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=Solar Water Disinfection System with Solar distillation = | =Solar Water Disinfection System with Solar distillation = | ||
Similar to [http://www.sodis.ch/ Solar Water Disinfection System (SODIS)] initiated by Professor [http://ddc.aub.edu.lb/projects/health/solar-water/acra.html Aftim Acra], Solar Water Disinfection System with solar distillation is a water purification system at household level based on solar radiations with additional use of solar heating. Since SODIS is only ideal to disinfect small quantities of micro-biologically contaminated water of low turbidity, a solar heated distillation process is combined with the conventional SODIS. Contaminated water is first distilled by using a solar heated low-temperature distillation system to remove any non-volatile solid impurities such as salts, sediment and heavy metals. However, the distilled water is not drinkable since the water may still contain | Similar to [http://www.sodis.ch/ Solar Water Disinfection System (SODIS)] initiated by Professor [http://ddc.aub.edu.lb/projects/health/solar-water/acra.html Aftim Acra], Solar Water Disinfection System with solar distillation is a water purification system at household level based on solar radiations with additional use of solar heating. Since SODIS is only ideal to disinfect small quantities of micro-biologically contaminated water of low turbidity, a solar heated distillation process is combined with the conventional SODIS. Contaminated water is first distilled by using a solar heated low-temperature distillation system to remove any non-volatile solid impurities such as salts, sediment and heavy metals. However, the distilled water is not drinkable since the water may still contain some pathogenic [http://en.wikipedia.org/wiki/Microorganisms microorganisms] . To address this problem, the distilled water is then contained in clean and transparent PET bottles or glass bottles and are exposed to the sun light for a certain amount time (depending on the intensity of the sun light) allowing the radiations to deactivate any [http://en.wikipedia.org/wiki/Waterborne_diseases waterborne pathogens]<ref>[http://www.who.int/water_sanitation_health/gdwqrevision/watborpath/en/index.html Waterborne pathogens,WHO]</ref> in the contaminated water. Solar water disinfection is an effective way to purify drinking water as it is recommended by [http://www.who.int/en/ World Health Organization]<ref>[http://www.who.int/household_water/research/technologies_intro/en/ World Health Organization]</ref>. It uses only solar energy and can be built using only recycling materials, thus, the system is environmentally sustainable. | ||
==Theory== | ==Theory== | ||
Water distillation is a physical process that filter solid impurities out of fluid based on differences in the [http://en.wikipedia.org/wiki/Volatility_(physics) volatility]. At a given temperature, substances with higher volatility (water in this case) vaporizes more readily than substances(solid impurities) with lower volatility. The water vapor would be directed to a cool region which would condense the water vapor back into liquid state, leaving all the non-volatile solid impurities such as salts, sediment and heavy metals behind. However, the distilled water may not be suitable for drinking since it may still contain some [http://en.wikipedia.org/wiki/Volatile_organic_compound volatile organic compounds]<ref>[http://www.ec.gc.ca/nopp/voc/EN/bkg.cfm Volatile Organic Compounds in Consumer and Commercial Products, definition of VOCs]</ref> or/and pathogenic microorganisms (bacteria, viruses and in some cases protozoans) The rate of vaporization is proportional to the vapor pressure and the fluid temperature. | |||
The principle of SODIS is based on [http://www.appropedia.org/Uv_water_treatment#Aftim_Acra_.26_SODIS Ultraviolet water treatment ]. It uses two components of the sunlight for the water disinfection process :[http://en.wikipedia.org/wiki/Ultraviolet Ultraviolet radiation]and [http://en.wikipedia.org/wiki/Infrared_radiation infrared radiation]. UV-A radiation(wavelength 320-400 nm) interacts with the DNA, nucleic acids and enzymes of the organic cell, destroys the cell molecular structures which leads to cell deaths. UV-A radiation also reacts with oxygen dissolved in the water producing highly reactive forms of oxygen (oxygen free radicals and [http://en.wikipedia.org/wiki/Hydrogen_peroxide Hydrogen peroxide]], that can help the germicidal process. Infrared radiation is a long-wave form of sun radiation, it can be felt as heat, as it is responsible for raising the fluid temperature. Studies had proven that 99.9%<ref>[http://www.searo.who.int/en/Section1257/Section2263/info-kit/SODIS_Manual_med.pdf Solar Disinfection System Manual by EAWAG and SANEC]</ref> of microorganisms within water are eliminated if the water is heat heated to 50-60°C for one hour. | The principle of SODIS is based on [http://www.appropedia.org/Uv_water_treatment#Aftim_Acra_.26_SODIS Ultraviolet water treatment ]. It uses two components of the sunlight for the water disinfection process :[http://en.wikipedia.org/wiki/Ultraviolet Ultraviolet radiation]and [http://en.wikipedia.org/wiki/Infrared_radiation infrared radiation]. UV-A radiation(wavelength 320-400 nm) interacts with the DNA, nucleic acids and enzymes of the organic cell, destroys the cell molecular structures which leads to cell deaths. UV-A radiation also reacts with oxygen dissolved in the water producing