Naphthalene detection by a bioluminescence sensor applied to wastewater samples

A bioluminescence detection system using Pseudomonas fluorescens HK44 was applied for naphthalene measurement in the range 0–0.5mgl−1, lower than the maximum of 1mgl−1 recommended by EPA. Diluted sample injections of naphthalene were added to 0.2 or 0.4gl−1 cellular concentrations used in the detection medium. The lowest cell density (0.2gl−1) exhibited a linear response up to naphthalene concentration of about 0.4mgl−1 being selected to be used in the subsequent experiments. The same system was applied to samples of influent and effluent streams of a biological wastewater treatment from a petroleum industry containing 2.4 and 1.1mg hydrocarbonsl−1, respectively, including naphthalene. The output signal of the biosensor system for the influent stream sample was fully compatible with the results obtained for the naphthalene solutions. Results obtained with the effluent sample showed that other contaminants than naphthalene may influence the biosensor response and are under investigations.