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Biochar soil amendments for increased crop yields: How to design a “designer” biochar
Author(s) -
Zygourakis Kyriacos
Publication year - 2017
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.15870
Subject(s) - biochar , adsorption , fertilizer , freundlich equation , langmuir , nutrient , mass transfer , chemistry , soil water , desorption , diffusion , amendment , environmental science , soil science , environmental chemistry , chemical engineering , pyrolysis , thermodynamics , chromatography , organic chemistry , political science , law , physics , engineering
The development and testing of a transient adsorption/desorption model that describes the response of biochar particles to nutrient pulses simulating the application of fertilizer is presented in this study. Intraparticle nutrient transfer occurs both by diffusion through liquid‐filled pores and by surface diffusion, and nutrient adsorption is described by Langmuir–Freundlich (Sips) isotherms. Simulation results show that the ability of a biochar to adsorb and then slowly release the nutrient is modulated by a complex interplay of external mass transfer, intraparticle diffusion (both pore and surface diffusion), and adsorption dynamics. The nutrient retention potential of biochar‐amended soils is quantified and is shown to depend on multiple factors that include chemical and physical biochar properties, soil permeability, water flow, and the method of fertilizer application. These findings may explain why biochars with similar properties can potentially have widely different impacts on crop yields, as has been repeatedly reported in the literature. © 2017 American Institute of Chemical Engineers AIChE J , 63: 5425–5437, 2017