This paper shares experiences of the southern and eastern Africa rainwater network on rainwater harvesting.It also shares the lessons drawn from policy research awareness creation and networking building of national n...This paper shares experiences of the southern and eastern Africa rainwater network on rainwater harvesting.It also shares the lessons drawn from policy research awareness creation and networking building of national networks and assessment of promising water harvesting techniques in the Sub-Saharan Africa.The concerted promotional effort of the southern and eastern Africa rainwater network has resulted in the general acceptance of rainwater harvesting as a viable option for boosting domestic water supply agricultural production and environmental sustainability.To date twelve nationally registered rainwater harvesting associations have been established which are providing leadership and capacity building in rainwater harvesting.Governments and donors are also aligning their policies towards providing increased financial institutional and technical support for upscaling rainwater-harvesting techniques. This paper concludes that diligent land and water management is necessary for yielding the highest benefits from rainwater.In addition to enabling policies and institutions there must be ample budgetary support to increase adoption of the technology.展开更多
In this paper we address the topic of energy and water optimization in the production of bioethanol from corn and switchgrass. We show that in order for these manufacturing processes to be attractive,there is a need t...In this paper we address the topic of energy and water optimization in the production of bioethanol from corn and switchgrass. We show that in order for these manufacturing processes to be attractive,there is a need to go beyond traditional heat integration and water recycling techniques. Thus,we propose a strategy based on mathe-matical programming techniques to model and optimize the structure of the processes,and perform heat integration including the use of multi-effect distillation columns and integrated water networks to show that the energy effi-ciency and water consumption in bioethanol plants can be significantly improved. Specifically,under some circum-stances energy can even be produced and the water consumption can be reduced below the values required for the production of gasoline.展开更多
Leather industry is an important light industry in China.Leather making requires a series of chemical treatment.Degreasing,unhairing and chrome tanning wastewaters are the main portions of tannery wastewater.Reclaimin...Leather industry is an important light industry in China.Leather making requires a series of chemical treatment.Degreasing,unhairing and chrome tanning wastewaters are the main portions of tannery wastewater.Reclaiming and reusing these wastewaters can eliminate 80% of COD,75% of BOD,95% of chromium and 93% of sulfuret,furthermore reduce environment impact,decrease treatment costs,save chemicals and water.Some application methods of wastewater reclamation and reuse for different operations were reported.The suitable reclamation and reuse technologies can enable leather making processes more rational,and realize the recovery and recycle of several chemicals in the tannery.Resourceful utilization of tannery wastewater should mate with renovating production technology,updating equipment,and must be guaranteed sufficiently by environmental protection measures.展开更多
Large quantities of fresh water are used intensively in the washing, cutting, peeling and disinfection of fruits and vegetables, resulting in high solids loading of the wash-water. Review of the literature shows that ...Large quantities of fresh water are used intensively in the washing, cutting, peeling and disinfection of fruits and vegetables, resulting in high solids loading of the wash-water. Review of the literature shows that there is limited information available on how to treat this wash-water on-site. Accordingly, an investigative program was established by sampling wash-water from two industrial partners processing root vegetables to determine the best available approach. Bench scale technologies tested for solids removal were dissolved air flotation （DAF） and centrifuge, followed by ultraviolet （UV） disinfection to evaluate the potential for water reuse. The results showed that DAF and centrifuge were able to remove solids at an efficiency greater than 95%. The DAF process was also able to remove higher levels of dissolved matter and nutrients in comparison to the centrifuge. The DAF process was also able to produce waters with higher transmittance, which leads to improved filtration and UV disinfection for water reuse. Membrane filtration feasibility testing showed that high quality waters can be produced as low as 2 NTU and 4 NTU, following pretreatment with DAF and centrifuge, respectively. However, filtration was unable to remove E. coll. Collimated beam results show that UV disinfection is needed to allow for water reuse.展开更多
文摘This paper shares experiences of the southern and eastern Africa rainwater network on rainwater harvesting.It also shares the lessons drawn from policy research awareness creation and networking building of national networks and assessment of promising water harvesting techniques in the Sub-Saharan Africa.The concerted promotional effort of the southern and eastern Africa rainwater network has resulted in the general acceptance of rainwater harvesting as a viable option for boosting domestic water supply agricultural production and environmental sustainability.To date twelve nationally registered rainwater harvesting associations have been established which are providing leadership and capacity building in rainwater harvesting.Governments and donors are also aligning their policies towards providing increased financial institutional and technical support for upscaling rainwater-harvesting techniques. This paper concludes that diligent land and water management is necessary for yielding the highest benefits from rainwater.In addition to enabling policies and institutions there must be ample budgetary support to increase adoption of the technology.
基金the Center for Advanced Process Decision-making at Carnegie Mellon University and NSF Grant CBET096654
文摘In this paper we address the topic of energy and water optimization in the production of bioethanol from corn and switchgrass. We show that in order for these manufacturing processes to be attractive,there is a need to go beyond traditional heat integration and water recycling techniques. Thus,we propose a strategy based on mathe-matical programming techniques to model and optimize the structure of the processes,and perform heat integration including the use of multi-effect distillation columns and integrated water networks to show that the energy effi-ciency and water consumption in bioethanol plants can be significantly improved. Specifically,under some circum-stances energy can even be produced and the water consumption can be reduced below the values required for the production of gasoline.
文摘Leather industry is an important light industry in China.Leather making requires a series of chemical treatment.Degreasing,unhairing and chrome tanning wastewaters are the main portions of tannery wastewater.Reclaiming and reusing these wastewaters can eliminate 80% of COD,75% of BOD,95% of chromium and 93% of sulfuret,furthermore reduce environment impact,decrease treatment costs,save chemicals and water.Some application methods of wastewater reclamation and reuse for different operations were reported.The suitable reclamation and reuse technologies can enable leather making processes more rational,and realize the recovery and recycle of several chemicals in the tannery.Resourceful utilization of tannery wastewater should mate with renovating production technology,updating equipment,and must be guaranteed sufficiently by environmental protection measures.
文摘Large quantities of fresh water are used intensively in the washing, cutting, peeling and disinfection of fruits and vegetables, resulting in high solids loading of the wash-water. Review of the literature shows that there is limited information available on how to treat this wash-water on-site. Accordingly, an investigative program was established by sampling wash-water from two industrial partners processing root vegetables to determine the best available approach. Bench scale technologies tested for solids removal were dissolved air flotation （DAF） and centrifuge, followed by ultraviolet （UV） disinfection to evaluate the potential for water reuse. The results showed that DAF and centrifuge were able to remove solids at an efficiency greater than 95%. The DAF process was also able to remove higher levels of dissolved matter and nutrients in comparison to the centrifuge. The DAF process was also able to produce waters with higher transmittance, which leads to improved filtration and UV disinfection for water reuse. Membrane filtration feasibility testing showed that high quality waters can be produced as low as 2 NTU and 4 NTU, following pretreatment with DAF and centrifuge, respectively. However, filtration was unable to remove E. coll. Collimated beam results show that UV disinfection is needed to allow for water reuse.
