Optimization of Blended Biochar Pellet by the Use of Nutrient Releasing Model

• Main Authors: JoungDu Shin, SangWon Park
• Format: Article
• Language: English
• Published: MDPI AG 2018-11-01
• Series: Applied Sciences
• Subjects: biochar pellet; modified Hyperbola model; nutrient release; pelletization; pig manure compost
• Online Access: https://www.mdpi.com/2076-3417/8/11/2274

For the recycling of biomass conversion materials, this experiment was conducted to investigate plant nutrient releasing characteristics, and to determine an optimum blended ratio of biochar for producing a biochar pellet based on a column leaching study. The treatments consisted of only pig manure compost (PMC) as a control, pig manure compost pellets (PMCP), and biochar pellets (BCP) blended with biochar and pig manure compost with the following ratios: 9:1, 8:2, 4:6, and 2:8. Results showed that the accumulated amount of ammonium nitrogen (NH₄-N) was in order of PMC > PMCP > BCP (2:8) > BCP (4:6) > BCP (8:2) > BCP (9:1) ratios. The highest accumulated amounts of phosphate phosphorus (PO₄-P) and potassium (K) were 1953 and 1917 mg L^−1 in the PMC and PMCP, but the lowest in the BCP (9:1) were 223 and 1078 mg L^−1, respectively. It was shown that the highest accumulated amount of silicon dioxide (SiO₂) was 2329 mg L^−1 in the BCP (8:2), but the lowest in the PMC was 985 mg L^−1. The estimations for accumulated NH₄-N, PO₄-P, K, and SiO₂ releasing amounts in all the treatments were significantly fitted with a modified Hyperbola model. The optimum mixing rate was estimated to be BCP (2:8). Therefore, biochar pellets might be useful in obtaining basic information on slow-release fertilizer for sustainable agriculture.