Department of Irrigation, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.
Department of Agroecology, Aarhus University, Denmark.
Waste Manag Res. 2022 Jul;40(7):932-939. doi: 10.1177/0734242X211060611. Epub 2021 Dec 8.
One of the approaches for recycling and reusing agricultural and animal wastes is to pyrolyse the residues and subsequently use them as soil amendments. The prevalence of several feedstocks suggests that it is necessary to investigate the optimal combinations of feedstocks and pyrolysis temperature for use as soil amendments. This study was done to evaluate five combinations of raw materials (sugarcane bagasse, rice husk, cow manure and pine wood) and their biochars produced by slow pyrolysis at 300°C and 500°C for soil amendment. Several physicochemical properties (electrical conductivity (EC), pH, cation exchange capacity (CEC), total organic matter content (C) total porosity (TP), total nitrogen (N), particle density (PD) and bulk density (BD)) were investigated. Comparison among feedstocks showed that the highest PD, BD and CEC were observed in WM (cow manure-pine wood). The pyrolysis process increased the PD, TP, N and monovalent cations and decreased EC, CEC and BD. Compared to the feedstock, pyrolysis increased the N content, but higher temperatures lowered the N content. Pyrolysis at 500°C reduced the EC, N, CEC and biochar yield by 18%, 13%, 21% and 24% respectively, compared to 300°C. Pyrolysis at 500°C increased the pH, Na and K by 17%, 12% and 22%, respectively, compared to 300°C. Considering the physicochemical properties of biochar and the costs, the bagasse-wood-rice (BWR) combination and temperature of 300°C are suggested for biochar production for soil amendment.
一种回收和再利用农业和动物废物的方法是对残留物进行热解，然后将其用作土壤改良剂。有几种原料的流行表明，有必要研究作为土壤改良剂使用的原料和热解温度的最佳组合。本研究旨在评估五种原料（甘蔗渣、稻壳、牛粪和松木）及其在 300°C 和 500°C 下进行慢速热解制成的生物炭作为土壤改良剂的五种组合。研究了几种物理化学性质（电导率（EC）、pH 值、阳离子交换容量（CEC）、总有机碳含量（C）、总孔隙度（TP）、总氮（N）、颗粒密度（PD）和堆积密度（BD））。原料之间的比较表明，WM（牛粪-松木）的 PD、BD 和 CEC 最高。热解过程增加了 PD、TP、N 和单价阳离子，降低了 EC、CEC 和 BD。与原料相比，热解增加了 N 含量，但较高的温度降低了 N 含量。与 300°C 相比，500°C 热解使 EC、N、CEC 和生物炭产率分别降低了 18%、13%、21%和 24%。与 300°C 相比，500°C 热解使 pH 值、Na 和 K 分别增加了 17%、12%和 22%。考虑到生物炭的物理化学性质和成本，建议使用蔗渣-木材-稻壳（BWR）组合和 300°C 的温度来生产生物炭以用于土壤改良。
