Fractionation of Fresh Wastewater and Solubility of Phosphorus in Short-Term Storage

In this research the characteristics of fresh wastewater were studied by filtration of organic material and nutrients. Besides the short-term dissolving of phosphorus was determined. The size fractions of oxygen demand for 7 days (BOD7), total organic carbon (TOC), phosphorous (P) and nitrogen (N) were separated to 0.1 μm. Most of the phosphorous, nitrogen and organic carbon was under 0.1 μm fractions. Most of the biological oxygen demand was over 12 μm fractions although the fraction under 0.1 μm was 37%. The amount of phosphorus over 0.45 μm increased 25% after 3 days' storage.