TO COMPARE THE REMOVAL EFFICIENCY OF TWO CONSTRUCTED BIOFILTERS (BIOSAND AND BIOCHAR WATER FILTRATION SYSTEM) FOR IRRIGATION IN TWO AREAS IN WEST COAST BERBICE

The purpose of this study was to compare the removal efficiency of two types of constructed biofilter treatments, the BioSand and BioChar filters, for the purpose of irrigation in two areas of West Coast Berbice, Guyana, South America. Various water parameters were tested based on salinity, nutrients and miscellaneous. It was determined if the parameters were within the range of the Food and Agriculture Organization (FAO) guidelines for irrigation water. For the raw/source water, the parameters were within range except Total Coliforms and Escherichia coli. For both of the biofilter treatments, all of the parameters were within range except Potassium, Total Coliforms and Escherichia coli. For both of the biofilter treatments, Total Dissolved Solids, Sodium, Chloride and Potassium levels were higher than the raw/source water. For the BioSand filter treatment, the Electrical Conductivity level was higher than the raw/source water. This filter had removal efficiencies of 20.0%, 50.0%, 30.0%, 16.34% and 90.84% respectively for Sulphate, Phosphate, Chemical Oxygen Demand, Total Coliforms and Escherichia coli. pH was reduced from weakly acidic in the source water (6.00) to slightly acidic (6.62). For the BioChar filter treatment, the Sulphate and Chemical Oxygen Demand levels were higher than the raw/source water. This filter had removal efficiencies of 6.67%, 25.0%, 22.84%, and 62.84% respectively for Electrical Conductivity, Phosphate, Total Coliforms and Escherichia coli. pH was reduced from weakly acidic in the source water (6.00) to slightly alkaline (7.09). The Schmutzdecke layer played a major role in the removal of the bacteria. Therefore, the BioChar filter treatment had a greater removal efficiency than the BioSand filter treatment.