Title of Invention

A PROCESS FOR MAKING AN IMPROVED MEDIA FOR ARSENIC REMOVAL FROM WATER

Abstract

An improved media for removing arsenic from water based on anion exchange resin formed by reducing the moisture content of anion exchange resin by treating it with saturated brine solution then loading of metal having arsenic removal property in the form of anionic complex, onto anion exchange resin material and carrying out metal loading by equilibrating a gel type strong base anion exchange resin, Tulsion A-23, with a solution of ferric chloride, sodium chloride and hydrochloric acid followed by treating of metal loaded resin with alkaline permanganate solution of sodium hydroxide and potassium permanganate which also introduces oxidative properties into resin, and eventually washing of this resin media with demineralized water to remove traces of adhered chemicals.

Full Text

FORM-2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION (Section 10, rule 13) "An Improved Media for Arsenic Removal from Water" Thermax Limited with Corporate office at Thermax House, 4 Pune-Mumbai Road, Shivajinagar, Pune 411005, Maharashtra, India. an Indian Company registered under the provisions of the Companies Act, 1956, The following specification particularly describes the nature of the invention and the manner in which it is to be performed: - FIELD OF THE INVENTION The present invention relates to media for removal of Arsenic from drinking water. In particular, the present invention relates to synthesis and use of media for removal of Arsenic from drinking water. More particularly, the present invention relates to synthesis and use of Arsenic removal media having redox properties, which is capable of removing both major types of inorganic Arsenic from ground water, more efficiently and without any pre-treatment such as oxidation etc. BACKGROUND OF THE INVENTION Arsenic is naturally occurring element in earth crust i.e. in rocks, soils, minerals and ores. Water which comes in contact with such deposits often gets contaminated with dissolved form of Arsenic. Arsenic contamination in some areas gets elevated as a result of erosion from local rocks and dissolution from soil & ores. Arsenic is widely used in metallurgy, glassware, ceramic, dyes, herbicides and pesticides, refining, wood preservative and fertilizer industries. Effluents from such industries are also responsible for high Arsenic levels in nearby water bodies. Problem of high Arsenic levels in ground water is more predominant in eastern states of India and in almost all parts of Bangladesh. Arsenic levels in these areas are as high as few thousands of ppb. Arsenic contaminated drinking water poses the biggest threat to public health as Arsenic is recognized as highly toxic and poisonous element for centuries and it can contribute to long term morbidity and mortality. United States Environmental Protection Agency (USEPA) has maintained 10 micrograms/lit as maximum contamination level (MCL) for Arsenic in drinking water. 2 Arsenic is present in nature in either organic form or in inorganic form. Organic Arsenic is mostly present in seafood but it is much harmless as it can be easily discarded by human body. Inorganic Arsenic is much poisonous to body and it is mostly present in two anionic forms in nature. Trivalent Arsenic [As(III)] is called as 'Arsenite' whereas 'Arsenate' is pentavalent Arsenic [As(V)]. In the pH range of 4-10, trivalent Arsenic is present as neutral species whereas pentavalent Arsenic is present as anionic or negatively charged species. Maybe due to this reason, pentavalent Arsenate is much easy to remove than trivalent arsenite by any conventional technique of Arsenic removal. Due to toxic and poisonous nature of Arsenic, it is therefore very important to develop a cost effective and efficient solution for removal of Arsenic from water that is used for domestic purpose, especially which goes for human consumption. Removed Arsenic from ground water can become a solid source for Arsenic, which is widely and mostly used in synthesis of wood preservatives and herbicides apart from various other industrial processes mentioned above. World demand for Arsenic trioxide, which is used as a major raw material, is about 100000 metric tons/year. At present, almost all Arsenic trioxide is obtained from residues of mineral processing such as flue dust from sulfide smelting. At present, many systems for Arsenic removal from ground water are fully developed and commercially available. These systems are mainly based on different techniques namely coagulation followed by precipitation, adsorption, membranes and ion exchange. Effective removal of Arsenic can be achieved by coagulation with ferric salts followed by precipitation or similar conventional Iron-Manganese removal processes. However such processes are not suitable for small projects due to high costs and want of trained operators. Effective separation of precipitate from treated water is also critical and important and needs close monitoring by well-trained personnel. Disposal of large volumes of contaminated sludge is one of the major drawbacks of this technique. 