Landfill leachate treatment using single and mixed freshwater cyanobacterial isolates / Aina Yasmin Daud

Increasing volume of waste disposal and improper management of landfill have been contributing to the heavily polluted leachate. Local freshwater cyanobacteria collected from a water feature located in a public school in Shah Alam, Selangor was screened for its morphology and ability to proliferate in a short period. It was then further identified based on polyphasic approach that combines both the morphological and molecular identification by the 16S rRNA gene sequencing method. The local cyanobacteria isolate (A1) was identified up to only the genus level, Cyanobacterium of the order Chroococcales. The A1 isolate was used with another identified cyanobacteria, Anabaena sp. to observe their effectiveness in remediating leachate pollution either as monoculture or in mixed culture. Prior to the phycoremediation, the characterization of Jeram Sanitary Landfill leachate had been carried out. The biological oxygen demand (BOD₅) and chemical oxygen demand (COD) determined were 22.37 mg/L and 58.33 mg/L, respectively. The pH value of the raw leachate was 7.84 while the concentration of ammonia-nitrogen (NH3-N), nitrite (NO2-) and nitrate (NO3-) were 82.7 mg/L, 88.67mg/L and 89.43mg/L, respectively. The used of a single Anabaena sp.demonstrates the most effective in the removal of all contaminants exist in the leachate. The removal of COD was the highest at 105.71% followed by BOD₅ at 92.71%. Among the three nitrogen forms observed, the NO3- removal at 82.09% by Anabaena sp. was the highest. Meanwhile, the mixed isolates and A1 isolate did not show a great potential as contaminant removal except for NH3-N at 85.08%. and 77.90%, respectively. 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.