Evaluation of organic matter, density and porosity of Oxisol in contact with leachate from urban solid waste

ABSTRACT

The objective of this research is to evaluate soil density, porosity, and also the organic matter due to soil-leachate interaction in Oxisol, at two depths: 0.2 and 1.5 m. Soil samples were collected undisturbed and the leachate in a landfill. Diffusion columns, without any flow, were used, where the soil was submerged in the leachate for 90 days. The organic matter was obtained by gravimetric determination (IAPAR). Density, micro and macro porosity were obtained according to the stress table test (EMBRAPA). Regression analysis was performed to study the factors effects and their interactions for the organic matter parameter. The main conclusions were: major changes in physical soil properties occur in the first days of contact; soil bulk density at 0.2 m decreased by 5.9%, while at 1.5 m it increased by 5.61%; macroporosity did not changed to 0.2 m, but decreased by 11% for 1.5 m; microporosity for both depths studied increased, respectively, by 4.25 and 21,14%. The soil organic matter had a low correlation with the leachate BOD₅ and a significant correlation with its COD; the increase of the soil organic matter was significant at the time of the contact.

Keywords:
soil density and porosity; municipal solid waste; leachate