CARTIF Centro Tecnológico, 47151, Boecillo, Valladolid, Spain.
ITAP Institute, University of Valladolid, 47010, Valladolid, Spain.
Environ Sci Pollut Res Int. 2021 May;28(19):24731-24743. doi: 10.1007/s11356-020-10918-6. Epub 2020 Oct 3.
This work evaluates the release of phosphorus contained in the digestate from the anaerobic digestion of pig manure, through an acidification process. The objective of this acidification is to increase the amount of phosphorus available in the digestate liquid fraction and, subsequently, recover this element by chemical precipitation in the form of struvite or calcium phosphate. Two digestate samples (one fresh and one old) were studied and treated by adding various amounts of sulphuric acid to the different digestate fractions (raw digestate, solid fraction and liquid fraction). For the raw digestate, phosphorus releases higher than 95% were obtained for pH 4.0. In the last part of the experiment, the influence of acid pre-treatment on the reaction yield of phosphorus precipitation, in the form of struvite or calcium phosphate, was determined. Improvements in reaction yield were obtained up to 15% for struvite and 80% for calcium phosphate, increasing also in 7.5 times the amount of phosphorus available in the digestate liquid fraction, for both cases.
本工作评估了通过酸化过程从猪粪厌氧消化中释放出的消化液中的磷。酸化的目的是增加消化液液体部分中可用磷的含量，并随后以鸟粪石或磷酸钙的形式通过化学沉淀回收该元素。研究了两个消化液样品（一个新鲜的和一个旧的），并通过向不同的消化液部分（原始消化液、固体部分和液体部分）添加不同量的硫酸来处理它们。对于原始消化液，在 pH 值为 4.0 时获得了高于 95%的磷释放。在实验的最后部分，确定了酸预处理对以鸟粪石或磷酸钙形式沉淀磷的反应产率的影响。对于鸟粪石，反应产率提高了 15%，对于磷酸钙，反应产率提高了 80%，同时也使消化液液体部分中可用磷的含量增加了 7.5 倍，这两种情况均有提高。
