Abstract The main goal of this study was to investigate the influence of pH and grain size of biochar on its physicochemical properties and on the quantity and quality of humic substances released from biochar. The studies were conducted on 5 biochar fractions and on the mixture of all fractions. Influence of grain size on physicochemical properties of biochar was characterized by analyzing changes in total carbon content, ash, density, total surface charge, average adsorption energy, specific surface area, content of functional groups and FTIR spectra. The effect of pH and grain size of biochar on releasing organic compounds were examined at pH of the extraction solution: 3, 5, 7 and 9 by analyzing aqueous extracts for changes in organic carbon content and for variation of humification degree coefficients. The results showed the grain size affected physicochemical properties of investigated material. The fraction

中文翻译：

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pH 值和颗粒大小对生物炭理化性质和释放的腐殖质的影响

摘要 本研究的主要目的是研究生物炭的pH值和粒径对其理化性质以及生物炭释放的腐殖质数量和质量的影响。研究是对 5 种生物炭馏分和所有馏分的混合物进行的。通过分析总碳含量、灰分、密度、总表面电荷、平均吸附能、比表面积、官能团含量和FTIR光谱的变化来表征晶粒尺寸对生物炭理化性质的影响。通过分析水提取物的有机碳含量变化和腐殖化度系数的变化，在提取溶液的 pH 值：3、5、7 和 9 下检查了 pH 值和生物炭颗粒大小对释放有机化合物的影响。结果表明，晶粒尺寸影响了所研究材料的理化性质。分数