Beuth University of Applied Sciences, Luxemburger Str. 10, 13353 Berlin, Germany.
Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter Str. 11, 12489 Berlin, Germany.
Environ Res. 2017 May;155:353-358. doi: 10.1016/j.envres.2017.02.034. Epub 2017 Mar 20.
The importance of secondary raw materials for phosphorus (P) fertilizer production is expected to increase in the future due to resource depletion, supply risks, and heavy metal contamination of fossil phosphate resources. Municipal wastewater is a promising source for P recovery. In Germany for instance, it contains almost 50% of the total amount of P that is currently applied as mineral fertilizer. Several procedures have been developed to recover and re-use P resulting in a growing number of recycling fertilizers that are currently not regulated in terms of fertilizer efficiency. We tested various materials and matrices for their total P content, solubility of P in neutral ammonium citrate (P) and water, and performed robustness tests to check if existing analytical methods are suitable for those new materials. Digestion with inverse aqua regia was best suited to determine the total P content. P sample preparation and analyses were feasible for all matrices. However, we found significant time and temperature dependencies, especially for materials containing organic matter. Furthermore, several materials didn't reach equilibrium during the extractions. Thus, strict compliance of the test conditions is strongly recommended to achieve comparable results.
由于资源枯竭、供应风险以及化石磷资源的重金属污染，未来对于磷（P）肥生产用二级原料的重要性预计将会增加。城市污水是一种很有前途的磷回收来源。例如，在德国，城市污水中所含的磷几乎占目前作为矿物肥料施用量的 50%。已经开发了几种回收和再利用磷的程序，从而导致越来越多的回收肥料目前在肥料效率方面不受监管。我们测试了各种材料和基质的总磷含量、在中性柠檬酸铵（P）和水中的磷溶解度，并进行了稳健性测试，以检查现有的分析方法是否适用于这些新材料。用反王水消解最适合测定总磷含量。所有基质的 P 样品制备和分析都是可行的。然而，我们发现存在明显的时间和温度依赖性，特别是对于含有有机物的材料。此外，几种材料在提取过程中没有达到平衡。因此，强烈建议严格遵守测试条件，以获得可比的结果。
