鸡粪腐解过程腐殖质结合态铜变化及其与铜淋失的关系

Dynamics of humic substance complexed copper and its relationship to copper leaching during composting of chicken manure

采用H2O、NaOH以及NaOH-Na4P2O7混合液3种浸提剂对不同腐解期鸡粪中的腐殖质结合态铜(HS-Cu)进行提取,在研究腐殖质碳和铜变化的基础上,通过粪肥淋溶试验,研究了铜淋失量变化以及与腐殖质结合态铜的关系。结果显示,鸡粪中以NaOH-Na4P2O7提取的HS-Cu最高,平均占粪肥全铜量的46.8%;其次是NaOH提取的HS-Cu,平均占全铜量的34.5%,H2O提取的HS-Cu最少,仅占全铜量的6%左右。随腐解进行,NaOH-Na4P2O7提取的HS-Cu逐渐增加,而NaOH提取的HS-Cu在腐解50 d以前呈增加趋势,而50 d以后变化不大;H2O提取的HS-Cu在腐解21 d前明显增加,21 d后则下降。NaOH-Na4P2O7提取的HS-Cu以胡敏酸结合态(HA-Cu)为主,H2O提取的HS-Cu则以富里酸结合态(FA-Cu)为主;NaOH提取的HS-Cu在腐解50 d以前以FA-Cu为主,50 d以后则以HA-Cu为主。粪肥铜淋失量在腐解35 d以前随腐解进行逐渐增加,35 d以后有所降低;淋失量平均占全铜量的20%左右。铜淋失量与H2O、NaOH提取的HS-Cu或腐殖质碳呈显著正相关,而与NaOH-Na4P2O7提取的HS-Cu无相关。

Changes of humic substances and their complexed copper during composting of chicken manure with different extractants of H2O, NaOH and NaOH-Na4P2O7 was studied, and leaching experiment was conducted to investigate the dynamics of copper leaching and its relationship to humic substances complexed copper（HS-Cu）. The results showed that NaOH-Na4P2O7 extractable HS-Cu was the highest among three extractants of NaOH-Na4P2OT, NaOH and H2O, and the average amount of extractable HS-Cu was 46.8%, 34.5% and 6% of total copper, respectively. During the decomposing process, NaOH-Na4P2O7 extractable HS-Cu increased with decaying time. NaOH extractable HS-Cu also increased in the period of decaying for 50 days, and after that time there was no significant change. H2O extractable HS -Cu increased in the period of decaying for 21 days and then decreased. For the NaOH-Na4P2O7 extractable HS-Cu, humic acid complexed copper （HA-Cu） was the main form, but for the H2O extractable HS-Cu, the fulvic acid complexed copper （FA-Cu） was the main form. For the NaOH extractable HS-Cu, FA-Cu was main form before decaying for 50 days, and after that time, HA-Cu was the main form. Copper leaching increased with the decomposing process before decaying for 50 days and then decreased. The average amount of leaching copper was about 20 percent of total copper, which was correlated to NaOH or H2O extractable HS-Cu and organic carbon, but was not correlated to NaOH- Na4P2O7 extractable HS-Cu.