highly reactive forms of oxygen (oxygen free radicals and [http://en.wikipedia.org/wiki/Hydrogen_peroxide Hydrogen peroxide]], that can help the germicidal process. Infrared radiation is a long-wave form of sun radiation, it can be felt as heat, as it is responsible for raising the fluid temperature. Studies had proven that 99.9%<ref>[http://www.searo.who.int/en/Section1257/Section2263/info-kit/SODIS_Manual_med.pdf Solar Disinfection System Manual by EAWAG and SANEC]</ref> of microorganisms within water are eliminated if the water is heat heated to 50-60°C for one hour. In order to disinfect contaminated water for drinking, it is recommended to expose the contaminated water to full sunlight using clear [http://en.wikipedia.org/wiki/PET_bottle Polyethylene terephthalate (PET)] bottles for 6<ref>[http://www.searo.who.int/en/Section1257/Section2263/info-kit/SODIS_Manual_med.pdf Solar Disinfection System Manual by EAWAG and SANEC]</ref> hours.If water temperatures exceed 50°C, one hour of exposure is sufficient to obtain safe drinking water.When the weather is cloudy for more than 50% , the contaminated water need to be exposed for 2 consecutive days. The treatment efficiency can be improved by raising the fluid temperature and exposing the contaminated water to additional reflecting surfaces such as aluminium- or corrugated iron sheets. | ||
for anti bacterial propos | for anti bacterial propos | ||
has a germicidal effect. | has a germicidal effect. | ||
== Solar Water Disinfection System Construction== | == Solar Water Disinfection System Construction== | ||
Revision as of 02:01, 29 March 2010
Solar Water Disinfection System with Solar distillation
Similar to Solar Water Disinfection System (SODIS) initiated by Professor Aftim Acra, Solar Water Disinfection System with solar distillation is a water purification system at household level based on solar radiations with additional use of solar heating. Since SODIS is only ideal to disinfect small quantities of micro-biologically contaminated water of low turbidity, a solar heated distillation process is combined with the conventional SODIS. Contaminated water is first distilled by using a solar heated low-temperature distillation system to remove any non-volatile solid impurities such as salts, sediment and heavy metals. However, the distilled water is not drinkable since the water may still contain some pathogenic microorganisms . To address this problem, the distilled water is then contained in clean and transparent PET bottles or glass bottles and are exposed to the sun light for a certain amount time (depending on the intensity of the sun light) allowing the radiations to deactivate any waterborne pathogens[1] in the contaminated water. Solar water disinfection is an effective way to purify drinking water as it is recommended by World Health Organization[2]. It uses only solar energy and can be built using only recycling materials, thus, the system is environmentally sustainable.
Theory
Water distillation is a physical process that filter solid impurities out of fluid based on differences in the volatility. At a given temperature, substances with higher volatility (water in this case) vaporizes more readily than substances(solid impurities) with lower volatility. The water vapor would be directed to a cool region which would condense the water vapor back into liquid state, leaving all the non-volatile solid impurities such as salts, sediment and heavy metals behind. However, the distilled water may not be suitable for drinking since it may still contain some volatile organic compounds[3] or/and pathogenic microorganisms (bacteria, viruses and in some cases protozoans) The rate of vaporization is proportional to the vapor pressure and the fluid temperature.
The principle of SODIS is based on Ultraviolet water treatment . It uses two components of the sunlight for the water disinfection process :Ultraviolet radiationand infrared radiation. UV-A radiation(wavelength 320-400 nm) interacts with the DNA, nucleic acids and enzymes of the organic cell, destroys the cell molecular structures which leads to cell deaths. UV-A radiation also reacts with oxygen dissolved in the water producing highly reactive forms of oxygen (oxygen free radicals and Hydrogen peroxide], that can help the germicidal process. Infrared radiation is a long-wave form of sun radiation, it can be felt as heat, as it is responsible for raising the fluid temperature. Studies had proven that 99.9%[4] of microorganisms within water are eliminated if the water is heat heated to 50-60°C for one hour. In order to disinfect contaminated water for drinking, it is recommended to expose the contaminated water to full sunlight using clear Polyethylene terephthalate (PET) bottles for 6[5] hours.If water temperatures exceed 50°C, one hour of exposure is sufficient to obtain safe drinking water.When the weather is cloudy for more than 50% , the contaminated water need to be exposed for 2 consecutive days. The treatment efficiency can be improved by raising the fluid temperature and exposing the contaminated water to additional reflecting surfaces such as aluminium- or corrugated iron sheets.
for anti bacterial propos has a germicidal effect.
Solar Water Disinfection System Construction
Figures
Bottle Selection
- Transparent, smooth surface PET bottle
- Concerns about PET bottle safety under UV light
Turbid Water Filtration System
Using solar heat evaporation ( Water Distillation)
Turbid Water Filtration System Construction
more Figures