Determination of total phosphorus in waters and wastewaters by on-line UV/thermal induced digestion and flow injection analysis

Abstract

An on-line flow-injection system for the determination of total phosphorus in waters and wastewaters is described. Digestion was performed using a UV photoreactor and a thermal digestion unit connected in series. The orthophosphate formed was detected as phosphomolybdenum blue after on-line filtration. Reagent and digestion conditions required to give optimal oxidation and hydrolysis of organic and condensed model compounds are reported. The flow-injection method gave complete recovery for all the model organic P compounds tested, and > 85% recovery for condensed phosphates. When the proposed method was applied to a series of wastewater samples, the results obtained were in close agreement w..