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 JWARP  Vol.12 No.6 , June 2020
Process Adaption of a Small WWTP Operated at Low Loading Conditions for Substantial Energy Savings
Abstract: The very long tradition of the activated sludge treatment model within the water industry has demonstrated very versatile possibilities to adopt the operation mode for different enhancements. By looking into other treatment models within the activated sludge family it is possible to find alternatives for the operation. This paper concentrates on the possibilities to improve even small WWTP with respect to energy savings. The small plant in Northern Sweden, called Rosvik WWTP, is given as an example. Some important findings related to the intermittent aeration mode may be summarized as follows: 1) An energy savings for the operation of the small WWTP with respect to aeration needs that resulted in a decrease of the energy power supply by more than 35%, as compared with the previous operation based on continuous aeration; 2) The up to date effluent levels with respect to the main pollutants have remained at very good levels in 2020, P-level averages 0.16 mg P/l versus consent level < 0.5 mg P/l; COD-level 40 versus < 70 mg/l and BOD7 9 versus < 15 mg/l; 3) Sometimes, also improved sludge settling characteristics have been observed, thus providing improved discharge figures; 4) The potential to develop an enhanced biological phosphorus removal. There are however some needed conditions to accomplish these improvements: 1) Reliable on-line probes for both oxygen control, SS-concentration control and optionally also for nitrogen control; 2) A flexible automation system that allows the needed process modifications to take place; 3) And finally, very important dedicated and competent plant operators, with the needed curiosity for operation improvements.
Cite this paper: Sweco, S. and Pireva, R. (2020) Process Adaption of a Small WWTP Operated at Low Loading Conditions for Substantial Energy Savings. Journal of Water Resource and Protection, 12, 472-479. doi: 10.4236/jwarp.2020.126028.
References

[1]   Arden, E. and Lockett, W.T. (1915) The Oxidation of Sewage without the Aid of Filters. Journal of the Society of Chemical Industry, 827-943.

[2]   Irvine, R. (1983) Technology Assessment of Sequencing Batch Reactors. Contract No. 68-03-3055 U.S. Environmental Protection Agency, Cincinnati, pp. 1-70.

[3]   Morling, S. (2019) Swedish Experience and Excellence in Wastewater Treatment Demonstrated Especially in Phosphorus Removal. Journal of Water Resource and Protection, 11, 333-347.
http://www.scirp.org/journal/jwarp
https://doi.org/10.4236/jwarp.2019.113019


[4]   Berg, J. and Morling, S. (2013) Process Adaption and Modifications of a Nutrient Removing Wastewater Treatment Plant in Sri Lanka Operated at Low Loading Conditions. Materials Sciences and Applications, 4, 299-306.
https://doi.org/10.4236/msa.2013.45038

[5]   Morling, S., et al. (2016) Energy Savings and Process Performance at a WWTP Operated with Intermittent Aeration at Low Temperature and High Organic Load. The 13th IWA Leading Edge Conference on Water and Wastewater Technologies, Jerez de la Frontera, 13-16 June 2016.

[6]   Marklund, S. and Morling, S. (1994) Biological Phosphorus Removal at Temperatures from 3℃ to 10℃—A Full Scale Study of a Sequencing Batch Reactor Unit. Canadian Journal of Civil Engineering, 21, 81-88.
https://doi.org/10.1139/l94-008

 
 
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