Maximum Dye Uptake Capacity Research Articles

Okra Micro-Cellulose Crystal (MCC) and Micro-Clay Composites for the Remediation of Copper, Nickel, and Dye (Basic Yellow II) from Wastewater

Water pollution by contaminants such as toxic metals and dyes is now a major concern due to their high toxicity and persistence in the environment. Advances in nanotechnology have enabled the use of micro/nanomaterials to treat and purify water in various industries. In this study, Bijoypur clay was modified with ethyldiamine and incorporated into an okra fiber (Abelmoschus esculentus) micro-cellulose crystal (MCC) to produce a composite that could absorb copper (Cu), nickel (Ni), and dyes like basic yellow (II) from industrial wastewater. Composites were prepared using different percentages of MCC and clay. Atomic absorption spectroscopy (AAS) was used to determine the concentrations of Cu and Ni whereas a UV–Visible spectrophotometer measured the absorbance of basic yellow (II). The synthesized composites were extensively characterized using a range of techniques including thermogravimetry (TG) and differential thermogravimetry (DTG), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Results show that both the MCC and clay could absorb Cu, Ni, and basic yellow (II) from the contaminated wastewater. The MCC and clay composite showed the maximum efficiency of metals removal, which was up to 95% (24 mg/g) for Cu at pH 6, 20 min contact time, 2 g/L adsorbent dose, and 100% (31 mg/g) for Ni at pH 8, 60 min contact time, and 2 g/L adsorbent dose, respectively, at the initial concentration of 50 mg/L. The maximum dye uptake capacity of 85% (19 mg/g) was observed by the MCC and clay composite under optimized conditions at the initial concentration of 50 mg/L, pH 8, 30 min contact time, and 1 g/L adsorbent dose compared to the pure clay, which had an efficiency up to 26% for Cu and 24% for dye removal. All of the results indicate that incorporating clay into MCC increases the absorption capacity of contaminants from wastewater, which could be more effective for environmental applications compared to untreated cellulose.

Fabrication of MgFe2O4/polyaniline nanocomposite for amputation of methyl red dye from water: Isotherm modeling, kinetic and cost analysis

Several industries utilize synthetic dyes to color their products, resulting in generation of wastewater containing strong-colored organics. The discharge of these toxic dyes into effluents has adverse effects both on human being and aquatic ecosystem. As a result, it is important to eliminate these dyes prior to discharge of wastewater into the aquatic system. Polyaniline (PANI) based novel nanocomposites are gaining popularity due to the tunable electrical conductivity, high surface area, eco-friendly nature, which illustrate PANI based nanocomposites as suitable materials for wastewater amputation. Thus in this research, a novel nanocomposite comprising of magnesium ferrite and PANI (MgFe2O4-PANI-NC) was successfully prepared and used for adsorptive elimination of methyl red (MR) dye from water. The developed nanocomposite could efficiently remove the methyl red (MR) dye from water at solution pH of 7.0 which is advantageous for safe disposal of treated effluent without further treatment. The highest MR dye uptake efficiency of 90.23(±1.55)% was achieved at initial MR dye concentration of 50 mg/L, MgFe2O4-PANI-NC dose of 1.0 g/L, and contact time of 30 min. The experimental data follow the pseudo-second-order kinetic model accurately and isotherm modeling reveals the adsorption of MR dye onto the MgFe2O4-PANI-NC follows Langmuir model with maximum dye uptake capacity of 98.04 mg/g. The cost analysis revealed that the fabrication cost of MgFe2O4-PANI-NC is around $100.60/kg. After 5th consecutive cycle of repetitive use, the removal efficiency of MR dye drops from 90.23(±2.02) % to 80.52(±1.39) % which shows the high stability and reusable characteristics MgFe2O4-PANI-NC for real field application.

