Use of hydrocyclones for optimizing crucial sludge parameters in CAS WWTP, focusing on: SVI and required aerobic sludge age for maintained nitrification
Zajac, Sara (2025)
2025
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2025051512003
https://urn.fi/URN:NBN:fi:amk-2025051512003
Tiivistelmä
In order to address the growing capacity issues that are being brought on by urbanization, this thesis focuses on the potential of hydrocyclone technology to optimize sludge treatment parameters at the Søholt Wastewater Treatment Plant in Silkeborg, Denmark. The amelioration is prioritized in three crucial process indicators: the aerobic sludge age needed to sustain stable nitrification in a traditional activated sludge system, nitrification rates, and the Sludge Volume Index.
Following the installation of a hydrocyclone station in June 2024, the technology’s effectiveness was assessed through both primary experimentation and secondary operational data extracted from the plant’s Supervisory Control and Data Acquisition system. The controlled aeration of diluted sludge samples with added ammonium chloride was used to evaluate the nitrification performance, while experimental procedures were carried out in compliance with DS/EN 14702-1:2006 for SVI analysis. Additionally, to evaluate the process changes seen after installation, historical data on sludge age and other operational parameters were compared with current values.
Although valuable insights have been found about the role of hydrocyclones in amelioration of sludge settleability and supporting stable nitrification, several limitations have been acknowledged. The limited time frame since installation may not have allowed for the observation of long-term effects, and outcomes may have been influenced by factors such as suboptimal ammonium dosing during nitrification testing, seasonal variations, and changes in influent characteristics over time. Furthermore, variations in historical sludge age data must be interpreted with caution due to potential differences in external conditions.
Despite these limitations, hydrocyclones are presented as a promising tool for enhancing the resilience and efficiency of wastewater treatment processes. The importance of continued monitoring and long-term research is emphasized in order to validate and expand upon these initial findings.
Following the installation of a hydrocyclone station in June 2024, the technology’s effectiveness was assessed through both primary experimentation and secondary operational data extracted from the plant’s Supervisory Control and Data Acquisition system. The controlled aeration of diluted sludge samples with added ammonium chloride was used to evaluate the nitrification performance, while experimental procedures were carried out in compliance with DS/EN 14702-1:2006 for SVI analysis. Additionally, to evaluate the process changes seen after installation, historical data on sludge age and other operational parameters were compared with current values.
Although valuable insights have been found about the role of hydrocyclones in amelioration of sludge settleability and supporting stable nitrification, several limitations have been acknowledged. The limited time frame since installation may not have allowed for the observation of long-term effects, and outcomes may have been influenced by factors such as suboptimal ammonium dosing during nitrification testing, seasonal variations, and changes in influent characteristics over time. Furthermore, variations in historical sludge age data must be interpreted with caution due to potential differences in external conditions.
Despite these limitations, hydrocyclones are presented as a promising tool for enhancing the resilience and efficiency of wastewater treatment processes. The importance of continued monitoring and long-term research is emphasized in order to validate and expand upon these initial findings.