CIRAD, UPR Recyclage et risque, Réunion, France.
Environ Sci Technol. 2010 Sep 15;44(18):6926-32. doi: 10.1021/es101651w.
It is now well-known that copper (Cu) can accumulate on the surface of soils upon which pig slurry has been applied. This is due to the high quantity of Cu in pig slurry resulting from its use as a growth promoter in animal feeds. The mobility and bioavailability of Cu from pig slurry spreading can be better predicted by determining the speciation of this element in addition to its total concentration. The aim of this study was to present a multitechnique approach to investigate Cu speciation in pig slurry. First, size fractionation and chemical characterization of each size fraction were performed to complement results obtained in raw samples. Micro X-ray fluorescence spectroscopy (μXRF) highlighted the colocalization of Cu and sulfur (S). Finally, X-ray absorption near-edge structure spectroscopy (XANES) showed that Cu speciation in raw pig slurry and size fractions could be described by Cu(2)S and that its oxidation state is Cu(I). In addition, geochemical calculation demonstrated that chalcocite (Cu(2)S) was the major Cu species present under pig slurry lagoon physical-chemical conditions. This Cu speciation in pig slurry may be the main reason for the observed Cu accumulation at the soil surface.
现在人们已经熟知，猪粪施用于土壤后，土壤表面会积累铜（Cu）。这是由于猪粪作为动物饲料中的生长促进剂，其中含有大量的 Cu。通过确定猪粪中 Cu 的形态，除了其总浓度之外，还可以更好地预测其在猪粪施撒过程中的迁移性和生物有效性。本研究旨在提出一种多技术方法来研究猪粪中的 Cu 形态。首先，进行了大小分级和每个分级的化学特征分析，以补充原始样品的结果。微 X 射线荧光光谱（μXRF）突出显示 Cu 和硫（S）的共定位。最后，X 射线吸收近边结构光谱（XANES）表明，原始猪粪和分级的 Cu 形态可以用 Cu（2）S 来描述，其氧化态为 Cu（I）。此外，地球化学计算表明，在猪粪泻湖物理化学条件下，辉铜矿（Cu（2）S）是主要的 Cu 物种。猪粪中的这种 Cu 形态可能是观察到的土壤表面 Cu 积累的主要原因。
