In this study, tracer tests and organic removal tests were conducted on three different ponds in the purpose of evaluating the influence of the flow velocity and dispersion on the hydraulic efficiency of the pond. The...In this study, tracer tests and organic removal tests were conducted on three different ponds in the purpose of evaluating the influence of the flow velocity and dispersion on the hydraulic efficiency of the pond. The authors have compared the hydraulic flow patterns among ponds with different configurations. Experimental and theoretical analyses were performed. This study indicated that the flow characteristics of square ponds are different from that of baffled ponds; the flow velocity and dispersion are equally important factors which affect the pond hydraulics; the number of inserting baffles can be optimized; and the hydraulic efficiency of multistage ponds is superior to that of baffled ponds.展开更多
in this study, an ecological model established by the authors is used to simulate the ge-neral operation characteristics of wastewater stabilization pond system. Some conclusions are useful for understanding the mech...in this study, an ecological model established by the authors is used to simulate the ge-neral operation characteristics of wastewater stabilization pond system. Some conclusions are useful for understanding the mechanisms of stabilization pond. and the design and operation of the pond system.展开更多
The current study summarizes the current status of wastewater stabilization ponds(WSPs)treatment plants that have already been built in 11 governorates throughout Egypt.Moreover,this study aims to determine the most a...The current study summarizes the current status of wastewater stabilization ponds(WSPs)treatment plants that have already been built in 11 governorates throughout Egypt.Moreover,this study aims to determine the most appropriate chlorine dose for waste stabilization ponds(WSPs)effluents to ensure the treated effluents are suitable for reuse in unrestricted irrigation and to comply with the current legislation on direct discharge onto water bodies.According to the findings,the chlorine doses used as a disinfectant in the treated effluents of the majority of WSP treatment plants ranged from 3 to 13 mg/L.Meanwhile,two of the WSPs treatment plants effluents,the Qus WSPs treatment plant in Qena governorate and the Al Zarabii WSPs treatment plant in Asyut governorate used high chlorine doses reached to 17 and 19 mg/L,respectively.This is due to the fact that both the Qus and Al Zarabii WSPs treatment plants have a high organic load,which necessitated the use of more chlorine to achieve the optimum chlorine dose at 13 mg/L for Qus and 11mg/L for Al Zarabii.The findings demonstrated that chlorine has a powerful effect in completely removing bacteria.Furthermore,in most chlorine-treated wastewater final effluents,as the chlorine doses increased,the chlorophyll-a reading decreased.The amount of trihalomethanes(THMs)produced as disinfectant byproduct was measured.The results proved that the water can be used in unrestricted irrigation,and after adding chlorine,it can be dumped on water bodies without health risks.展开更多
In Japan, various countermeasures have been taken to improve the water quality of public waters such as rivers and lakes. Though water quality has improved, it is still insufficient. In summer, eutrophication is seen ...In Japan, various countermeasures have been taken to improve the water quality of public waters such as rivers and lakes. Though water quality has improved, it is still insufficient. In summer, eutrophication is seen in lakes and inner bays, as well as rivers. As a countermeasure to prevent eutrophication, the removal treatment of nutrient salts such as nitrogen and phosphorus is done, in addition to organic substance elimination in the domestic sewerage system. This report will show the water quality characteristics of rivers and ponds in Japan. It is considered that these investigative results are effective when the water quality improvement of the stabilization ponds where eutrophication occurs are examined in China.展开更多
The construction of waste rock dumps on existing tailing ponds has been put into practice in China to save precious land resources. This work focuses on the safety assessment of the Daheishan molybdenum mine waste roc...The construction of waste rock dumps on existing tailing ponds has been put into practice in China to save precious land resources. This work focuses on the safety assessment of the Daheishan molybdenum mine waste rock dump under construction on two adjoining tailings ponds. The consolidation of the tailings foundation and the filling quality of the waste rock are investigated by the transient electromagnetic method through detecting water-rich areas and loose packing areas, from which, the depth of phreatic line is also estimated. With such information and the material parameters, the numerical method based on shear strength reduction is applied to analyzing the overall stability of the waste rock dump and the tailings ponds over a number of typical cross sections under both current and designed conditions, where the complex geological profiles exposed by site investigation are considered. Through numerical experiments, the influence of soft lenses in the tailings and possible loose packing areas in the waste rock is examined. Although large displacements may develop due to the soft tailings foundation, the results show that the waste rock dump satisfies the safety requirements under both present and designed conditions.展开更多
