猪粪堆肥中铜锌与腐殖质组分的结合竞争

为研究猪粪堆肥中铜锌与腐殖质组分的结合竞争,以猪粪和秸秆为堆腐原料,进行了为期36 d的好氧堆肥实验,研究猪粪堆肥过程中腐殖质组分(胡敏酸和富里酸)、胡敏酸结合态铜锌、富里酸结合态铜锌含量的变化。结果表明,堆肥结束后,腐殖化程度提高,胡敏酸碳含量增加394.4%,富里酸碳含量降低64.9%,腐殖化指数从0.24增加到3.33;随着堆肥的进行,胡敏酸结合态铜锌含量分别增加394.3%和56%,而富里酸结合态铜锌含量分别下降17.5%和28.4%;相关分析表明,胡敏酸结合态铜、富里酸结合态锌与胡敏酸、富里酸碳含量及腐殖化指数均成显著相关(P<0.01);堆肥过程中,胡敏酸结合态铜与富里酸结合态铜之比大于1,而胡敏酸结合态锌与富里酸结合态锌小于1,另外,胡敏酸中的Cu/Zn大于1,而富里酸中的Cu/Zn小于1,表明在腐殖质中铜主要与胡敏酸结合,而锌主要与富里酸结合。研究揭示了猪粪堆肥中重金属铜锌与不同腐殖质组分的结合竞争关系,为畜禽粪便堆肥土地利用的风险评估和风险控制提供科学依据。

Competitive binding of copper and zinc with humus fraction during pig manure composting

Aerobic composting experiment which pig manure and rice straw were used as the basic raw materials was conducted to research the competitive binding of copper and zinc with humic acid (HA) and fulvic acid (FA). The contents of HA, FA, humic acid-Cu (HA-Cu), humic acid-Zn (HA-Zn), fulvic acid-Cu (FA-Cu) and fulvic acid-Zn (FA-Zn) during 36 days composting were investigated. Results show that the humification increased, in which the carbon content of HA increased by 394.4% and the carbon content of FA decresed by 64.9%, the humification index (HI) increased from 0.24 to 3.33. The concentration of HA-Cu increased by 394.3%, but the concentration of FA-Cu reduced by 17.5%. The concentration of HA-Zn increased by 56%, but the concentration of FA-Zn reduced by 28.4%. Correlation analysis reveals that HA-Cu and FA-Zn were significantly correlated with the carbon content of HA, FA and HI (P<0.01). The ratio of HA-Cu to FA-Cu is greater than 1, but the ratio of HA-Zn to FA-Zn is less than 1. Moreover, the ratio of copper to zinc in HA is greater than 1 and the ratio of copper to zinc in FA is less than 1. These results indicate that copper combines mainly with HA, but zinc combines mainly with FA. The study reveals competitive binding of copper and zinc with different humus fraction and provides the scientific basis for the risk assessment and risk control of land utilization of manure compost.