Removal of Heavy Metals from Aqueous Solution by Using Low Cost Rice Husk in Batch and Continuous Fluidized Experiments

Abstract

Abstract-This study aims to evaluate the performance efficiency of the proposed adsorbent (rice husk). The adsorptive capacity and removal efficiency of the rice husk were evaluated for the removal of heavy metals of (Cd, Pb and Cr) from aqueous solutions. The results showed the following removal efficiencies: (97.96% for Cd, 90% for Pb, and 84% for Cr). Adsorbent loading capacities for cadmium determined by batch studies were verified through continuous column experiments (fluidized bed). It was found that the maximum adsorption capacity of the candidate adsorbent (5.54) mg/g in Cd batch system. A set of equilibrium isothermal experiments were conducted and fitted with two models; Langmuir and Freundlich. The equilibrium isotherms of rice husk were found to be of a favorable type and Freundlich isotherm model gave the best fit to represent the experimental data of this system with correlation coefficient equals to 0.9934. Eleven continuous experiments were carried out in fluidized bed column to study the effect of initial concentrations, bed depth and flow rate on the performance of adsorption process. Also it was made a comparison between the efficiency of the rice husk adsorbent in removing of Cd(II) with the well-known adsorbent of activated carbon in continuous fluidized bed process. The results proved that the rice husk to be an efficient and economic adsorbent for the removal of different heavy metals from wastewater.Index Terms-Heavy metals, adsorption, rice husk, batch experiment, continuous fluidized bed experiments.

Removal of Tetracycline from Wastewater Using Circulating Fluidized Bed

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Synthesis and Characterization of Rice Husk Biochar and its Application in the Adsorption Studies of Lead and Copper

“…They include membrane filtration, electrocoagulation, reverse osmosis, ion exchange, precipitation, and solvent extraction. However, these methods have the drawbacks of the high cost of purchasing and maintenance of the instruments, expensive chemicals are required, and also the formation of chemical sludge [5].…”

Preparation and characterization of rice husk adsorbents for phenol removal from aqueous systems

“…However, thermochemical conversion of rice husk, such as by pyrolysis, gasification, and combustion, can be used to generate value-added by-products [ 8 ], and thus substantially reduce the pressure on the environment. Rice husk has been extensively utilized to adsorb phenolic compounds [ 1 , 9 , 10 ], copper [ 11 – 13 ], lead [ 13 , 14 ], hexavalent chromium [Cr(VI)] [ 15 ], malachite green [ 16 ], 2, 4-dichlorophenol [ 17 ], cadmium [ 11 , 14 , 18 , 19 ], zinc and manganese [ 11 , 13 ], selenium [ 18 ], humic acids [ 20 ], oil and oil products [ 21 ], dye [ 22 ], and fluoride [ 23 ].…”