Water 2018, 10(10), 1410; https://doi.org/10.3390/w10101410
Model-Based Analysis of Increased Loads on the Performance of Activated Sludge and Waste Stabilization Ponds
1
Department of Animal Sciences and Aquatic Ecology, Ghent University, 9000 Ghent, Belgium
2
Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, 9000 Ghent, Belgium
3
National Institute for Applied Statistics Research Australia, University of Wollongong, 2522 New South Wales, Australia
*
Author to whom correspondence should be addressed.
Received: 10 September 2018 / Revised: 30 September 2018 / Accepted: 3 October 2018 / Published: 10 October 2018
(This article belongs to the Section Water and Wastewater Treatment)
Abstract
In a way to counter criticism on low cost-effective conventional activated sludge (AS) technology, waste stabilization ponds (WSPs) offer a valid alternative for wastewater treatment due to their simple and inexpensive operation. To evaluate this alternative with respect to its robustness and resilience capacity, we perform in silico experiments of different peak-load scenarios in two mathematical models representing the two systems. A systematic process of quality assurance for these virtual experiments is implemented, including sensitivity and identifiability analysis, with non-linear error propagation. Moreover, model calibration of a 210-day real experiment with 31 days of increased load was added to the evaluation. Generally speaking, increased-load scenarios run in silico showed that WSP systems are more resilient towards intermediate disturbances, hence, are suitable to treat not only municipal wastewater, but also industrial wastewater, such as poultry wastewater, and paperboard wastewater. However, when disturbances are extreme (over 7000 mg COD·L−1), the common design of the natural system fails to perform better than AS. Besides, the application of sensitivity analysis reveals the most influential parameters on the performance of the two systems. In the AS system, parameters related to autotrophic bacteria have the highest influence on the dynamics of particulate organic matter, while nitrogen removal is largely driven by nitrification and denitrification. Conversely, with an insignificant contribution of heterotrophs, the nutrient removal in the pond system is mostly done by algal assimilation. Furthermore, this systematic model-based analysis proved to be a suitable means for investigating the maximum load of wastewater treatment systems, and from that avoiding environmental problems and high economic costs for cleaning surface waters after severe overload events. View Full-TextKeywords:
activated sludge; waste stabilization pond; climate change; peak load; scenario analysis; sensitivity analysis
▼
Figures
Graphical abstract
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
Share & Cite This Article
MDPI and ACS Style
Ho, L.; Pompeu, C.; Van Echelpoel, W.; Thas, O.; Goethals, P. Model-Based Analysis of Increased Loads on the Performance of Activated Sludge and Waste Stabilization Ponds. Water 2018, 10, 1410.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.