Enhancement of biosorption capability of imidazolium-based ionic liquid-treated Prosopis juliflora for the removal of malachite green from wastewater.

Due to its toxicity effect, treating toxic pollutants discharged from textile effluent is challenging for living beings. In the present study, the comparative biosorption potential of imidazolium-based ionic liquid-treated Prosopis juliflora (ILPJS) and untreated P. juliflora (PJS) was investigated for the removal of toxic pollutant, malachite green (MG) from aqueous solution. The textural, surface morphology, and functional analysis of ILPJS and PJS were examined using BET (Brunauer-Emmett-Teller) analysis, SEM (Scanning electron microscopy) analysis, and FTIR (Fourier-transform infrared spectroscopy) analysis. Textural property (BET surface area) and surface morphology containing irregular heterogeneous surface for ILPJS were significantly improved than PJS, thereby facilitating significant biosorption of MG. Based on the conventional optimization studies, the essential biosorption parameters for the removal of MG using ILPJS were found to be: initial pH (9.0), contact time (30 min), and biosorbent dosage (0.2 g). The maximum biosorption capacity of PJS and ILPJS were obtained to be 6.91 and 13.64 mg/g at 40 °C, respectively. The spontaneous and endothermic biosorption of MG was confirmed by thermodynamic analysis. The regeneration study indicated the greater reusability of ILPJS and PJS for MG removal till the fifth cycle. Based on the previous literature, this is the first report comparing the removal of toxic pollutant MG using ILPJS and PJS.

Prosopis juliflora is an invasive weed that causes a severe challenge to ecological diversity and rural livelihoods due to the continuous consumption of water throughout the year, leading to the depletion of groundwater reserves. To control its invasion and growth, weed has been applied as biosorbents to remove toxic pollutant, malachite green (MG). This is the first report comparing the pretreatment of P. juliflora using imidazolium-based ionic liquid (ILPJS) with raw P. juliflora (PJS) for the biosorption of MG. The biosorption capacity of ILPJS for MG removal was 1.97 times higher than PJS. The enhancement in biosorption capacity might be the possibility of better textural and surface morphology of chemically treated P. juliflora. Thermodynamic studies revealed the endothermic and spontaneous nature of the biosorption of MG on PJS. With the invasion of this weed over thousands of hectares of land in India, PJS is the ideal biosorbent for removing toxic chemical pollutants and preserving the groundwater level.

Removal of cationic and anionic toxic pollutants from simulated solutions using Sterculia foetida pod (SFP): equilibrium isotherm, kinetics, and characterization.

The present work explores the sorption performance of Sterculia foetida pod (SFP) for the removal of methylene blue (MB) and chromium (Cr6+) from simulated solutions separately. The material characteristics namely textural analysis (specific surface area: 2.45 m2/g), morphological behavior (heterogeneous morphology containing pores and cavities), functional analysis (COO- stretching, C-O-C stretching vibrations, and -OH stretching) and thermal behavior (279.4 °C) were examined by various analytical techniques namely BET, SEM, FTIR, and TGA. Using non-linear Langmuir isotherm analysis, the maximal sorption capacity of SFP for the removal of MB and Cr6+ was predicted to be 74.1 mg/g and 27.3 mg/g, respectively. The optimized condition for sorption of MB and Cr6+ onto SFP was: dosage: 0.07 mg/L, initial pH: 7 (MB), and 2 (Cr6+). Thermodynamic data analysis confirmed the endothermic, favorable, spontaneous, and physisorption nature of sorption. The SFP has shown significant regeneration capacity in the consecutive runs (MB: 92.5% removal till 5th trial; Cr6+: 97.6% removal till 3rd trial). Based on these findings, SFP is a promising low-cost and eco-friendly candidate for the removal of anionic and cationic toxic pollutants in the absence of energy and chemical expenditure.NOVELTY STATEMENTSterculia foetida pod (SFP) explored for the removal of anionic and cationic toxic pollutants in the absence of energy and chemical expenditure.Mechanism for the interaction between toxic pollutants and SFP was predicted.Better sorption capacity (MB: 74.1 mg/g; Cr6+: 27.8 mg/g) and better regeneration capacity (MB: 92.5% for 5th trial; Cr6+: 97.6% for 3rd trial) was achieved.A feasible and spontaneous nature of sorption process toward the removal of MB and Cr6+ was demonstrated using thermodynamic relations.

Delonix regia seed pod-an efficient biosorptive candidate toward the removal of Rhodamine B from simulated wastewater: characterization, kinetics, and equilibrium approach.