3 Adsorption of Arsenic on activated alumina is simpler but less effective technique. Though it removes arsenate very effectively, removal of arsenite is very poor. This leads to overall low Arsenic removal capacity of media. Generally alumina is used as non-regenerable media meant for one time use only. Due to this, disposal of spent media is also one of the major problems with this technique. Presence of other anions in water such as phosphates and sulfates can also seriously hamper the Arsenic capacity of alumina. Granular ferric oxides / hydroxides (GFO and GFH) are also used for removal of Arsenic and works on adsorption technique. Though Arsenic removal capacities of these media are far better than alumina, problems arising due to their incapability of regeneration still remain with GFO and GFH. It is mentioned that disposal of spent media is safe and secure as adhered Arsenic can not leach out under normal environmental conditions. However, leaching of Arsenic may occur due to changing global environment especially due to frequent occurrences of phenomena of 'acid rain'. Usage of reverse osmosis and nano-filtration membranes for Arsenic removal is also reported. However, this option is not commercially accepted for drinking water application due to high operational costs. Since these membranes are subjected directly to raw water, there is a threat of organic / inorganic fouling. To avoid this fouling, suitable pre-treatment and periodic maintenance with chemicals is necessary. This increases the overall application costs further. It has also got another disadvantage of high water rejections as compared to other conventional methods. In this technique, Arsenic is not getting bound and complexed to any type of solid matrix but it gets concentrated in reject water and remains in same soluble and dangerous form. Disposal of reject water is another area of concern for this technology. Since Arsenic is present in anionic form in water, it is possible to remove it by using anion exchange resin. However simple resin does not offer any selectivity towards Arsenic and presence of other anions such as chloride, fluoride, sulfate, phosphate etc greatly hamper the overall capacity of resin for Arsenic removal. Since arsenite is present as a neutral 4 species, removal of the same with anionic resin is virtually zero. Due to these drawbacks usage of simple anion exchange resin for removal of Arsenic is not popular. Among all these technologies, GFO / GFH seems to be the most popular one despite of its inability for usage in repeated cycles and lot of research has been done using these media for removal of Arsenic from ground water. Most probable reason for its wide use is its high capacity of overall Arsenic removal and also a substantially higher ability to adsorb arsenite as compared to other media. Research paper titled 'Comparative studies for selection of technologies' by J. C. Saha et al, 'Granular ferric hydroxide for elimination of Arsenic from drinking water' by B. N. Pal and 'Arsenic removal from drinking water using granular ferric hydroxide' by O. S. Thirunavukkarasu et al discuss the usage of various media for Arsenic removal, superiority of GFO / GFH over other media, ability of GFO / GFH to remove arsenite effectively and also their ability to achieve MCL of 10 micrograms/lit Arsenic in drinking water. Only disadvantage of this media looks like its inability of regeneration and repeated cycle use. Recently, researchers have come up with a new type of Arsenic removal media having GFO / GFH precipitated inside a solid spherical ion exchange resin matrix. This media offers all advantages of GFO / GFH of Arsenic removal. In addition, it is best suitable for column operations due to spherical shape. Crosslinked polymer matrix of resin provides the substrate durability to the media and reduces the chances of loss of media due to attrition. It is possible to elute Arsenic from spent media, regenerate it and use it in multiple cycles leading to reduced cost of operation. 5 PRIOR ART An U.S. patent application No. 6,368,510 claiming an A system for removing arsenic from a water source over a continuous period of time comprising means connected to said water source for converting arsenite in said water source to arsenate; means connected to said arsenite converting means for removing arsenate in said water flowing from said arsenite converting means; and said water flowing from said arsenate removing means comprises an arsenic concentration level of about 10 parts per billion or less. An U.S. patent application No. 5,601,721 claiming an acrylic, strong base, anion exchange column can also be employed to remove arsenic, iron, and vanadium from an aqueous fluid film processing system, comprising: (a) passing the aqueous liquid through an acrylic, strong base, anion exchange resin to produce a resin effluent having a total selenocyanate concentration less than the total selenocyanate concentration in the aqueous liquid; (b) eluting the resin with an aqueous solution to form a selenocyanate-containing eluent; and (c) repeating steps (a) and (b) at least 25 cycles without substantial fouling of the acrylic, strong base, anion exchange resin prior to regenerating said resin; An U.S. patent application No. 6,706,195 claiming a system for continuously removing arsenic from