Potential efficiency and energy usage in a leachate treatment process

Generated leachate in landfills is often as a result of the infiltration of rain, surface or running water into waste bodies. Numerous studies have revealed the potential impacts of leachate escape from landfill disposal facilities on human and environmental health. Although much is been done in most landfills in South Africa to ensure minimal leachate escape into immediate soil, surface and groundwater reserves, much more is still required. As such, the option of leachate treatment is gradually been explored. The potential efficiency and energy usage of a landfill waste water treatment plant (WWTP) for a simple leachate treatment process is explored. The WWTP process involves the basic treatment of the leachate with subsequent sequencing batch reactors (SBR), reverse osmosis unit (RO) and evaporation for additional concentration of RO yield. The process efficiency is appraised by conductivity, chemical oxygen demand (BOD), biochemical oxygen demand (BOD) and total nitrogen (TN) measurements. Energy usage is estimated by electrical input power, motor efficiency of power-consuming units and functional hours. 2.2% of the of the WWTP total operational real power consumption is gotten for the primary treatment process with 16.7% corresponding SBR operation and 13.2% RO unit. 2 unit evaporators consumes 61.5% and 0.78% for leachate recirculation to landfill from the total energy usage. Therefore, RO is taken as the most efficient leachate treatment process as it can dispense substantial amounts of water from the landfill leachate pond whereas, the evaporators are energy demanding.