Experimental Method of Treating the Leachate Using Various Physical Chemical Processes

Abstract

The leachate collected on the West side of the Johnston, Rhode Island Central Landfill contains iron, manganese and total oil and grease. This leachate must be treated to the pretreatment standards of the City of Cranston Water Pollution Control Facility before being discharged into the Cranston sewer system. A batch study was conducted to evaluate the coagulation-flocculation-sedimentation system required for treating the leachate. In this batch study the jar test was conducted to obtain the data for developing a regression model. Using the developed regression model and trial and error, three different sets of design parameters were evaluated. Using these sets of design parameters three different coagulation-flocculation-sedimentation systems were evaluated to determine the most cost effective design. The construction, operation and maintenance costs of the most cost effective coagulation-flocculation-sedimentation system was evaluated. In addition the most commonly practical system, aeration-sedimentation-filtration, was designed. The construction, operation and maintenance costs of the aeration-sedimentation-filtration system was evaluated. A detention pond was designed as a standby unit for both systems. The construction, operation and maintenance costs of the coagulation-flocculation-sedimentation system was much less than the aeration-sedimentation-filtration system.