Nitrogen and phosphorus recovery using innovative technology in soft cheese production: preliminary results from the NENUPHAR project

The Danube River Basin in Hungary has experienced considerable environmental pressure due to the continuously increasing volume of waste streams, primarily originating from agricultural and industrial activities. Among these, dairy wastewater has emerged as a major contributor to pollution. In particular, whey ‐ traditionally considered a low‐value by‐product of cheese‐making – has frequently been discharged with minimal treatment to reduce costs.
However, the waste load of whey may be substantially higher than that of an equivalent volume of domestic wastewater. It is typically characterized by a high organic matter content, with chemical oxygen demand (COD) levelsreaching up to 100,000 mg/L and biological oxygen demand (BOD) levels ranging from 27,000 to 60,000 mg/L. Furthermore, whey contains significant concentrations of nutrients, including nitrogen and phosphorus, which, if not properly treated, may contribute to eutrophication in receiving aquatic ecosystems.  In this study, a novel approach was explored for the treatment of dairy industry wastewater. The developed technology integrates active oxidation with membrane filtration to maximize the retention of valuable substances while minimizing the negative environmental impact. This innovative technical solution was successfully implemented within an existing dairy production infrastructure. Laboratory experiments involved sampling at various stages of the treatment process, followed by comprehensive chemical and microbiological analyses. The effectiveness of this treatment was evaluated using standard photometric methods.
Specifically, the COD, nitrogen, and phosphorus contents of samples treated with ozone and membrane filtration were analyzed. Preliminary results indicated that the retention of nitrogen and phosphorus ranged between 94.5% and 99.46%, while COD levels were reduced by 99.63% at just 10% output power of the ozone generator. The removal of pathogenic microorganisms was also nearly complete, with close to 100% retention.