Co-plasma processing of banana peduncle with phosphogypsum waste for production of lesser toxic potassium–sulfur rich biochar
Production of macro-nutrient rich biochar is important to broaden its use as soil fertilizer. In this work, we report production of potassium–sulfur rich biochar through co-plasma processing of banana peduncle biomass with phosphogypsum waste. Biochars were produced using indigenous low-power (15 kW) extended arc thermal plasma reactor in 7 min under three different plasmagen gases i.e., argon, oxygen, and ammonia. Plasmagen gases showed differential and significant effect on potassium, sulfur and toxic element contents of biochar. Biochars showed relatively higher potassium (4.2–12.7%) and sulfur (13.3–17.8%) contents than phosphogypsum (potassium − 0.02% and sulfur − 12.5%). In addition, leachable fraction of fluoride and heavy metals decreases in biochars. Among plasmagen gases, retention of potassium and sulfur content was relatively higher in argon, whereas fluoride and heavy-metal leaching reduced maximum in ammonia. X-ray diffraction analysis showed the presence of potassium and sulfur as K2SO4 and CaS minerals in biochars. These findings highlights about application of co-plasma processing of nutrient-rich biomass with phosphogypsum waste for production of lesser toxic nutrient-rich biochar.
KeywordsWaste biomass Fertilizer industry solid waste Thermal plasma technology Nutrient-rich biochar Heavy metals
The authors sincerely thanks Paradeep Phosphates Limited, Odisha for providing the phosphogypsum samples for present research study. We thanks Central Characterization Cell and Mineral Processing Department, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar for providing analytical support. A A Karim is indebted to University Grants Commission, India for financial assistance under Maulana Azad National Fellowship (MANF-2012-13-MUS-BIH-10945). The research work has also utilized funding and support from CSIR funding at CSIR-IMMT, Bhubaneswar as RSP-4020 project and DST-INSPIRE Fellowship (ID: IF130029) of S Mohapatra.
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