摘要
Chicken manure was composted for 110 d to evaluate changes in organic carbon (C) and humic substance-complexed copper (HS-Cu) extracted with water,sodium hydroxide (NaOH),and sodium pyrophosphate and sodium hydroxide mixture (Na 4 P 2 O 7-NaOH).The average HS-Cu content from the Na 4 P 2 O 7-NaOH extraction accounted for 46.8% of the total Cu in the compost,followed by those from the NaOH and water extractions,which accounted for 34.5% and 6% of the total Cu in the compost,respectively.NaOH-Na 4 P 2 O 7-extractable HS-Cu increased throughout the composting process.NaOH-extractable HS-Cu increased during the first 50 d of composting and then leveled off.Water-extractable HS-Cu enhanced during the first 21 d and then decreased.Water-extractable HS-Cu was not correlated to NaOH-or NaOH-Na 4 P 2 O 7-extractable organic C.The average amount of Cu leached from the compost was about 20% of the total Cu in the chicken manure and Cu leaching increased during the first 35 d of composting and then decreased.Leaching of Cu was significantly correlated to the concentrations of HS-Cu extracted with NaOH and water,but was not correlated to the concentration of HS-Cu extracted with NaOH-Na 4 P 2 O 7.Thus,NaOH-and water-extractable HS-Cu were relatively labile and NaOH-Na 4 P 2 O 7-extractable HS-Cu was relatively immobile.Composting process after rapid decomposition could result in low potential of Cu leaching because of formation of more NaOH-Na 4 P 2 O 7-extractable HS-Cu.
Chicken manure was composted for 110 d to evaluate changes in organic carbon (C) and humic substance-complexed copper (HS-Cu) extracted with water, sodium hydroxide (NaOH), and sodium pyrophosphate and sodium hydroxide mixture (Na4P2O7-NaOH). The average HS-Cu content from the Na4P2O7-NaOH extraction accounted for 46.8% of the total Cu in the compost, followed by those from the NaOH and water extractions, which accounted for 34.5% and 6% of the total Cu in the compost, respectively. NaOH-Na4P2O7-extractable HS-Cu increased throughout the composting process. NaOH-extractable HS-Cu increased during the first 50 d of composting and then leveled off. Water-extractable HS-Cu enhanced during the first 21 d and then decreased. Water-extractable HS-Cu was not correlated to NaOH- or NaOH-Na4P2O7-extractable organic C. The average amount of Cu leached from the compost was about 20% of the total Cu in the chicken manure and Cu leaching increased during the first 35 d of composting and then decreased. Leaching of Cu was significantly correlated to the concentrations of HS-Cu extracted with NaOH and water, but was not correlated to the concentration of HS-Cu extracted with NaOH-Na4P2O7. Thus, NaOH- and water-extractable HS-Cu were relatively labile and NaOH-Na4P2O7-extractable HS-Cu was relatively immobile. Composting process after rapid decomposition could result in low potential of Cu leaching because of formation of more NaOH-Na4P2O7-extractable HS-Cu.
基金
Project supported by the Ministry of Science and Technology of China (No. 2007BAD89B16)
the National Natural Science Foundation of China (No. 39800093)
the National Undergraduate Innovational Experimentation Program of China
the Youth Planning Program of Northwest A & F University,China