Speciation of Cu and Zn during composting of pig manure amended with rock phosphate.
Pig manure usually contains a large amount of metals, especially Cu and Zn, which may limit its land application. Rock phosphate has been shown to be effective for immobilizing toxic metals in toxic metals contaminated soils. The aim of this study work was to investigate the effect of rock phosphate on the speciation of Cu and Zn during co-composting of pig manure with rice straw. The results showed that composting process and rock phosphate addition significantly affected the changes of metal species. During co-composting, the exchangeable and reducible fractions of Cu were transformed to organic and residue fractions, thus the bioavailable Cu fractions were decreased. The rock phosphate addition enhanced the metal transformation depending on the level of rock phosphate amendment. Zinc was found in the exchangeable and reducible fractions in the compost. The bioavailable Zn fraction changed a little during the composting process. The composting process converted the exchangeable Zn fraction into reducible fraction. Addition of an appropriate amount (5.0%) of rock phosphate could advance the conversion. Rock phosphate could reduce metal availability through adsorption and complexation of the metal ions on inorganic components. The increase in pH and organic matter degradation could be responsible for the reduction in exchangeable and bioavailable Cu fractions and exchangeable Zn fraction in rock phosphate amended compost.
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Duian
D
Lu
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China. Electronic address: lixiawang414@gmail.com.
Lixia
L
Wang
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China.
Baixing
B
Yan
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China.
Yang
Y
Ou
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Jiunian
J
Guan
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Yu
Y
Bian
College of Plant Science, JiLin University, Changchun 130062, PR China.
Yubin
Y
Zhang
D000818:Animals; D001682:Biological Availability; D002627:Chemistry, Physical; D003300:Copper / Q000737:chemistry*; D004553:Electric Conductivity; D006863:Hydrogen-Ion Concentration; D008372:Manure; D008670:Metals / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry; D012275:Oryza; D010710:Phosphates / Q000737:chemistry*; D012987:Soil; D013552:Swine; D013696:Temperature; D013997:Time Factors; D015032:Zinc / Q000737:chemistry*
D008372:Manure; D008670:Metals; D009930:Organic Chemicals; D010710:Phosphates; D012987:Soil; D003300:Copper; D015032:Zinc
Composting; Pig manure; Rock phosphate; Toxic metal