The sewage sludge sampling from Datansha sewage treatment plant were analyzed
and the mass fractions(× 10-2) of N
P
K and organic matter are respectively 4. 28
2. 11 1. 09 and 12. 84 %
and those(× 10-6) of Cd. Hg
Cr
Pb
Zn and Cu are respectively 3. 98
1. 74
228
612
2257 and 179. According to the environmental capacity of heavy metals
the application rates of sewage sludge are 191 and 183 t/hm2. a for 15 and 50 years application term respectively. The application rate of sewage sludge is 8. 4 t/hm2. a for N environmental capacity.