Field of the invention The present invention relates to a cartridge for use in water purification devices to release consistent amounts of benefit agent to water from a solid source of the benefit agent housed in the cartridge.

The invention has been developed primarily for use in drinking water application and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use.

Background of the invention

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.

A large population of people in the world live in developing and under-developed countries where there is a severe shortage of hygienic potable water. There are various types of water purification devices that have been developed. Some of them are based on gravity flow which is particularly suitable for people living in rural areas or in places where there are no public water purification systems and people have to depend directly on ground and/or underground water sources like wells, tube-wells, ponds and rivers. These gravity flow water purification systems work without the requirement of electricity and running water. Other types of water purification systems use various technologies for example ultra-violet rays, reverse osmosis to ensure microbiological purity of water.

Halogenation or Chlorination of water is one of the most reliable ways of pre-treating water to make the water free from different types of microorganisms. Apart from ensuring microbiological purity of water there have been several attempts to provide water compositions fortified with dietary supplements such as vitamins and minerals while keeping in mind the need for making it free of objectionable colour, odour and taste.

IN205592 (Unilever), discloses a chemical sanitizing system which comprises a sanitizing unit containing the chemical sanitizing agents or biocides and having an opening at the bottom thereof, means for feeding in water to be sanitized having a nozzle like top selectively disposed adjacent thereunder and facing said opening at the bottom of said unit and said nozzle like top having a selective angular conical outer surface such as to favour regulated contact and delivery of said active sanitizing agent upon contact of the flowing stream of the water with the exposed sanitizing agent through said opening. The chemical dispensing unit is preferably of cylindrical cross- section holding the biocide tablets stacked one over the other on a perforated disc or a non woven fabric. There is a water inlet centrally located under the biocide holder. This design is suitable only for a gravity fed water purification device where the pressure of the water entering biocide or chemical sanitizing system is very low and generally significantly lower than 1 psig. This cannot be used for water purification system where the input water pressures are high and hence will flood and soak the solid source of the biocide or other benefit agents making them soggy and thus the amount of benefit agent carried by the water will not be consistent or uniform.

Our co-pending applications WO2013053627 and WO2013139548, disclose a dietary supplement dosing device capable of releasing predetermined amounts of dietary supplement to water.

W01 1013142 (Tata Chemicals, 201 1 ), discloses an auto shut off device for liquids comprising of at least one liquid inlet, at least one liquid outlet, a casing that defines an opening, and a stopper shaped to close the opening comprising of a top, bottom and side surfaces. The stopper further defines a liquid inlet aperture on the top surface, a liquid outlet aperture on the top surface; a connecting passage connecting the liquid inlet aperture to the liquid outlet aperture, a liquid inlet passage connecting the liquid inlet to the liquid inlet aperture, and a liquid outlet passage connecting the liquid outlet aperture to the liquid outlet. A water dissolvable tablet and a plunger are placed within the casing the plunger including a plug configured to block the liquid inlet aperture. This discloses an auto shut-off mechanism by using a low soluble chemical and when the chemical is exhausted the plunger will stop the water flow. The low soluble material is not a benefit agent.

The provision of a compartment positioned coaxially around the vertical passage prevents the tablet from getting submerged in the water and thereby a controlled amount of the benefit agent can be dispensed into water. W01 1013142, does not disclose a compartment and so cartridge can not prevent the tablet from getting submerged in water and this is of no consequence as it is not designed to solubilise the tablet in a regulated manner. In a water purification system where the input water pressure is high it is very difficult to ensure consistent dosing of the benefit agents like halogen or of dietary

supplements to water because of the high pressure at which water flows into the purifying device. Solid source of benefit agents like halogens or other dietary supplements have very high dissolution rate in water and therefore tend to get soggy. This poses a great challenge in developing mechanisms that ensure controlled flow of water through solid sources of benefit agents and doses appropriate amounts of the benefit agent into water. Controlled release of the benefit agent in water is dependent on several other factors which make designing of water purifiers very complicated and expensive, thus unaffordable for common use. The above complications have always limited the use of benefit agents like the halogen or other dietary supplement source to batch or gravity flow applications.

Delivery from a solid source requires careful designing of the cartridge that should ensure that the solid source of the benefit agent is not submerged at any time for instance during use when there is continuous flow of water and also when there is no flow of water.

