Biosorption by Escherichia coli bacteria of polluting metals chromium Cr (VI) and copper Cu (II)

The increasing activity of the electroplating industry on environmental pollution comes from heavy metals such as chromium Cr(VI) and copper Cu(II) which are toxic. One method of waste treatment is the biosorption method using microorganisms, namely bacteria. This study aims to evaluate the biosorption ability of Escherichia coli towards Cr(VI) and Cu(II) metals, as well as the optimum conditions and ratio of absorbed metals. This study was conducted experimentally by culturing Escherichia coli in nutrient broth medium that had been given standard solutions of Cr(VI) and Cu(II) metals with varying concentrations (4, 8, 12 and 16 ppm) and ratios (1:1, 1:3 and 3:1). Metal absorption was analyzed using a UV-Vis spectrophotometer. The results showed that Escherichia coli was able to absorb both metals. The optimum biosorption percentage for Cr(VI) was 83.40% at a total concentration of 4 ppm in a 1:3 ratio, while Cu(II) was 75.08% at a 3:1 ratio, and the bacteria achieved maximum absorption capacity on day 6.