One-way conformation memory polymers for unidirectional removal of dyes and hot wastewater reuse from textile effluents

Thermoresponsive polymers that adapt their conformation transition from coil to globule in response to temperature change have aroused great interest in the last two decades. However, thermally induced phase separation behavior often involves dynamically reversible switching between two distinct conformations during multiple heating–cooling cycles, which hinders their potential applications in many directional, nonreturn molecule delivery systems. Here, inspired by a nonreturn valve, a new class of thermo-irreversible starch derivatives (TIRS) is presented. As an unprecedented one-way conformation memory polymer, TIRS exhibits usual lower critical solution temperature type fast responses to temperature stimuli, but this phase transition behavior involves ir-reversible switching upon cooling. The extent of hysteresis (reversible, semi-reversible and ir-reversible) between heating and cooling ramps can be fine-tuned by varying the degree of substitution of starch derivatives. The unique conformation-adaptive feature of TIRS makes it a very interesting candidate for the unidirectional removal of dyes and hot wastewater reuse from textile effluents. TIRS shows a maximum dye uptake capacity of 3984 mg/g and excellent decoloration efficiency of 99.6% at optimized flocculation conditions. After flocculation with dyes, the temporary conformation of flocs can be memorized and self-locked due to the unidirectional solubility switching of TIRS from water-soluble flocculants to water-insoluble adsorbents, which avoids unnecessary desorption and re-solubilization of the flocculant. Clarified hot water can be employed as reuse water in new dyeing operations due to low flocculant residues in reclaimed water. This work offers a new approach to design and fabricate check-valve-like materials for self-adaptive, ir-reversible smart delivery systems.

Biosorptionally treated dye wastewater employed in “Olla-pot coupled microbial fuel cell” for tomato (Solanum lycopersicum L.) irrigation and bio-electricity production

This study presents a novel amalgamation of biosorption, Olla-Pot (OP) irrigation, and microbial fuel cells for the development of sustainable technology to remediate dye wastewater and reuse for crop irrigation and bioelectricity production. Biosorption of acid blue 193 dye on spent tea waste was carried out, and biosorptionally treated wastewater (TW) was employed in “Olla-Pots” for tomato irrigation. Additionally, Olla-pots has been infused with MFCs to take advantage of the organic load of TW to generate electricity. In biosorption studies, the Langmuir isotherm model was found to be the best fit (R2=0.9973) with maximum dye uptake capacity of 35.972 mg/g at 298 K. The Olla-pot MFC achieved 66.38 ± 1.58% of COD removal efficiency and 2.23 mW/m2 of power density with TW. This approach of using biosorptionally treated wastewater in an ancient and simple irrigation technique can become a suitable option for the interlinking of efficient wastewater treatment and water conservation strategy.

Removal of Rose Bengal dye from aqueous solutions using biosorbent obtained from Mangifera indica

Rose Bengal dye is a xanthene class [4, 5, 6, 7-tetrachloro-2', 4', 5', 7'-tetraiodofluorescein] compound with high molecular weight of 1016.7 g/mol. The leaves of Mangifera indica has been used to prepare a homogeneous powdered biosorbent for the removal of Rose Bengal dye from aqueous solution. Maximum dye uptake capacity is achieved for initial dye concentration of 20 mg/L at biosorbent dosage of 0.2 g at neutral p H. Scanning electron microscope (SEM) image, Energy Dispersive X-ray (EDX) and Fourier Transform Infrared (FTIR) spectra display changes in the morphological properties, elemental compositions and functional groups respectively before and after adsorption of RB dye on MI. The maximum monolayer adsorption capacity of MI for RB dye is found to be 0.824 mg per 0.2 g of adsorbent. Freundlich isotherm model best fits the experimental data compared to the results obtained from Langmuir-1 and Langmuir-2 model equations. The pseudo-second order model-1 best describe the kinetics of the adsorption of Rose Bengal dye on MI. The thermal degradation characteristics of Mangifera indica before and after adsorption are studied. The pyrolysis of dye adsorbed biomass at 900°C result in a total degradation of 93.15% with peak weight reduction of 0.0508 mg/min at 528°C.

Utilization of dye-loaded activated carbon as a potential alternative fuel source: a feasibility study through calorific and thermo-gravimetric analysis.

