Removal of Rhodamine B Dye Using Activated Carbon Prepared from Palm Kernel Shell and Coated with Iron Oxide Nanoparticles

Magnetic biochar as a revolutionizing approach for diverse dye pollutants elimination: A comprehensive review

The term "biomass" encompasses all substances found in the natural world that were once alive or derived from living organisms or their byproducts. These substances consist of organic molecules containing hydrogen, typically oxygen, frequently nitrogen, and small amounts of heavy, alkaline earth and alkali metals. Magnetic biochar refers to a type of material derived from biomass that has been magnetized typically by adding magnetic components such as magnetic iron oxides to display magnetic properties. These materials are extensively applicable in widespread areas like environmental remediation and catalysis. The magnetic properties of these compounds made them ideal for practical applications through their easy separation from a reaction mixture or environmental sample by applying a magnetic field. With the evolving global strategy focused on protecting the planet and moving towards a circular, cost-effective economy, natural compounds, and biomass have become particularly important in the field of biochemistry. The current research explores a comparative analysis of the versatility and potential of biomass for eliminating dyes as a sustainable, economical, easy, compatible, and biodegradable method. The elimination study focused on the removal of various dyes as pollutants. Various operational parameters which influenced the dye removal process were also discussed. Furthermore, the research explained, in detail, adsorption kinetic models, types of isotherms, and desorption properties of magnetic biochar adsorbents. This comprehensive review offers an advanced framework for the effective use of magnetic biochar, removing dyes from textile wastewater.

Emerging iron-based mesoporous materials for adsorptive removal of pollutants: Mechanism, optimization, challenges, and future perspective

Iron-based materials (IBMs) have shown promise as adsorbents due to their unique physicochemical properties. This review provides an overview of the different types of IBMs, their synthesis methods, and their properties. Results found in the adsorption of emerging contaminants to a wide range of IBMs are discussed. The IBMs used were evaluated in terms of their maximum uptake capacity, with special consideration given to environmental conditions such as contact time, solution pH, initial pollutant concentration, etc. The adsorption mechanisms of pollutants are discussed taking into account the results of kinetic, isotherm, thermodynamic studies, surface complexation modelling (SCM), and available spectroscopic data. A current overview of molecular modeling and simulation studies related to density functional theory (DFT), surface response methodology (RSM), and artificial neural network (ANN) is presented. In addition, the reusability and suitability of IBMs in real wastewater treatment is shown. The review concludes with the strengths and weaknesses of current research and suggests ideas for future research that will improve our ability to remove contaminants from real wastewater streams.

Trapping Rhodamine B dye using functionalized mango (Mangifera indica) pod

The use of acid-modified mango pod (AMMP) sorbent for removing Rhodamine B (Rh-B) dye from aqueous media was investigated. Raw mango pod (RMP) and AMMP sorbents were characterized using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), powdered X-ray diffractogram (PXRD), Fourier transform infrared (FTIR), point of zero charge pH (pH_pzc ), and Boehm titration (BT) techniques. Batch adsorption was employed to examine the influence of operational factors. Sorption kinetic parameters were calculated using pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The pseudo-second-order model best fitted the adsorption kinetic data most with maximum correlation coefficient (R²  > 0.99). The process of the adsorption was controlled by both boundary layer and intraparticle diffusion mechanisms. Four isotherm models (Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin) were utilized to analyze the equilibrium data at various temperatures. Freundlich model gave the best fit with the maximum regression (0.99), while the Langmuir isotherm model established a maximum monolayer adsorption capacity of 500 mg g^-1 . Thermodynamic parameters studied revealed that the interaction is spontaneous and endothermic in nature. The cost analysis of the current study provides convincing proof that AMMP is efficient for removing Rh-B dye from solution by providing a saving of 225.2 USD/kg, which is eight times cheaper than commercial activated carbon. Consequently, the study revealed that AMMP is a viable, effective, and sustainable sorbent for Rhodamine B dye removal. PRACTITIONER POINTS: The powdered X-ray diffractogram (PXRD) showed the formation of new and intense peaks with the presence of highly organized crystalline structures on acid-modified mango pod (AMMP). Surface morphology of AMMP showed well-developed open surface pores required for effective adsorption of Rh B dye molecules. Economic feasibility of the present study showed that AMMP is more affordable than commercial activated carbon that costs USD 259.5/kg, thus translated to a saving cost of USD 225.2/kg and more than 7.5 times cheaper than the commercial activated carbon (CAC).

