Microbial and chemical profile of a ponds system for the treatment of landfill leachate

Abstract

The present study describes the behavior of spatio-temporal variation of parameters and microbial profile of a pilot stabilization ponds system, consisted of three serial ponds, for the treatment of landfill leachate. Bacterial diversity was determined through molecular techniques (FISH, PCR and phylogenic analysis), while the phytoplankton community was evaluated through optical microscopy and quantified by the Sedgewick-Rafter chamber. Physicochemical parameters were also evaluated. The ponds system presented the following removal efficiency: 56% for TCOD; 83% for SBOD5 and 82% for N-NH4(+). Moreover, the analysis of chlorophyll a and DO showed stratification in the mass of water by the vertical profile. The analysis of the phytoplankton community showed a low number of species, with a predominance of Chlamydomonas sp. and presence of Cryptomonas sp. in lower density. The bacterial diversity analysis showed the presence of Planctomycetales, Verrucomicrobiales, some Desulfovibionaceae sulfate-reducing bacteria and Pseudomonas sp.

Keywords: Landfill; Leachate; Microbial dynamics; Phytoplankton community; Stabilization ponds.