The contents of DTPA extractable Fe, Cu, Mn and Zn of sludge were 52.3, 28.7, 38.2 and 32.8 mg kg−1and the total were 232, 186, 260 and 161 mg kg−1, respectively
The contents of DTPA extractable Fe, Cu, Mn and Zn of sludge were 52.3, 28.7, 38.2 and 32.8 mg kg−1and the total were 232, 186, 260 and 161 mg kg−1, respectively