SIMULTANEOUS REMOVAL OF NITRATE AND PHOSPHATE FROM KITCHEN WASTEWATER USING GROUNDNUT HUSK BIOCHAR

Abstract

Biochar as a green, economically efficient, and ecological adsorbent shows a great potential in tackling water pollutants by its widely availability feedstock, low-cost and favourable surface characteristics. Eutrophication of water bodies is caused due to large amounts of phosphorus and nitrogen elements which are usually discharged into the environment. In this study, groundnut husk biochar was used to remove nitrate and phosphate from kitchen wastewater at different dosages. Wastewater of 100 mL was added to each of the groundnut husk biochar in a conical flask and agitated at 150 rpm for 60 minutes. Adsorption efficiency of groundnut husk biochar for nitrate ranged from 98.03% to 98.18% and phosphate ranged from 99.92% to 99.95%. Nitrate and phosphate showed a maximum adsorption capacity of 9.78 × 10-4 mg/g and 4.64mg/g × 10-3. The adsorption processes for nitrate and phosphate are better described by heterogeneous interactions than by the uniform monolayer hypothesis, which is simplified by the Langmuir model. This study showed a very high adsorption efficiency of groundnut husk biochar. This indicates that low-cost groundnut husk biochar adsorbents can be used for removal of nitrate and phosphate from wastewater. Similar adsorptive experiments can be carried out using different agricultural waste to produce biochar as this can contribute to environmental safety and cleanliness.