The disodium salt of Rose Bengal [4, 5, 6, 7-tetrachloro-2', 4', 5', 7'-tetraiodofluorescein] commonly finds application in medical procedures and its removal from aqueous solution is difficult owing to its high molecular weight of 1017.67g/mol. Activated carbon was prepared from Prosopis juliflora and immobilized into sodium alginate beads and doped with aniline for enhanced adsorption of Rose Bengal. The effect of initial dye concentration, beads' dosage, contact time, and the temperature over the adsorption of Rose Bengal dye were studied. The optimum conditions derived for maximum dye uptake capacity were 4mg/L of initial dye concentration, contact time of 60min with the adsorbent dosage of 0.2g, and temperature of 303K at neutral pH. The equilibrium data were found to be best fitted for Langmuir -1 model, whereas the kinetics were interpreted through Ho-Mckay's pseudo-second-order equation. The adsorbents were subjected to thermo-gravimetric studies to determine the activation energy under a heating rate of 20°C/min. The activation energy was computed using Broido's plot and was found to be 35.21 ± 0.84kJ/mol for the activated carbon, and 16.77 ± 2.19kJ/mol for the dye-adsorbed beads. The heat capacity was determined through differential scanning calorimetry and was calculated to be 19.41J/g°C for activated carbon and 39.43J/g°C for beads post-adsorption of Rose Bengal dye.

Rapid and high-performance adsorptive removal of hazardous acridine orange from aqueous environment using Abelmoschus esculentus seed powder: Single- and multi-parameter optimization studies

In this research, the performance of naturally abundant lignocellulosic by-product, Abelmoschus esculentus, and its processed seed powder referred as AESP, as a potential biosorbent for the removal of acridine orange (AO) from the aqueous environment was examined. The AESP biosorbent was characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis, diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FTIR) and pHZPC analyses. The average size of the biosorbent according to particle size distribution analysis was found to be ∼132 μm. The batch adsorption experiments were conducted by altering the parameters such as contact time, solution pH, biosorbent dosage, initial dye concentration, stirring speed and temperature. Sorption of cationic AO dye onto AESP was found to be rapid, and the equilibrium condition reached within 30 min. The isotherms (Langmuir, Freundlich, Redlich-Peterson and Sips), kinetic models (pseudo-first order, pseudo-second order, Elovich, intra-particle diffusion, Bangham and modified-Freundlich models) and thermodynamic parameters were also evaluated. High values of determination coefficients (R2) and minimal values of non-linear error functions (i.e. HYBRD, RMSE, MPSD, ARE, APE and χ2) indicated that experimental data were best fitted with Sips isotherm and pseudo-second order kinetic model. Accordingly, the maximum loading capacity of AESP was found to be 259.4, 284.3 and 346.5 mg/g for the temperatures of 15, 30 and 45 °C, respectively. The thermodynamic parameters showed that the adsorption of AO onto the AESP surface was an endothermic and spontaneous process. Besides these, the central composite experimental design (CCD) superimposed with response surface methodology (RSM) modeling was also employed to investigate the effect of four significant parameters (solution pH, contact time, initial AO concentration and AESP dosage) and their interaction-term effects on the adsorption capacity of AESP and to formulate the mathematical model for the experimental data using multi-variate statistical analysis. Maximum dye uptake capacity under the optimum conditions of variables (pH 8.96, contact time 32.06 min, initial dye concentration 867.71 mg/L and AESP dosage 1.89 g/L) was 312.1 mg/g at temperature 30 °C, and it was found to be very close to the experimentally determined values (313.4 ± 0.057 mg/g). The promising reusability potential of AESP using 0.1 M HCl, implied that, the lignocellulosic biosorbent AESP might be helpful for the appropriate designing of the environmental-friendly purification systems.

