Determination of Anionic Surfactants in Beam House Tannery Effluents by Simplified Spectrophotometric Method Using Methylene Blue

Abstract

A simplified spectrophotometric method was used for the determination of anionic surfactants (AS), based on the formation of the ionic pair AS – MB (Anionic Surfactants – Methylene Blue). In this method, the quantity of chloroform used was greatly reduced as well as the time and quantity of sample necessary to perform the assay. The filtration stage was also eliminated. The method used is simplified because it displaces the transfer equilibrium of the ionic pair AS – MB towards the organic phase and augments the volumetric relationship of chloroform/sample. The concentration of the AS in the beam house tannery effluents was found to be 1.16 mg/L of AS as against the limit of 15 mg/L set by FEPA showing that the concentration of the AS released into the environment at the moment does not necessarily pose a threat to the environment. Except if it is accumulated over time. The molar absorptivity of the azodye coupled with MB was found to be 5.65998 x 104 dm3mol-1cm-1.