Optimizing Cell Preparation Technique to Enhance Adsorption Capacity of Pseudomonas Putida 5-X to Heavy Metal Ions

A heavy metal accumulation bacterium Pseudomonas putida 5-x isolated from electroplating effluent was used as biosorbent for heavy metal removal from wastewater. In order to compete with physical adsorbent, the optimization of the cell preparation technique for further improving its heavy metal adsorption capacity was conducted. Experimental results showed that the variation of medium compositions and cell growth age, and different cell pre-treating technique would result in the variation of the cell surface components and structural, hence the variation of adsorption capacity of the cell to heavy metal ions. With optimum cell culture conditions and pretreatment technique, the Cu^{2 +} adsorption capacity of the cell was obviously increased from 51.2 mg g^{− 1} to 89.6 mg g^{− 1}. The optimised P. putida 5-x cell could be reused at least five cycles to remove heavy metal ions from electroplating effluent with about 95% removal efficiency.

Key words:

• Biosorption
• Cell culture
• Cell growth age
• Cell pretreatment
• Copper.

ACKNOWLEDGMENTS

The work was supported by the China Natural Science Foundation (No. 50222204).

Notes

¹Non-nutrient-limiting medium;

²Nitrogen source-limiting medium;

³Sulfate-limiting medium;

⁴Phosphor-limiting medium;

⁵Carbon source-limiting medium.

*Cu^{2 +} adsorption capacities were determined in a pH 6.5 solution containing 50 mg L^{− 1} Cu^{2 +} and 0.5 g L^{− 1} biosorbent. All data was average value of three experimental results.

¹All data are the average values of five adsorption/desorption cycles.