NUTRIENT REMOVAL COSTS OF MUNICIPAL WASTEWATER TREATMENT OF BUDAPEST

Abstract

In Budapest a large portion of wastewater enters the Danube without any treatment (the level of biological treatment is around 20%). Harmonisation up to EU standards in Budapest needs significant solutions in the field of sewerage and wastewater treatment. These solutions would mean considerable costs. This study analyses different development scenarios, and their costs. The investigated scenarios are the following: - autonomous development (Scenario 1) in this scenario all the population of Budapest will be connected to sewerage, and new wastewater treatment capacity will not be built. The calculated P and K emissions by population are in Table 4; - stand-still scenario (Scenario 2) in this scenario we hypothesize, that the nutrient emission will not increase. The estimated values of N, P emission of this scenario are in Table 5; - 25% emission reduction (Scenario 3) in this case the limit factor is the N too. To the 25% N reduction 1.5 million PE size primary and secondary new treatment and 300 thousand PE N elimination capacity should be built. In this scenario the P discharge is less than in the present by 53%. The estimated nutrient discharge by population is in Table 6; - 50% emission reduction (Scenario 4) in this scenario 1.5 million PE size new primary and secondary sewage treatment capacity, over it 1.3 million PE nitrification-denitrification, and 200 thousand PE chemical phosphorus elimination capacity in South Budapest WWTP are needed. The values of P. N emissions in this case are in Table 7; - harmonisation up to EU standards (Scenario 5) this scenario gives very strict requirements. This would mean a demand for 1.5 million PE size new primary and secondary, 2 million PE nitrification-denitrification, and over it 2 million PE biological-chemical phosphorus elimination sewage treatment capacity. There is not any reality to build it until 2000. The significant investment of building 550 km sewer, around 100 pump stations, 30 km pressure conduits and a new wastewater treatment plant need phased implementation. The values of the estimated nutrient discharge by population is in Table 8. The investment costs of sewage treatment at different scenarios are in Table 9. The costs of nutrient elimination can be 200 million ECU (Scenario 1) to 1510 million ECU (Scenario 5). The significant investments need phased implementation.