Phosphorus and nitrogen profile measurements to locate phosphorus limitation in a fixed bed filter

Water Science and Technology : a Journal of the International Association on Water Pollution Research
Sigrid M ScherrenbergJ H van der Graaf

Abstract

The European Union presented in 2000 the European Water Framework Directive (WFD). Within the WFD approach the focus is more and more on ultra low nitrogen (<2.2 mg N-total/L) and phosphorus concentrations (<0.15 mg P-total/L) in waste water treatment plant (WWTP) effluent. Nitrogen concentrations of 2.2 mg N-total/L can be reached with denitrifying filters as a tertiary treatment step. When combining nitrogen and chemical phosphorus removal in a filter, phosphorus limitation may occur. After nitrite accumulation, caused by phosphorus limitation, was measured in the filtrate water of the dual media filter, research was started to locate, to understand and to solve the problem. Profile measurements for nitrate, nitrite and orthophosphorus (PO(4)-P) combined with COD and O(2) were conducted. Results show that the minimal required PO(4)-P/NO(x)-N ratio is 0.006 mg/mg after coagulation and flocculation. Profile measurements have proven to be a useful tool. It showed how nitrate and orthophosphorus are removed through the filter bed and it showed the consequences for the PO(4)-P/NO(x)-N ratio. When orthophosphorus is removed more rapidly compared to nitrate the PO(4)-P/NO(x)-N ratio decreases. When the PO(4)-P/NO(x)-N ratio becomes ...Continue Reading

Related Concepts

Related Feeds

Blood Clotting Disorders

Thrombophilia includes conditions with increased tendency for excessive blood clotting. Blood clotting occurs when the body has insufficient amounts of specialized proteins that make blood clot and stop bleeding. Here is the latest research on blood clotting disorders.

Related Papers

Water Science and Technology : a Journal of the International Association on Water Pollution Research
Sigrid M ScherrenbergJ H van der Graaf
Water Science and Technology : a Journal of the International Association on Water Pollution Research
Sigrid M ScherrenbergJ H van der Graaf
Water Science and Technology : a Journal of the International Association on Water Pollution Research
J P Boltz, G T Daigger
Water Research
J S VrouwenvelderM C M van Loosdrecht
© 2022 Meta ULC. All rights reserved