@inbook{e71f3204c9004b9eaf9e3ea19e5c07c9,
title = "Evaluation of Qualitative Trend Analysis as a Tool for Automation",
abstract = "Ammonium (NH4 +) load based aeration control on biological wastewater treatment plants saves costs and enhances nitrogen removal. However, the need for maintenance intensive NH4+ sensors hamper the controls application in practice. Alternatives, in the form of soft-sensors are broadly discussed in academia. A soft-sensor recently described in literature exploits the pH effects induced by biological NH4 + oxidation. This concept is now further developed by means of qualitative trend analysis (QTA). Previously, the qualitative path estimation (QPE) algorithms was proposed as a fast and reliable QTA algorithm for batch process data analysis. It does not allow online application in continuous flow systems however. In this work, a modification of QPE, call qualitative state estimation (QSE), is proposed as a suitable algorithm for continuous-flow systems. Initial tests indicate that the QSE algorithms is a robust technique for extraction of relevant information in a full-scale environment. At the WWTP Hard in Winterthur, this resulted in cost-saving automation of the aeration system. This contribution summarizes these first results.",
keywords = "Ammonia control, Biological wastewater treatment, Hidden Markov model, Kernel regression, Process monitoring",
author = "Th{\"u}rlimann, {Christian M.} and D{\"u}rrenmatt, {David J.} and Kris Villez",
note = "Publisher Copyright: {\textcopyright} 2015 Elsevier B.V.",
year = "2015",
doi = "10.1016/B978-0-444-63576-1.50116-3",
language = "English",
series = "Computer Aided Chemical Engineering",
publisher = "Elsevier B.V.",
pages = "2531--2536",
booktitle = "Computer Aided Chemical Engineering",
}