The pit cycle: from fruit residue to phosphate filter and alternative fertilizer
Abstract
Stone fruit kernel shells are pyrolised in a biochar product, which has very good sorption properties for phosphate (PO4) from liquid media. These core-shell coals are thus able to take up PO4 from phosphate-contaminated surface waters, constructed wetlands or wastewaters and sorb them on their surfaces. The PO4-enriched biochar is a suitable fertilizers in agriculture and replaces imported mineral phosphorus fertilizers. Additionally, this approach closes the carbon cycle (through the carbonized core shells) and P-cycle (through the sorbed nutrients), and produces a new recyclable product from a residue in food processing. The suitability of phosphate-loaded biochar as P fertilizers is determined by means of nutrient analyzes, PO4 release tests and plant availability tests. We anticipate that the PO4 sorbed to the biochar is readily available and released to the soil system. We further think, that the microbial mediated transfer of P to the plants plays an important but underestimated role. With the use of oxygen stable isotope analysis of PO4 we can define the proportion of microbially mediated transfer of P. During PO4 uptake and cycling in cells the original isotope oxygen signature equilibrates with the soil water. A slightly 18O enriched PO4 will be bound onto the biochar and added to the soil. We will monitor the extent of alterations of the oxygen isotope signature and hence define the involvement of soil microbial processes in the desorption, transport and plant uptake of phosphate derived from an organic P fertilizers.
Biochar phosphate oxygen stable isotope
Publikationen
Project staff
Andrea Watzinger
Priv.-Doz. Mag.rer.nat. Dr.rer.nat. Andrea Watzinger
andrea.watzinger@boku.ac.at
Tel: +43 1 47654-91175
Project Leader
01.07.2017 - 30.09.2019