arsenic-contaminated water comprising: a plurality ranging from 10 to 25 of immobile vessels, each containing a resin bed capable of binding arsenic from said contaminated water and yielding purified water and a arsenic-contaminated resin bed; a plurality of electronically controlled valves fitted to each one of the immobile vessels, one of said valves admitting arsenic-contaminated water to the vessel, one removing purified water, one admitting regenerant, one admitting rinse liquid and one or more removing regenerant 6 and/or rinse liquid; and an electrical controller directing the plurality of electrically controlled valves so that when the system is in operation continuously removing arsenic, contaminated water is flowed to a subset of vessels, regenerant is flowed to a subset of vessels containing the most highly arsenic-contaminated resin bed and rinse liquid is flowed to a subset of vessels containing the least arsenic-contaminated resin bed. An U.S. patent application No. 5,182,023 claiming an automated film processing system, comprising: A process for treating a arsenic-contaminated aqueous waste to recover usable water comprising the steps of: passing the arsenic-contaminated water through an ultrafilter membrane to remove solids to create an arsenic-containing aqueous filtrate chemically treating the filtrate to produce a filtrate having a pH of from about 6 to about 8; and subjecting the filtrate to reverse osmosis at elevated pressure of up to about 1,000 psig to yield a permeate stream having less than about 50 ppb arsenic and a reject stream containing the balance of the arsenic. An U.S. patent application No. 5,591,346 claiming A method for reducing arsenic concentration in a wastewater or drinking water stream contaminated with arsenic-containing contaminants comprising arsenate, said process comprising the step of contacting the contaminated water stream with an iron(III)-complexed cation exchange resin to form an acid exchangeable iron(III) arsenate complex immobilized on said cation exchange resin and an effluent stream having reduced arsenic concentration. An U.S. patent application No. 7,153,434 claiming A method for removing silicon dioxide from a contaminant-removal media bed comprising the steps of: adding a scrub 7 solution to a media bed containing silicon dioxide, the scrub solution comprising an acidic solution of sodium fluoride; allowing the scrub solution to remove the silicon dioxide; and removing the scrub solution containing the silicon dioxide from the media bed. Further stating a method for removing a contaminant from water comprising: feeding a flow of water to a contaminant-removal media bed; periodically stopping the flow water to the contaminant-removal media bed; backwashing the contaminant removal bed with a scrub solution comprising an acidic solution of sodium fluoride; allowing the contaminant-removal media bed to soak in the scrub solution; removing the scrub solution from the contaminant-removal media bed; and resuming feeding the flow of water to the contaminant-removal media bed An U.S. patent application No. 2006037913 describes the art of precipitating a metal like iron inside the anion exchange resin. Metal ion in form of an anionic complex is first loaded on anion exchange resin and then the said metal is precipitated as metal hydroxide inside the resin by alkali treatment. Anion exchange resin modified in this fashion by precipitation of iron oxide can be effectively used for removal of Arsenic from ground water. However, such media may show less capacity for removal of arsenite ions and may need oxidation with Chlorine or Ozone as a pre-treatment, which oxidizes arsenite into arsenate. Installation of such pre-treatment will certainly increase the overall application cost. Hence it was felt that there is a need to develop such a media which will effectively remove both forms of Arsenic from water without any pre-treatment of oxidation and provide effective, efficient and commercially feasible solution to the problem of Arsenic removal. OBJECTS OF THE INVENTION The object of this invention is to develop a media for removal of Arsenic from water. 8 Another object of this invention is to develop a media which can effectively remove both forms of Arsenic viz. arsenite and arsenate from water. Yet another object of this invention is to develop an ion exchange based media which can remove both forms of Arsenic from water and which does not need any pre-treatment of oxidation. Yet another object of this invention to develop an anion exchange resin based media for removal of both forms of Arsenic and which also have in-built redox properties that can effect in-situ oxidation of arsenite into arsenate. Yet another object of this invention is to develop above mentioned media from which loaded Arsenic from spent media can be easily eluted and recovered, resin can be regenerated and use in multiple cycles. Another objective of this invention is to develop low cost, robust Arsenic removal media having all above mentioned qualities and which can provide an effective, efficient and commercially feasible solution to a problem of Arsenic removal from water. SUMMARY OF THE INVENTION Present invention relates generally to the development and usage of anion exchange material based Arsenic removal media which iron hydroxide is precipitated inside the resin material and which also contains manganese dioxide based functionality which can catalyze oxidation reactions. Improved Arsenic removal media presented in this invention is synthesized by first loading the Iron in the form of anionic complex into the semi-dried anion exchange resin in chloride form followed by its precipitation under strong oxidative environment. 