Cationic surfactant-modified biosorption of anionic dyes by dried Rhizopus arrhizus

ABSTRACTThe biosorption of an anionic dye Remazol Black B onto a filamentous, dried fungus, Rhizopus arrhizus, was studied in the presence of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB), which was used as a pH shifter. Without surfactant, the maximum dye uptake capacity was achieved at pH 2.0 and was 434.0 mg dye g−1 dried fungal biomass. Again, without surfactant, the highest dye uptake capacity, 27.8 mg dye g−1 dried biomass, occurred at pH 8.0 calculated from the Langmuir adsorption model. Addition of CTAB changed the pH at which the highest dye uptake was obtained. At an initial pH of 8.0 with different CTAB concentrations, the dye uptake capacity increased from 27.8 to 500.0 mg dye g−1 dried biomass. Furthermore, when 200 mg L−1 surfactant was added to the biosorption medium at pH 8.0, the amount of dye removed increased significantly. Four equilibrium adsorption models were applied to the results. The applicability of each isotherm was determined using regression correlation and fitting curves. According to the Langmuir model, without surfactant, the highest dye removal capacity at pH 8.0 was found to be 27.8 mg dye g−1 dried biomass, rising to 500.0 mg g−1 dried biomass with 200 mg L−1 CTAB.

Treatment of Colored Effluent using Surfactant Modified Bamboo Leaves Powder

Batch adsorption experiments were carried out to remove color from aqueous medium using a novel bioadsorbent prepared from bamboo leaves. Methylene blue (MB) dye was chosen as the source of color and it was adsorbed on bamboo leaves powder (BLP) and surfactant modified BLP using Triton X-100 (TX-100) and Sodium dodecyl sulfate (SDS), separately. The effects of various process parameters, viz. contact time, adsorbent dose, pH, temperature, and stirring speed were investigated in detail. Adsorption efficiencies of all the three adsorbents were compared and analyzed. The performance of SDS modified BLP was found to be excellent. Thermodynamic parameters and reaction kinetics were studied to know the nature and mechanism of adsorption. The results showed that MB adsorption followed pseudo second order kinetics and was endothermic in nature. The adsorption equilibrium was also investigated with the Langmuir, Freundlich, and Temkin isotherm models. The Langmuir isotherm was fitted well with a maximum dye uptake capacity of 125, 143, and 200 mg/g for BLP, BLP modified with TX-100, and SDS, respectively. A regeneration technique was proposed in order to reuse the adsorbent for better economy of the process. Finally, a process calculation was reported to know the amount of adsorbent required for efficient removal of MB.

Biosorption characteristics of Aspergillus fumigatus for the decolorization of triphenylmethane dye acid violet 49

This study focuses on the possible use of Aspergillus fumigatus to remove acid violet 49 dye (AV49) from aqueous solution. In batch biosorption experiments, the highest biosorption efficiency was achieved at pH 3.0, with biosorbent dosage of 3.0 gL(-1) within about 30 min at 40 °C. The Langmuir and Freundlich models were able to describe the biosorption equilibrium of AV49 onto fungal biomass with maximum dye uptake capacity 136.98 mg g(-1). Biosorption followed a pseudo-second-order kinetic model with high correlation coefficients (R (2) > 0.99), and the biosorption rate constants increased with increasing temperature. Thermodynamic parameters indicated that the biosorption process was favorable, spontaneous, and endothermic in nature, with insignificant entropy changes. Fourier transform infrared spectroscopy strongly supported the presence of several functional groups responsible for dye-biosorbent interaction. Fungal biomass was regenerated with 0.1 M sodium hydroxide and could be reused a number of times without significant loss of biosorption activity. The effective decolorization of AV49 in simulated conditions indicated the potential use of biomass for the removal of color contaminants from wastewater.

Biosorption of indigo from aqueous solution by dead fungal biomass Aspergillus alliaceus

The capacity of a nonviable Aspergillus alliaceus to remove the textile indigo dye from aqueous solution was investigated using different parameters such as pH and temperature. The effects of pH (at a pH range from 1 to 8) and temperature (at 30, 40 and 50°C) on dye biosorption were studied. The indigo dye bioremoval reached its maximum with 99% after 240 min, at pH 4. In batch experiments, the biosorption capacity increased with the increase of the temperature, and the maximum dye uptake capacity of the biosorbent was 195 mg/g at 500 mg/l dye concentration at 50°C. The modeling of the experimental data at equilibrium was performed with Langmuir and Freundlich isotherms. On the basis of regression coefficient values, the Freundlich model is almost more successful in representing experimental isotherm data for the biosorption of indigo on inactive A. alliaceus than the Langmuir model.

