Removal of Cr(VI) from aqueous solutions by using activated carbon supported iron catalysts as efficient adsorbents

Abstract

Purpose The purpose of this paper is to focus on the removal of hexavalent chromium [Cr(VI)] from wastewater by using activated carbon-supported Fe catalysts derived from walnut shell prepared using a wetness impregnation process. The different conditions of preparation such as impregnation rate and calcination conditions (temperature and time) were optimized to determine their effects on the catalyst’s characteristics. Design/methodology/approach The catalyst samples were characterized using thermogravimetric analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption of Cr(VI) by using using activated carbon supported Fe catalysts derived from walnut shell as an adsorbent and catalyst was investigated under different adsorption conditions. The parameters studied were contact time, adsorbent dose, solution pH and initial concentrations. Findings Results showed that higher adsorption capacity and rapid kinetics were obtained when the activated walnut shell was impregnated with Fe at 5 per cent and calcined under N2 flow at 400°C for 2 h. The adsorption isotherms data were analyzed with Langmuir and Freundlich models. The better fit is obtained with the Langmuir model with a maximum adsorption capacity of 29.67 mg/g for Cr(VI) on Fe5-AWS at pH 2.0. Originality/value A comparison of two kinetic models shows that the adsorption isotherms system is better described by the pseudo-first-order kinetic model.

Preparation of activated carbon from biomass and its’ applications in water and gas purification, a review

“…Physically activated Fe-supported walnut shell AC (Derdour, Bouchelta, Khorief Naser-Eddine, Medjram, & Magri, 2018) and Ceiba pentandra hulls AC (Gonz alez-Garc ıa, 2018) prepared for the removal of chromium appeared to have very low adsorption capacities that are < 30 mg/g meanwhile chemically activated date pits AC (Ahmed, 2016a) and chestnut oak shells AC (Niazi, Lashanizadegan, & Sharififard, 2018) have higher adsorption capacities of 120.5 mg/ g and 85.47 mg/g. This shows that for the removal of chromium, chemically activation is preferable to optimize the adsorption process.…”

Optimization of adsorption of Cr(VI) from aqueous solution by Leucaena leucocephala seed shell activated carbon using design of experiment

“…In recent time, rapid removal of Cr(VI) from water/wastewater has been proven to be possible by activated carbonbased adsorbents. Nowadays research is therefore focused on derivation of adsorbents from carbon-based materials such as coconut tree sawdust (Selvi et al 2001), walnut shell (Derdour et al 2018), hazelnut shell (Kobya 2004), peanut shell (Al-Othman et al 2012), paper mill sludge (Gorzin and Abadi 2017), Luffa sponge (Wang et al 2016), corn cob (Murugesan et al 2013), Delonix regia pods (Renuga et al 2010), bamboo waste (Dula et al 2014) and melon husk (Akpan et al 2015). Another carbonaceous material which can serve as a potential starting ingredient for an adsorbent is Leucaena leucocephala seed shell.…”

Fabrication of Highly Microporous Structure Activated Carbon via Surface Modification with Sodium Hydroxide

“…Carboxylic functional groups were observed in 2337 cm −1 [31,32] for the PKS-activated carbon modified with 25% NaOH. Moreover, the peaks at 3740 cm −1 and 3400 cm −1 corresponding to the -NH 2 stretching and -OH stretching of hydroxyl groups [33] were observed in both of the NaOH surface modified samples. CS-activated carbon modified with NaOH caused the appearance of several new absorption peaks.…”

“…CS-activated carbon modified with NaOH caused the appearance of several new absorption peaks. These peaks can be classified as follows: C≡C group (2348 cm −1 ) [33] and C−N stretching vibration absorption peaks (1221 cm −1 ) [34]. Alternative polymerization conditions occurred with NaOH surface modification, which serves as a useful control to demonstrate the importance of surface area for rapid micropollutant removal [35].…”