The object of the present invention is to provide a cartridge having a solid source of a benefit agent for use in water purification devices to release consistent amounts of a benefit agent to water. It is another object of the present invention to provide a cartridge having a solid source of a benefit agent for use in water purification devices when the inlet water pressure is between 0.1 psig to 20 psig to release consistent amounts of benefit agent to water.

The present inventors have been able to achieve a cartridge for use in water purification devices where the inlet water pressure is very low and for devices that function at pressures upto 20 psig to release consistent amounts of a benefit agent to water from a solid source of the benefit agent by ensuring that the benefit agent tablet is not submerged in water.

Summary of the invention

Thus, according to the present invention there is provided a cartridge for use in a water purification device comprising:

(i) an inlet (1 ) for feed water and an outlet (2) for treated water;

(ii) a vertical passage (3) in fluid communication with the inlet (1 );

(iii) a compartment (4) in fluid communication with the vertical passage (3) and the outlet (2);

(iv) an air tight lid (5) to close the mouth of the compartment (4);

(v) said lid including a housing (6) adapted to comprise at least one benefit agent tablet (7);

wherein the compartment (4) is positioned coaxially with the vertical passage and the vertical passage extends upwardly towards the tablet (7) and, the end of the vertical passage is spatially separated from the tablet and whereby in operation the water leaving the vertical passage touches the exposed face of the tablet.

The features and advantages of the invention will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples, embodiment and figures given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se.

Detailed description of the invention

The present invention provides a cartridge for use in water purification devices. Cartridge:

The cartridge of the present invention includes an inlet, an outlet, a vertical passage, a compartment having an air tight lid, a housing in the lid adapted to hold a benefit agent tablet. The cartridge is preferably capable of being integrated into a storage type water purification device or directly to an inline supply of water. It is also preferable to include a storage tank in fluid communication with the outlet of the cartridge so that purified water can be stored before use.

The cartridge of the present invention is suitable for use in water purification devices where the inlet water pressure is preferably in the range of 0.1 to 20 psig.

Inlet and outlet:

The cartridge includes an inlet for feed water and an outlet for treated water. The inlet or the outlet of the cartridge preferably has a valve and it is particularly preferred that the inlet includes the valve. The valve is provided preferably when the cartridge is integrated with a storage type water purification device or when the cartridge has a downstream storage tank. The purpose of providing the valve is to preferably stop the flow of water into the cartridge when the water in the storage tank has reached an optimum level or is full. The closing and opening of the valve is preferably actuated by the level of water present in the storage tank downstream the cartridge. Preferably the valve is a manually operated valve for example a ball valve or the valve is a solenoid valve or it is a valve connected with a float for sensing the level of water in the storage tank.

Vertical passage: The cartridge includes a vertical passage. The vertical passage is in fluid

communication with the inlet and extends upwardly towards the tablet and leads the feed water entering the cartridge through the inlet to the exposed face of the tablet. The vertical passage thus extends upwardly towards the benefit agent tablet and preferably passes through the compartment. The portion of the vertical passage which receives the water from the inlet is preferably at substantially the same level as the inlet. The vertical passage is preferably elongated and is preferably designed to have a cross section of any geometric shape, more preferably the cross section is circular. The cross-sectional area of the vertical passage is preferably designed based on the pressure of water entering the inlet of the cartridge but more preferably ranges from 2 square millimeter to 14 square millimeter so that cartridge can be operated preferably from 0.1 psig to 20 psig input water pressure. It is particularly preferred that when the pressure of water is around 2 psig the cross sectional area is preferably not more than 14 square millimeter. The end of the vertical passage is spatially separated from the tablet and in operation the water leaving the vertical passage touches the exposed face of the tablet. The cross section at the end of the vertical passage is preferably such that the water exiting the passage forms a jet of water and touches the exposed face of the tablet and preferably does not submerge the benefit agent tablet. More preferably there is an air column between the exposed face of the benefit agent tablet and the end of the vertical passage to ensure that the benefit agent tablet is not submerged in water. The distance between the exposed face of the benefit agent tablet and the end of the vertical passage is preferably 2.5 millimeters to 4 millimeters more preferably 3 millimeters. Compartment:

The cartridge includes a compartment that is in fluid communication with the vertical passage and the outlet. The compartment is preferably positioned coaxially with the vertical passage. The compartment includes an air tight lid to close the mouth of the compartment. The lid keeps the compartment air tight and includes a housing adapted to include atleast one benefit agent tablet. The air tight lid provides for separating the water in the compartment from the exposed face of the tablet by an air column so that the water in the compartment does not submerge the benefit agent tablet and preferably only allows a jet of water from the vertical passage to contact the exposed face of the tablet to allow the water to carry with it the dissolved benefit agent.

