African Journal of Chemistry

African Journal of Chemistry Vol. 1 (3), pp. 071-076, December, 2013.© International Scholars Journals

Full Length Research Paper

Essence of photoelectric colorimetric assays of alcoholic methyl red dye solution in the purification of azo dye-contaminated waste-water

Obimba Kelechukwu Clarence

Department of Biochemistry, School of Science, Federal University of Technology Owerri, P.M.B 1526, Owerri, Imo State, Nigeria.

E-mail: kechrisob@yahoo.com. Tel. 07034851899.

Accepted 20 November, 2013

Abstract

The aim of the present research is: to determine the wavelength of maximum absorption of white light by alcoholic methyl red dye solution, to construct/plot the standard concentration calibration curve of the alcoholic methyl red dye solution, to find the Beer-Lambert’s concentration limits of alcoholic methyl red dye solution and to determine unknown concentrations of alcoholic methyl red dye in waste water samples, in a simulation model experiment. The wavelength of maximum absorption (1.18), of white light by 0.01% w/v alcoholic methyl red dye solution (pKa: 4.76, 25°C) was determined by photoelectric colorimetric technique and is in the range of 470-529 nm. A serial dilution of a 0.01% alcoholic methyl red dye stock solution, was prepared and used in constructing a standard concentration calibration curve, whose equation is A470-529 nm = 320C% w/v. The Beer-Lambert’s constant and Beer-Lambert’s concentration limits of alcoholic methyl red dye solution are 320 (% w/v. cm)-1 and 0.0025% w/v, respectively. The results observed of the simulation model experiment, indicate that the simulated treated-waste water samples of concentrations of alcoholic methyl red dye: 0.0012 ± 0.0002, 0.00047 ± 0.0001 and 0.0003125 ± 0.0001, were significantly lower (p<0.05) than a given standard limit low of 0.00125 ± 0.00001% w/v (mean ± standard error, % w/v) of alcoholic methyl red dye solution and thus were purified with an efficiency >90%. The photoelectric colorimetric assay is efficient for use in purification steps of azo dye-contaminated waste-water.

Key words: Waste-water effluents, simulation model, Beer-Lambert’s concentration limits.