Adsorption Of Methyl Orange On Waterworks Sludge In Waste Water

The adsorption of methyl orange on waterworks sludge in waste water was discussed in the paper. Results show that the low cost and high capacity of waterworks sludge makes it attractive adsorbent for the removal of methyl orange from wastewater. The adsorption mass for methyl orange is 0.76mg/g. The adsorption behavior and mechanism of methyl orange adsorption on waterworks sludge were studied. Kinetic studies showed that methyl orange adsorption on waterworks sludge fitted the second-order kinetic model. The second-order rate constants (k(2)) calculated from the equation was 0.058g.mg(-1).min(-1). Isotherm studies illustrated that adsorption could be described by Freundlich isotherm model, with the correlation coefficients over 0.89. The adsorption thermodynamic parameters such as change in free energy (Delta G), enthalpy (Delta H), entropy (Delta S) were also determined. Values of Delta H for methyl orange adsorption on waterworks sludge was -0.009k.J.mol(-1). The negative value of Delta G and Delta H indicated the adsorption process was spontaneous and exothermic.