Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia.
Environ Sci Technol. 2011 Sep 1;45(17):7249-57. doi: 10.1021/es201710z. Epub 2011 Aug 15.
Despite its pivotal role in determining the risks and time frames associated with contaminant release, metal speciation remains a poorly understood aspect of biosolids chemistry. The work reported here used synchrotron-based spectroscopy techniques to investigate the speciation of copper and zinc in a range of Australian biosolids. High resolution element mapping of biosolids samples using micro X-ray fluorescence spectroscopy revealed considerable heterogeneity in key element associations, and a combination of both organic and inorganic copper and zinc binding environments. Linear combination fitting of K-edge X-ray absorption spectra indicated consistent differences in metal speciation between freshly produced and stockpiled biosolids. While sulfide minerals play a dominant role in metal binding in freshly dewatered biosolids, they are of lesser importance in dried biosolids that have been stockpiled. A degree of metal binding with iron oxide minerals was apparent but the results did not support the hypothesis that biosolids metals are chiefly associated with iron minerals. This work has potential implications for the long-term stability of metals in biosolids and their eventual fate following land application.
尽管金属形态在确定污染物释放的风险和时间框架方面起着关键作用，但它仍然是生物固体化学中一个理解得很差的方面。这里报道的工作使用基于同步加速器的光谱技术来研究一系列澳大利亚生物固体中铜和锌的形态。使用微 X 射线荧光光谱对生物固体样品进行高分辨率元素映射显示出关键元素关联存在相当大的异质性，以及有机和无机铜和锌结合环境的组合。K 边 X 射线吸收光谱的线性组合拟合表明，新生产和储存的生物固体之间的金属形态存在一致的差异。虽然硫化物矿物在刚脱水的生物固体中对金属结合起着主导作用，但在已储存的干燥生物固体中，它们的重要性较小。铁氧化物矿物对金属有一定程度的结合，但结果并不支持生物固体金属主要与铁矿物有关的假设。这项工作对生物固体中金属的长期稳定性及其随后土地应用的最终命运具有潜在影响。
