Adsorption of Phosphate and Nitrate Using Modified Spent Coffee Ground and Its Application as an Alternative Nutrient Source for Plant Growth

Phosphate (PO43-) and Nitrate (NO3-) are two main nutrients that cause water eutrophication. In the other hand, the presence of PO43- and NO3- is needed for plant growth. The aims of this study are to recycle Spent Coffee Ground (SCG) modified with calcium hydroxide for adsorption PO43- and NO3-. The optimum adsorption capacity for PO43- and NO3- is 36.74 mg/L and 20.21 mg/L, respectively. The Freundlich isotherm model was suitable for PO43- and NO3- adsorption. The kinetic model for adsorption was linear using Pseudo-second order. The application of modified SCG after enrichment with PO43- and NO3- for plant growth (Raphanus sativus) showed optimum growth at a dose of 0.3% with value of germination index was 203%.