docile solar water filter world’s first inexpensive solar water filter innovated by : shripad vaidya 103, saimandir busstop, near govt. milk center, ayodhyanagar, nagpur 440024 maharashtra email:skvaidya1234@rediffmail.com importance of clean water: the health burden of poor water quality is enormous. it is estimated that around 37.7 million indians are affected by waterborne diseases annually, 1.5 million children are estimated to die of diarrhoea alone and 73 million working days are lost due to waterborne disease each year. the resulting economic burden is estimated at $600 million a year. exploring simple, low-cost filteration technologies: once impurity is detected in a water source, there is need for filteration. in case of rural areas, modern water purification technologies might not be viable. in villages, it is important that simple technologies that are easy to use and can be operated without much technical know-how be promoted. the price factor is also important as technologies with high operational and recurring costs might not be useful. water purification should be possible at the household level. meaning of the word docile: easily managed & teachable. different parts: 1) lower vessel for collection of filtered clean water. 2) upper vessel (pet bottle) for filling the water which has to be filtered. 3) center tube for transmission of water vapors to lower vessel. 4) filtration tubes (eight in numbers). how this filter works: the filter is kept under the direct sun rays. the upper vessel has a transparent body so that sun rays should travel through the water. the surrounding surface is made up of aluminium foil so that it should be reflect more and more sun rays through the water inside the pet bottle. when sun rays enter into the bottle these rays disinfects the water with the help of the method very well known as “sodis”. sodis is a method of disinfecting water using only sunlight and plastic pet bottle. this is a free and effective method for decentralized water treatment, usually applied at the household level and is recommended by the world health organization as a viable method for household water treatment. principle of disinfection: exposure to sunlight has been shown to deactivate diarrhea-causing organisms in polluted drinking water. three effects of solar radiation are believed to contribute to the inactivation of pathogenic organisms: • uv-a interferes directly with the metabolism and destroys cell structures of bacteria. • uv-a (wavelength 320-400 nm) reacts with oxygen dissolved in the water and produces highly reactive forms of oxygen (oxygen free radicals and hydrogen peroxides), that are believed to also damage pathogens. • cumulative solar energy (including the infrared radiation component) heats the water. if the water temperatures rise above 50°c, the disinfection process is three times faster. at water temperatures higher than 45°c (113°f), synergistic effects of uv radiation and temperature further enhance the disinfection efficiency. principle of distillation: these sun rays increases temperature of the water. in hot summer seasons the water gets converted into the water vapor inside the pet bottle. these water vapors through the center tube reaches the lower vessel where the atmosphere is cool enough due to water accumulation (lower vessel is also heat proof). here vapor gets converted into water. the quality of this water is very pure just like distilled water. principle of filtration under sun heat rays scanners: water travels upward very slowly through the filtration tubes hence every drop of water comes under the heat rays scanners of the sun. this makes the water more pure. increased surface area due to transparent plastic tubes increases the efficiency of purification. principle of capillary pumping against gravity : in this docile solar water filter (invented by shripad vaidya of nagpur) the water drops from upper vessel travels upward in the filtration tubes against gravity under the capillary pumping effect thus the impurity automatically remains away. because of this specialty this filter can even be used in muddy water where other normal filters can not work. filtration tubes also having the series of filters hence there is no chance of remaining any mud particle inside the water. clean water reaches inside the lower vessel. principle of separation under gravity: when muddy water or water with impurities is kept at a pet bottle for a long time without any movement then these mud particles along with other impurities settles down at the bottom of the water container hence get separated from clean water. other activities on micro level: when sun rays starts heating the water, the hot water comes up and cold water remain down it facilitates the filtration process and supports upward capillary movement. though there is not enough temperature of sunrays then also we can get the water just equivalent as a quality of boiled water with the help of these activities took place on micro level. another activity took place at filtration tubes. when water micro particles climbs up they get sufficiently heated we can observe the condensation of micro particle at top places. it shows that on micro level evaporation and condensation of these water particles took place in these filtration tubes. we are using the transparent tubes and cotton inside and this activates the trapping of the heat inside the filtration tubes. in this way increase of heat inside the filtration tubes develops the sufficient high temperature resulting in the evaporation of micro water particles. because of these filtration tubes (made of cotton inside) the total surface area of water particles exposed to the sunrays increases which helps in quick heating of those particles. this starts trail of evaporation and condensation activities inside filtration tubes thus makes water more pure. filtration tubes also filters light impurities like oil by soaking the oily impurities. it changes it’s colour of filtration tubes gives indication as the indicator for replacing the tube accordingly. thus we get more pure water. this is the peculiarity of this solar water filter which makes it successful in all seasons. specialities: 1) it is handy and portable. 2) it can be made with the help of the material which is easily available. 3) inexpensive, cheap in cost and robust enough. 4) the main limitation of solar power is that its initial cost is higher. in this docile solar water filter there is no use of any panel to create electricity etc. and direct sun rays are used hence the cost is very low. in this way it has advantageous to the user. 5) there is no use of any solar panel hence any one can make it and use it hence this is suitable to every one. in this way solar energy can be much utilized. electricity can also be saved. 