Leachate Pollutants Adsorption Using Potassium Hydroxide and Surfactant Modified Bentonite for Possible Use as Slow Release Fertiliser

Leachate pollutants adsorption using potassium hydroxide (KOH) and Surfactant Modified Bentonite (SMB) have been used as a new method for leachate treatment. KOH was used for removing the heavy metal elements and natural bentonite (NB) and SMB as adsorbents to adsorb ammoniacal-nitrogen, nitrate and phosphate. The suitable conditions for adsorbents are obtained using the percentage removal of colour, iron, COD, ammoniacal-nitrogen, nitrate and phosphate. The results obtained at optimum conditions for dosage and pH for NB was 233.3 g/L at pH 9. By comparison, for SMB they were 166.7 g/L at pH 8. For the contact time, using slow mixing and rapid mixing, SMB is better than NB. From the SEM-EDX analysis of weight percentage, after the NB and SMB treatments the elements of nitrogen, phosphorus and potassium for NB increased by 1.04, 1.32 and 5.13%; respectively; also for SMB 1.30, 2.25 and 6.81% respectively. It is clear that SMB gives better adsorption than NB and can be used for future application as a slow release fertiliser for plants.