Humic acids are amorphous organic macromolecules that are responsible for the color of natural water. They play an important role in the formation of disinfection by-products, the stabilization of wastewater sludge, and the treatment of wastewater. An ultrasonic process is applied as a pretreatment method for the purpose of reducing the risk of chlorinated by-products. Experimental results indicate that the initial pH, ionic strength, and chlorine demand affect the amount of total organic carbon removal and Cl2 consumption significantly. The formation of chlorinated by-products depends on both the initial pH and ionic strength. Experimental results also propose a good agreement that the humic acid can be removed efficiently by ultrasonic pretreatment under aerobic conditions. In this study, when the ultrasound/O2 process is used as a pretreatment method, the biodegradability which is defined as the formation of BOD5 increases with sonication time.

This content is only available as a PDF.