| Title of Invention | A PROCESS FOR MAKING A DUAL SUBSTRATE FILTER MATERIAL |
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| Abstract | Contaminated water is of major concern especially in rural areas, where affordable purification technologies are still a distant dream. The present invention describes a filter material using carbon embedded silica extracted from industrial residue, for removal of contaminants, especially metal contaminants. The said filter material can be used for purification of water especially in rural areas. |
| Full Text | FORM 2 THE PATENT ACT 1970 (39 OF 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION TITLE OF THE INVENTION FILTER MATERIAL FOR LIQUIDS AND PROCESS OF USING THE SAME APPLICANT Dr Sachin A Mandavgane FILTER MATERIAL FOR LIQUIDS AND PROCESS OF USING THE SAME FIELD OF THE INVENTION The present invention relates to the field of filter materials for filtering liquids and process for using the same, and, more particularly, to the field of filters containing activated carbon particles. BACKGROUND OF THE INVENTION Water may contain many different kinds of contaminants including particulates, harmful chemicals, and microbiological organisms, such as bacteria, parasites, protozoa and viruses. Water-borne diseases are the greatest threat to global health, with diarrhea, jaundice, typhoid, cholera, polio, and gastroenteritis spread by contaminated water. Around 37.7 million Indians are affected by waterborne diseases annually, 1.5 million children are estimated to die of diarrhea 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. Rural India has more than 700 million people residing in about 1.42 million habitations spread over 15 diverse ecological regions. Meeting the drinking water needs of such a large population can be a daunting task. The non-uniformity in level of awareness, socio-economic development, education, poverty, malpractices, rituals and water availability add to the complexity of the task. In such case, providing pure water to such a high population is almost impossible. Another water-borne health hazard is due to chemical contaminants such as chlorine, taste, odor, lead, arsenic, volatile organic compounds (VOC), trihalomethanes (THM), chromium, heavy metals, fluorides, arsenic, selenium, etc. It is estimated that about 70 million people in 20 states are at risk due to excess fluoride and around 10 million people are at risk due to excess arsenic in ground water. Apart from this, increase in the concentration of chloride, Total Dissolve Solids, nitrate, iron in ground water is of great concern for a sustainable drinking water program. Treated water from the municipal supply may contain fewer amounts of bacteria but there is no provision for removal of metal contaminants from this water. About 85 % of rural population in India is solely depended on ground water, which is depleting at a fast rate. While 'traditional diseases' such as diarrhea continue to take a heavy toll, 66 million Indians are at risk due to excess fluoride and 10 million due to excess arsenic in groundwater. In all, 1, 95,813 habitations in the country are affected by poor water quality. Industrial development has also added to the unsafe quality of water, including ground water. Excessive release of toxic metals into the environment due to industrialization has created a great global concern. In many countries, there are deadly consequences associated with exposure to contaminated water, especially metal contaminants. Heavy metals such as cadmium, nickel, and zinc ions in aqueous solutions are toxic. Therefore the main objective of the present invention is to develop modern water purification technology especially useful to rural area, which is simple, easy to use and can be operated without much technical know-how. The price factor is also important as technologies with high operational and recurring costs might not be useful in country like India. There is also the objective of the present invention to develop a cost effective method for water purification, using easily available and cheaper materials. Rice husk is an agricultural waste, obtained from the rice mills. Rice husk is mostly used as a fuel in the boiler furnaces of various industries to produce steam. The Rice Husk Ash (RHA) is collected from the particulate collection equipment attached upstream to the stack of the rice husk-fired boilers. Since RHA is available in plenty and it has very high potential as an adsorbent, the present invention deals with the mesoporous characteristics of carbon embedded RHA and its adsorption characteristics for Cd(li), Ni(ll) and Zn(ll) ions from aqueous solutions. Adsorption in Rice Husk Ash is due to the surface complex formation between the metal ions and the acidic surface function group of activated carbon. Removal efficiency is influenced by various factors such as solution concentration, solution pH, ionic strength, nature of adsorbate, adsorbent modification procedure, physical properties (surface area, porosity), and chemical nature of the activated carbon. Removal of heavy metal ions by adsorption using activated carbon can be increased by impregnation of activated carbon with suitable chemicals which is based on simple chemical reactions that are common in chemistry such as acid-base