Biosorption of reactive red 2 using positively charged Metapenaeus monoceros shells

Metapenaeus monoceros shell used for the removal of reactive red 2 from an aqueous solution was studied by batch biosorption system. The maximum dye uptake capacity was examined at biosorbent dosage, different pH, contact time and initial dye concentration. From the study the maximum dye uptake capacity was obtained as 166mg/g at an optimal condition of 0.1g/L of biosorbent dosage, pH value of 2 and initial dye concentration of 100mg/L. When compared to the Langmuir isotherm model, the equilibrium data were fitted well with the Freundlich isotherm model. The kinetic data were fitted well with the pseudo second order rate equation when compared to the pseudo first order rate equation. The biosorbent characteristics were observed by SEM and FTIR analyses.

Biodecolorization of a persistent organic dye from model wastewater using Curvularia spp

The textile industry produces a huge volume of wastewater, out of which 10–50% of these effluents are discharged into the aquatic environment without being treated. The discharge of these colored compounds in the environment causes considerable nonaesthetic pollution and serious health-risk factors. In this study an effort has been made to biodecolorize simulated dye wastewater containing Reactive Red 195 by isolated fungus Curvularia spp. The experiments have been performed by varying the influencing parameters, such as initial concentration, pH, and temperature. Maximum decolorization of 66% was obtained for 0.01 g/l of dye concentration and at pH 5. Maximum decolorization of 75.33% was obtained at a temperature of 40°C (in 48 h). The optimum condition for maximum dye uptake capacity is: initial dye concentration 0.02 g/l, temperature 40°C, pH 5, and an inoculum size of 5 ml (approximately 1.0 × 105 cells/ml).

Comparison of Remazol Black B biosorptive properties of live and treated activated sludge

Biosorption of Remazol Black B, a vinyl sulfone type reactive dye, from aqueous solution was investigated to compare the binding capacities of untreated (live) and treated (dried, autoclaved, acid (H 2SO 4)-treated, base (NaOH)-treated) activated sludge in this study. Remazol Black B uptake was strongly affected by the solution pH and optimum adsorption pH value was determined as 2 for all the live and treated activated sludge biosorbents. It was seen that the sorption capacity of each biosorbent enhanced with decreasing temperature. Dye uptake also increased with increasing initial dye concentration up to 500 mg l −1 for each biomass type. Contrary to assumption it is found that all the treatment methods diminished the dye biosorption capacity of activated sludge. Among the five biosorbents, live activated sludge had a maximum dye uptake capacity of 134.8 mg g −1 at 25 °C. The Langmuir–Freundlich adsorption model described the equilibrium data of each dye–biosorbent system accurately in the concentration and temperature ranges studied. The pseudo-second-order adsorption model defined the overall adsorption kinetics of each biosorption process exactly.

Biosorption of C.I. Direct Blue 199 from aqueous solution by nonviable Aspergillus niger

The capacity and mechanism with which nonviable Aspergillus niger removed the textile dye, C.I. Direct Blue 199, from aqueous solution was investigated using different parameters, such as initial dye concentration, pH and temperature. In batch experiments, the biosorption capacity increased with decrease in pH, and the maximum dye uptake capacity of the biosorbent was 29.96 mg g(-1) at 400 mg L(-1) dye concentration and 45 degrees C. The Langmuir and Freundlich models were able to describe the biosorption equilibrium of C.I. Direct Blue 199 onto the fungal biomass. Biosorption followed a pseudo-second order kinetic model with high correlation coefficients (r(2)>0.99). Thermodynamic studies revealed that the biosorption process was successful, spontaneous and endothermic in nature.