Preparation of activated carbon from dried pods of Prosopis cineraria with zinc chloride activation for the removal of phenol

Abstract

Utilization of agrowaste materials for the production of activated carbon, as an excellent adsorbent with large surface area, is well established industrially, for dephenolation of wastewater. In the present work, dried pods of Prosopis cineraria-a novel and low-cost agrowaste material-were used to prepare activated carbons by zinc chloride activation. Batch adsorption experiments were carried out to study the effects of various physicochemical parameters such as initial phenol concentration, adsorbent dose, initial solution pH, and temperature. Pseudo-first-order second-order and diffusion kinetic models were used to identify the possible mechanisms of such adsorption process. The Langmuir and Freundlich equations were used to analyze the adsorption equilibrium. Maximum removal efficiency of 86 % was obtained with 25 mg L(-1) of initial phenol concentration. The favorable pH for maximum phenol adsorption was 4.0. Freundlich equation represented the adsorption equilibrium data more ideally than the Langmuir. The maximum adsorption capacity obtained was 78.32 mg g(-1) at a temperature of 30 °C and 25 mg L(-1) initial phenol concentration. The adsorption was spontaneous and endothermic. The pseudo-second-order model, an indication of chemisorption mechanism, fitted the experimental data better than the pseudo-first-order Lagergren model. Regeneration of spent activated carbon was carried out using Pseudomonas putida MTCC 2252 as the phenol-degrading microorganism. Maximum regeneration up to 57.5 % was recorded, when loaded phenol concentration was 25 mg L(-1). The data obtained in this study would be useful in designing and fabricating an efficient treatment plant for phenol-rich effluents.

Application of response surface methodology for Cd(II) adsorption on maize tassel-magnetite nanohybrid adsorbent

“…The ZPC, moisture content, particle size, total ash content, bulk density, iodine number, BET surface area and total pore volume of the MT-MN were determined using procedures reported elsewhere [29,30]. The zero point charge (ZPC) and surface functional groups of the adsorbent were determined by powder addition method and Boehm titration, respectively [19].…”

“…The total ash content was 3.12%, showing that the adsorbent had a good quality and could have good adsorption capacity [29,30]. The bulk density affects the rate of adsorption of metal ions onto MT-MN.…”

Response surface methodology for optimization of Cd(II) adsorption from wastewaters by fabricated tartaric acid-maize tassel magnetic hybrid sorbent

“…A higher moisture content may demand an additional weight of the adsorbent during the adsorption process. The total ash content of the adsorbent was determined to be 2.86%, implying it could have good adsorption efficiency towards Cd(II) ions [31,32]. The bulk density of TAC-MH was 0.83 mg/L indicating its suitability for the adsorption process.…”

Effect of operating parameters on dye wastewater treatment using Prosopis cineraria and kinetic modeling

“…The COD removals versus time observations were fitted using three different kinetic models. The pseudo-second-order equation was proposed for solid phase sorption [20] and the linear form of this equation presented as Eq. (3) was fitted.…”