ANALYSIC OF FLUORIDE CONTENT IN INDUSTRIAL WASTEWATER BY THE SPECTROPHOTOMETRIC METHOD

Abstract

This article shows the results of the process of fluoride analysis in waste
water by spectrophotometric method using the aluminum - xylenol orange
complex, applying this process to analyze the fluoride content in the industrial
wastewater samples. The rule of the method is based on a decrease of the color
intensity of the complex of Al(III) with xylenol orange (XO) complex in the
presence of fluoride. The method was applied to the determination of fluoride
under the optimum conditions (Al3+ and XO ratio is 1 : 1wavelength 555nm,
pH = 5.0, KNO3 0.1M). The linear range of method from 0 to 3.0mg/l,
LOD = 0.082mg/l, LOQ = 0.273mg/l, RSD% = 0.527 % (n = 10).