1. School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China
2. Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, P. R. China
3. National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan 410125, P. R. China