苎麻生物脱胶过程中黄酮和脱胶酶的回收利用

发布时间：2018-02-26 21:43

  本文关键词： 苎麻生物脱胶 总黄酮 脱胶酶 回收利用　出处：《武汉纺织大学》2016年硕士论文　论文类型：学位论文

【摘要】：苎麻是我国特有的纺织纤维作物,它的纤维细长柔韧,不易皱缩,弹力强,具有蚕丝般的光泽。然而,苎麻韧皮纤维被以果胶和半纤维素为主的胶质包裹,需尽可能去除胶质,才能满足纺纱要求。生物脱胶凭借污染小,纤维品质高,能耗低,成为未来苎麻脱胶发展的方向。但传统的生物脱胶过程主要关注纤维加工的效率和质量,很少留意到苎麻韧皮及脱胶废液中具有潜在利用价值的资源,使资源沦为废物,回收利用这些资源将有利于苎麻加工的综合经济效益,加速生物脱胶技术的推广。本研究以苎麻脱胶共生菌群RAMCD407沤麻废液为研究对象,通过化学分析,确定脱胶废液中具有潜在利用价值的成分,然后对黄酮和脱胶酶的回收工艺进行了研究。理化分析表明,苎麻脱胶废水废液的COD值依然较高,达到了8620mg/mL,主要含蛋白质、糖类、黄酮等物质,含量分别达到4.2g/L、0.6g/L、0.389%,化学成分系统预试显示还含有少量酚类、有机酸、萜类等;酶活分析显示脱胶废液中剩余的果胶酶活高达3828U/mL,木聚糖酶活高达2708U/mL,纤维素酶为381U/mL。因此,脱胶废液中黄酮和脱胶酶有较高的回收利用价值。废液中的黄酮来源于苎麻韧皮,测试表明,苎麻韧皮中黄酮含量高达1.238%。本研究比较了在苎麻生物脱胶的不同工艺阶段回收黄酮的可操作性和效率结果表明:采用乙酸乙酯萃取法从脱胶废液中回收黄酮时,由于黄酮在脱胶的不同阶段被耗损和稀释,回收效率较低,只有0.413%,而且回收试剂难以循环利用,加重了环境污染;采用乙醇-超声波法在脱胶前从苎麻韧皮中回收黄酮,采用优化后的工艺:原麻在浸提前机械锤麻分纤,液固比30:1,乙醇浓度60%,超声时间40 min,提取温度30℃,结果韧皮黄酮的回收率为1.238%,同时,经过敲麻结合乙醇-超声波浸提处理后,苎麻的生物脱胶时间由原来19h缩短至了13h,废液中的COD也由原来的8620mg/mL,降低至5785mg/mL,证实了该工艺具有良好的经济效益和环境效益。从苎麻脱胶废液中回收剩余酶活采用了膜过滤工艺:超滤膜截留分子量为8KDa,运行压力0.08MPa,收回了废液中89.5%蛋白质,其中果胶酶、木聚糖酶和纤维素酶酶活回收率依次为85.04%、82.35%和86.67%。对回收的复合进行了脱胶实验,在优化有的条件下(温度45℃、pH8.0、浴比1:10、复合酶量1:3)处理3h~4h原麻即可分纤,残胶率低于9.0%,综合脱胶效果接近于目前的商品酶。
[Abstract]:Ramie is a unique textile fiber crop in China. Its fiber is slender, flexible, easy to shrink, elastic and has a silky luster. However, Ramie phloem fiber is wrapped mainly with pectin and hemicellulose, which should be removed as much as possible. Biological degumming has become the development direction of Ramie degumming in the future because of its low pollution, high fiber quality and low energy consumption. However, the traditional biological degumming process mainly focuses on the efficiency and quality of fiber processing. Little attention was paid to the potential resources of Ramie phloem and degumming waste liquid, which reduced the resources to waste, and the recycling and utilization of these resources would benefit the comprehensive economic benefit of Ramie processing. In this study, Ramie degumming symbiotic bacteria RAMCD407 retting waste liquor was used as the research object, and the components of the degumming waste liquor with potential utilization value were determined by chemical analysis. Then the recovery process of flavonoids and degumming enzymes was studied. The physicochemical analysis showed that the COD value of Ramie degumming wastewater was still high, reaching 8620 mg / mL, mainly containing protein, sugar, flavonoids, etc. The chemical composition system showed that there were also a small amount of phenols, organic acids, terpenes, etc. The enzyme activity analysis showed that the remaining Pectinase activity in the degumming waste liquid was as high as 3828 U / mL, xylanase activity was as high as 2708 U / mL / mL, and the cellulase level was 381UU / mL. therefore, Flavonoids and degumming enzymes in the degumming waste liquor have high recovery value. The flavonoids in the waste liquor are derived from Ramie phloem. The content of flavonoids in Ramie phloem is as high as 1.238. In this study, the maneuverability and efficiency of flavonoids recovery in different stages of Ramie biological degumming were compared. The results showed that: when extracting flavonoids from degumming waste liquor by ethyl acetate extraction, Because the flavonoids were consumed and diluted in different stages of degumming, the recovery efficiency was low, only 0.413%, and the recycling reagent was difficult to recycle, which aggravated the environmental pollution, and the flavonoids were recovered from Ramie phloem by ethanol-ultrasonic method before degumming. The optimized technology was used as follows: preimpregnation of raw hemp with mechanical hammer hemp, liquid-solid ratio of 30: 1, ethanol concentration of 60: 1, ultrasonic time of 40 min, extraction temperature of 30 鈩，

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