Continuous Sorption of Chromium Ions from Simulated Effluents using Citric Acid Modified Sweet Potato Peels

Abstract

Adsorptive removal of chromium ion in aqueous medium using activated sweet potato peel (SPP) was studied in a laboratory-scale fixed bed column. Specifically, the effect of process parameters such as bed depth, flowrate and chromium ion concentration in aqueous solution, on the adsorption efficiency of the acid modified sweet potato peel was examined. Column adsorption analysis showed that at the flow rate of 0.5 cm3/min, bed height of 6 cm and column influent concentration of 30 mg/dm3, the optimum chromium (VI) ion removal of 87.5% was attained with the equilibrium adsorption capacity of 2.4548 mg/g. Continuous adsorption models such as Yoon-Nelson, Adam-Bohart and the Bed-Depth Service Time (BDST) model, were used to analyse the experimental data and based on correlation coefficient, BDST model best aligned with the obtained experimental data with correlation coefficient, R2, value of 96.43%. The bed capacity, No, and the rate constant, Ka, were calculated as 4.259 mg/dm3 and 0.01045 L/mgmin respectively at optimum column conditions. Results confirmed that acid modified SPP can be used to remove or reduce concentrations of Cr (VI) ions to allowable limits before disposal into water bodies.
 Keywords: Continuous sorption, chromium ions, sweet potato peel, kinetic isotherms, breakthrough curves

Journal of Water and Land Development

“…Considering the industrial applications of adsorption, the identification of the advance time is vital since it defines the operational limit of the column. This fact is defined as the time interval in which the output concentration is higher than the threshold established, however such saturation was not reached in this study [YAHYA et al 2020]. It was established that in the study time, the biomass can be used because they have a high capacity for heavy metal adsorption [MISHRA et al 2016].…”

Adsorption Study of Continuous Heavy Metal Ions (Pb2+, Cd2+, Ni2+) Removal Using Cocoa (Theobroma cacao L.) Pod Husks

“…According to the removal yields for both bed depth, it can be said that 7.5 cm bed has greater efficiency than the 4 cm bed for the removal of cadmium ions. These results may be caused due to the higher amount of adsorbent increases the presence of active sites of adsorption in the adsorbent surface [ 60 ] and the residence time; therefore, the diffusion of the ions is more effective, since the contact between the phases is more intimate as reported by Khalfa et al [ 61 ], who found that exhaustion time increased with the increase of bed depth from 2 to 6 cm. Cortés, R. [ 62 ] also evaluated the effect of two different bed depths (5 and 15 cm) for the removal of cadmium using natural zeolite.…”