Faced with the world’s environmental and energy-related challenges,researchers are turning to innovative,sustainable and intelligent solutions to produce,store,and distribute energy.This work explores the trend of us...Faced with the world’s environmental and energy-related challenges,researchers are turning to innovative,sustainable and intelligent solutions to produce,store,and distribute energy.This work explores the trend of using a smart sensor to monitor the stability and efficiency of a salt-gradient solar pond.Several studies have been conducted to improve the thermal efficiency of salt-gradient solar ponds by introducing other materials.This study investigates the thermal and salinity behaviors of a pilot of smart salt-gradient solar ponds with(SGSP)and without(SGSPP)paraffin wax(PW)as a phase-change material(PCM).Temperature and salinity were measured experimentally using a smart sensor,with the measurements being used to investigate the stabilizing effects of placing the PCM in the solar pond’s lower convective zone.The experimental results show that the pond with the PCM(SGSPP)achieved greater thermal and salinity stability,with there being a lesser temperature and salinity gradient between the different layers when compared to a solar pond without thePCM(SGSP).The use of the PCM,therefore,helped control the maximum and minimum temperature of the pond’s storage zone.The UCZ has been found to operate approximately 4 degrees above the average ambient temperature of the day in the SGSPP and 7 degrees in SGSP.Moreover,an unstable situation is generated after 5 days from starting the operation and at 1.9 m from the bottom,and certain points have the tendency to be neutral from the upper depths in 1,3 m of the bottom.展开更多
The mining industry has contributed tremendously to the global economy.However,waste generated by this activity poses many challenges.Current low-cost technologies for the removal of heavy metals from mining wastewate...The mining industry has contributed tremendously to the global economy.However,waste generated by this activity poses many challenges.Current low-cost technologies for the removal of heavy metals from mining wastewater include biosorption,adsorption,CWs(Constructed Wetlands)and waste stabilization ponds.This chapter focuses on sustainable mining wastewater treatment technologies with emphasis on gold mining wastewater.It discusses the technical and environmental challenges associated with mining effluent treatment,process conditions for optimum plant performance,efficiency,limitations and the economics of treating mining wastewater.The overall treatment cost of metal contaminated wastewater depends on the process employed and the local conditions.In general,technical applicability,cost-effectiveness and plant simplicity are the key factors in selecting the most suitable treatment method.Proper management of the spent biosorbent and solid wastes generated is also discussed.展开更多
After the chemical and biological analyses of grey water from Butare Central Prison in Butare city, District of Huye, southern province of Rwanda, the resulting data were used in preliminary calculations of a natural ...After the chemical and biological analyses of grey water from Butare Central Prison in Butare city, District of Huye, southern province of Rwanda, the resulting data were used in preliminary calculations of a natural system based treatment facility. In our region, natural systems, lagoons and constructed wetlands were identified as potential effective technologies for wastewater treatment due to the low cost and favorable climate. In our study, the authors calculated two systems of treatment plants, one based on two ponds associated with a constructed wetland and another based on three ponds. This study aims at raising awareness of the required land surface that can allow the use of extensive technologies in treating domestic wastewater from the prison. Depending on the system and on the design equation used, those systems differ from their dimensions. Those systems led to overall surface areas between 0.6 ha and 1 ha. In the next stage that will take an interest in studying the feasibility of the project, the decision will be made in favor of one of the calculated systems in compliance with the accuracy and site specifications that are still to be studied.展开更多
文摘In this study, tracer tests and organic removal tests were conducted on three different ponds in the purpose of evaluating the influence of the flow velocity and dispersion on the hydraulic efficiency of the pond. The authors have compared the hydraulic flow patterns among ponds with different configurations. Experimental and theoretical analyses were performed. This study indicated that the flow characteristics of square ponds are different from that of baffled ponds; the flow velocity and dispersion are equally important factors which affect the pond hydraulics; the number of inserting baffles can be optimized; and the hydraulic efficiency of multistage ponds is superior to that of baffled ponds.
文摘in this study, an ecological model established by the authors is used to simulate the ge-neral operation characteristics of wastewater stabilization pond system. Some conclusions are useful for understanding the mechanisms of stabilization pond. and the design and operation of the pond system.
基金“The Academy of Scientific Research and Technology(ASRT)”Egypt,for funding and supporting this work through the project entitled“Evaluation and upgrading of the stabilization ponds in Egypt for wastewater reuse,combined with production of value-added bioactive compounds from algae”project ID No.:4504.
文摘The current study summarizes the current status of wastewater stabilization ponds(WSPs)treatment plants that have already been built in 11 governorates throughout Egypt.Moreover,this study aims to determine the most appropriate chlorine dose for waste stabilization ponds(WSPs)effluents to ensure the treated effluents are suitable for reuse in unrestricted irrigation and to comply with the current legislation on direct discharge onto water bodies.According to the findings,the chlorine doses used as a disinfectant in the treated effluents of the majority of WSP treatment plants ranged from 3 to 13 mg/L.Meanwhile,two of the WSPs treatment plants effluents,the Qus WSPs treatment plant in Qena governorate and the Al Zarabii WSPs treatment plant in Asyut governorate used high chlorine doses reached to 17 and 19 mg/L,respectively.This is due to the fact that both the Qus and Al Zarabii WSPs treatment plants have a high organic load,which necessitated the use of more chlorine to achieve the optimum chlorine dose at 13 mg/L for Qus and 11mg/L for Al Zarabii.The findings demonstrated that chlorine has a powerful effect in completely removing bacteria.Furthermore,in most chlorine-treated wastewater final effluents,as the chlorine doses increased,the chlorophyll-a reading decreased.The amount of trihalomethanes(THMs)produced as disinfectant byproduct was measured.The results proved that the water can be used in unrestricted irrigation,and after adding chlorine,it can be dumped on water bodies without health risks.
