posted on 2022-01-11, 11:14authored byOumar Sacko, Xu Feng, John R. Morris, Roberto McAlister Council-Troche, Sandeep Kumar, James Weifu Lee
A dramatic enhancement by a factor
of 15 for the production of
ozonized biochar molecular products measured as dissolved organic
carbon (DOC) was achieved by an innovative biochar ozonization process.
The filtrate of the ozonized biochar molecular products contained
substantially more carboxyl groups than that of the nonozonized biochar.
The ozonized biochar molecules are now identified to be highly potent,
even at a ppm DOC concentration level, to “unlock” phosphorus
(P) from insoluble phosphate material hydroxyapatite (HA). At a DOC
concentration of 600 ppm, the filtrates from the wet-ozonized pine
400 biochar and the dry-ozonized rogue biochar substances were both
able to solubilize HA, resulting in a concentration of solubilized
phosphorus up to 396.8 ± 28.8 and 339.6 ± 8.5 mg HPO42–/L, respectively. Even at a DOC concentration
as low as 10 ppm, the ozonized biochar molecules solubilized up to
8.3 ± 1.1 mg/L of phosphate. At neutralized pH 7, the efficiency
in solubilizing phosphate decreased, indicating the importance of
the protonic effect. The ozonized biochar organic acids solubilized
more phosphate than a hydrochloric acid solution with the same pH,
thus showing the applicability of this green chemistry with ozonized
biochar molecules to unlock P from insoluble phosphate rock materials.
The discovery of ozonized biochar molecules capable of unlocking P
is highly relevant to agricultural phosphorus and environmental sustainability
on the Earth.