9 The said anion exchange resin in this case can be of any type such as gel, isoporous or macroporous. Though strong base anion exchange resin is preferred for this modification, weak base resin in hydrochloride salt form can also be used. The said anion exchange resin may have crosslinked polystyrene, polyacrylic or any other suitable matrix. Synthesis of such resins is well known art and the same has been already reported in number of references and patents. The said ion exchange material can be in the form of spherical shaped beads, granules, flakes, membranes etc. Particle size of resin may vary from 25 microns to 1400 microns. However the preferred size is 300-1200 microns. Use of semi-dried resin is recommended for loading metal ion as presence of water decreases the stability of the complex between metal ion and resin, which lead to less loading of metal ion inside the resin. Though Iron is preferred as a metal to be precipitated inside the resin, other metals capable of adsorbing Arsenic such as Titanium, Manganese etc can be used. The loaded metal is then precipitated inside the resin by alkali treatment under strong oxidative condition. This can be achieved by using alkaline permanganate solution, which also gives the media ability to catalyze oxidation reaction. Alkali used can be any alkali metal or alkaline earth metal hydroxide, ammonium hydroxide etc. Thus, the present invention proposes the development of improved media for Arsenic removal comprising the following steps. 1. Reducing the moisture content of anion exchange resin by suitable method, 10 2. loading of metal having Arsenic removal property in the form of anionic complex, onto anion exchange resin material, 3. Treatment of metal loaded resin with alkaline permanganate solution which precipitate the metal inside the resin and also introduces oxidative properties into resin, 4. Final washing of media with demineralized water to remove traces of adhered chemicals. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the process of synthesis of improved Arsenic removal media based on anion exchange resin wherein a metal like iron is precipitated as ferric hydroxide inside the resin and which also have functionality which can exhibit oxidation potential. As mentioned earlier, metal like iron is first loaded onto anion exchange resin in the form of anionic species and it forms complex with the resin. It is a well known fact that metal like iron can form tetrachloride complex (FeCl4-1) in presence of high chlorides and under acidic pH. This tetrachloride complex bears negative charge and thus easily gets loaded onto anion exchange resin replacing exchangeable chloride ion already present on the resin to form a metal - resin complex. For higher loading of metal on the resin it is therefore very important that stability of complex between metal and resin should be high. Stability of this complex increases proportionally with the acidity of environment. Hence, the stability of complex may reduce if the acidity of environment reduces. Presence of water in the environment reduces the its acidity which in turn reduces the stability of complex and finally amount of metal loading also decreases. Thus, usage of semi-dried resin is recommended for higher loading of metal ion onto resin. Totally dry resin will have highest metal loading but it is generally avoided as total drying of resin followed by re-wetting with water may decrease the physical strength of 11 resin and may even affect bead integrity especially in case of gel and isoporous resin. Treatment with saturated brine solution or air drying of resin can reduce moisture content of resin to make it suitable for metal loading. In this invention, metal loading was carried out by equilibrating Tulsion A-23, which is gel type strong base anion exchange resin in chloride form, with a solution of ferric chloride, sodium chloride and hydrochloric acid for suitable period. It was found that amount of metal loaded onto the resin is directly equivalent to the total exchange capacity of resin and also it is the maximum threshold value for metal loading. As mentioned earlier, iron is loaded as FeCl4-1 on the resin by replacing original exchangeable chloride ion. So the maximum amount of iron that can go on resin is decided by total exchange capacity of resin and can not exceed even if you use very high quantities of Ferric chloride and other chemicals. In the next step of invention, metal loaded resin is filtered out and directly treated with a solution of sodium hydroxide and potassium permanganate. It is strongly recommended that washing of metal loaded resin by water or any other solvent should not be done as it may elute the loaded metal from the resin. Sodium hydroxide provides the necessary