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Separation under the influence of magnetic field has been widely explored to tackle environmental issues related to centrifuging and filtration. In this work, activated carbon produced from pomegranate husk (PHAC) using dual stage chemical activation was magnetized with iron salts and used for adsorption of 4-chlorophenol (4CP) from the synthetic wastewater. Adsorption experiments were conducted in batch mode to determine the removal efficiency of magnetized activated carbon pomegranate husk (MPHAC) as a function of initial 4CP concentration, solution pH, MPHAC dose, contact time, ionic strength, and temperature. The rough surface of MPHAC containing pores on the surface had a total pore volume of 0.623 cm 3 /g with a surface area of 1168 m 2 /g. The 4CP adsorption was highly dependent on ionic strength, solution pH, and temperature; the equilibrium was reached in 60 min of contact time. Kinetic models and equilibrium isotherms were employed to assess the fitness of adsorption data; results were fitted best with the Liu model giving maximum adsorption capacities of 446.89 ± 20.75 and 183.64 ± 17.85 mg/g for 1 and 2 g/L of MPHAC, respectively. For the investigation of the adsorption kinetics, Avrami fractionary-order model showed the best fit of the experimental data compared to other kinetic models., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In the present work, the fabrication of activated carbon (AC) from pomegranate husk (PHAC) by dual consecutive activation processes with ZnCl 2 and NaOH as a chemical agent was studied. After that, the synthesized PHAC was used for adsorption of 4-chlorophenol (4CP) as a highly toxic compound for the human health and the environment. Different analytical techniques characterized the synthesized PHAC using ZnCl 2 /NaOH. The isotherms of N 2 adsorption and desorption showed that total pore volume (V total ) and specific surface area (S BET ) of PHAC were 0.404 cm 3 /g and 811.12 m 2 /g, respectively. The 4CP adsorption by PHAC studies revealed that the highest 4CP removal efficiency was 100% and obtained at 50, 100, and 150 mg/L of 4CP concentration with 2.5 g/L of PHAC. Based on the batch experiments, the highest 4CP removal was achieved at pH 6, 2.5 g/L of PHAC, and contact time of 60 min. The 4CP adsorption data of equilibrium and kinetics were successfully fitted to Langmuir's isotherm and Avrami fractional order.

The compound 4-chlorophenol (4-CP) is known to be a highly toxic compound having harmful effects on human health and the environment. To date, the removal of 4-CP by advanced oxidation processes (AOPs) has attracted tremendous attentions. The persulfate-based AOPs show higher oxidation, better selectivity, wider pH range, and no secondary pollution compared to the traditional Fenton-based AOPs. Carbon materials with low cost and chemical stability are useful for the activation of persulfate (PS) to produce reactive species. Herein, we magnetized activated carbon synthesized from pomegranate husk (MPHAC). By using 4-CP as a model organic pollutant, tests of the activation of PS via MPHAC for the removal of 4-CP were performed. Batch processes were carried out to study the influence of different parameters (initial solution pH, catalyst dose, PS dose, and initial 4-CP concentration) on the adsorption of 4-CP on PHAC with ferric oxide (Fe3O4-PHAC). The results show that under the obtained optimal conditions (MPHAC dose: 1250 mg/L, PS dose: 350 mg/L, solution pH 5, an initial 4-CP concentration of 100 mg/L, and a contact time of 60 min), a 4-CP removal factor of 99.5% was reached by the developed MPHAC/PS system. In addition, it was found that reusing MPHAC in five successive cycles is feasible because the catalyst in the last cycle kept exhibiting a high potential for 4-CP absorption, indicating the economically viable procedure. Therefore, this study provides a comprehensive understanding on the degradation of 4-CP by the magnetized activated carbon persulfate system. [ABSTRACT FROM AUTHOR]