Assessment of Characterization Procedures for the Implementation of Anaerobic Digestion Model No.1

Abstract

In this paper, comparison were made among the characterization processes, designed for influent characterization in Anaerobic Digestion Model No.1 (ADM1) to choose one of the best available. The two procedures chosen are elemental analysis and conversion of Activated sludge Model (ASM) output to ADM1 input variables (ASM2ADM interface) given by John B. Copp, 2003. The Matlab code for elemental analysis was developed to facilitate computation and a c-file of the ASM2ADM interface was provided by the department of Industrial Electrical Engineering and Automation, Lund University Sweden. Both of these methods have been used in the collection of wastewater data from various locations and the demand for chemical oxygen (COD) after separation compared to experimental results. In almost all cases total fractionated COD from ASM2ADM interface was approximately equal to experimental COD. While as fractionation by elemental analysis shows variation from experimental value. Linear curve fitting was done between experimental COD and fractionated COD to check their equivalency. The elemental analysis method has lower value of coefficient of determination (R2 = 0.5468) than ASM2ADM interface (R2 = 0.9453). Based on the model requirements, it was concluded that ASM2ADM interface is the best option for influent characterization. Apart from obtaining good correlation with experimental COD, it provides all input variables for implementation of ADM1. While elemental analysis provide fewer fractionation and hence assumption of other input variables is must leading to deviation from actual model features. Features of both methods are also discussed in the paper.