Dynamic mathematical model of high rate algal ponds (HRAP)

• Published in: Water science and technology Vol. 48; no. 2; pp. 197 - 204
• Main Authors: JUPSIN, H, PRAET, E, VASEL, J.-L
• Format: Conference Proceeding Journal Article
• Language: English
• Published: London IWA 01-01-2003; IWA Publishing
• Subjects: Advection; Aerated lagoons; Aeration; Algae; Anoxia; Applied sciences; Biological and medical sciences; Biological treatment of waters; Bioreactors; Biotechnology; Computer simulation; Density stratification; Environment and pollution; Eukaryota; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General purification processes; Growth rate; Heterotrophic organisms; Heterotrophs; Hydrodynamics; Industrial applications and implications. Economical aspects; Inorganic carbon; Lagoons; Light intensity; Luminous intensity; Mathematical models; Models, Theoretical; Nitrogen dioxide; Oxygen; Phytoplankton; Pollution; Ponds; Population Dynamics; Reactors; Respiration; River water; Rivers; Sediments; Set theory; Stratification; Tanks; Waste Disposal, Fluid - methods; Wastewaters; Water Movements; Water quality; Water treatment and pollution
• ISBN: 9781843394464; 1843394464
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2003.0120

This article presents a mathematical model to describe High-Rate Algal Ponds (HRAPs). The hydrodynamic behavior of the reactor is described as completely mixed tanks in series with recirculation. The hydrodynamic pattern is combined with a subset of River Water Quality Model 1 (RWQM1), including the main processes in liquid phase. Our aim is to develop models for WSPs and aerated lagoons, too, but we focused on HRAPs first for several reasons: Sediments are usually less abundant in HRAP and can be neglected, Stratification is not observed and state variables are constant in a reactor cross section, Due to the system's geometry, the reactor is quite similar to a plugflow type reactor with recirculation, with a simple advection term. The model is based on mass balances and includes the following processes: *Phytoplankton growth with NO3-, NO2- and death, *Aerobic growth of heterotrophs with NO3-, NH4+ and respiration, *Anoxic growth of heterotrophs with NO3-, NO2- and anoxic respiration, *Growth of nitrifiers (two stages) and respiration. The differences with regard to RWQM1 are that we included a limiting term associated with inorganic carbon on the growth rate of algae and nitrifiers, gas transfers are taken into account by the familiar Adeney equation, and a subroutine calculates light intensity at the water surface. This article presents our first simulations.