alkaline medium in which iron can get easily precipitated. Presence of Permanganate in this precipitation serves various purposes. Firstly it provides the strong oxidative environment that ensures precipitation of iron as ferric hydroxide only, which is responsible for Arsenic adsorption. Traces of any residual ferrous ions can get oxidized into ferric ions during precipitation. As loaded iron gets precipitated, resin regains its chloride ionic form. In presence of permanganate ions, some of the chloride ions are replaced by permanganate due to higher selectivity. Thus ionic form of resin becomes a mixed one i.e. chloride and permanganate. This loaded permanganate is capable of catalyzing oxidation reactions and it can increase the oxidation state of many elements such as iron and Arsenic. 12 When such a resin is put into use for Arsenic removal, the loaded permanganate ions can catalyze oxidation of As(III) into As(V). Thus, pre-treatment of ozone / chlorine oxidation is not required in case of this modified resin. As mentioned earlier, adsorption of As(V) is more easy, fast and effective than As(III). It is desirable that maximum As(III) should get oxidized into As(V) so that overall capacity of media for Arsenic removal will increase. Probable mechanism of this oxidation can be as follows. When a resin in permanganate form comes in contact with water containing other anions, every anion will compete with each other for getting loaded onto the resin. Since selectivity of permanganate ion will be highest due to its high molecular weight and high concentration as compared to other common anions in ground water, it will ultimately remain on resin. However for a short time period, it will be in equilibrium with competing anion and during this period, it will be present as free permanganate ion. During this period it will regain its oxidative property, will catalyze necessary oxidation of As(III) to As(V), then go back to the resin and get loaded onto it. Thus, there will not be any permanent leaching of permanganate from resin or even consumption of it as it will only catalyze the oxidation without taking part in reaction. There is one more possibility by which this permanganate can increase overall capacity for Arsenic removal. Since the media will be used for treating ground water, it will be subjected to many more ions along with Arsenic. Most common ion that can appear in ground water is iron. Iron in water is present in Fe(II) for which is the soluble form of iron. Loaded permanganate on media can oxidize soluble Fe(II) ions in water to insoluble Fe(III) form and precipitate it in form of iron oxide flakes in the resin bed. This ferric hydroxide can also act as adsorbent for Arsenic and thus enhance overall efficiency of the media for removal of Arsenic. During synthesis of media, enough time has to be given for reaction to occur between metal loaded resin and solution of sodium hydroxide and potassium permanganate so as to 13 ensure complete precipitation of ferric hydroxide and also replacement of chloride ions on resin by permanganate ions. Finally resin media is separated by filtration and washed with demineralized water till the effluent is free of any alkalinity and permanganate. Resultant media can be directly used for removal of Arsenic from water. One way to use this media for removing arsenic from water is by filing a column with the media and passing water through such column so that the arsenic is absorbed by this media. The synthesis of media can be carried out in a batch mode under stirring or in continuous mode by column operation. As mentioned earlier, this improved media is regenerable and can be used for multiple cycles. Loaded Arsenic in spent resin can be easily eluted along with loaded metal by acid treatment. Arsenic from the eluent can be recovered. Eluted resin can be subjected to similar steps such as brine treatment for reducing moisture, metal loading, precipitation by alkaline permanganate solution and final washing to get back the original media. EXAMPLES The invention is now described with reference to following example, however it should not be considered as limitations to the invention. Example 1- 600 ml ( 373 gm) of Tulsion A-23 was stirred in 1250 ml of 30% sodium chloride solution for 2 hours. Brine was then filtered under vacuum and resin was then subjected to a reaction with a solution of 315 ml of 36% ferric chloride, 500 ml of 30% brine and 17.5 ml cone. Hydrochloric acid. Slurry was stirred at room temperature for minimum 8 hours and liquid part was filtered under vacuum. Metal loaded resin was then subjected to a reaction with solution of 75 gm of Sodium hydroxide flakes, 1200 gm Potassium permanganate crystals and 1875 ml water. Slurry was stirred at ambient temperature for 2 hours. Resin was 14 then separated by filtration and washed with demineralized water till the effluent was free of alkalinity and permanganate. Resultant resin volume was 560 ml and its weight was 482 gm. Moisture content of resin was 51.80% Initial resin weight 373 gm Moisture content 53% Initial resin dry weight 175.31 gm Final resin weight 482 gm Final resin moisture content 51.80% Final resin dry weight 232.32 gm Weight gain 32.52% This resin was tested