Phosphorus (P) rich ash from biomass incineration is a potential promising alternative for non-renewable phosphate rock. This study considered the P recovery potential of poultry manure ash, sewage sludge ash and meat and bone meal ash through wet chemical extraction. X-ray diffraction analysis showed that these three ash types had a distinct P mineralogy. If inorganic acids were used for the extraction, the P extraction efficiency was not or only slightly affected by the P mineralogy. Contrarily, for the organic acids, alkaline extraction liquid and chelating agents considered, the P extraction efficiency was highly affected by the P mineralogy, and was also affected by the elemental composition of the ash and/or the chemical characteristics of the extraction liquids. Alkaline extraction liquids showed in general low heavy metal co-extraction, in contrast to the inorganic acids. From an economic point of view, of all extraction liquids considered, sulfuric acid was the most interesting to extract P from all three ash types. Oxalic acid could be a more sustainable option for P extraction from sewage sludge ash. In addition, extraction of poultry manure ash with ethylenediaminetetraacetic acid showed a relatively high P extraction efficiency combined with relatively low heavy metal co-extraction.Graphic Abstract
- Home
- Search
Sort by