BIOLOGICAL TREATMENT OF LANDFILL LEACHATE FROM BENIN CITY, NIGERIA

Municipal landfill leachate was treated with water hyacinth and algae plants. Water hyacinth was used during the first and third (last) treatment stages, while algae were used for the second treatment stage. Physiochemical and microbiological parameters such as pH, BOD, COD, DO etc. were determined for the untreated and treated leachate using standard method of analysis.The results obtained show that pH, total alkalinity and chloride increased throughout the treatment stages in the range of 1.43 to 13.64%. However, DO, BOD and COD decreased in the range of 7.5 to 60% during the water hyacinth treatment stages and increased in the range of 39.13 to 133.33% during the algae treatment stages. Nitrate increased in the range of 16.92 to 34.78% during water hyacinth treatment stages and decreased to 6.19% in the algae treatment stage. Total solids, total phosphate, ammonia, sulphate, potassium, zinc, manganese, iron and microorganism population decreased in the range of 0.69 to 100% throughout the treatment stages. This indicates that on the average, water hyacinth and algae are capable of treating municipal landfill leachate.