At the start of the water purification process when no water has flown into the cartridge through the inlet, the compartment is filled with air. When the cartridge is integrated into a non-storage type water purification device or directly connected to a source of water without a downstream storage tank, water entering the cartridge through the inlet displaces only a portion of the air column in the compartment and a balance between the air column and water in the compartment is reached and maintained during use as the compartment is sealed with an air tight lid. The air column ensures that the benefit agent tablet in the housing of the air tight lid is not flooded. It is preferred to integrate the cartridge to a water purification device or provide the cartridge with a storage tank for storing purified water. When such a storage tank is provided downstream the cartridge the air column in the compartment is maintained preferably by providing a valve at the inlet of the cartridge which stops the flow of water into the cartridge upon actuation by the level of water in the storage tank. Dispensing of purified water from the storage tank reduces the water level in the tank which actuates the inlet valve to open and allows water to enter the cartridge.

Air tight lid:

The cartridge includes an air tight lid including a housing adapted to include at least one benefit agent tablet. The housing preferably includes a holding means for holding the tablet at the highest point of the housing. The holding means preferably is a polymeric sleeve enclosing the benefit agent tablet or a perforated base plate on which the benefit agent tablet rests.

In an embodiment of the invention the holding means is preferably a polymeric sleeve and the benefit agent tablet is encased in the polymeric sleeve to leave only one face of the tablet exposed. The polymeric sleeve preferably protects the three faces of the benefit agent tablet from leaching into water and leaves one face to be exposed to water. The polymeric sleeve further preferably provides support to the tablet in the housing. If the benefit agent is a halogen based biocide material it is preferable that the polymeric sleeve is made of a halogen resistant material, preferably selected from halogen resistant material such as silicon, ethylene propylene diene monomer (EPDM) and copolymer of hexa fluoro-polypropylene and Vinylidene fluoride (Viton from Du- pont). It is particularly preferred that the polymeric sleeve is elastic in nature so that the benefit agent tablet is well supported in the housing as the tablet is preferably held in an inverted or hanging position. In yet another embodiment of the present invention the holding means is preferably a perforated base plate is situated at the opening of the housing on which atleast one benefit agent tablet rests. When two or more benefit agent tablets are present, they are preferably stacked one above the other. Mounted on the uppermost tablet preferably a movable support is stacked. The movable support may be a plate, a disc or a tablet shaped member, most preferably a tablet shaped member. The movable support is preferably made of a material which is inert to water and the benefit agent tablet. Alternately the movable support may be made of any material and coated with an inert material such that it does not react with water and the benefit agent tablet. The movable support is usually brightly coloured for example in red, blue or green. It is preferred that the housing has a fixed top end and preferably a resilient member situated between the movable support and the fixed top end. The resilient member may be a spring or a bellow. The movable support resting on top of the tablets descends by the force of gravity as the tablets are consumed. The resilient member provides additional force to ensure that the movable support descends as the tablets are consumed by urging against the movable support plate.

The movable support may preferably have a plug means that plugs the end of the vertical passage when the tablet in the housing is consumed and provides for auto shut off mechanism.

Benefit agent:

The benefit agent is preferably a solid biocide or a dietary supplement and is preferably in the form of a tablet. When a plurality of tablet is present, they are configured such that they are stacked one on top of the other in the housing.

The composition of the benefit agent tablet preferably includes less than 95% fillers, more preferably less than 90% and still more preferably less than 85% fillers. It is preferred that the composition of the benefit agent tablet has a benefit agent to filler ratio of 1 :10 more preferably 1 :8, further preferably 1 :6 and most preferably 1 :4.

