Approbation of the texture analysis imaging technique in the wastewater treatment plant. Issue 1 (1st January 2017)

• Record Type: Journal Article
• Authors: Sivchenko, N.; Ratnaweera, H.; Kvaal, K.
• Editors: Cameselle, Claudio
• Is Part Of: Cogent engineering. Volume 4:Issue 1(2017)
• Publication Date: 2017-01-01
• Subjects: coagulation -- wastewater treatment plant -- image analysis -- texture analysis -- effluent turbidity prediction; Engineering -- Periodicals; Technology -- Periodicals; Engineering; Technology; Periodicals; 620
• DOI: 10.1080/23311916.2017.1373416
• Languages: English
• ISSNs: 2331-1916

Abstract

Abstract: Monitoring of effluent turbidity is essential to evaluate the coagulation process in wastewater treatment plants (WWTPs). A digital imaging system based on the texture analysis of flocs has been tested in a Norwegian municipal WWTP to predict changes in coagulation conditions and outlet turbidity. Principal component analysis (PCA) was applied to prove that the textural features of flocs' images depend on the inlet wastewater parameters and coagulation conditions. Partial least squares regression (PLSR) was performed for the outlet turbidity prediction. The best model resulted in 86.6% prediction accuracy using two wastewater quality parameters (inlet flow and inlet turbidity) and 4 textural feature vectors retrieved from the images of flocs. Furthermore, the outlet turbidity predicted by this model resulted in a lower amount of underestimated values compare to the model, which contained only wastewater quality parameters. A new term—floc texture index (FTI) summarizes the textural features of flocs' images resulting in a single variable (thought linear combination). This further simplifies the current multivariate dosage control system. Analysing the plant data indicates that an FTI value below 6 would result in the outlet turbidity values above 5. This can be used as an early warning system of coagulation failure. The results of these studies demonstrate the potential of the digital imaging system to improve an existing online coagulant dosing control strategy.