The effect of F/M on acidification characteristics during anaerobic digestion of kitchen waste was investigated. Under different F/M,p H,alkalinity,ethyl alcohol,volatile fatty acids(VFAs),and biogas production status...The effect of F/M on acidification characteristics during anaerobic digestion of kitchen waste was investigated. Under different F/M,p H,alkalinity,ethyl alcohol,volatile fatty acids(VFAs),and biogas production status of acidification effluent in 96 h were observed. The study results showed that the content of propionic acid + acetic acid reached 56%-80% when F/M≤1. 0,which was mainly known as propionic acid type of fermentation and was accompanied by methane. The value of alkalinity was only 3 000-4 000 mg/L,which indicated that the stability was weak in the system. When 1. 0 < F/M≤2. 5,the concentration of butyric acid + acetic acid was in the range of 77%-85%,and acid production rate per unit load was more than 250 mg VFAs/g VS,which was known as butyric acid type of fermentation. The fermentation type was stable and could provide more available VFAs for subsequent methanation processes because the value of alkalinity reached 5 650 mg/L. When F/M≥2. 5,the content of ethanol + acetic acid was 80%-92%,which was known as ethanol type of fermentation. And p H of 96 h was only 5. 0( F/M = 3. 0) and 4. 3(F/M =4.0),and acidification was serious and the stability was weak in the system,which would hinder the subsequent methanation process.Therefore,F/M influenced fermentation type,and it can provide a target product for subsequent methanation process by controlling F/M in a reasonable range.展开更多
Since alkaloids are the major active constituents of Rhizoma corydalis(RC),a convenient and accurate analytical method is needed for their identification and characterization.Here we report a method to profile the alk...Since alkaloids are the major active constituents of Rhizoma corydalis(RC),a convenient and accurate analytical method is needed for their identification and characterization.Here we report a method to profile the alkaloids in RC based on liquid chromatography-tandem quadrupole time-of-flight mass spectrometry(LC–Q-TOF-MS/MS).A total of 16 alkaloids belonging to four different classes were identified by comparison with authentic standards.The fragmentation pathway of each class of alkaloid was clarified and their differences were elucidated.Furthermore,based on an analysis of fragmentation pathways and alkaloid profiling,a rapid and accurate method for the identification of unknown alkaloids in RC is proposed.The method could also be useful for the quality control of RC.展开更多
基金Supported by National Science and Technology Support Program(2015BAD21B03,2014BAC24B01)
文摘The effect of F/M on acidification characteristics during anaerobic digestion of kitchen waste was investigated. Under different F/M,p H,alkalinity,ethyl alcohol,volatile fatty acids(VFAs),and biogas production status of acidification effluent in 96 h were observed. The study results showed that the content of propionic acid + acetic acid reached 56%-80% when F/M≤1. 0,which was mainly known as propionic acid type of fermentation and was accompanied by methane. The value of alkalinity was only 3 000-4 000 mg/L,which indicated that the stability was weak in the system. When 1. 0 < F/M≤2. 5,the concentration of butyric acid + acetic acid was in the range of 77%-85%,and acid production rate per unit load was more than 250 mg VFAs/g VS,which was known as butyric acid type of fermentation. The fermentation type was stable and could provide more available VFAs for subsequent methanation processes because the value of alkalinity reached 5 650 mg/L. When F/M≥2. 5,the content of ethanol + acetic acid was 80%-92%,which was known as ethanol type of fermentation. And p H of 96 h was only 5. 0( F/M = 3. 0) and 4. 3(F/M =4.0),and acidification was serious and the stability was weak in the system,which would hinder the subsequent methanation process.Therefore,F/M influenced fermentation type,and it can provide a target product for subsequent methanation process by controlling F/M in a reasonable range.
基金The work was funded by the National Natural Science Foundation of China(Nos.81202950 and 81102795)National Key Project of the Scientific and Technical Supporting Programs of China(No.2012ZX10004301-608).
文摘Since alkaloids are the major active constituents of Rhizoma corydalis(RC),a convenient and accurate analytical method is needed for their identification and characterization.Here we report a method to profile the alkaloids in RC based on liquid chromatography-tandem quadrupole time-of-flight mass spectrometry(LC–Q-TOF-MS/MS).A total of 16 alkaloids belonging to four different classes were identified by comparison with authentic standards.The fragmentation pathway of each class of alkaloid was clarified and their differences were elucidated.Furthermore,based on an analysis of fragmentation pathways and alkaloid profiling,a rapid and accurate method for the identification of unknown alkaloids in RC is proposed.The method could also be useful for the quality control of RC.
