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Comparative effectiveness of biochar derived from tropical feedstocks on the adsorption for ammonium, nitrate and phosphate

Zou Ganghua, Shan Ying, Dai Minjie, Xin Xiaoping, Nawaz Muhammad, Zhao Fengljang

Archives of Environmental Protection

2022

Vol. 48, no. 4

25--34

Biochar has been extensively studied as a soil amendment to reduce nutrients losses. However, the comparative effectiveness of biochar adsorption capacity for ammonium (NH4 -N), nitrate (NO3 -N), and phosphate (PO4-P) remains unknown. In the present study, the effects of feedstock (banana stem and coconut shell) and temperature (300, 500, and 700°C) on biochar adsorption ability for NH4-N, NO3-N, and PO4-P were investigated and fitted by three adsorption models, viz Freundlich, Langmuir, and linear. Freundlich (R2 = 0.95–0.99) and Langmuir (R2 = 0.91–0.95) models were found suitable for adsorption of NH4 -N. The maximum adsorption capacity (Qm) for coconut shell biochar increased with pyrolysis temperature (Qm = 12.8–15.5 mg g-1) and decreased for banana stem biochar (Qm = 12.9–9.7 mg g-1). In the case of NO3 -N adsorption, Freundlich (R2 = 0.82–0.99) and linear model (R2 = 1.00) were found suitable while Langmuir model showed much less contribution, similarly adsorption of PO4-P, was not supported by these three models. The minimum concentrations required for adsorption of phosphate were recorded as 36, 8, and 3 mg L-1 using pyrolyzed biochar at the temperatures of 300, 500, and 700°C, respectively. These results indicate that the feedstock and pyrolysis temperature, as well as aquatic nutrient concentration, were important factors for the adsorption of inorganic nitrogen and phosphorus.

The impact of heat treatment on the components of plant biomass as exemplified by Junniperus sabina and Picea abies

Drygaś B., Depciuch J., Puchalski Cz., Zaguła G.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

2016

Vol. 5, No 3

41--50

Torrefaction is the process of drying biomass at high temperatures in order to transform it into biofuels with properties and composition resembling carbon. The impact of high temperature breaks the chains of hemicellulose, lignin and cellulose and degrades the biomass to simpler organic compounds. The aim of this publication was to specify the impact of the duration of the heat treatment on the stability of biomass structures such as lignocellulose illustrated with examples of selected species of conifers. The research material consisted of shoot tips of Junniperus sabina and Picea abies. The material used in the process was air-dried, dried at 150oC and torrefied at temperatures of 200, 250 and 300oC in a LECO camera – TGA 701 apparatus for 30 minutes. Fresh needles and their torrefied products were measured spectroscopically using FTIR Vertex 70v made by Bruker. Microscopic photographs of samples were taken in the scales 10 μm, 20 μm, and 50 μm using the TESCAN VEGA3 scanning electron microscope. The unprocessed plant material did not differ significantly from one another – the FTIR spectra of both plants exhibited the same functional groups. The biomass heat treatment led to significant changes in its chemical composition and topographic changes in the obtained biochars.