The use of calcium alginate-activated carbon composite material in fixed-bed columns for methylene blue removal from wastewater

Abstract

Four calcium alginate (ALG)-activated carbon (AC) composites were prepared by ionic gelation method using calcium alginate and Merck activated carbon at different ratio ALG/AC ranging from 1/1 to 1/4. The obtained spherical beads samples were characterized by scanning electron microscopy, zero point of charge (pHZPC) and Fourier transform infrared spectrometry spectroscopy and tested for methylene blue removal from aqueous solutions in continuous mode. The bed depth service time model adequately described methylene blue adsorption onto the prepared composites. Parameters effecting breakthrough curves such as bed depth, flow rate and inlet dye concentration were investigated using Adams—Bohart, Thomas, and Yoon—Nelson models which showed good fit for the breakthrough curves. It has been found that the amount of adsorbed dye decreases with increas-ing ALG/AC ratio and Ct/C0 values reaching a maximum value of 40.70 mg/g. Adsorption through a packed bed column is a feasible and economical technique for the removal of dyes. We can conclude that the composite material of calcium alginate and activated carbon can effectively be used to remove dyes from wastewater.