摘要
[目的]利用秸秆发酵腐植酸，优化最佳提取工艺。[方法]利用高效秸秆降解菌株进行秸秆发酵，提取腐植酸，研究提取温度、提取时间、NaOH浓度及用量对腐植酸提取量的影响，优化最佳提取工艺，并测定提取得到的腐植酸pH、羧基、交换容量（CEC）等理化性质。[结果]在1 g发酵秸秆中加入40 mL 0．020 g／mL NaOH，于65℃下水浴2．0 h，可得到最大腐植酸提取量，为0．176 g。腐植酸中总酸性基为0．0019 mol／g，总羧基为0．0001 mol／g，交换容量（CEC）为0．0039 mol／g；E465＝0．175，E665＝0．020，E4／E6＝8．735，凝聚限度为0．0064 mmol／L。[结论]经过单因素优化，腐植酸提取量增加。腐植酸是一种弱酸性物质，其羧基含量较低，交换容量较小，并具有一定凝聚性。
Abstract
Objective] By using straw fermentation of humic acid, the optimum technique conditions for extraction of humic acid were obtained. [Method] Humic acid was extracted from fermented rice straw by effective straw degradation strains.Effects of temperature, duration, dosage and concentration of NaOH on yield of humic acid were studied.The physicochemical properties of the extracted humic acid, such as pH, carboxyl and CEC were determined.[Result] In the water bath of 65℃, 1 g straw with 40 mL solution of 0.020 g/mL NaOH can get the maximum humic acid yield 0.176 g.The total acid base of humic acid was 0.001 9 mol/g, the total carboxyl group was 0.000 1 mol/g, and the exchange capacity (CEC) was 0.003 9 mol/g;E465 =0.175, E665 =0.02, E4/E6 =8.735, condensation limit was 0.006 4 mmol/L.[Conclusion] Through single factor optimization, the yield of humic acid is increased.Humic acid is a weak acid material, its carboxyl group content is low, the exchange ca-pacity is small, and has a certain cohesion.
基金项目
浙江省科技计划项目(2016C32092)
嘉兴市科技计划项目(2015BZ23005)
浙江省大学生科技创新活动计划暨新苗人才计划项目(2015R417036)
国家科技期刊平台
NSTL
维普
万方数据