or neutralization, complex formation, precipitation, hydrolysis and catalytic reactions. For example, if activated carbon is impregnated by molecules, ions and chelating agents that can combine with transition metal ions to form precipitation, complex or chelates, they can improve adsorption of metal cations significantly. Precipitated amorphous silica obtained from RHA has very high surface area and pore diameter. The silica as such and with deposited activated carbon is a well known adsorbent. Extensive work has been done on use of RHA as an adsorbent. Various studies address RHA as an adsorbent for metal tons like copper, nickel, zinc, lead, arsenic, mercury, cadmium and gold from aqueous solution. RHA has good adsorptive properties to remove dyes like Brilliant Green (BG) dye and Indigo Carmine dye from aqueous medium. PCT application WO2010005936) describes multi-stage water filters comprising activated carbon particles. PCT application WO2007042965 describes water filters and methods incorporating activated carbon particles and surface carbon nano filaments. PCT application W01994027914 describes a continuous flow water purifying device for disinfecting non-potable water, filter containing biocidal resins. US patent 7,712,613 describes a filter and filter material for providing or treating potable water, using a filter material formed from a mixture of mesoporous and microporous activated carbon particles, coated with silver. US patent 7,413,663 describes a water treatment apparatus containing activated carbon and resins. US patent 7,413,653 describes a portable filtered drinking water system for removing undesirable tastes, odors, and contaminants from potable water. US patent 7,749,394, US patent 7,740,765, US patent 7,712,613, US patent 7,614,506, disclose methods of providing potable water that include providing a filter of filter particles consisting of mesoporous activated carbon to remove bacteria and viruses from the water. US patent 7,510,652 describes an apparatus for removing sulfur-containing compounds from liquid fuels. US patent 7,491,337 describes a method and apparatus for the purification of water, in particular to the removal of surfactants and optionally organic, inorganic and/or biological contaminants from water using adsorption filtration techniques. US patent 7,332,082 describes a system and method for biological purification of water, in particular from swimming facilities. US patent 6,475,386 describes a filter for purifying domestic drinking water using oxidized activated carbon along with other adsorbents. US patent 6,800,111 describes a method for recovering catalytic metals where resins are used for metal removal. US patent 6,375,735 discloses amorphous precipitated silica, silica gels, and amorphous carbons derived from biomass and methods of producing them with and without adhered or deposited amorphous carbons, produced by acidifying a caustic silicate solution for using in polishing silicon wafers in the manufacture of computer chips and other electronic devices. Thus there is a need to develop a modern water purification technology especially useful to rural area, which is cost effective, simple, easy to use, can be operated without much technical know-how, has least operational and recurring costs and is made using easily available and cheaper materials. To meet the above objects and to overcome the problems existing in the prior art, the present invention describes water filter materials containing activated carbon particles. DETAILED DESCRIPTION OF THE INVENTION It is an object of the present invention to develop a filter material comprising of carbon embedded silica In yet another object of the invention, the filter material may be either homogeneous or heterogeneous In one more object of the present invention, the filter particles forming the filter material can be uniformly or non-uniformly distributed in the filter material In yet another object of the present invention, the filter particles forming the filter material need not be identical in shape or size and may be provided in either a loose or interconnected form partially or wholly bonded by a binder or other means to form an integral structure. In one more object of the present invention, the carbon embedded silica may be extracted from Rice Husk Ash (RHA) by chemical treatment In yet another object of the present invention, the chemical treatment may include alkali, preferably NaOH In one more form of the present invention, RHA may be chemically treated for 60 minutes at a temperature of 95-100°C and at 1 atmospheric pressure In yet another form of the invention, the carbon embedded silica may be precipitated from alkalinized RHA by acidification In one more form of the present invention, the precipitated carbon embedded silica may be purified by subjecting to successive washings with water and drying in oven In yet another form of the invention, the purified carbon embedded silica filter particles are in form of amorphous powder In yet another form of the present invention, the size of the filter particles may be between 1 to 20 micrometers, more preferably 3 to 5 micrometers, with a BET pore surface area of 100 m2/g and pore diameter of 18.347 nanometers In one more object of the present invention, the filter particles