealed carbon (52.6%), oxygen (24.5%) and potassium (7.1%) as the major component of the biochar. The elemental analysis showed carbon, hydrogen and nitrogen compositions of 55.4%. 2.6% and 1.2%, respectively. Moreover, a biochar yield of 36.2% was obtained. The adsorption of both dye molecules was well correlated by the Freundlich isotherm, supported by the Scatchard model analysis. Kinetics was well fitted to the film diffusion and pseudo-second-order models, while thermodynamics showed an endothermic and spontaneous dye uptake on IBBC. The adsorption capacity of the biochar for EBT and CB was 59.24 mg/g and 63.69 mg/g respectively. Percentage desorption of 87.5% for EBT and 82.3% for CB was achieved during regeneration of the dye-loaded biochar. Moreover, IBBC showed good potentials to be reused for adsorption. The results revealed the potentials of the novel biochar for efficient adsorption of both cationic and anionic dye species.

Azo Dye Adsorption onto Cobalt Oxide: Isotherm, Kinetics, and Error Analysis Studies

The current study focused on utilizing cobalt oxide to eliminate hazardous Eriochrome Black T (EBT) dye. The impact of pH (2, 4, 7, 8, and 10) and temperature (45, 50, and 55 °C) was examined for EBT removal. The results show that the maximum sorption occurred at pH = 2 and that the removal percentage increased with increasing temperature. Five non-linear regression methods were used to predict the best isotherm and kinetic models. A coefficient of non-determination, K2, was very helpful for selecting the RMSD function as a preferable error function among the five methods. Isothermal models to illustrate equilibrium sorption information, the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models were used. The results showed that the Langmuir model (R2 = 0.99) was the most favorable, indicating monolayer sorption of EBT occurred. The kinetics models were analyzed using pseudo-first-order and pseudo-second-order whereas the sorption information was well described by the pseudo-second-order model (R2 = 0.99). The results of the thermodynamic study appeared that the adsorption of EBT was endothermic, feasible, spontaneous, and physical adsorption.