for Arsenic removal from water separately for As(III) and As(V), in comparison with resin obtained from experiment 2. Example 1- 600 ml ( 373 gm) of Tulsion A-23 was stirred in 1250 ml of 30% sodium chloride solution for 2 hours. Brine was then filtered under vacuum and resin was then subjected to a reaction with a solution of 315 ml of 36% ferric chloride, 500 ml of 30% brine and 17.5 ml cone. Hydrochloric acid. Slurry was stirred at room temperature for minimum 8 hours and liquid part was filtered under vacuum. Metal loaded resin was then subjected to a reaction with solution of 75 gm of Sodium hydroxide flakes and 375 ml water. Slurry was stirred at ambient temperature for 2 hours. Resin was then separated by filtration and washed with demineralized water till the effluent was free of alkalinity. Resultant resin volume was 520 ml and its weight was 408 gm. Moisture content of resin was 49.97% Initial resin weight 373 gm Moisture content 53% Initial resin dry weight 175.31 gm Final resin weight 408 gm Final resin moisture content 49.97% Final resin dry weight 204.12 gm 15 Weight gain 16.43% Higher weight gain for experiment 1 resin can be due to conversion of resin into permanganate form. This resin was tested for Arsenic removal from water separately for As(III) and As(V), in comparison with resin obtained from experiment under identical conditions. Details of resin testing and results Column Details 12mm id glass columns in series Resin volume 100 mis in supplied form. Resin bed height in Na 100 to 106 Cms Service flow rate 40 BV/h. Empty bed contact time 1.5 min Run termination point When the effluent leakage is 10 % of influent feed water. Influent Water used for study.(NSF 53 challenge water) (All ppm as CaCO3, except Arsenic) Mg= 49.5 ppm, SO4=52, NO3 =1.62, F=1.8, Silica=16.6, Ca=100, pH=7.6 and As= 0.3 ppm as As Resin details Arsenate (ASV) removal Arsenite (ASIII) removal As leak ppb Bed vol treated As leak ppb Bed vol treated Experiment 1 resin Experiment 2 resin It seems that both resins are showing almost similar performance when used for As(V) removal. However in case of As(III) resin prepared with permanganate ion introduction shows better performance as compared to other one. 16 We Claim, 1. An improved media for removing arsenic from water based on anion exchange resin comprising the steps of: reducing the moisture content of anion exchange resin by treating it with saturated brine solution, loading of metal having arsenic removal property in the form of anionic complex, onto anion exchange resin material, carrying out metal loading by equilibrating a gel type strong base anion exchange resin, such as Tulsion A-23, with a solution of ferric chloride, sodium chloride and hydrochloric acid treating of metal loaded resin with alkaline permanganate solution of sodium hydroxide and potassium permanganate which also introduces oxidative properties into resin, washing of this resin media with demineralized water to remove traces of adhered chemicals. removing arsenic from water by filing a column with the media and passing water through such column so that the arsenic is absorbed by this media. 2. The improved media of claim 1, wherein the said metal having arsenic removal property is iron. 3. The improved media of claim 1, wherein the said base material is anion exchange resin having gel, isoporous or macroporous crosslonked postyrene or polyacrylic matrix. 4. The improved media of claim 1, wherein the said base material is anion exchange resin having atleast one amine functional group. 5. The improved media of claim 1, wherein the said base anion exchange resin is semi-dried prior to loading of metal. 6. The improved media of claim 1, wherein atleast one metal in the form of anionic complex is loaded on the semi-dried resin. 7. The improved media of claim 1, wherein precipitation of metal is carried out under strong oxidizing environment. 8. The improved media of claim 1, wherein ionic form of resin is partially converted into permanganate form during metal precipitation. 9. The improved media of claim 1, wherein a solution of alkali or alkaline earth metal hydroxide / carbonate / bicarbonate or ammonium hydroxide and a strong oxidizing agent such as potassium permanganate is used for precipitation of loaded metal into the resin. 10. The method of removing contaminants such as arsenic by using media of claim 1 wherein no pre-treatment of oxidation is required. Dated this 19th July, 2007 ABSTRACT An improved media for removing arsenic from water based on anion exchange resin formed by reducing the moisture content of anion exchange resin by treating it with saturated brine solution then loading of metal having arsenic removal property in the form of anionic complex, onto anion exchange resin material and carrying out metal loading by equilibrating a gel type strong base anion exchange resin, Tulsion A-23, with a solution of ferric chloride, sodium chloride and hydrochloric acid followed by treating of metal loaded resin with alkaline permanganate solution of sodium hydroxide and potassium permanganate which also introduces oxidative properties into resin, and eventually washing of this resin media with demineralized water to remove traces of adhered chemicals.

