Modeling the Temperature Pattern of a Covered Anaerobic Pond with Computational Fluid Dynamics

Abstract

This paper presents the development of a 3D computational fluid dynamics (CFD) model of a covered deep anaerobic pond treating raw sewage. The model was based on an unsteady-state laminar flow which was solved in accordance with the finite volume method and simulated the hydrodynamic pattern and thermal energy balance of the anaerobic pond throughout a year of operation. The model input included hourly ambient air temperature, monthly soil temperature profile, daily influent wastewater temperature and velocity, which were incorporated through an external routine in C ++ . Numerical simulation was validated by temperature measurements from the experimental pond. The mean relative error and correlation factor out of 164 temperature values of the simulated pond, in comparison with the experimental one, was 9.34% and 0.91, respectively. The average temperature of the simulated pond throughout the experimental period was 18.9 • C. The validated 3D thermal model can be used as a tool for assessing and evaluating the impact of various design modifications (changes in construction material, adding insulation, installing a heat exchanger, etc.) on the thermal behaviour of an anaerobic pond, aiming at its average temperature increase which will, in turn, positively affect its organic removal performance. The thermal model presented, is the first stage of a complete anaerobic pond model which will include wastewater quality transport and basic biochemical reaction mechanisms of the anaerobic decomposition process present in an anaerobic pond. The complete anaerobic pond model will be able to predict the effluent COD of the pond.

Oxidation pond for municipal wastewater treatment

“…CFD benefits the researcher insomuch as he or she is able to determine how varying the effects of conditions within waste stabilization ponds would affect the performance of removing various constituents. This is beneficial whenever the conditions are unfavorable for sampling (Karteris et al 2005). Various authors discuss the significance of the use of CFD in its ability to analyze treatment performance.…”

“…Alvarado et al (2012) determined that sludge accumulation and settling of sludge within waste stabilization ponds increases as water moves away from the inlet and the velocity decreases. Karteris et al (2005) created a temperature model within a covered anaerobic pond under unsteady state conditions. Sweeney et al (2007) analyzed the effects of the presence of sunlight when considering the water quality between the summer and winter months.…”

Impact of Sludge Layer Geometry on the Hydraulic Performance of a Waste Stabilization Pond

“…The rapid advance of computer technology has allowed computational fluid dynamics (CFD) to be applied to wastewater treatment. CFD models have been successfully applied for analysis and optimization of the hydraulics of WSPs in previous studies (Wood et al, 1995;Wood et al, 1998;Peterson et al, 2000;Salter et al, 2000;Shilton, 2000;Vega et al, 2003;Karteris et al, 2005;Sweeney et al, 2005;Verbyla et al, 2013b).…”

Integration of mixing, heat transfer, and biochemical reaction kinetics in anaerobic methane fermentation

“…The principal components involved in the development of a heat transfer model for a digester include weather conditions, solar radiation, the digester location, the digester configuration and its building material, the surrounding soil properties, as well as the influent temperature and flow rate. A few numerical studies published thus far quantify heating and temperature control for covered lagoons, plug‐flow, and complete‐mix digesters (Axaopoulos et al, 2001; Gebremedhin et al, 2005; Karteris et al, 2005; Wu and Bibeau, 2006). These studies do not, however, relate the impact of heat transfer to the digestion process.…”