Enhancement of azo dye bioremediation using chemically modified polypropylene biocarrier: Comparative analysis and kinetic modeling

Abstract

The present study focused on the surface modification of conventional polypropylene (PP) biocarrier via chemical oxidation and calcium coating for the azo dye degradation. The chemical treatment resulted in the hydrophobic PP (contact angle of 94°) into a hydrophilic material (contact angle of 70°), which ultimately enhanced the bacterial adhesion. In addition, the batch study revealed that the quantity of fixed biomass and the extracellular polymeric substance secretion was increased by 1.51 and 2.13 times, respectively, in the case of the modified biocarrier (i.e., KMNO4-Ca-PP). The performance of the biocarriers for Acid blue 113 dye removal was studied in moving bed biofilm reactor (MBBR) systems by optimizing process parameters, namely dye concentration and hydraulic retention time. The modified biocarriers filled MBBR showed maximum dye removal efficiency of 83.75 % at optimized conditions. Moreover, the modified Stover-Kincannon and Monod models were well fitted with the experimental values.