Seasonal variations in moisture content and the distribution of total organic carbon in landfill composites: case of active and closed landfills in Lagos, Nigeria

The compositional trend and characteristics of active and closed landfill composites with depth was evaluated, in order to establish possible relationships between seasonal variations in moisture content, distribution of total organic carbon (TOC) and pH stability. A bulk system of composite classification was used. Both landfills had similar waste constituents, but varied widely in relation to the measured parameters. The TOC levels of the landfills were more influenced by the less degraded component than by the depth. Moisture content in both landfills had a positive significant statistical relationship with less degraded weight (P<0.01) and a negative relationship with more degraded weight (P<0.05), but was not significantly related to pH. These data suggest that seasonal variations and the less degraded component of samples are major factors influencing the moisture content and distribution of TOC in active and closed landfills, irrespective of difference in the disposal period of the waste into landfill.