Removal of Methylene Blue and Neutral Red Dyes from Spiked Waste-Water Using Edtad Modified Cellulose Obtained from Pennisetum purpureum

The presence of dyes in aquatic effluents is highly visible, undesirable, carcinogenic to human beings and toxic to living organisms. EDTAD modified cellulose extracted from Pennisetum purpureum was studied as an adsorbent for the removal of cationic dyes from spiked waste-water. Shimadzu Fourier Transform Infrared spectrophotometer, was used to analyze functional groups of cellulose and EDTAD modified cellulose. The characteristic peaks at 1260 cm-1, 1634 cm-1, 1058 cm-1, and 1740 cm-1 indicated formation of ester bond linkages associated with the introduction of EDTAD thus successful modification of cellulose. Shimadzu UV-VIS 1800 series determined the degree of dye concentration. Optimum adsorption was determined by varying the dosage, pH, contact time, and the initial concentration of the dyes.

An increase in adsorbent mass increased the percentage removal for both dyes up to a maximum of 98%. Low pH levels prompted low percentage removal as compared to higher pH values for both dyes. Kinetic studies were carried out using the Freundlich and Langmuir isotherms, to investigate the rate of adsorption. Methylene blue and neutral red dyes seemed to conform to langmuir with high R2 values of 0.999 and 0.997 respectively while freundlich isotherm had values of 0.9969 and 0.9835, indicating that the adsorption surface of the EDTAD modified cellulose was monolayer. Methylene Blue adsorption capacity was 200mg/g while for Neutral Red dye was 149.25mg/g. The kinetics were well depicted by pseudo second order model whose correlation coefficients were closer to unity than those of the first order model. The efficiency of EDTAD modified cellulose from Pennisetum purpureum as an adsorbent in the removal of dyes renders it a remedy to the various problems caused by dyes to aquatic life and human beings.