以木薯淀粉为原材料,环氧丙烷为醚化剂,氢氧化钠为催化剂,在微波-超声波辅助条件下制备羟丙基木薯性淀粉。采用紫外可见分光光度计测量羟丙基木薯淀粉取代度,研究了微波功率、超声波功率、反应时间、环氧丙烷用量、淀粉质量浓度、氢氧...以木薯淀粉为原材料,环氧丙烷为醚化剂,氢氧化钠为催化剂,在微波-超声波辅助条件下制备羟丙基木薯性淀粉。采用紫外可见分光光度计测量羟丙基木薯淀粉取代度,研究了微波功率、超声波功率、反应时间、环氧丙烷用量、淀粉质量浓度、氢氧化钠用量对羟丙基木薯淀粉取代度的影响。通过单因素实验及正交实验获得制备羟丙基木薯淀粉的最佳实验条件,并采用X射线衍射分析(XRD)、场发射扫描电镜(FESEM)对其进行表征。结果表明:最佳制备羟丙基木薯淀粉条件为淀粉质量浓度为20%,环氧丙烷用量为2 m L,反应时间为2.5 min,微波:超声波功率为24W:500 W,氢氧化钠用量为淀粉质量的0.7%;X射线衍射,场发射扫描电镜表明羟丙基木薯淀粉的形态发生部分变化,反应主要发生在无定型区。展开更多
This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digest...This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digester performance for untreated primary, excess activated and mixed sludge were compared to combined microwave-ultrasonic pretreated primary, excess activated and mixed sludge. All sludge samples were subjected to Microwave treatment at 2450 MHz, 800 W and 3 min followed by ultrasonic treatment at a density of 0.4 W/mL, amplitude of 90%, Intensity of 150 W, pulse of 55/5 for 6min. Methane production in pretreated primary sludge was significantly greater (11.9 ml/g TCOD) than the methane yield of the untreated primary sludge (7.9 ml/g TCOD). Cumulative methane production of pretreated Excess Activated Sludge (EAS) was higher (66.5 ml/g TCOD) than the methane yield from pretreated mixed sludge (44.1 ml/g TCOD). Furthermore, digested EAS showed significantly higher dewaterability (201 s) than digested primary sludge (305 s) or mixed sludge (522 s). The average Methane: Carbondioxide ratio from EAS (1.85) was higher than that for mixed untreated sludge (1.24). VS reduction was also higher for EAS than the other two sludge types. However, pretreatment of EAS resulted in significant reduction in dewaterability due to higher percentage of fine floc particles in the pretreated EAS.展开更多
以银杏叶为材料,研究了乙醇浓度、微波功率、微波处理时间、料液比、银杏叶粉碎颗粒大小以及微波-超声波协同作用对银杏黄酮提取效率的影响。结果表明微波处理,微波-超声波协同处理可以显著提高银杏黄酮的提取率。确定了最佳的微波处理...以银杏叶为材料,研究了乙醇浓度、微波功率、微波处理时间、料液比、银杏叶粉碎颗粒大小以及微波-超声波协同作用对银杏黄酮提取效率的影响。结果表明微波处理,微波-超声波协同处理可以显著提高银杏黄酮的提取率。确定了最佳的微波处理条件:70%乙醇为萃取液,料液比1∶20,粉末颗粒80目,微波功率50W,微波处理时间4 m in,处理后水浴回流提取2 h所得提取液的黄酮提取率达到81.76%,比直接水浴提取提高了1.3倍,微波-超声波协同处理的黄酮提取率达到83.54%。展开更多
文摘以木薯淀粉为原材料,环氧丙烷为醚化剂,氢氧化钠为催化剂,在微波-超声波辅助条件下制备羟丙基木薯性淀粉。采用紫外可见分光光度计测量羟丙基木薯淀粉取代度,研究了微波功率、超声波功率、反应时间、环氧丙烷用量、淀粉质量浓度、氢氧化钠用量对羟丙基木薯淀粉取代度的影响。通过单因素实验及正交实验获得制备羟丙基木薯淀粉的最佳实验条件,并采用X射线衍射分析(XRD)、场发射扫描电镜(FESEM)对其进行表征。结果表明:最佳制备羟丙基木薯淀粉条件为淀粉质量浓度为20%,环氧丙烷用量为2 m L,反应时间为2.5 min,微波:超声波功率为24W:500 W,氢氧化钠用量为淀粉质量的0.7%;X射线衍射,场发射扫描电镜表明羟丙基木薯淀粉的形态发生部分变化,反应主要发生在无定型区。
文摘This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digester performance for untreated primary, excess activated and mixed sludge were compared to combined microwave-ultrasonic pretreated primary, excess activated and mixed sludge. All sludge samples were subjected to Microwave treatment at 2450 MHz, 800 W and 3 min followed by ultrasonic treatment at a density of 0.4 W/mL, amplitude of 90%, Intensity of 150 W, pulse of 55/5 for 6min. Methane production in pretreated primary sludge was significantly greater (11.9 ml/g TCOD) than the methane yield of the untreated primary sludge (7.9 ml/g TCOD). Cumulative methane production of pretreated Excess Activated Sludge (EAS) was higher (66.5 ml/g TCOD) than the methane yield from pretreated mixed sludge (44.1 ml/g TCOD). Furthermore, digested EAS showed significantly higher dewaterability (201 s) than digested primary sludge (305 s) or mixed sludge (522 s). The average Methane: Carbondioxide ratio from EAS (1.85) was higher than that for mixed untreated sludge (1.24). VS reduction was also higher for EAS than the other two sludge types. However, pretreatment of EAS resulted in significant reduction in dewaterability due to higher percentage of fine floc particles in the pretreated EAS.
文摘以银杏叶为材料,研究了乙醇浓度、微波功率、微波处理时间、料液比、银杏叶粉碎颗粒大小以及微波-超声波协同作用对银杏黄酮提取效率的影响。结果表明微波处理,微波-超声波协同处理可以显著提高银杏黄酮的提取率。确定了最佳的微波处理条件:70%乙醇为萃取液,料液比1∶20,粉末颗粒80目,微波功率50W,微波处理时间4 m in,处理后水浴回流提取2 h所得提取液的黄酮提取率达到81.76%,比直接水浴提取提高了1.3倍,微波-超声波协同处理的黄酮提取率达到83.54%。
