Biosorption of Heavy Metals from Aqueous Solution by the Novel Biosorbent Pectobacterium Sp ND2

In this study, the biosorption of heavy metal ions such as Cd(II), Cu(II), Zn(II), and Pb(II), was investigated using a new bacterial species isolated from the soil of the industrial zone of Xuzhou city. Sequence analysis of the 16S rRNA gene showed that the bacteria were Pectobacterium sp., denoted as ND2. In order to optimize the conditions for the biosorption of heavy metal ions, the effects of various physico-chemical parameters were assessed, including pH value, contact time, initial metal ion concentration, biosorbent dose, and temperature. Under the optimal condition, the maximum ion biosorption capacity (mg/g) of Pectobacterium sp. ND2 was ranked in the order of Cd(II)(44.9 mg/g) > Cu(II)(38.6 mg/g) > Zn(II)(34.2 mg/g) > Pb(II)(31.2 mg/g). Both Langmuir and Freundlich isotherm models were used to explain this adsorption phenomenon. The FTIR analysis of surface chemical functional groups of Pectobacterium sp. ND2, revealed the involvement of carboxyl, amino and phosphate groups in the adsorption process. In addition, adsorption-desorption studies indicated that 0.1M nitric acid is an efficient desorbent for Cd(II), Cu(II), Zn(II), and Pb(II) ions, with maximum recovery rates of more than 90%. (C) 2017 American Institute of Chemical Engineers