Developing a multipoint titration method with a variable dose implementation for anaerobic digestion monitoring

Determination of metabolites from an anaerobic digester with an acid base titration is considered as superior method for many reasons. This paper describes a practical at line compatible multipoint titration method. The titration procedure was improved by speed and data quality. A simple and novel c...

Full description

Saved in:
Bibliographic Details
Published in:Water science and technology 2009-01, Vol.59 (12), p.2395-2403
Main Authors: Salonen, K, Leisola, M, Eerikäinen, T
Format: Article
Language:English
Subjects:
Accuracy
Acetates
Acetic acid
Acids
Algorithms
Anaerobic digestion
Anaerobic treatment
Anaerobiosis
Biogas
Capacity
Computation
Control algorithms
Control theory
Environmental Monitoring - methods
Fatty acids
Ionic strength
Iterative methods
Mathematical analysis
Mathematical models
Matrix methods
Metabolites
Methods
Models, Theoretical
Nonlinear control
Phosphates
Slope
Titration
Titrimetry - methods
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Determination of metabolites from an anaerobic digester with an acid base titration is considered as superior method for many reasons. This paper describes a practical at line compatible multipoint titration method. The titration procedure was improved by speed and data quality. A simple and novel control algorithm for estimating a variable titrant dose was derived for this purpose. This non-linear PI-controller like algorithm does not require any preliminary information from sample. Performance of this controller is superior compared to traditional linear PI-controllers. In addition, simplification for presenting polyprotic acids as a sum of multiple monoprotic acids is introduced along with a mathematical error examination. A method for inclusion of the ionic strength effect with stepwise iteration is shown. The titration model is presented with matrix notations enabling simple computation of all concentration estimates. All methods and algorithms are illustrated in the experimental part. A linear correlation better than 0.999 was obtained for both acetate and phosphate used as model compounds with slopes of 0.98 and 1.00 and average standard deviations of 0.6% and 0.8%, respectively. Furthermore, insensitivity of the presented method for overlapping buffer capacity curves was shown.
ISSN:0273-1223
1996-9732
DOI:10.2166/wst.2009.275