Objective] This study aimed to eliminate the negative effects brought about by continuous, long-term accumulation of sodium ions in soil on soil environ-ment. [Method] Biological humic acids (BHAs) were extracted fr...Objective] This study aimed to eliminate the negative effects brought about by continuous, long-term accumulation of sodium ions in soil on soil environ-ment. [Method] Biological humic acids (BHAs) were extracted from fermented furfural residue via alkali-dissolution and acidification. The effects of solid-liquid ratio (mass ratio of fermented furfural residue to water), alkali concentration, extraction tempera-ture and extraction time on the content of BHA were investigated. Also its structure was characterized by FTIR. [Result] The optimal extraction conditions were as fol-lows: solid-liquid ratio of 1:7, KOH concentration of 6%, extraction temperature of 70℃ and extraction time of 1 h. Under the optimal conditions, the content of BHAs extracted was up to 8.5%. The infrared spectrum analysis indicated that BHA had more types of functional groups and lower molecular weight than commercial humic acid although they had similar structures. [Conclusion] The technique has the ad-vantages of simple operation and good stability, and is suitable for extracting BHAs. BHAs have a good prospect in developing new types of humic acid fertilizers.展开更多
文摘Objective] This study aimed to eliminate the negative effects brought about by continuous, long-term accumulation of sodium ions in soil on soil environ-ment. [Method] Biological humic acids (BHAs) were extracted from fermented furfural residue via alkali-dissolution and acidification. The effects of solid-liquid ratio (mass ratio of fermented furfural residue to water), alkali concentration, extraction tempera-ture and extraction time on the content of BHA were investigated. Also its structure was characterized by FTIR. [Result] The optimal extraction conditions were as fol-lows: solid-liquid ratio of 1:7, KOH concentration of 6%, extraction temperature of 70℃ and extraction time of 1 h. Under the optimal conditions, the content of BHAs extracted was up to 8.5%. The infrared spectrum analysis indicated that BHA had more types of functional groups and lower molecular weight than commercial humic acid although they had similar structures. [Conclusion] The technique has the ad-vantages of simple operation and good stability, and is suitable for extracting BHAs. BHAs have a good prospect in developing new types of humic acid fertilizers.