Academic journal article Journal of Environmental Engineering and Science

Optimization of Municipal Wastewater Biological Nutrient Removal Using ASM2d

Academic journal article Journal of Environmental Engineering and Science

Optimization of Municipal Wastewater Biological Nutrient Removal Using ASM2d

Article excerpt

Abstract: Activated sludge model No. 2d (ASM2d) was calibrated then used to determine optimal recycle rates and basin retention times, with respect to final N, soluble P (sP) or N plus sP concentrations for Modified Bardenpho (MB), Modified University of Cape Town (MUCT), and anaerobic-anoxic-oxic ([A.sup.2]O) biological nutrient removal processes. Simulations were conducted at two temperatures and three primary effluent (PE) concentrations (COD, TSS, TKN, sP). All BNR processes were shown to be capable of achieving an effluent sP concentration below 1 mg/L at all conditions when effluent N concentration was neglected. None of the processes were capable of producing an effluent with N concentrations below 5 mg/L at high PE concentration. The MB and MUCT processes were both successful in achieving a combined sP and N removal below 1 mg/L and 5 mg/L for low PE concentrations at 10 and 20 [degrees]C. Only the MB process, at 20 [degrees]C with medium PE concentrations, was found to achieve an effluent below 1 mg/L and 5 mg/L, respectively for sP and N. Recycle from the anoxic basin of the MUCT process had an insignificant effect on N and sP removals. All input variables to the MB and [A.sup.2]0 process proved to be somewhat significant and it is recommended that they be kept within future experimental designs. Dynamic tests with real Ottawa plant influent flow data indicated that the MB process was more robust with respect to TN, sP, and CBODS removal than the MUCT process.

Key words: activated sludge, biological nutrient removal, simulation, model, ASM2d.

Resume: Le modele de boues activees no 2d (ASM2d) a ete etalonne puis utilise afin de determiner les taux optimaux de recyclage et de temps de sejour dans les bassins quant a la concentration finale de N, P soluble ou N plus P soluble pour les procedes d'elimination des nutriments biologiques suivants : Bardenpho modifie (MB), Modified University of Cape Town (MUCT) et anaerobie/anoxique/oxydant ([A.sup.2]O). Les simulations ont ete effectuees a deux temperatures et a trois concentrations d'effluent primaire (PE) (DCO, TSS, ATK, P sol.). Tous les procedes d'elimination des nutriments biologiques pouvaient atteindre, dans l'effluent, une concentration P sol. inferieure a 1 mg P/L sous toutes les conditions o l'on ne tenait pas compte de la concentration en N de l'effluent. Aucun des procedes n'a pu produire un effluent avec des concentrations de N inferieures a 5 mg N/L a une forte concentration de polyelectrolytes (PE). Les procedes MB et MUCT ont tous les deux reussis a atteindre une elimination de N et P sol. combine inferieure a 1 mg P/L et 5 mg N/L pour des faibles concentrations de PE a 10 et a 20 [degre]C. Seul le procede MB, a 20 [degre]C et avec des concentrations moyennes de PE a reussi a atteindre un effluent inferieur a 5 mg N/L et 1 mg P/L. Le produit recycle du basin anoxique du procede MUCT a un impact insignifiant sur l'elimination du N et du P sol. Toutes les variables d'entree des procedes MB et [A.sup.2]0 se sont averees importantes et il est recommande qu'elles soient conservees pour les schemas experimentaux futurs. Des essais dynamiques utilisant de vraies donnees d'ecoulement de debit influent d'une usine d'Ottawa indiquaient que le procede MB etait plus robuste par rapport a l'elimination de l'azote total, P sol. et DCOS des matieres carbonees que le procede MUCT.

Mots cles: boues activees, elimination des nutriments biologiques, simulation, modele, ASM2d.

[Traduit par la Redaction]

Introduction

The Robert O. Pickard Environmental Centre (ROPEC) (Ottawa, Canada) is a secondary wastewater treatment plant that treats dilute municipal wastewater (Table 1) and discharges to the Ottawa River. Concern of cultural eutrophication of the receiving water and in anticipation of new regulations ROPEC investigated upgrade scenarios that would allow simultaneous removal of BOD, N and (or) soluble P (sP).

Biological nutrient removal (BNR) processes (Sedlak 1991; Cooper et al. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.