Acceleration of sludge drying using resin emulsions and estimation of drying acceleration mechanism

Abstract

Sludge accounts for the highest percentage of waste emissions and needs to be treated efficiently for environmental issues, such as water problems, sanitation and CO2 emission. Although various processes for sludge treatment, such as dewatering, fermentation, drying, carbonization, composting etc., have been developed, effective sludge drying technique was investigated in this study, which can apply not only to organic, but also to inorganic sludge. Besides, the efficient sludge drying process has a potential to exceed the energy conversion efficiency of methane fermentation process by improving the drying efficiency. However, drying technique implemented in this study does not improve the efficiency of sludge drying equipment as in the traditional way, but accelerates sludge drying rate by changing the sludge properties itself to those suitable for drying by adding drying accelerator. In this experiment, resin emulsions were used as a drying accelerator, and sludge drying experiments were conducted using 30 different resin emulsions. The drying acceleration mechanism of resin addition sludge was also inferred by evaluating the change of the resin-addition sludge property. The results revealed that the physical properties of the resin have little influence on the drying acceleration, but the development of hydrophobicity associated with resin curing may have a significant effect on sludge drying acceleration.