Evaluation of matematical models for the growth of microalgae Characium sp. UKM1, Chlorella sp. UKM2 and Coelastrella sp. UKM4 in synthetic leachate

Abstract

Microalgae have a potential as a phycoremediation agent for wastewater and the metabolites produced from microalgae in biomass can be applied in the field of biotechnology. The growth of microalgae in wastewater indicates the feasibility of microalgae to live in an extreme environment and acts as a phycoremediation agent. Therefore, the best mathematical model for microalgae growth kinetic grown in wastewater needs to be elucidated to determine the correct model for future use. In this study, the evaluation of the best mathematical model for three local microalgae, Characium sp. UKM1, Chlorella sp. UKM2 and Coelastrella sp. UKM4 cultured in synthetic leachate will be analysed by three mathematical models which is logistic, modified logistic and modified Gompertz model. Beside that, statistical analysis was conducted to determine the best model by determination of adjusted regression (adj R2), sum square error (SSE), root mean square error (RMSE), bias factor (BF), accuracy factor (AF) and standard error prediction (%SEP) values. Result shows the best model for Characium sp. UKM1, Chlorella sp. UKM2 and Coelastrella sp. UKM4 grown in synthetic leachate is modified Gompertz model. This is due to several characteristics such as the residual plot that fitted to the mathematical model, BF values near to one, also the lowest %SEP value compared to the other mathematical models. In conclusion, the modified Gompertz model is the best fitting model for microalgae growth in synthetic leachate.