Zhu Weiqin, Yao Wu, Zhang Zhi, Wu Yang
Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou, 310036, People's Republic of China,
Environ Sci Pollut Res Int. 2014 Nov;21(22):12684-92. doi: 10.1007/s11356-014-3216-x. Epub 2014 Jun 25.
Vermicomposting is an eco-friendly method for disposing of livestock and poultry manure. In addition, dissolved organic matter (DOM) can serve as a carrier that enhances the migration and transformation of heavy metals. Here, pig manure amended with rice straw was vermicomposted with Eisenia fetida. The DOM content, molecular weight distribution, and spectroscopic properties of the amended pig manure were measured before and after vermicomposting. The Cu and Zn concentrations in the earthworms increased from 8.24 and 17.63 to 40.75 and 362.78 mg/kg separately after vermicomposting, and the earthworms also increased the heavy metal availability in the vermicompost. Relative to the DOM properties of conventional compost, the DOM molecular weight decreased and varied widely following vermicomposting, and the C/N ratio of the DOM in the vermicompost treatments decreased from 10.37 to 8.60. The Fourier transform far-infrared (FTIR) and fluorescence spectra of the DOM indicated that the amounts of oxygen-containing structures increased while the ratio of humic acid to fulvic acid decreased following vermicomposting. Accordingly, the earthworms augmented the heavy metal mitigation risk in the pig manure. This augment potentially resulted from the decreased humic acid-to-fulvic acid (HA/FA) ratio from DOM structural changes.
蚯蚓堆肥是一种处理畜禽粪便的环保方法。此外,溶解有机物(DOM)可作为载体促进重金属的迁移和转化。在此,将添加稻草的猪粪与赤子爱胜蚓进行蚯蚓堆肥。在蚯蚓堆肥前后测定了添加猪粪的DOM含量、分子量分布和光谱性质。蚯蚓堆肥后,蚯蚓体内的铜和锌浓度分别从8.24和17.63增加到40.75和362.78mg/kg,蚯蚓还提高了蚯蚓堆肥中重金属的有效性。相对于传统堆肥的DOM性质,蚯蚓堆肥后DOM分子量降低且变化范围广,蚯蚓堆肥处理中DOM的C/N比从10.37降至8.60。DOM的傅里叶变换远红外(FTIR)和荧光光谱表明,蚯蚓堆肥后含氧结构的数量增加,而腐殖酸与富里酸的比例降低。因此,蚯蚓增加了猪粪中重金属的缓解风险。这种增加可能是由于DOM结构变化导致腐殖酸与富里酸(HA/FA)比例降低所致。