Documents:

1395-MUM-2007-ABSTRACT(20-7-2002).pdf

1395-MUM-2007-ABSTRACT(20-7-2007).pdf

1395-MUM-2007-ABSTRACT(20-7-2008).pdf

1395-mum-2007-abstract(granted)-(26-6-2009).pdf

1395-mum-2007-abstract.doc

1395-mum-2007-abstract.pdf

1395-MUM-2007-CANCELLED PAGES(6-4-2009).pdf

1395-MUM-2007-CLAIMS(20-7-2007).pdf

1395-MUM-2007-CLAIMS(25-7-2008).pdf

1395-MUM-2007-CLAIMS(AMENDED)-(25-7-2008).pdf

1395-mum-2007-claims(granted)-(26-6-2009).pdf

1395-mum-2007-claims.doc

1395-mum-2007-claims.pdf

1395-MUM-2007-CORRESPONDENCE 1(20-6-2008).pdf

1395-MUM-2007-CORRESPONDENCE 20-6-2008.pdf

1395-MUM-2007-CORRESPONDENCE(25-7-2008).pdf

1395-MUM-2007-CORRESPONDENCE(6-4-2009).pdf

1395-MUM-2007-CORRESPONDENCE(IPO)-(14-10-2008).pdf

1395-MUM-2007-CORRESPONDENCE(IPO)-(17-7-2009).pdf

1395-MUM-2007-CORRESPONDENCE(IPO)-(30-4-2008).pdf

1395-mum-2007-correspondence-received.pdf

1395-mum-2007-description (complete).pdf

1395-MUM-2007-DESCRIPTION(COMPLETE)-(20-7-2007).pdf

1395-MUM-2007-DESCRIPTION(COMPLETE)-(6-4-2009).pdf

1395-mum-2007-description(granted)-(26-6-2009).pdf

1395-MUM-2007-FORM 1(20-7-2007).pdf

1395-MUM-2007-FORM 1(20-7-2008).pdf

1395-MUM-2007-FORM 2((TITLE PAGE)-(20-7-2007).pdf

1395-mum-2007-form 2(20-7-2007).pdf

1395-mum-2007-form 2(6-4-2009).pdf

1395-MUM-2007-FORM 2(COMPLETE)-(20-7-2007).pdf

1395-mum-2007-form 2(granted)-(26-6-2009).pdf

1395-MUM-2007-FORM 2(TITLE PAGE)-(20-7-2007).pdf

1395-MUM-2007-FORM 2(TITLE PAGE)-(6-4-2009).pdf

1395-mum-2007-form 2(title page)-(granted)-(26-6-2009).pdf

1395-MUM-2007-FORM 26(20-6-2008).pdf

1395-MUM-2007-FORM 3(25-7-2008).pdf

1395-mum-2007-form-1.pdf

1395-mum-2007-form-18.pdf

1395-mum-2007-form-2.doc

1395-mum-2007-form-2.pdf

1395-mum-2007-form-26.pdf

1395-mum-2007-form-3.pdf

1395-mum-2007-form-9.pdf

1395-MUM-2007-POWER OF ATTORNEY 20-6-2008.pdf

1395-MUM-2007-SPECIFICATION(AMENDED)-(6-4-2009).pdf