This study focused on the comparative analysis of biosorption performance of Delonix regia seed pod toward the removal of Rhodamine B (RB) from simulated solution using native (DRSP) and chemically treated form (ADRSP). The surface morphology, structural analysis, textural properties, and thermal analysis of DRSP and ADRSP were examined using scanning electron microscopy (SEM), BET analysis, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), respectively. FTIR analysis concluded that surface functional groups like hydroxyl -OH stretching, C-N stretching, and C = C stretching of the aromatic ring were largely responsible for the attachment of RB. The chemical treatment enhanced the surface morphology of D. regia seed in terms of heterogeneity, distinct depth cavities, and irregular pores responsible for RB biosorption. The biosorption of RB was investigated using parametric analyses such as solution pH, biosorbent dosage, contact time, initial RB concentration, and operating temperature. The obtained equilibrium data were fitted with different isotherm and kinetic models. Langmuir isotherm model and pseudo-second-order kinetic were well suitable for the biosorption of RB using DRSP and ADRSP. The maximum monolayer biosorption capacities (mg/g) of DRSP and ADRSP were predicted to be 39.37 and 60.61, respectively. Using thermodynamic principles, the removal of RB was found to be thermodynamically feasible, endothermic, and spontaneous process. The results of the present study proved that DRSP and ADRSP can be identified as promising biosorbents for the removal of RB.

The potential utilization of Delonix regia seed pod (native and chemically treated forms) for the removal of Rhodamine B (RB) from simulated water. Surface morphology, surface area, functional analysis, and thermal analysis of both native (DRSP) and treated forms (ADRSP) to understand materials properties before biosorption of RB. Parametric effects of dosage, initial pH, initial pollutant concentration, and temperature on biosorption capacity and biosorption (%) using native and treated forms of bisorbents. Implantation of different kinetic models and two-parameter isotherm models to examine the feasibility and type of biosorption. The maximum biosorption capacity (mg/g) of DRSP and ADRSP is predicted to be 39.37 and 60.61 using the Langmuir isotherm model, respectively. Identification of possible biosorption mechanism using the functional group analysis. Negative values of Gibbs free energy change (ΔG0) and positive values of entropy change (ΔS0), enthalpy change (ΔH0) demonstrating the thermodynamic feasibility, increase in randomness at the solid-liquid interphase and endothermic biosorption.

Ipomoea carnea: a novel biosorbent for the removal of methylene blue (MB) from aqueous dye solution: kinetic, equilibrium and statistical approach.

The biosorption potential of cost-effective and agricultural residue, Ipomoea carnea wood (ICW) was examined by the removal of cationic dye, methylene blue (MB) from aqueous solution. The surface morphology, structural and thermal properties of untreated ICW were analyzed using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Thermo-gravimetric Analysis (TGA), respectively. The effects of different parameters namely concentration of biosorbent, initial pH, initial MB composition and temperature on biosorption capacity and biosorption (%) were studied. The kinetic and equilibrium models were developed to fit the experimental data on MB biosorption. The maximum biosorption capacity of 39.38 mg g-1 was obtained at 40 °C using Langmuir model. The removal of MB was found to be significantly varying with temperature. Box-Behnken design was applied to optimize the biosorption parameters. The optimized condition for MB biosorption was evaluated as dosage of 3.1 g L-1, pH of 7.04, Temperature of 49.1 °C, MB concentration of 30.48 mg L-1 and maximum biosorption (%) of 83.87. The regeneration of ICW was investigated by five cycles using a suitable eluting agent. Hence, ICW without any pretreatment and chemical modification is a potential candidate for the removal of MB in terms of availability and economy of the process.Novelty statementIpomoea carnea wood (ICW) without any pretreatment explored a potential biosorbent for the removal of methylene blue (MB) in terms of availability and economy of the process.The physico-chemical properties of ICW characterized using Scanning Electron Microscopy, Fourier transform infrared spectroscopy and Thermo-gravimetric Analysis showed ICW as a promising biosorbent for MB removal.Presence of heterogeneous with rugged morphological structure, cavities, irregular shape and size of large pores provide the better biosorption capability for MB molecules using ICW without any pretreatment or chemical modification.Analysis of kinetic and isotherm models was performed to examine the better fitness of experimental data with model. Thermodynamic parameters indicating feasible and endothermic MB biosorption.Statistical design of experiments is used to optimize the condition and corresponding maximum MB removal using Derringer's desired function methodology.Untreated ICW is a potential reusable biosorbents, effectively employed in successive biosorption and desorption process for the removal of MB from aqueous solutions.