Contents and Characteristics of Heavy Metals in the Livestock and Poultry Manure from the Large-scale Farms in Hebei Province, China

The different types of livestock and poultry manure, including pig manure, chicken manure, cow manure were collected from the typical large-scale farms in Hebei Province and heavy metals contents in the samples were analyzed. The results showed that the median contents of heavy metal Cu, Zn, Cd, Pb, Cr, As, Hg and Ni in the livestock and poultry manure were below the limitations of Manure Composition of Germany and Organic Fertilizer of China(NY 525-2012). However, according to the limitations, the exceeding rates of the concentrations of Cu, Zn, Cr, Cd, Pb, Ni, Hg and As in the livestock and poultry manure were 41.73%, 50.39%, 31.50%, 5.51%, 0.79%, 7.87%, 4.63% and 12.60%, respectively. The order of the exceeding rates for heavy metals in chicken manure was Zn > Cr > Cu > Ni > As > Cd > Pb > Hg. The exceeding rates of the concentrations of Cu, Zn and Cr in chicken manure were 22.22%, 40.74% and 33.33%, respectively. The order of the exceeding rates for heavy metals in pig manure was Cu > Zn > Cr > As > Ni/Cd and the contents of other heavy metals did not exceed the limitation. The exceeding rates of the concentrations of Cu, Zn, Cr and As in pig manure were 80.43%、78.26%、30.43% and 21.74%, respectively. The order of the exceeding rates for heavy metals in cow manure was Cr > Hg > Zn and the contents of other heavy metals did not exceed the limitation. Estimated on the application rate of 15 t·hm-2, the safety application years of pig manure, chicken manure and cow manure were 26, 79 years and 207 years, respectively. Therefore, the livestock and poultry manure from large-scale farms should been disposed before used.