Abstract: A composition for treating nutrient deficient wastewater from a paper-making process, which eliminates the use of conventional treatments and efficiently provides essential nutrients for biologically degrading organic pollutants, comprising urea and phosphoric acid. A method for treating nitrogen and phosphorus deficient wastewater with a treatment composition of urea and phosphoric acid in varying concentrations depending on the nitrogen and phosphorus content of the wastewater.

Abstract: Rinse acid collected from an aluminum bright dipping operation is reacted with soda alkalies at 80.degree. C or higher to yield a solution of trisodium phosphate, Na.sub.3 PO.sub.4, sodium aluminate, NaAlO.sub.2, sodium nitrate, NaNO.sub.3, and trace insolubles. The hot solution is quickly filtered to remove all insoluble impurities and then cooled so that the trisodium phosphate crystallizes out which, after filtering, leaves a mother liquor containing some remaining trisodium phosphate and soluble impurities, namely, sodium aluminate and sodium nitrate. The mother liquor is then recycled repeatedly with further batches of rinse acid to maximize the phosphate recovery.