The demand for potable water is rising rapidly due to an ever-increasing population,economic activities,and dwindling water supplies.To provide adequate water supplies in the future,understanding the issues and challe...The demand for potable water is rising rapidly due to an ever-increasing population,economic activities,and dwindling water supplies.To provide adequate water supplies in the future,understanding the issues and challenges in the reuse of water and developing appropriate strategies for reuse will be critical.One way to augment water supplies for residential use is to reuse graywater- the wastewater from kitchens,bathrooms,and laundries.In this article,we critically review the evolution of water reuse,the definition of graywater,graywater reuse practices,volumes and flow in different situations,and graywater characteristics.We then examine the issues associated with different graywater treatment methods and how using graywater for irrigation around homes affects soil quality and plant growth.The study concludes that graywater treatment costs,human health risks,and its effect on soil quality are some of the challenges that need to be addressed in the future for widespread and sustainable reuse of graywater for irrigation around homes.展开更多
Use of municipal water in residences can be decreased substantially by allowing“graywater”effluent from showering and other activities to fill the toilet reservoir.This paper considers a system developed in Germany ...Use of municipal water in residences can be decreased substantially by allowing“graywater”effluent from showering and other activities to fill the toilet reservoir.This paper considers a system developed in Germany for treatment and storage of shower wastewater for use in flushing the toilet.Based on literature data for distributions of shower duration and water flow rate,the volume of municipal water saved using the German system has been estimated for several usage scenarios.Results show significant savings of water that depend on the size of the treatment and storage tanks used in the graywater system as well as the number of toilet flushes per day.For example,a scenario with four residents each flushing nine times per day with 80 liter treatment and storage tanks shows a 50%chance that the savings in municipal water use for the toilet will exceed 73%.Because the timing of showers and toilet flushes is assumed to follow a uniform distribution throughout the day,the calculated tank sizes may be underestimates.展开更多
Outdoor green walls are gaining popularity for enhancing building aesthetics and promoting healthy and sustainable urban environment.However,concerns about their high water consumption in the context of ongoing water ...Outdoor green walls are gaining popularity for enhancing building aesthetics and promoting healthy and sustainable urban environment.However,concerns about their high water consumption in the context of ongoing water crises highlight the need for alternative water sources,such as recycled water.This research investigated the effects of recycled water irrigation and plant growth-promoting bacteria(PGPB)on four plant species for green walls in Mashhad,Iran:Festuca ovina,Ophiopogon japonicus,Aptenia cordifolia,and Carpobrotus edulis.Over nine months(March to December 2022),researchers conducted experiments using three water types(graywater,wastewater,and urban water)as the main factor and four bacterial treatments(Mix B1,Mix B2,Mix B3,and a control)as the sub-factor,with three replications of split-plot layout based on a randomized complete block design.Results showed significant differences in aesthetic qualities,with optimal visual quality achieved by applying Mix B2 or B3 with wastewater for Aptenia cordifolia,Carpobrotus edulis,and Festuca ovina;and Ophiopogon japonicus performed best with Mix B1 and graywater.The research highlights the potential of using Aptenia cordifolia with Mix B3 and wastewater irrigation for outdoor green walls,especially in arid and semi-arid climates.展开更多
Higher education institutions are implementing environmentally friendly practices as never before.According to a 2009 survey undertaken by the Sustainable Endowments Institute,a nonprofit organization based in Cambrid...Higher education institutions are implementing environmentally friendly practices as never before.According to a 2009 survey undertaken by the Sustainable Endowments Institute,a nonprofit organization based in Cambridge,Massachusetts,more than 300 colleges and universities have become greener over the past few years despite tighter budgets and widely fluctuating energy costs.Three-quarters of these schools have adopted green building policies and about 44 percent have at least one LEED-certified building or are in the process of constructing one.Emory University in suburban Druid Hills outside Atlanta,Georgia,is one of the more forward-looking of these institutions.In 2005,university president James Wagner began the greening of the 600-acre campus by forming a committee to develop an environmental agenda for guiding the institution’s future.The following year,Emory opened an Office of Sustainability Initiatives to implement this policy.The university’s long-term goals include reducing campus energy use by 25 percent per square foot and food,materials,and electronic wastes by 65 percent per square foot—all by 2015.Already,the installation of water-saving fixtures and irrigation in accordance with drought restrictions helped to reduce water consumption by 12 percent between 2007 and 2009.As part of its eco-friendly policy,Emory now requires all new structures on campus to earn a LEED silver rating from the U.S.Green Building Council.So far,the university has achieved LEED certification of 13 buildings on campus—5 gold,5 silver,and 3 certified,including classroom,administrative,research,and healthcare facilities.In addition,six completed or nearly completed buildings are awaiting LEED certification.Ayers Saint Gross Architects and Planners of Baltimore helped to boost the sustainability at Emory,beginning in 1998 with a master plan for the campus.The firm updated this strategy in 2005 just as the university began studying ways of becoming greener.Responding to this mandate,the plan called for native plantings and recycling receptacles on campus,and rerouting vehicular traffic away from the university core,among other environmentally sensitive measures.Ayers Saint Gross has gone on to complete four,eco-friendly buildings at Emory.Each design conveys a distinctive architectural identity through varied types of metal panels and fenestration patterns.At the same time,the buildings’red-tiled roofs and exteriors of stucco and stone harmonize with the historic architecture originally designed by Beaux-Arts architect Henry Hornbostel at the heart of the campus.These new structures include a mixed-use building housing the university’s admissions office,a bookstore,and a café.A green roof is positioned over the parking garage connected to this building.Rainwater is collected in tanks below grade for irrigating the site.More sophisticated are the rainwater harvesting and graywater recycling systems devised by Ayers Saint Gross for two of three freshman residence halls designed by the firm.These green measures are particularly well suited to residence halls as they capitalize on constant water usage in the buildings through toilets,sinks,showers,and laundry facilities.At the same time,they educate the students as to the merits of sustainable design by making visible the process of collecting and recycling water from inside and outside the residence halls.展开更多
文摘The demand for potable water is rising rapidly due to an ever-increasing population,economic activities,and dwindling water supplies.To provide adequate water supplies in the future,understanding the issues and challenges in the reuse of water and developing appropriate strategies for reuse will be critical.One way to augment water supplies for residential use is to reuse graywater- the wastewater from kitchens,bathrooms,and laundries.In this article,we critically review the evolution of water reuse,the definition of graywater,graywater reuse practices,volumes and flow in different situations,and graywater characteristics.We then examine the issues associated with different graywater treatment methods and how using graywater for irrigation around homes affects soil quality and plant growth.The study concludes that graywater treatment costs,human health risks,and its effect on soil quality are some of the challenges that need to be addressed in the future for widespread and sustainable reuse of graywater for irrigation around homes.
