Adsorptive removal of reactive dyes from aqueous solution using activated carbon synthesized from waste biomass materials

Abstract

High-activity mesoporous carbons were prepared from wild almond shells and coir pith by phosphoric acid activation and applied for adsorption of the dyes, C.I. Reactive Red 2 and C.I. Reactive Yellow 145A. The BET surface areas of these activated carbons were found to be 1133.25 and 1210.58 m 2 /g, respectively. The equilibrium data were best described by the Langmuir isotherm in all the cases. The maximum dye adsorption capacity shown by the activated carbon produced from coir pith was 2022.9 mg/g for C.I. Reactive Red 2 and 1694.3 mg/g for C.I. Reactive Yellow 145A at 60°C with initial concentration of 1000 mg/L. Pseudo-second-order kinetic model gave a good fit, with the intraparticle diffusion being one of the essential rate-controlling steps. Thermodynamic analysis revealed that the adsorption of both the dyes on activated carbons was spontaneous and endothermic in nature. The t test analysis showed that the difference between adsorption capacities of the produced activated carbons was not significant at 95 % confidence level at all the temperatures studied.

Crosslinked Egg White as Eco‐Friendly, Reusable, and Cost‐Effective Biosorbent for Rapid Removal of Indigo Carmine

“…Sometimes, increase in initial dye concentration causes an increase in the loading capacity of the adsorbent. This phenomenon rarely occurs and is due to the high driving force for mass transfer at a high initial dye concentration …”

“…This phenomenon rarely occurs and is due to the high driving force for mass transfer at a high initial dye concentration. [31,32] In the present study, the effect of initial dye concentration was studied with changing IC concentration from 25-200 mg g À1 at pH 2 (25 mL, 0.05 g of biosorbent). Figure 4a shows the effect of initial dye concentration on biosorption.…”

Adsorptive removal of naphthalenesulfonic acids using wild almond shell activated carbon from aqueous solution

“…As the solution pH increased, adsorption of both the acids onto AC decreased. At pH 2.0, the AC is positively charged since its pH of zero point charge is 6.5 [26]. The greater adsorption of H-and g-acid onto AC is attributed to the electrostatic attractions between AC and ionized sulfonic acid groups of the adsorbate.…”

Adsorption of Reactive Dyes from Wastewater Using Cationic Surfactant-modified Coffee Husk Biochar

“…Furthermore, many studies have reported that adsorption with biochar is effective in the removal of reactive dyes from aqueous solution, such as reactive black 5 removal using palm shell biochar (Mook et al, 2016), reactive red 2 removal using coir pith biochar (Thitame and Shukla, 2016), and reactive blue 171 removal using Enteromorpha prolifera biochar (Sun et al, 2013). Besides, surface modification of the biochar with surfactants could enhance the adsorption capacity and ensure environmental friendliness (Puasa et al, 2018).…”