Papers by Author: Er Li Zhao

Abstract: The present study was undertaken to evaluate the feasibility of Pseudomonas fluorescens biomass for the removal of cadmium ions from aqueous solutions. Batch experiments were performed to study the adsorption of cadmium on pH, Pseudomonas fluorescens biomass adsorbent with respect to initial Cd(II) concentration, contact time and biomass dose. The experimental data were modeled by Langmuir and Freundlich isotherm models. Langmuir model resulted in the best fit of the adsorption data. The maximum adsorption capacity for Cd(II) was 66.25 mg/g (pH 5.0 and 5 g/L biomass dose). Kinetics of adsorption followed second-order rate equations. The FTIR results of Pseudomonas fluorescens biomass showed that biomass has different functional groups and these functional groups are able to react with metal ion in aqueous solution. The results of the present study suggest that Pseudomonas fluorescens biomass can be used beneficially in treating industrial effluents containing heavy metal ions.

Abstract: The optimal conditions of production of biopolymer by the culture of Pseudomonas fluorescens were examined, using brewery wastewater to replace glucose as carbon source and energy source in the culture medium. Results showed that the COD concentration in brewery wastewater favorable for the production of the biopolymer was 6000 mg•L-1, and an optimal culture condition of inoculum size of 5%(v/v), 28°C, initial pH 7.0 and shaking speed of 150 r•min-1, under the optimal culture conditions, the highest flocculating activity achieved for Kaolin suspension was 97.5% and 3.67 g biopolymer /L broth was obtained. The biopolymer was effective in flocculating some soluble reactive dyes in aqueous solution, reactive Light-Yellow K-4G and reactive Turquoise Blue KN-G with a decolorization efficiency of 95.8 and 96.2%, respectively，using 25 mL of the flocculant in 500 mL of 100 mg•L-1 dye solution.The decolorization efficiency was dependent on the flocculant dosage and solution pH.

Abstract: The objective of this study is to assess the environmentaly friendly Ni(II) adsorption from synthetic wastewater using Pseudomonas alcaligenes biomass (PA-2). The ability of PA-2 to remove the Ni(II) ions was investigated by using batch biosorption procedure. The effects such as pH, dosage of biosorbent, Ni(II) initial concentration and sorbate–sorbent contact time and agitating speed on the adsorption capacities of PA-2 were studied. Biosorption equilibriums were rapidly established in about 60 min and the adsorption kinetics followed the pseudo-second order kinetic model. The maximum Ni(II) adsorption capacity determined from Langmuir isotherm were 82.23 mg/g PA-2 at pH 5.0, at 25±2°C and shaker speed 150 rpm, respectively. The carboxyl , hydroxyl and amino groups of the PA-2 were involved in chemical interaction with the Ni(II) ions depicted by Fourier transform infrared spectroscopic (FTIR) results. The study points to the potential of new use of Pseudomonas alcaligenes biomass as an effective biosorbent for the removal of Ni(II) and from environmental and industrial wastewater.