Leachate Treatment Using Clay/Stone Filters

Abstract

Leachate from sanitary landfill from Agbor in Ika South Local Government Area of Delta State, Nigeria was analysed using its physiochemical characteristics.  Cation exchange capacity percolation rate studies and mineralogical analysis of clays collected from Amai and Otorho in Ukwuani Local Government Area of Delta State were coded AM and OT, using x-ray diffrctometer were tested on the leachate (Raw and after treatment). The clays were mixed in ratio 1:4 (pebbles:clay) using one and three flow through columns.  Clays showed the presence of kaolin, quartz, illite and mixed layer.  Raw samples have BOD 80.60 - 210.00 mg/dm3 COD 842.00 - 933.20 mg/dm3, NH3+-N 0.80 - 11.20 mg/dm3, TSS 61.20 - 70.20 mg/dm3, TDS 510.00- 734.00 mg/dm3, Ca 0.01- 16.00 mg/dm3 and Salinity 0.90 - 2.10%, percolation rate studies 2.94 x 10-7 – 3.76 x 10-7, cation exchange capacity 4-9 cmol/kg.    The values were above WHO and NESREA standards, but after treatment, BOD values were 3.00 – 6.20 mg/dm3, COD 15.00 – 18.00 mg/dm3, NH3+ - N 0.32 – 0.42 COD 15.00 – 18.00 mg/dm3, TSS 10.10 – 22.50 mg/dm3, Ca 10 - 12 mg/dm3, Salinity 0.08 – 0.31 %. This shows that clay/stone filters are efficient, low cost purifying system and environmentally friendly, they fall within acceptable limits. Keyword: Leachate, column, x-ray diffractometer, clay, percolation rate.