Landfill leachate treatment using single and mixed freshwater cyanobacterial isolates

Abstract

The increasing volume of waste disposal and improper management of landfill has been contributing to the heavily polluted leachate. Local freshwater cyanobacteria were identified based on the polyphasic approach that combines morphological and molecular identification by the 16S rRNA gene sequencing method. The local cyanobacteria isolate (A1) was identified as the genus Cyanobacterium of the order Chroococcales. The A1 isolate together with identified cyanobacteria, Anabaena sp. was used to observe their effectiveness in remediating leachate pollution either as monoculture or in mixed culture. Prior to the phycoremediation, the characterization of leachate had been carried out. The biological oxygen demand (BOD5), chemical oxygen demand (COD), pH value, concentration of ammonia-nitrogen (NH3-N), nitrite ( N O 2 − ) , and nitrate ( N O 3 − ) of the raw leachate determined were 22.37 mg/L, 58.33 mg/L, 7.84, 82.7 mg/L, 88.67mg/L and 89.43mg/L, respectively. The use of a single Anabaena sp. demonstrates the most effective in the removal of all contaminants that exist in the leachate. The removal of COD was the highest at 105.71% followed by BOD5 at 92.71% and NO3- at 82.09%. This finding suggested that in order to achieve optimum removal of BOD5, COD, NH3-N, NO2 - and NO3 - content in leachate sample, treatment by Anabaena sp. should be applied.