Affiliation:
1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
2. Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
Abstract
It is vital to remove cadmium from wastewater because of its potential harm to the natural environment and human health. It was found that sulfate-reducing bacteria (SRB) had a good fixing effect on Cd under a strict anaerobic environment. However, there are few reports on the immobilization effect and mechanism of SRB on Cd in an anoxic environment. This study revealed the effects of initial Cd2+ concentration, initial SO42− concentration, temperature, pH, and C/N ratio on the immobilization of Cd2+ by SRB in aqueous solution under an anoxic environment. The experimental results showed that under the conditions of initial concentration of Cd2+ within 0 mg/L~30 mg/L, initial concentration of SO42− within 1200 mg/L, temperature within 25 °C~35 °C, pH neutral, and C/N ratio of 20:1, the immobilization rate of Cd2+ by SRB is above 90%. The characterization results showed that bioadsorption and chemical precipitation were the main mechanisms of SRB immobilization of Cd2+ in an anoxic environment.
Funder
Key Research and Development Projects of the Science and Technology Department of Hunan Province