Application of Mixed Microbial Culture Biofilms for Manganese (II), Cobalt (II), and Chromium (VI) Biosorption by Horizontal Rotating Tubular Bioreactor

Abstract

Industrial wastewater contaminated with toxic heavy metals is a big ecological and environmental problem. Applying biological materials to effectively remove and recover heavy metals from contaminated wastewaters has gained importance as promising alternative to conventional treatment techniques. Thus, the objective of the presented paper is the investigation of the capability of microorganisms, isolated from polluted (metal-laden) soil, to biosorb toxic metals from aqueous solutions. Biosorption process for heavy metal removal was conducted in a new pilot scale horizontal rotating tubular bioreactor (HRTB). This bioreactor provides conditions for microorganism'sg r o w t hi naf o r mo fs u s p e n d e d cells and biofilm. Biofilm is capable to protect microorganisms from interaction with toxic metals in the surrounding environment. Three metals were selected as model examples: cations of manganese and cobalt and hexavalent chromium (an oxyanion). Optimized bioreactor conditions, namely, medium inflow rate (F) and bioreactor rotation speed (n) for biofilm formation and metal removal were monitored, and under optimized bioreactor conditions, promising results were obtained.

Role of Exopolysaccharides of Pseudomonas in Heavy Metal Removal and Other Remediation Strategies

“…This ultimately reduced the overall biofilm density. This is especially important for heavy metal removal since high-volumetric-density biofilms generally exhibit higher sorption capacities in comparison with low-density biofilms that are characterized by the low content of ExPs [ 70 ]. Similarly, Abinaya Sindu and Gautam [ 71 ] noted that the exposure of the P. aeruginosa MTCC 2297 strain to metal fatty acid salts that included cadmium(II) stearate led to poor development of the biofilm with the least amount of ExPs.…”