Techno-economic assessment for ozonation of biological sludge from rubber industry

Abstract

Rubber industry produced sludge from their wastewater treatment plant facility and disposed either directly to the landfill or to a third party. The disposal of sludge required a lot of money for the transportation and tends to spend a lot of money to dispose the sludge. For any industry, the less cost spend, the better. In order to reduce the cost of sludge disposal, sludge must be reduced. The best way to reduce excess sludge is by ozonation. The aim of this project is to assess the ozonation of biological sludge from rubber industry in terms of techno-economic assessment. The biological sludge is being collected from Shorubber (Malaysia) Sdn Bhd wastewater treatment plant facility in Jejawi Arau, Perlis. This experiment is being conduct in laboratory scale where ozone is being introduced through a porous fritted diffuser. The result obtained shows that the longer the ozone is introduced, the more ozone dosage is introduced, the more sludge is being disintegrated. Therefore, Total Chemical Oxygen Demand (TCOD) is decreased, the Soluble Chemical Oxygen Demand (SCOD) remain stable, the Total Solid (TS), Volatile Solid (VS), Total Suspended Solid (TSS), Volatile Suspended Solid (VSS), and ammonia-nitrogen (NH3-N) are decreased, and lastly, the Sludge Volume Index (SVI) is increased. All of this result shows that ozonation is very effective to disintegrate sludge, therefore reducing the sludge production, and ultimately reducing the cost of sludge disposal. The cost of sludge disposal will be reduced from RM189,000.00 per year to RM177,093.00 per year and saved up to RM11,907.00 per year, that is 6.3% of cost savings.