South China Agricultural University, South China Agricultural University, South China Agricultural University, South China Agricultural University, affiliation not provided to SSRN, Chinese Academy of Sciences (CAS) - Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (CAS) - Guangzhou Institute of Geochemistry, affiliation not provided to SSRN, China University of Geosciences (CUG) - School of Water Resources and Environment and Research Center of Environmental Science and Engineering, South China Agricultural University, South China Agricultural University, affiliation not provided to SSRN, South China Agricultural University and South China Agricultural University