Feasibility Study to Retrofit Existing Rotary Drum into A Chemical Sludge Thermal Dewatering System Through Lab-Scale Experimental Investigations

Abstract

The adoption of the landfill method for chemical sludge management is an issue of concern as landfill leachates can cause negative impacts on the environment. Furthermore, the high moisture content in chemical sludge has resulted in higher disposal costs due to its heavyweight. This research study is conducted to determine the optimum thermal dewatering condition for chemical sludge through experimental testing and thereafter deduce a recommendation to retrofit an existing rotary drum for chemical sludge dewatering. The water removal rate from chemical sludge was evaluated through thermal dewatering experiments using a lab-scale furnace. Referring to results obtained, increased dewatering temperature and dewatering time, and decreased volume of chemical sludge has improved the water removal rate. The highest water removal rate is 82% when 1.0 cm³ chemical sludge sample is dewatered under a temperature of 250ºC for 90.0 min. Based on the economic evaluation between current chemical sludge handling and newly installed rotary drum dewatering methods, an estimate of one hundred and fifty-four thousand Malaysian Ringgit in annual net-saving is expected to be achieved through dewatering of chemical sludge in retrofitted equipment. The finding has justified the feasibility of retrofitting the current rotary drum for chemical sludge dewatering.