文摘In Japan, various countermeasures have been taken to improve the water quality of public waters such as rivers and lakes. Though water quality has improved, it is still insufficient. In summer, eutrophication is seen in lakes and inner bays, as well as rivers. As a countermeasure to prevent eutrophication, the removal treatment of nutrient salts such as nitrogen and phosphorus is done, in addition to organic substance elimination in the domestic sewerage system. This report will show the water quality characteristics of rivers and ponds in Japan. It is considered that these investigative results are effective when the water quality improvement of the stabilization ponds where eutrophication occurs are examined in China.
基金Projects(51209118,71373245)supported by the National Natural Science Foundation of ChinaProject(2014JBKY01)supported by the Fundamental Research Funds for CASST,China
文摘The construction of waste rock dumps on existing tailing ponds has been put into practice in China to save precious land resources. This work focuses on the safety assessment of the Daheishan molybdenum mine waste rock dump under construction on two adjoining tailings ponds. The consolidation of the tailings foundation and the filling quality of the waste rock are investigated by the transient electromagnetic method through detecting water-rich areas and loose packing areas, from which, the depth of phreatic line is also estimated. With such information and the material parameters, the numerical method based on shear strength reduction is applied to analyzing the overall stability of the waste rock dump and the tailings ponds over a number of typical cross sections under both current and designed conditions, where the complex geological profiles exposed by site investigation are considered. Through numerical experiments, the influence of soft lenses in the tailings and possible loose packing areas in the waste rock is examined. Although large displacements may develop due to the soft tailings foundation, the results show that the waste rock dump satisfies the safety requirements under both present and designed conditions.
基金supported and funded by the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)(Grant Number IMSIU-RG23098).
文摘Faced with the world’s environmental and energy-related challenges,researchers are turning to innovative,sustainable and intelligent solutions to produce,store,and distribute energy.This work explores the trend of using a smart sensor to monitor the stability and efficiency of a salt-gradient solar pond.Several studies have been conducted to improve the thermal efficiency of salt-gradient solar ponds by introducing other materials.This study investigates the thermal and salinity behaviors of a pilot of smart salt-gradient solar ponds with(SGSP)and without(SGSPP)paraffin wax(PW)as a phase-change material(PCM).Temperature and salinity were measured experimentally using a smart sensor,with the measurements being used to investigate the stabilizing effects of placing the PCM in the solar pond’s lower convective zone.The experimental results show that the pond with the PCM(SGSPP)achieved greater thermal and salinity stability,with there being a lesser temperature and salinity gradient between the different layers when compared to a solar pond without thePCM(SGSP).The use of the PCM,therefore,helped control the maximum and minimum temperature of the pond’s storage zone.The UCZ has been found to operate approximately 4 degrees above the average ambient temperature of the day in the SGSPP and 7 degrees in SGSP.Moreover,an unstable situation is generated after 5 days from starting the operation and at 1.9 m from the bottom,and certain points have the tendency to be neutral from the upper depths in 1,3 m of the bottom.
文摘The mining industry has contributed tremendously to the global economy.However,waste generated by this activity poses many challenges.Current low-cost technologies for the removal of heavy metals from mining wastewater include biosorption,adsorption,CWs(Constructed Wetlands)and waste stabilization ponds.This chapter focuses on sustainable mining wastewater treatment technologies with emphasis on gold mining wastewater.It discusses the technical and environmental challenges associated with mining effluent treatment,process conditions for optimum plant performance,efficiency,limitations and the economics of treating mining wastewater.The overall treatment cost of metal contaminated wastewater depends on the process employed and the local conditions.In general,technical applicability,cost-effectiveness and plant simplicity are the key factors in selecting the most suitable treatment method.Proper management of the spent biosorbent and solid wastes generated is also discussed.
文摘After the chemical and biological analyses of grey water from Butare Central Prison in Butare city, District of Huye, southern province of Rwanda, the resulting data were used in preliminary calculations of a natural system based treatment facility. In our region, natural systems, lagoons and constructed wetlands were identified as potential effective technologies for wastewater treatment due to the low cost and favorable climate. In our study, the authors calculated two systems of treatment plants, one based on two ponds associated with a constructed wetland and another based on three ponds. This study aims at raising awareness of the required land surface that can allow the use of extensive technologies in treating domestic wastewater from the prison. Depending on the system and on the design equation used, those systems differ from their dimensions. Those systems led to overall surface areas between 0.6 ha and 1 ha. In the next stage that will take an interest in studying the feasibility of the project, the decision will be made in favor of one of the calculated systems in compliance with the accuracy and site specifications that are still to be studied.
