Surface Complexation Modeling For the Stabilization of an Industrial Sludge by Alternate Materials

The main aim of this paper is to model the behavior of a mixture of 30% fly ash, 60% black cotton soil, 30% heavy metal laced industrial sludge, and 15% cement for sorption of chromium and copper at different pH values. It was found that the mixture of 30% fly ash, 60% soil, 30% sludge, and 15% cement was the ideal combination found from extensive leaching experiments for heavy metals such as Cr+6 and Cu+6. Owing to practical difficulties of carrying out leaching tests over a wide range of pH values, visual minteq was used to simulate these conditions. It is found that the model predicts the retention behavior accurately and was further confirmed with the output of previous experimental work. A series of visual minteq simulations revealed that surface complexation and reduction play an important role in the sorption process. It was concluded that the hazardous sludge laced with heavy metals can be stabilized. The study would benefit the design engineers in understanding and in finding alternate means for treating industrial sludge waste