6) it will give the pure water to every poor if introduced by proper promotion. 7) in summer seasons the level of water table goes down at the same time the consumption of water also increases. thus the problem of muddy water increases. this filter is best suitable for such conditions. 8) we can increase the capacity of this filter by number of ways by making simple changes like increasing the capacity of vessels, increasing the diameter of filtration tubes etc. 9) it can be used in the remote areas where there is no electricity or even no vehicles can reach like forests etc. 10) this is teachable equipment. if this docile solar water is promoted and taught then it can be used world wide and thus every one can remain healthy by keeping away the water borne diseases. the schools can promote this as an educational kit for solar energy use. 11) the solar energy was in use with the help of many equipments like solar heaters, solar pumps, solar lamps etc. but solar water filter which can be used practically was not available up till now. hence this is the first of its kind in the world. the departments for solar energy promotion can promote this filter in the interest of the public at large. 12) limca book of records has taken the entry of shripad vaidya for his environment friendly innovation of solar water filter. 13) this solar water filter is pollution free means it does not produce any noise, do not emit any gas nor use any chemical. it also does not use any battery or panel hence not produce any e-waste. hence it is an eco friendly innovation. 14) this solar water filter is completely harmless because it is free from any electric circuits hence no chance of any electricity shocks while handled by children etc. 15) because we get the filtered water quality as clean as boiled water hence the conventional energy used to boil water can be saved. 16) this solar water filter can be erected in bigger sizes also. 17) generally it is difficult to develop compact solar appliances but this solar water filter is compact in design. other additional applications like chemical filters (depending upon the requirement of the particular region) can also be attached to it at its final output point. 18) it can be dismantled, transported and assembled any where due to lighter weight. 19) it is very easy to clean the filter parts or change them. 20) here the medium of filtration used is cotton which is traditionally accepted and proven filter material. in addition to this it has some herbal qualities (like disinfective in nature etc.), which are harmless and beneficial in nature. 21) this solar water filter can also be used effectively where only saline water is available for drinking purpose. 22) to achieve higher disinfection rate at night the additional arrangement of ultraviolet light with solar charger can be attached with the same equipment. 23) it is the first equipment in which capillary pumping method is practically used. trees use this method for supplying water from root to high tops. this capillary pumping does not require any power. 24) this is also the first solar equipment which works without use of any solar panel. thus uses the sun heat directly without any conversion device. 25) ethically this solar water filter enters into the category of gandhian innovations because its application is world wide, cheap, useful to the common man and teachable from one to another. some additional information: heat and uv radiation overall, the results of both microbiological and epidemiological indicate that solar disinfection of household water has the ability to appreciably improve its microbial quality and to reduce household diarrheal disease of consumers. because of its simplicity, low cost, and the need for only beverage bottles and sunlight, solar disinfection is an appropriate technology for disinfection of household water in the developing world.the uv radiation technology is simple to use and highly effective for inactivating microbes in drinking water, and it does not introduce chemicals or cause the production of harmful disinfection by-products in the water. boiling or heating of water with fuel has been used to disinfect household water since ancient times. it is effective in destroying all classes of waterborne pathogens (viruses, bacteria and bacterial spores, fungi and protozoans and helminth ova) and can be effectively applied to all waters, including those high in turbidity or dissolved constituents. although some authorities recommend that water be brought to a rolling boil for to 1 to 5 minutes, the who gdwq recommend bringing the water to a rolling boil as an indication that a high temperature has been achieved. these boiling requirements are likely to be well in excess of the heating conditions needed to dramatically reduce most waterborne pathogens, but observing a rolling boil assures that sufficiently high temperatures have been reached to achieve pathogen destruction. although boiling is the preferred thermal treatment for contaminated water, heating to pasteurization temperatures (generally $ 60oc) for periods of minutes to tens of minutes will destroy most waterborne pathogens of concern. even heating to as little as 55oc for several hours has been shown to dramatically reduce non-sporeforming bacterial pathogens as well as many viruses and parasites, including the waterborne protozoans cryptosporidium parvum, giardia lamblia and entamoeba histolytica. clear plastic bottles are considered preferable for use in this solar water filter over glass because they are lighter, less likely to break, and less costly. bottles made of polyethylene terephthlate (pet) are preferred to those made of polyvinylchloride (pvc), other plastics and most types of glass because they are less likely to leach harmful constituents into the water. in addition, they are lightweight, relatively unbreakable, chemically stable and not likely to impart tastes and odors to the water. pet bottles require period replacement because they can be scratched and they become deformed if temperatures exceed 65oc. a major disadvantage of boiling is its consumption of energy in relation to the availability, cost and sustainability of fuel. it is estimated that 1 kilogram of wood is needed to boil 1 liter of water. in areas of the world where wood, other biomass fuels or fossil fuels are in limited supply and must be purchased, the costs of boiling water are prohibitive. therefore, boiling household water is unrealistic and inaccessible for many of the world's poorest people due to the scarcity and high cost of fuels and the lack of sustainability of biomass or fossil fuels in the community or region. in some areas of the world the use of wood and wood-derived fuels is also a concern because it contributes to the loss of woodlands and the accompanying ecological damage caused by deforestation.