Removal of Copper(II) Ions from Aqueous Solution Using Sphingomonas paucimobolis Biomass

Sphingomonas paucimobilis biomass has been successfully utilized to degrade several persistent organic pollutants (POPs). However, few studies have been conducted using it to remove heavy metal ions from aqueous solutions. In the present study, the biosorption of copper(II) ions was investigated using non-living Sphingomonas paucimobilis biomass isolated from activated sludge, as obtained from the Lianyungang Dapu sewage treatment plant in China. The effects of several parameters including solution pH, contact time and ionic strength on the Cu(II) ion uptake were studied. The biomass was characterized by scanning electron microscopy/X-ray energy dispersive spectroscopy (SEM-EDS) and Fourier-transform infrared spectrometry (FT-JP). The applicability, of the Langmuir and Freundlich models was tested. The correlation coefficients (R-2) of. both models were greater than 0.9. The maximum adsorption capacities were found to be 50.1 mg/g for Cu(II) ions at 20 degrees C. The adsorption process was rapid and followed pseudo-second-order kinetics. Optimum adsorption was achieved at pH 5. The adsorption was also found to be dependent on the NaCl concentration employed. The Sphingomonas paucimobilis biomass could serve as an adsorbent for the removal of Cu(II) ions from industrial effluents.