Modelling to Lower Energy Consumption in a Large WWTP in China While Optimising Nitrogen Removal

Mónica Vergara-Araya, Verena Hilgenfeldt, Di Peng, Heidrun Steinmetz and Jürgen Wiese
Additional contact information
Mónica Vergara-Araya: Department for Water, Environment, Construction and Safety, Magdeburg-Stendal University of Applied Sciences, Breitscheidstr. 2, 39114 Magdeburg, Germany
Verena Hilgenfeldt: Institute Water Infrastructure Resources, Technical University of Kaiserslautern (TUK), Paul-Ehrlich-Str. 14, 67663 Kaiserslautern, Germany
Di Peng: Institute Water Infrastructure Resources, Technical University of Kaiserslautern (TUK), Paul-Ehrlich-Str. 14, 67663 Kaiserslautern, Germany
Heidrun Steinmetz: Institute Water Infrastructure Resources, Technical University of Kaiserslautern (TUK), Paul-Ehrlich-Str. 14, 67663 Kaiserslautern, Germany
Jürgen Wiese: Department for Water, Environment, Construction and Safety, Magdeburg-Stendal University of Applied Sciences, Breitscheidstr. 2, 39114 Magdeburg, Germany

Energies, 2021, vol. 14, issue 18, 1-24

Abstract: In the last decade, China has sharply tightened the monitoring values for wastewater treatment plants (WWTPs). In some regions with sensitive discharge water bodies, the values (24 h composite sample) must be 1.5 mg/L for NH 4 -N and 10 mg/L for total nitrogen since 2021. Even with the previously less strict monitoring values, around 50% of the wastewater treatment plants in China were permanently unable to comply with the nitrogen monitoring values. Due to the rapid changes on-site to meet the threshold values and the strong relation to energy-intensive aeration strategies to sufficiently remove nitrogen, WWTPs do not always work energy-efficiently. A Chinese WWTP (450,000 Population equivalents or PE) with upstream denitrification, a tertiary treatment stage for phosphorus removal and disinfection, and aerobic sludge stabilisation was modelled in order to test various concepts for operation optimisation to lower energy consumption while meeting and undercutting effluent requirements. Following a comprehensive analysis of operating data, the WWTP was modelled and calibrated. Based on the calibrated model, various approaches for optimising nitrogen elimination were tested, including operational and automation strategies for aeration control. After several tests, a combination of strategies (i.e., partial by-pass of primary clarifiers, NH 4 -N based control, increase in the denitrification capacity, intermittent denitrification) reduced the air demand by up to 24% and at the same time significantly improved compliance with the monitoring values (up to 80% less norm non-compliances). By incorporating the impact of the strategies on related processes, like the bypass of primary settling tanks, energy consumption could be reduced by almost 25%. Many of the elaborated strategies can be transferred to WWTPs with similar boundary conditions and strict effluent values worldwide.

Keywords: energy efficiency; wastewater treatment; nitrogen removal; modelling; simulation; optimisation (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/1996-1073/14/18/5826/pdf (application/pdf)
https://www.mdpi.com/1996-1073/14/18/5826/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:14:y:2021:i:18:p:5826-:d:635750

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().