文摘Use of municipal water in residences can be decreased substantially by allowing“graywater”effluent from showering and other activities to fill the toilet reservoir.This paper considers a system developed in Germany for treatment and storage of shower wastewater for use in flushing the toilet.Based on literature data for distributions of shower duration and water flow rate,the volume of municipal water saved using the German system has been estimated for several usage scenarios.Results show significant savings of water that depend on the size of the treatment and storage tanks used in the graywater system as well as the number of toilet flushes per day.For example,a scenario with four residents each flushing nine times per day with 80 liter treatment and storage tanks shows a 50%chance that the savings in municipal water use for the toilet will exceed 73%.Because the timing of showers and toilet flushes is assumed to follow a uniform distribution throughout the day,the calculated tank sizes may be underestimates.
文摘Outdoor green walls are gaining popularity for enhancing building aesthetics and promoting healthy and sustainable urban environment.However,concerns about their high water consumption in the context of ongoing water crises highlight the need for alternative water sources,such as recycled water.This research investigated the effects of recycled water irrigation and plant growth-promoting bacteria(PGPB)on four plant species for green walls in Mashhad,Iran:Festuca ovina,Ophiopogon japonicus,Aptenia cordifolia,and Carpobrotus edulis.Over nine months(March to December 2022),researchers conducted experiments using three water types(graywater,wastewater,and urban water)as the main factor and four bacterial treatments(Mix B1,Mix B2,Mix B3,and a control)as the sub-factor,with three replications of split-plot layout based on a randomized complete block design.Results showed significant differences in aesthetic qualities,with optimal visual quality achieved by applying Mix B2 or B3 with wastewater for Aptenia cordifolia,Carpobrotus edulis,and Festuca ovina;and Ophiopogon japonicus performed best with Mix B1 and graywater.The research highlights the potential of using Aptenia cordifolia with Mix B3 and wastewater irrigation for outdoor green walls,especially in arid and semi-arid climates.
文摘Higher education institutions are implementing environmentally friendly practices as never before.According to a 2009 survey undertaken by the Sustainable Endowments Institute,a nonprofit organization based in Cambridge,Massachusetts,more than 300 colleges and universities have become greener over the past few years despite tighter budgets and widely fluctuating energy costs.Three-quarters of these schools have adopted green building policies and about 44 percent have at least one LEED-certified building or are in the process of constructing one.Emory University in suburban Druid Hills outside Atlanta,Georgia,is one of the more forward-looking of these institutions.In 2005,university president James Wagner began the greening of the 600-acre campus by forming a committee to develop an environmental agenda for guiding the institution’s future.The following year,Emory opened an Office of Sustainability Initiatives to implement this policy.The university’s long-term goals include reducing campus energy use by 25 percent per square foot and food,materials,and electronic wastes by 65 percent per square foot—all by 2015.Already,the installation of water-saving fixtures and irrigation in accordance with drought restrictions helped to reduce water consumption by 12 percent between 2007 and 2009.As part of its eco-friendly policy,Emory now requires all new structures on campus to earn a LEED silver rating from the U.S.Green Building Council.So far,the university has achieved LEED certification of 13 buildings on campus—5 gold,5 silver,and 3 certified,including classroom,administrative,research,and healthcare facilities.In addition,six completed or nearly completed buildings are awaiting LEED certification.Ayers Saint Gross Architects and Planners of Baltimore helped to boost the sustainability at Emory,beginning in 1998 with a master plan for the campus.The firm updated this strategy in 2005 just as the university began studying ways of becoming greener.Responding to this mandate,the plan called for native plantings and recycling receptacles on campus,and rerouting vehicular traffic away from the university core,among other environmentally sensitive measures.Ayers Saint Gross has gone on to complete four,eco-friendly buildings at Emory.Each design conveys a distinctive architectural identity through varied types of metal panels and fenestration patterns.At the same time,the buildings’red-tiled roofs and exteriors of stucco and stone harmonize with the historic architecture originally designed by Beaux-Arts architect Henry Hornbostel at the heart of the campus.These new structures include a mixed-use building housing the university’s admissions office,a bookstore,and a café.A green roof is positioned over the parking garage connected to this building.Rainwater is collected in tanks below grade for irrigating the site.More sophisticated are the rainwater harvesting and graywater recycling systems devised by Ayers Saint Gross for two of three freshman residence halls designed by the firm.These green measures are particularly well suited to residence halls as they capitalize on constant water usage in the buildings through toilets,sinks,showers,and laundry facilities.At the same time,they educate the students as to the merits of sustainable design by making visible the process of collecting and recycling water from inside and outside the residence halls.
