Transformation of dissolved organic phosphorus to phosphate using UV/H₂O₂

Phosphorus (P) driven eutrophication remains a problem in waterways worldwide. High P levels can significantly alter ecosystems, changing species composition and diversity. Most current P treatment technologies cannot adequately remove recalcitrant forms of P from the water column. As a result, this study evaluated the UV/H₂O₂advanced oxidation process (AOP) for the photodegradation of recalcitrant-P in natural waters to biologically available phosphate, which is analogous to soluble reactive P (SRP). In turn, SRP can be removed using available P treatment technologies. The UV/H₂O₂AOP was tested in synthetic waters and natural water from the Florida Everglades. Results showed that the photodegradation of recalcitrant P to SRP is possible using UV fluences of at least 5.1 J/cm²and H₂O₂doses of at least 50 mg H₂O₂/L. The UV/H₂O₂AOP was able to consistently convert recalcitrant-P to SRP in synthetic waters. However, the complex chemistry of Everglades water made consistent conversion of recalcitrant-P to SRP hard to achieve. An increase in the efficiency of UV lights is needed to make the UV/H₂O₂AOP economically feasible for conversion of recalcitrant-P to SRP in natural waters.