Search

In this study, biochar derived from agricultural bio-wastes of rice husk was used as a biosorbent for dye sequestration of Basic Blue 41 (BB41) and Basic Red 09 (BR09) from the aqueous solution. The structural characteristics of the biochar were performed through TGA, BET, SEM, EDX, and FTIR. The experimental conditions proved that 80% of dye removal was attained in the optimal operating conditions (dosage of 6 g L−1 (BB41), 1 g L−1 (BR09), pH of 7 (BB41) and 8 (BR09), temperature of 35 °C, and initial dye concentration of 50 mg L−1). Four different isotherms models were used to describe the adsorption process. Based on the correlation coefficient and percentage of error values, BB41 and BR09 sorption revealed that Langmuir model has better fit when compared to other models. The maximum adsorption capacities of BB41 and BR09 on rice husk biochar are 17.596 mg g−1 and 168.49 mg g−1, respectively. The thermodynamic parameters △H

Pumpkin peel (Cucurbita pepo L.) and bracts of plantain flower (Musa acuminate) are cellulosic and bio-degradable agricultural wastes available in abundance. This paper is aimed at assessing their potential as adsorbents by modifying into activated carbon for the adsorption of turquoise blue dye (TB). The performance was evaluated by altering the adsorption parameters such as pH, dosage, temperature, and initial dye concentration. The batch adsorption experiments were carried out with a fixed RPM and suitable contact time with different temperature ranges. The adsorbents were characterized using FTIR and SEM techniques. Adsorption isotherm study was also carried out. Adequate samples were withdrawn during the experiments to find out the concentration of dye that is adsorbed using a UV-vis spectrophotometer. From the studies, it is observed that the adsorption efficiency of pumpkin peels (PP) is higher than that of bracts of plantain flower (BP) and found to be promising alternatives for the removal of dye. Adsorption studies were modeled using Freundlich and Langmuir adsorption isotherms, and it was well fitted with Langmuir isotherm. ANN result showed that Levenberg-Marquardt (LM) algorithm was the best model bearing coefficient of regression (R2 = 0.9968) and mean square error (MSE =0.00013), on the dye removal. These results are very promising and, in our opinion, establish a milestone to a vital research field.

This study reported that the preparation and characterization of multiwalled carbon nanotubes supported iron phthalocyanine (FePc/MWCNTs) composite catalyst and examined the treatment efficiency using wastepaper recycling mill wastewater in a microbial fuel cell (MFC). The MWCNTs were uniformly decorated over the FePc nano particles. The obtained catalyst was characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction analysis, UV-visible spectrophotometry, energy-dispersive X-ray analysis (EDAX) Fourier-transform infrared spectroscopy (FTIR) analysis, BET analysis, Raman spectra, thermal gravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) analysis. In addition, the oxygen reduction reaction (ORR) of the catalyst has been investigated by cyclic voltammetry, linear sweep voltammetry analysis, and electrochemical impedance spectroscopy (EIS) analysis. There was an efficient removal of chemical oxygen demand (COD) with 87% and 0.650 W/m2 of power density achieved at 110 h of contact time. From this investigation, it is understood that the oxygen reduction reaction (ORR) of the FePc catalyst was improved by MWCNT supporting material. The obtained results suggested the excellent ORR activity of nanostructured FePc/MWCNTs as a promising alternative to conventional platinum-based electro catalyst for fuel cells.

The current research article investigates the remediation of methylene blue (MB), in continuous operation mode, utilizing compost as an adsorbent. The adsorbent was prepared from the water hyacinth plant waste by using effective microorganism (EM) which acts as a decomposer for the materials used. EM contains the various microbes that are responsible for the decomposition and it is available in the dormant liquid form which requires activation. The researcher performed a continuous study in which the following parameters are varied—bed complexity and flow rate. The findings of the study revealed that a maximum uptake of 301.79 mg/g was achieved and the removal efficiency is found to be around 85.44%. The overall sorption time zone, exhaustion time, breakthrough time, and volume of dye treated are also calculated. Modeling of experimental data is performed using bed depth service time (BDST) model and Thomas model. 0.01 M HCL was used as an elutant for the regeneration studies and maximum desorption efficiency of 85.44% was obtained.