Environmental Engineering,
Behnam mousazadeh; Nima . mohammadi; Touba hamoule
Abstract
Ziziphus nuts are abundant in Khuzestan province, Iran, and are considered as an unwanted natural biomass waste. The present study is aimed to develop low-cost activated carbon from Ziziphus nuts as a new precursor for the removal of phosphate from the water environment.the iron oxide modification was ...
Read More
Ziziphus nuts are abundant in Khuzestan province, Iran, and are considered as an unwanted natural biomass waste. The present study is aimed to develop low-cost activated carbon from Ziziphus nuts as a new precursor for the removal of phosphate from the water environment.the iron oxide modification was performed to simultaneously facilitate the adsorbent separation via a simple magnetic process and increase the phosphate removal capacity. The iron oxide/activated carbon composite (IOAC) was characterized using XRD, EDX, SEM, and BET methods. The specific surface area for IOAC reached 569.41 m2/g, comparable to that of the commercial activated carbon. While other similar derived-from-biomasses activated carbon reached the phosphate removal capacity of around 15 mg/g, IOAC demonstrated the excellent phosphate removal performance of as high as 27 mg/g. Also, IOAC showed fast adsorption kinetics, achieving equilibrium in only 60 minutes. According to the results, the pseudo-second-order kinetic model was more consistent with the data related to the phosphate adsorption onto the adsorbent than the pseudo-first-order model. The adsorption results using Langmuir, Freundlich, and Webber-Morris diffusion models were interpreting. The maximum Langmuir adsorption capacity was calculated to be 27 mg/L. The adsorbent was removed from the aqueous solution via a simple magnetic process.
Reaction Engineering, Kinetics and Catalysts,
Z. Shojaei; E. Iravani; M.A. Moosavian; M. Torab-Mostaedi
Volume 13, Issue 2 , April 2016, , Pages 3-21
Abstract
Adsorption of Ce(III) from aqueous solution by amino phosphate modified nano TiO2 was investigated. Effects of pH of solution, adsorbent dose, contact time, initial metal concentration and temperature were examined. Experimental data were fitted well by the pseudo second order model. Adsorption was well ...
Read More
Adsorption of Ce(III) from aqueous solution by amino phosphate modified nano TiO2 was investigated. Effects of pH of solution, adsorbent dose, contact time, initial metal concentration and temperature were examined. Experimental data were fitted well by the pseudo second order model. Adsorption was well described by Freundlich isotherm model with a maximum adsorption capacity of 25 mg g-1. According to the obtained thermodynamic parameters, the adsorption was a spontaneous and endothermic process. Effect of interfering cations was studied. The presence of Ca and Mg ions up to 150 mg L-1 showed no considerable effect on the adsorption of Ce(III). Regeneration of adsorbent was performed using HNO3 with efficiency greater than 84%. The quantities of distribution coefficient (Kd), the affinity of metal for retention onto solid phase, was the higher for Ce(III) than La(III). Due to the high sorption capacity, being plentiful and low cost it is concluded that the use of amino phosphate mofified nano titania as an appropriate adsorbent is promising for the removal of lanthanides especially Ce(III) from contaminated sites.