Growth and haevy metal removal by Klebsiella aerogenes at different pH and temperature

Abstract

A strain of Klebsiella aerogenes isolated from Rustamiyah Station for treatment of wastewater was examined for its ability to grow in a media supplimented with maximum tolerance concentrations of Pb⁺⁺, Zn⁺⁺, Ni⁺⁺ and Cd⁺⁺, separately, at different temperature and initial pH. The results indicated that at 28°C and during the first 24hr, Pb⁺⁺ and Ni⁺⁺ had no effect on the growth of the bacteria, while the presence of Zn⁺⁺ and Cd⁺⁺ decreased the cell count. The growth reached a maximum level after the second day and started to decrease gradually.

At 37°C, the bacterial count was less than that of 28°C in the presence of Pb⁺⁺ and Ni⁺⁺, while the presence of Zn⁺⁺ and Cd⁺⁺ had affected the growth slightly. No. bacterial multiplication occurred at 44°C. There was little difference between haevy metal removal at 28 and 37°C. At 44°C, no considrable removal took place.

In general, slightly acidic or neutral medium, was better for both the growth and metal removal.