Improving hydrodynamic performance of waste stabilisation ponds using three-dimensional numerical models

M. Li, H. Zhang, C. Lemckert, H. Stratton

Research output: A Conference proceeding or a Chapter in BookConference contribution

Abstract

Waste stabilisation ponds (WSPs) are widely used for wastewater treatment throughout the world. They are shallow constructed basins, typically located at the end of a treatment plant, that use natural microbiological, photosynthetic, biochemical, physico-chemical and hydrodynamic processes to generate a reduction of organic matters and pathogenic organisms in wastewater (Watters et al., 1973). They require little technical attention during operation, and are less demanding in terms of construction cost and energy consumption than other engineered wastewater treatment systems. Practical experience and research over the past few decades have established that hydrodynamics is one of the crucial factors determining WSP's overall treatment performance. The Department of Environment and Planning (1992) in the state of Tasmania surveyed 39 wastewater treatment systems and reported that 74% of the pond systems failed to achieve the discharge requirements, and it is due to the hydraulic problems including short-circuiting, stratification in hot Australian climates, and stagnant fluid in dead zones. Therefore, it is of primary importance that WSP's hydrodynamic performance be improved before WSP treatment efficiency can be guaranteed. A substantial number of numerical modelling studies have been undertaken to look into WSP hydrodynamics, both two-dimensionally and three-dimensionally. It is the ultimate goal of this study to use numerical modelling techniques to investigate measures to improve WSP hydrodynamic performance, consequently to propose retrofitting design. A validated three-dimensional numerical model using MIKE 3 by DHI (Danish Hydraulic Institute) was developed to study a typical pond with a dimension of 50 m (length) by 20 m (width) by 1.5 m (depth). The retrofitting scheme was proposed by placing baffles in the pond with different geometric ratios: the ratio of baffle length Lb to the width of the pond W: Lb/W, and the ratio of baffle spacing ?b to the length of the pond L: ?b/L. For generalised design guidance, baffles positively contribute to the hydraulic efficiency for ponds with a relatively small L/W ratio. Placing 8 baffles in a pond with L/W = 1.6 results in a ? (hydraulic efficiency) = 0.83 as oppose to ? = 0.23 if the pond is not baffled. However, ponds do not benefit from retrofitting baffles if their L/W ratios are large. Ultimately, this study is to provide regulators, decision makers, water managers and operators with information and tools to best operate and manage WSPs, to protect public and environmental health and optimise uses of the treated water.

Original languageEnglish
Title of host publicationProceedings - 21st International Congress on Modelling and Simulation, MODSIM 2015
EditorsTony Weber, Malcolm McPhee, Robert Anderssen
Place of PublicationAustralia
PublisherModelling and Simulation Society of Australia and New Zealand Inc. (MSSANZ)
Pages2507-2513
Number of pages7
ISBN (Electronic)9780987214355
DOIs
Publication statusPublished - 2015
Externally publishedYes
Event21st International Congress on Modelling and Simulation: Partnering with Industry and the Community for Innovation and Impact through Modelling, MODSIM 2015 - Held jointly with the 23rd National Conference of the Australian Society for Operations Research and the DSTO led Defence Operations Research Symposium, DORS 2015 - Broadbeach, Australia
Duration: 29 Nov 20154 Dec 2015

Publication series

NameProceedings - 21st International Congress on Modelling and Simulation, MODSIM 2015

Conference

Conference21st International Congress on Modelling and Simulation: Partnering with Industry and the Community for Innovation and Impact through Modelling, MODSIM 2015 - Held jointly with the 23rd National Conference of the Australian Society for Operations Research and the DSTO led Defence Operations Research Symposium, DORS 2015
CountryAustralia
CityBroadbeach
Period29/11/154/12/15

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  • Cite this

    Li, M., Zhang, H., Lemckert, C., & Stratton, H. (2015). Improving hydrodynamic performance of waste stabilisation ponds using three-dimensional numerical models. In T. Weber, M. McPhee, & R. Anderssen (Eds.), Proceedings - 21st International Congress on Modelling and Simulation, MODSIM 2015 (pp. 2507-2513). (Proceedings - 21st International Congress on Modelling and Simulation, MODSIM 2015). Modelling and Simulation Society of Australia and New Zealand Inc. (MSSANZ). https://doi.org/10.36334/MODSIM.2015.L16.li