Rhodamine B dye sequestration using Gmelina aborea leaf powder

Chemically prepared activated carbon derived from Gmelina aborea leaves (GALAC) were used as adsorbent for the removal of Rhodamine B (Rh-B) dye from aqueous solutions. The adsorptive characteristics of activated carbon (AC) prepared from Gmelina aborea leaves (GAL) were studied using SEM, FTIR, pH point of zero charge (pHpzc) and Boehm Titration (BT) techniques respectively. The effects of pH, contact time, initial dye concentration and solution temperature were also examined. Experimental data were analyzed using four different isotherm models: Langmuir, Freundlich, Temkin and Dubinin-Radushkevich. Four adsorption kinetic models: Pseudo-first-order (PFO), Pseudo-second-order (PSO), Elovich and Intraparticle diffusion models to establish the kinetics of adsorption process. The RhB dye adsorption on GALAC was best described by Langmuir isotherm model with maximum monolayer coverage of 1000 mg g-1 and R2 value of 0. 9999. The EDX analysis revealed that GALAC contained 82.81% by weight and 91.2% by atom of carbon contents which are requisites for high adsorption capacity. Adsorption kinetic data best fitted the PSO kinetic model. Thermodynamic parameters obtained for GALAC are (ΔGo ranged from -22.71 to -18.19 kJmol-1; ΔHo: 1.51 kJmol-1; and ΔSo: 0.39 kJmol-1 K-1respectively) indicating that the RhB dye removal from aqueous solutions by GALAC was spontaneous and endothermic in nature. The cost analysis established that GALAC is approximately eleven times cheaper than CAC thereby providing a saving of 351.41USD/kg. Chemically treated GAL was found to be an effective absorbent for the removal of RhB dye from aqueous solution.

Multiple nitrogen functionalized magnetic nanoparticles as an efficient adsorbent: synthesis, kinetics, isotherm and thermodynamic studies for the removal of rhodamine B from aqueous solution

The continuous demand for clean and affordable water needed for the survival of man is now a major challenge globally. Therefore, the treatment of wastewater generated from printing, textile and dyeing industries containing soluble dyes like rhodamine B (Rh-B) is of utmost important. This study investigates the efficiency of new multifunctionalized superparamagnetic nanoparticles (MNP-Tppy) for the removal of cationic Rh-B from aqueous solution. To afford MNP-Tppy, the surface of MNP was covalently functionalized with terpyridine ligand to enable an anionic charge on the adsorbent. The results of characterization including Brunauer-Emmett-Teller (BET) analysis, thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), scanning electron microscope (SEM) and fourier transform infra–red spectroscopy (FTIR) indicate that this superparamagnetic nanoparticle functionalized with multiple nitrogen atoms was successfully synthesized. Adsorption experiments involving the effect of pH, time, temperature, adsorbent dose and adsorbate concentration show that the maximum adsorption of Rh-B using MNP-Tppy was observed at pH 9 and removal was observed to increase as solution pH increases. Similarly, time variation shows that adsorbate removal increases as adsorption time increases until the removal attained equilibrium at 15 min. Kinetic studies conducted among four kinetic models using the data obtained from effect of time indicate that the adsorption process can best be described by the pseudo-second order model. Isotherm studies conducted at three different temperatures revealed that Langmuir isotherm model fitted well for the equilibrium data with q_m value of 113.64 mg g⁻¹ and thermodynamic studies showed that the adsorption process involving the removal of Rh-B from aqueous solution by MNP-Tppy is spontaneous, endothermic and realistic in nature. Lastly, Reusability experiments indicate that MNP-Tppy can be regenerated and re-used.

Application of optimized large surface area date stone (Phoenix dactylifera ) activated carbon for rhodamin B removal from aqueous solution: Box-Behnken design approach

Box-Behnken model of response surface methodology was used to study the effect of adsorption process parameters for Rhodamine B (RhB) removal from aqueous solution through optimized large surface area date stone activated carbon. The set experiments with three input parameters such as time (10-600min), adsorbent dosage (0.5-10g/L) and temperature (25-50°C) were considered for statistical significance. The adequate relation was found between the input variables and response (removal percentage of RhB) and Fisher values (F- values) along with P-values suggesting the significance of various term coefficients. At an optimum adsorbent dose of 0.53g/L, time 593min and temperature 46.20°C, the adsorption capacity of 210mg/g was attained with maximum desirability. The negative values of Gibb^'s free energy (ΔG) predicted spontaneity and feasibility of adsorption; whereas, positive Enthalpy change (ΔH) confirmed endothermic adsorption of RhB onto optimized large surface area date stone activated carbons (OLSADS-AC). The adsorption data were found to be the best fit on the Langmuir model supporting monolayer type of adsorption of RhB with maximum monolayer layer adsorption capacity of 196.08mg/g.

Adsorption properties of cationic rhodamine B dye onto metals chloride-activated castor bean residue carbons

This work was aimed to evaluate the feasibility of castor bean residue based activated carbons prepared through metals chloride activation. The activated carbons were characterized for textural properties and surface chemistry, and the adsorption data of rhodamine B were established to investigate the removal performance. Zinc chloride-activated carbon with specific surface area of 395 m2/g displayed a higher adsorption capacity of 175 mg/g. Magnesium chloride and iron(III) chloride are less toxic and promising agents for composite chemical activation. The adsorption data obeyed Langmuir isotherm and pseudo-second-order kinetics model. The rate-limiting step in the adsorption of rhodamine B is film diffusion. The positive values of enthalpy and entropy indicate that the adsorption is endothermic and spontaneous at high temperature.

Sustainable development of coconut shell activated carbon (CSAC) & a magnetic coconut shell activated carbon (MCSAC) for phenol (2-nitrophenol) removal

Slow pyrolysis coconut shell (CSAC) and magnetic coconut shell (MCSAC) activated carbons were prepared, characterized and used for aqueous 2-nitrophenol (2-NP) removal.

Recent advances in new generation dye removal technologies: novel search for approaches to reprocess wastewater

In order to control the negative impacts of dyes on living organisms, several techniques and methodologies have been developed for their removal from industry effluents and other water bodies.