Biodecolorization of Reactive Dyes Using Biochar Derived from Coconut Shell: Batch, Isotherm, Kinetic and Desorption Studies

Abstract

The present research examines the remediation of three different reactive dyes namely Reactive Orange 16 (RO16), Reactive Black 5 (RB5) Reactive Blue 19 (RB19) using biochar derived from coconut shell in an aqueous solution. The batch study showed that the pH of 2, temperature of 35 °C and biochar dosage of 1 g/L is the optimum condition for the maximum adsorption of reactive dyes. The adsorption isotherms demonstrated the highest uptake of 73.03 mg/g, 56.92 mg/g and 57.06 mg/g for RO16, RB5 and RB19 respectively. Isotherm studies predicted that the Toth model is the best fit model with a correlation coefficient greater than 0.9837. The kinetic study was carried out and results indicated that 120 minutes as an equilibrium time, the pseudo‐first‐order kinetic model and pseudo‐second‐order kinetic model were used to fit the experimental data. Finally, the reusability of the biochar was studied by using different elutants, sorbent to liquid ratio and regeneration cycles.

Industrial dye removal from tannery wastewater by using biochar produced from tannery fleshing waste: a road to circular economy

“…In general, it is stated that sorption is considered as physical sorption if the enthalpy lies in the range between 2.1 and 20.9 kJ•mol −1 , while if the enthalpy lies in between 20.9 and 418 kJ•mol −1 , then it is termed as chemical sorption [52]. Since in our case the value of ∆H was higher than 20.9 kJ•mol −1 , for the three tested biochars, it is suggested that SFR anionic dye sorption onto biochar surface takes place due to chemisorption [53,54]. The findings from the adsorption thermodynamics study were in agreement with the results of adsorption kinetics and isotherm studies demonstrated earlier, which confirm chemisorption mechanism for CR anionic dye.…”

Effect of Temperature and MgCl2 Concentration on the Catalytic Pyrolysis of Malt Waste Using Response Surface Methodology

“…Regarding possible biochar applications, some works in the literature recommend its use as an adsorbent for the decolorization of reactive dyes, [80–82] supercapacitor, [83] soil conditioner [84] and CO 2 adsorption material [85] . The high HHV of biochar from non‐catalytic pyrolysis of MW can allow its use as a renewable energy source, while the catalytic biochar can be used as soil amendment and a Mg source for the soil [86] …”

Biochar from sugarcane bagasse for reactive dye adsorption considering a circular economy approach

“…The acid pH values (lower than 3) were suggested to maximum removal of RB19 using different adsorbents. [24][25][26][28][29][30][31]…”

“…Some studies presented the feasibility of the biochar for RB19 removal, such as grapefruit peel. 24 dried pulp and paper sludge, 25 citrus waste, 26 coconut shell, 27,28 pomegranate seed powder, 29 rice straw ash 30 and pistachio shell. 31 Although there are several studies involving the RB19 removal by different activated biochar, no studies were carried out using activated biochar produced with sugarcane bagasse (AB).…”