Characterization and application of polysaccharides produced by Pseudomonas atacamensis M7D1 for chromium (III)...

The wastewater from various industries contaminated with heavy metals poses significant environmental challenges. Biosorption has emerged as a widely used method for removing heavy metals from industrial wastewater. Pseudomonas atacamensis M7D1 is known to produce polysaccharides, but the potential of its polysaccharides as an adsorbent for heavy metal removal still needs to be explored. This study investigated the ability of the extracellular polymeric substances (EPS), primarily composed of polysaccharides, from P. atacamensis M7D1 to adsorb Cr(III) from tannery effluent. The research involved EPS production, physicochemical characterization, and Cr(III) adsorption assessment. The maximum EPS production was 780 mg/l, which increased by 3.4 times (2670 mg/l) with the addition of NaCl. The produced EPS exhibited excellent temperature tolerance and high molecular weight (3.6 × 10⁵ g/mol). The optimal conditions to achieve maximum Cr(III) adsorption were an EPS concentration of 1.5 g/l, pH 4, and a temperature of 75 °C. These findings suggest that the EPS of P. atacamensis M7D1 has significant potential as an effective adsorbent for removing Cr(III) from contaminated wastewater.