1. College of Environmental Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, P. R. China
2. Jiangsu Key Laboratory of Anaerobic Biotechnology (Jiangnan University), Wuxi 214122, P. R. China
3. Shandong Province Metallurgical Engineering Co., Ltd., Jinan 250101, P. R. China