Simultaneous cleanup of Reactive Black 5 and cadmium by a desert soil bacterium

Abstract

Multi-contaminated industrial wastewaters pose serious environmental risks due to high toxicity and non-biodegradability. The work reported here evaluated the ability of Pseudomonas aeruginosa strain Gb30 isolated from desert soil to simultaneously remove cadmium (Cd) and Reactive Black 5 (RB5), both common contaminants in various industrial effluents. The strain was able to grow normally and decolorize 50 mg L -1 RB5 within 24 h of incubation in the presence of 0.629 m mol L -1 of Cd 2+ . In order to evaluate strain performance in RB5 detoxification, a cytotoxicity test using Human Embryonic Kidney cells (HEK293) was used. Cadmium removal from culture media was determined using atomic adsorption. Even in presence of (0.115 + 0.157 + 0.401 +0.381) m mol L -1 , respectively, of Cr 6+ , Cd 2+ , Cu 2+ and Zn 2+ in the growth medium, strain Gb30 successfully removed 35% of RB5 and 44%, 36%, 59% and 97%, respectively, of introduced Zn 2+ , Cu 2+ , Cr 6+ and Cd 2+ , simultaneously. In order to understand the mechanism of Cd removal used by P. aeruginosa strain Gb30, biosorption and bioaccumulation abilities were examined. The strain was preferentially biosorbing Cd on the cell surface, as opposed to intracellular bioaccumulation. Microscopic investigations using AFM, SEM and FTIR analysis of the bacterial biomass confirmed the presence of various structural features, which enabled the strain to interact with metal ions. The study suggests that Pseudomonas aeruginosa Gb30 is a potential candidate for bioremediation of textile effluents in the presence of complex dye-metal contamination.

Ecotoxicological and health concerns of persistent coloring pollutants of textile industry wastewater and treatment approaches for environmental safety

“…Among these microorganisms, bacteria have strong potential for the treatment of TIWWPs because these are easy to culture with fast life phase and capable to grow on different substances [57]. Further, bacteria can degrade or convert many toxic compounds into non-toxic products [5].…”

“…Further, bacteria can degrade or convert many toxic compounds into non-toxic products [5]. For example, many bacterial species like Arthrobacter, Pseudomonas, Bacillus, Aeromonas hydrophila and Lysinibacillus are reported capable to remove dyes, dissolved solids and heavy metals as well as reduce their toxicity upto a significant level [5,15,57]. Further, for the effective treatment of TIWW, various workers have reported that microbial consortium is more effective as compared to the axenic cultures (Table 3).…”

Diversity of Synthetic Dyes from Textile Industries, Discharge Impacts and Treatment Methods

“…Azo dyes account for the largest category (60-70%) of the total synthetic dyes industry due to their versatility, cost-effectiveness, simplicity of utilization, high stability and high intensity of the color [26,27]. This dye has a prominent chromophore (-N = N-) structure, ensuring the solubility of the dyes in water and its attachment to the fiber [28,29]. Azo dyes are classified into three groups (mono, di and poly) depending on the number of azo groups in their structure (Figure 1).…”

Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants

“…When the total monomer concentration is low, the probability of contact and collision between the monomers is low, so that the substitution and addition reactions cannot proceed ultimately, and the molecular chain of the generated organic high molecular polymer is short. The generation amount is small [26]. On the other hand, the total monomer concentration increases.…”