Removal of Cr(VI) from Aqueous Solutions by a Bacterial Biofilm Supported on Zeolite: Optimisation of the Operational Conditions and Scale‐Up of the Bioreactor

Abstract

The aim of this study was to investigate the feasibility of a bioreactor system and its scale-up to remove Cr(VI) from solution. The bioreactor is based on an innovative process that combines bioreduction of Cr(VI) to Cr(III) by the bacterium Arthrobacter viscosus and Cr(III) sorption by a specific zeolite. Batch studies were conducted in a laboratory-scale bioreactor, taking into account different operating conditions. Several variables, such as biomass concentration, pH and zeolite pre-treatment, were evaluated to increase removal efficiency. The obtained results suggest that the Cr removal efficiency is improved when the initial biomass concentration is approximately 5 g L -1 and the pH in the system is maintained at an acidic level. Under the optimised conditions, approximately 100 % of the Cr(VI) was removed. The scale-up of the developed biofilm process operating under the optimised conditions was satisfactorily tested in a 150-L bioreactor.

Removal of Chromium (VI) from Aqueous Solution Using Electro-Fenton Process

“…In order to avoid the effect of interference agents such as residual iron in the samples and produced sludge, all samples were centrifuged for 3 min (4000 rpm) using Centrifuge device (Hasan et al 2008;Anota et al 2006;Pazos et al 2010). The Cr(VI) removal was determined by the following Eq.…”

Simultaneous removal of Cr(VI) and phenol from synthetic binary solution using consortium culture of Bacillus sp. and E. coli immobilized on tea waste biomass in packed bed reactor

“…(17) and it was compared from experimental values of k p for different values of n is given in Table 7 and Table 8 for Cr(VI) and phenol, respectively. The effect of flow rate on the biodegradation and bioaccumulation rate of phenol and Cr(VI) was investigated by calculating the biodegradation and bioaccumulation rate constant k p for phenol and Cr(VI).…”

“…[15] Candida sp. [16] Arthrobacter viscosus [17] Bacillus subtilis [18] and phenol reducing microorganism are Bacillus stearothermophilus [19] Pseudomonas putida [20] Pseudomonas flurorescens [21] Acinetobacter sp. [22] Rhodococcus erythropolis [23] Acinetobacter sp.…”

Role of Microorganisms in Permeable Reactive Bio-Barriers (PRBBs) for Environmental Clean-Up: A Review

“…Furthermore, several strains of this genus have been identified in degradation of aromatic compounds which include 4-fluorophenol, 4-chlorobenzoate, phenol, p-hydroxybenzoic acid and monoand dichlorinated biphenyls (Ferreira et al 2008;Karigar et al 2006). Amongst various identified strains, the species Arthrobacter viscosus have high potential as bioreactive medium in the PRBBs for many of the organic compounds such as diethylketone, phenol, chlorophenol, o-cresol (Costa et al, 2012;Quintelas et al, 2010) as well as metals (Lameiras et al, 2008;Pazos et al, 2010). Besides their degradation potential, A. viscosus, a non-pathogenic bacterium releases a high amount of viscous extracellular polysaccharides (Lopez et al, 2003).…”