The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion ...The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents(benzoic acid,perfluorobutyric acid(PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet(UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column(TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column(TSKgel Super IC-A/C).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso-and n-butyric acids.The better separation and good detection was achieved by using the two columns(TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.展开更多
This study evaluated the build-back-better considerations in post-disaster recovery,following the devastation of Chipinge and Chimanimani communities by Cyclone Idai-induced floods in 2019.Conducted in 2020,the study ...This study evaluated the build-back-better considerations in post-disaster recovery,following the devastation of Chipinge and Chimanimani communities by Cyclone Idai-induced floods in 2019.Conducted in 2020,the study assessed the impact of Cyclone Idai-induced floods on communities in Chipinge and Chimanimani Districts of Zimbabwe;evaluated the build-back-better considerations;and analyzed the lessons learned.Based on a qualitative approach and case study design,the study depended on focus group discussions,interviews,and researcher observations to gather data from 85 participants.The findings indicate that Cyclone Idai-induced floods seriously impacted human lives,infrastructure,and livelihoods of communities that had been living with flood risk and vulnerability.Build-back-better considerations were absent in much of the post-disaster recovery effort to address the cyclone disaster impact.There are important early lessons for both practitioners and community members to learn from the Cyclone Idai event.These lessons still can inform policy and disaster risk reduction practice in the medium and long term.Build-back-better should be a mandatory objective in the recovery from any disaster impact.Continuous training is also recommended to improve the disaster knowledge of stakeholders and increase local ability to cope with future disaster events.展开更多
文摘The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents(benzoic acid,perfluorobutyric acid(PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet(UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column(TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column(TSKgel Super IC-A/C).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso-and n-butyric acids.The better separation and good detection was achieved by using the two columns(TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.
文摘This study evaluated the build-back-better considerations in post-disaster recovery,following the devastation of Chipinge and Chimanimani communities by Cyclone Idai-induced floods in 2019.Conducted in 2020,the study assessed the impact of Cyclone Idai-induced floods on communities in Chipinge and Chimanimani Districts of Zimbabwe;evaluated the build-back-better considerations;and analyzed the lessons learned.Based on a qualitative approach and case study design,the study depended on focus group discussions,interviews,and researcher observations to gather data from 85 participants.The findings indicate that Cyclone Idai-induced floods seriously impacted human lives,infrastructure,and livelihoods of communities that had been living with flood risk and vulnerability.Build-back-better considerations were absent in much of the post-disaster recovery effort to address the cyclone disaster impact.There are important early lessons for both practitioners and community members to learn from the Cyclone Idai event.These lessons still can inform policy and disaster risk reduction practice in the medium and long term.Build-back-better should be a mandatory objective in the recovery from any disaster impact.Continuous training is also recommended to improve the disaster knowledge of stakeholders and increase local ability to cope with future disaster events.
