Journal of Microbial & Biochemical Technology

Abstract

Kinetic Modeling of Mixed Culture Process of Anaerobic Co-digestion of Vegetable Wastes with Pistia stratiotes: A Scientific Attempt on Biomethanationy

Samuel J, Gujjala Lohit Kumar S and Rintu B

As co-digestion of two wastes together lead to balanced environment for biomethanation an attempt has been made in the present study to co-digest vegetable waste (VW) and Pistia stratiotes (PS) to overcome the acidification problem during mono-digestion of VW. Optimization of important process parameters for anaerobic co-digestion was done based on Central Composite Design (CCD) based Response Surface Methodology (RSM). Thereafter, modeling of the anaerobic digestion was carried out using first order, modified Gompertz and unstructured segregated model to study the process behavior. First order and modified Gompertz models were found to fit with the observed methane profile with R2 of ~0.99. In case of unstructured segregated model important kinetic constants such as Khs, KSS, KVFA were derived from the model and the values were found to be 0.1 d-1, 2.3 g/L and 881.68 mg/L, respectively. Based on these kinetic parameters, simulated cumulative methane production was generated which matched well with the observed methane yield within the error band of ± 20%. This showed that the developed model could represent the overall process behaviour of this novel anaerobic co-digestion using mixed anaerobic culture as an inoculum.