Abstract:
The disposal of generated leachate is one of the major problems in the composting of Organic Fraction of
Municipal Solid Waste (OFMSW). Therefore, it is essential to have a proper, environmental friendly
leachate disposal method. The objective of this study was to determine the quality of compost produced
from OFMSW by the application of leachate generated during composting process. Research was
conducted in composting yard at "Green Park" land filling site Kirindiwela, Western Province of Sri Lanka.
The experimental compost beds were prepared ( I x lx l m) manually in the composting site. Completely
randomized design (CRD) with four different leachate dilution levels (100%, 50%, 25% and 0% leachate),
each having three replicates was used for the experiment After one week, leachate (35 L) was added to
experimental composing units while turning of composting beds, once a week. Temperature was
measured daily while Electrical Conductivity (EC), pH, Moisture Content (MC), Organic Carbon (OC) were
recorded weekly. At the end of the study (~ 12 Weeks), composting quality parameters were also
determined. Temperature profiles in experimental composting piles during study period showed that the
composting process was satisfactory. pH though was acidic (5-7) at the beginning, reached to near 8 at
the end of the study. Showing that the organic matter was hydrolyzed by microorganism, electrical
conductivity was high (13-15 mS) at the beginning but finally reduced (~10). The electrical conductivity
of compost in all experimental composting piles were higher than the that of recommended EC (0.5-4.0
mS) values while pH, MC, OC and bulk density were within the recommended range. Further, Nitrogen,
Phosphorus, Potassium contents were well within the recommended range. Even though significant
increase of nutrients (N, P and K) in leachate added compost was noted, all nutrients were within the
recommended level. Therefore, it can be concluded that use of leachate does not have significant bad
impact on compost quality. Addition of leachate reduces the disposal burden of leachate while increasing
the nutrient levels of compost significantly.
