Investigation of removal possibilities of chromium(III) oxide from water solution in the presence of albumins

Abstract

System destabilization is a highly desirable phenomenon during colloidal impurity removal from sewages and wastewaters. Therefore, in this study, the stability of chromium(III) oxide suspension in the absence and presence of albumins [bovine serum albumin (BSA), ovalbumin (OVA), human serum albumin (HSA)] was investigated. Based on the analysis of experimental results, i.e., measurements of adsorption amount, electrokinetic potential, and metal oxide surface charge density as well as system stability, the mechanism of the suspension stabilization/destabilization was proposed. The examined system without the albumins is relatively stable at pH 3, 4.6, and 9 (TSI = 34.8, 36.6, 34.22, respectively), which is associated with the electrostatic stabilization phenomenon. In turn, the least stable is the suspension at pH 7.6 (TSI = 55.43). This is the result of the adsorbent zero surface charge. Regardless of solution pH, the BSA, OVA, or HSA adsorption causes an increase in the system stability (17.55 < TSI < 30). Probably, the steric stabilization is involved in this phenomenon, which results from the mutual repulsion of the adsorption layers formed on the solid surface. Thus, it can be concluded that the albumin presence in the industrial wastewaters impedes the chromium(III) oxide removal.