This paper discusses the adsorption of Direct Orange 26 azo dye on sunflower husk - an agricultural waste product. During the study, sorption kinetics and equilibrium as well as sorption capacity of the husk were investigated. The adsorption kinetics was analyzed using pseudo-first and pseudo-second order equations, which indicated a chemical sorption mechanism. The sorption equilibrium was approximated with the two-parameter Freundlich and Langmuir equations and the three-parameter Redlich-Peterson equation. The main experiments were carried out in a laboratory adsorption column under different process conditions. Experimental data were interpreted with the Thomas model, based on the volumetric flow rate, initial composition of the feed solution and mass of the adsorbent. The results of modeling the adsorption equilibrium, adsorption kinetics and adsorption dynamics were evaluated statistically.

In the present study, basic red 9 had been removed from synthetic waste water using animal waste. Cow dung ash had been prepared and characterized by scanning electron microscope. Morphology analysis shows very fine particles of less than 1 μm. The pH analysis study favours a pH of 8.5 for maximum dye removal. The removal of basic red 9 was very fast on cow dung ash. Percentage dye removal was 80.24% and 95.24 in 5 minutes and 90 minutes, respectively at initial dye concentration of 10 ppm.