Temperature-Toxicity Model for Oil Refinery Waste

A continuous flow kinetic model to predict the effects of temperature on the toxicity of oil refinery waste to the algae Selenastrum capricornutum is presented. The model is based on enzyme inhibition kinetics and employs phenol as the controlling toxicant. Data from semicontinuous and continuous flow cultures grown between 20°C and 28°C are used to verify the model and to determine the type of inhibition exerted by phenol on Selenastrum capricornutum. The data are fitted to competitive, uncompetitive, and noncompetitive inhibition models. The results indicate that phenol exerts competitive inhibition on the growth of Selenastrum capricornutum. Comparison of the competitive inhibition constants, K_I, developed for Selenastrum capricornutum exposed to phenol at 20°C, and 28°C, indicates that phenol toxicity increases with increasing temperature and can be described by the Arrhenius function.