Structural and Functional Features of Chars From Different Biomasses as Potential Plant Amendments

Frontiers in Plant Science

Urbana Bonas¹  Giacomo Lencioni¹  Marta Marmiroli¹  Francesca Mussi²  Elena Maestri²  Nelson Marmiroli²  Davide Imperiale³ 

[1] Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy;Interdepartmental Center for Energy and Environment (CIDEA), University of Parma, Parma, Italy;National Interuniversity Consortium for Environmental Sciences (CINSA), Parma, Italy;

关键词: biochar;    low-vacuum SEM/EDX;    phytotoxicity;    principal component analysis;    pyrolysis;    soil improvers;   

DOI  :  10.3389/fpls.2018.01119

来源: DOAJ

【 摘 要 】

Biochars result from the pyrolysis of biomass waste of plant and animal origin. The interest in these materials stems from their potential for improving soil quality due to increased microporosity, carbon pool, water retention, and their active capacity for metal adsorption from soil and irrigation water. Applications in agriculture have been studied under different conditions, but the overall results are still unclear. Char structure, which varies widely according to the pyrolysis process and the nature of feedstock, is thought to be a major factor in the interaction of chars with soil and their metal ion adsorption/chelation properties. Furthermore, biochar nutrients and their elemental content can modify soil fertility. Therefore, the use of biochars in agricultural settings should be examined carefully by conducting experimental trials. Three key problems encountered in the use of biochar involve (i) optimizing pyrolysis for biomass conversion into energy and biochar, (ii) physicochemically characterizing biochar, and (iii) identifying the best possible conditions for biochar use in soil improvement. To investigate these issues, two types of wood pellets, plus digestate and poultry litter, were separately converted into biochar using different technologies: pyrolysis/pyrogasification or catalytic (thermo)reforming. The following physicochemical features for the different biochar batches were measured: pH, conductivity, bulk density, humidity and ash content, particle size, total organic substances, and trace element concentrations. Fine porous structure analysis and total elemental analysis were performed using environmental scanning electron microscopy along with energy-dispersive X-ray spectrometry (EDX). Phytotoxicity tests were performed for each biochar. Finally, we were able to (i) differentiate the biochars according to their physicochemical properties, microstructure, elemental contents, and original raw biomass; (ii) correlate the whole biochar features with their respective optimal concentrations when used as plant fertilizers or soil improvers; and (iii) show that biochars from animal origin were phytotoxic at lower concentrations than those from plant feedstock.

【 授权许可】

Unknown