can be provided in simple forms such as powder, granules, fibers, and beads, or in the shape of a sphere, polyhedron, cylinder, as well as other symmetrical, asymmetrical, and irregular shapes, webs, screens, meshes, non-woven, woven, and bonded blocks, which may or may not be formed from the simple forms described above to form the filter material. EXAMPLE 1 Removal of Ni++from aqueous solution using carbon embedded silica Aqueous solution of 20 ppm Nickel Nitrate was adsorbed on different proportions of carbon embedded silica (CES) namely, 0.15, 0.3, 0.6, 0.9, 1.2 and 1.5gm/50ml solution for 20 hours at a const, temperature of 30° C. Atomic Adsorption Spectrophotometer was used to determine the metal ion concentration in aqueous media, before and after adsorption. The results are given in Table 1. Table 1 Sr. No Wt of CES Cone, in ppm (original) Cone, in ppm (after treatment) % Removal 1 0.15 20 0.627 96.86 2 0.30 20 0.312 98.44 3 0.60 20 0.366 98.17 4 0.90 20 0.400 98.00 5 1.20 20 0.593 97.03 6 1.50 20 0.270 98.65 EXAMPLE 2 Removal of Ni++ from aqueous solution using Rice Husk Ash Aqueous solution of 20 ppm Nickel Nitrate was adsorbed on different proportions of Rice Husk Ash, namely, 0.15, 0.3, 0.6, 0.9, 1.2 and 1.5gm/50ml solution for 20 hours at a const, temperature of 30° C. Atomic Adsorption Spectrophotometer was used to determine the metal ion concentration in aqueous media, before and after adsorption. The results are given in Table 2. Table 2 Sr. No Wt of RHA Cone, in ppm (original) Cone, in ppm (after treatment) % Removal 1 0.15 20 5.126 74.17 2 0.30 20 4.402 77.99 3 0.60 20 1.040 94.80 4 0.90 20 1.020 94.90 5 1.20 20 0.549 97.25 6 1.50 20 0.394 98.02 EXAMPLE 3 Effect of pH on metal removal Aqueous solution of Nickel Nitrate of 20 ppm was adsorbed on CES (0.3gm/50ml) for 20 hrs at a constant temperature of 30° C. The results are given in Table 3. Maximum, that is 94% Ni++ removal was achieved at pH = 6. Atomic Adsorption Spectrophotometer was used to determine the metal ion concentration in aqueous media, before and after adsorption. Table 3 Sr No. initial pH Cone.in ppm (original) Cone. In ppm (after treatment) % Removal 1 4 20 1.682 91.59 2 5 20 1.529 92.355 3 6 20 1.071 94.645 4 7 20 1.978 90.11 5 8 20 1.470 92.65 6 9 20 4.262 78.69 The results indicate that Carbon embedded silica is a better adsorbent then the untreated Rice Husk Ash. It is further understood by those skilled in the art that any modifications made in the examples related to different metals are obvious and without departing from the spirit and the scope thereof. I claim 1. A filter material for removing metal contaminants from liquids, said material comprising, chemically impregnated amorphous activated carbon embedded natural industrial residue 2. A filter material as in claim 1, wherein the natural industrial residue is rice husk ash 3. A filter material as in claims 1 and 2 wherein, the silica may be extracted from rice husk ash (RHA) by chemical treatment 4. A fitter material as in claims 1 and 3, wherein the chemical treatment consists of alkalization followed by acidification of the rice husk ash 5. A filter material as in claims 1 and 3, wherein the RHA may be chemically treated for 60 minutes at a temperature of 95-100°C and at 1 atmospheric pressure to precipitate the carbon embedded silica 6. A filter material as in claims 1 and 5, wherein precipitated carbon embedded silica may be purified by subjecting to successive washings with water and drying in oven 7. A filter material as in claims 1 and 6, wherein precipitated carbon embedded silica is impregnated so as to impart surface acidity or basicity using chemical but not limited to zinc chloride, phosphoric acid. 8. A filter material as in claims 1 and 7, wherein the pore diameter of filter particles is between 1 to 50 A0 (Armstrong), preferably 12-20 A0, and the BET pore surface area of the filter particles is of 100 m2/g 9. A process of removing metal contaminants from water, said process comprising a) Providing a filter material of carbon embedded silica extracted from rice husk ash b) Passing said liquid through the filter material c) Allowing contact period of at least 30 seconds between the metal contaminated liquid and said filter material d) Adsorbing the metal contaminant onto the filter material e) Collecting the purified liquid in collection devices 10.A method of removing metal contaminants from water substantially as described herein and illustrated with help of examples |
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| Patent Number | 272399 | ||||||||
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| Indian Patent Application Number | 2771/MUM/2010 | ||||||||
| PG Journal Number | 14/2016 | ||||||||
| Publication Date | 01-Apr-2016 | ||||||||
| Grant Date | 31-Mar-2016 | ||||||||
| Date of Filing | 05-Oct-2010 | ||||||||
| Name of Patentee | SACHIN A MANDAVGANE | ||||||||
| Applicant Address | DEPARTMENT OF CHEMICAL ENGINEERING, VISVESVARAYA NATIONAL INSTITUTE OF TECHNOLOGY, SOUTH AMBAZARI ROAD, NAGPUR 440 010. | ||||||||
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| PCT International Classification Number | B01D39/00,C02F1/00 | ||||||||
| PCT International Application Number | N/A | ||||||||
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