Biocide

The benefit agent is preferably a biocide and more preferably a halogen based biocide. The biocide is preferably selected from one or more of potassium

dichloroisocyanurate, sodium dichloroisocyanurate, trichlorocyanuric acid, chlorinated trisodium phosphate, calcium hypochlorite, lithium hypochlorite, monochloramine, dichloramine, [(monotrichloro)-tetra(monopotassium dichloro)] pentaisocyanurate, 1 ,3 dichloro-5,5-dimethyl hydantoin , paratoluene sulfodichloroamide, thrichloromelamine, N-chloramine, N-chlorosuccinimide, Ν,Ν'-dichloroazodicarbonamide, N-chloroacetyl- urea, Ν,Ν-dichloroazodicarbonamide, N-chloroacetyl-urea, N,N-dichlorbiurile, chlorinated dicyandiamide. A most preferred biocide for use as a tablet in the invention is trichlorocyanuric acid.

Dietary supplement

When the benefit agent is a dietary supplement it may be selected from one or more of a vitamin, mineral, electrolyte, flavor, nutrient or a mixture thereof. The dietary supplement may be sourced from either a chemical or natural source. The word dietary supplement is used throughout the text to basically refer to vitamin, mineral, electrolyte, flavour or a nutrient. Dietary supplement is provided in the solid form and is preferably in the form of a tablet. The tablet is preferably circular, square, rectangular, hexagon or oval in shape. The leading cross sectional dimension is preferably from 1 .0 cm to 5.0 cm, more preferably from 1.0 to 3.0 cm. The tablet preferably has a thickness in the range of 1 .0 cm to 10.0 cm, more preferably 1 .0 to 5.0 cm. According to a highly preferred aspect of the present invention, a natural source of vitamin and mineral is Phyllanthus emblica (Amla) extract.

Amla primarily includes tannins, bioflavonoids, carotenoids, alkaloids, and phenolic compounds, amino acids and carbohydrates which have extraordinary longevity and rejuvenating properties. Synthetic vitamin C does not provide vital nutrients such as rutin and bioflavonoids. Amla is valued for its unique tannins and flavonoids, which exhibit very powerful antioxidant properties. Amla is considered as a more potent antioxidant than Vitamin C. Vitamin C in Amla accounts for approximately 45 to 70 % of the antioxidant activity. There are no RDA levels for Amla. The present inventors have determined that it is beneficial to dose amla extract in a range between 2 to 50 ppm and preferably between 5 and 10 ppm since at concentrations more than 10 ppm, the fortified water is likely to get slightly coloured. It is preferred that we dose the vitamins and minerals at 10 to 20% of the recommended daily allowance (RDA) per liter of water. The dosage of these fortificants is selected such that it does not impart any negative organoleptic property to the water.

Alternatively, commercially available sources of vitamin C may be used herein.

Encapsulated ascorbic acid and edible salts of ascorbic acid may also be used.

Dietary supplement may also include iron selected from water-soluble iron compound, a water-dispersible particulate iron compound or mixtures thereof. In addition, the iron compound of the present invention is preferably selected from a complexed iron compound, a chelated iron compound, an encapsulated iron compound, or mixtures thereof. Highly bioavailable iron compound is preferably chosen to provide maximum health benefits. Iron-fortified water usually suffers from a metallic taste / aftertaste. The elimination of the metallic taste can be achieved by encapsulating the iron compound. The metallic taste can also be eliminated by binding the iron into a stable compound by complexing or chelating with a suitable ligand that does not permit the iron to be freely associated in water. Preferred iron compound forms also include encapsulates and complexes that preferably have a dispersed particle size in the water that is small enough to be barely visible in solution. Preferably, the dispersed particle size is about 100 nanometers (nm) or less, and more preferably about 80 nm or less. Ferrous iron is typically better utilized by the body than ferric iron. Ferrous amino acid chelates are particularly suitable as highly bioavailable forms when the ligand to metal ratio is at least 2:1. Highly bioavailable food grade ferrous salts that can be used in the present invention include ferrous sulphate, ferrous fumarate, ferrous succinate, ferrous gluconate, ferrous lactate, ferrous tartarate, ferrous citrate, ferrous amino acid chelates, as well as mixtures of these ferrous salts. Certain ferric salts can also provide a highly bioavailable source of iron. Highly bioavailable food grade ferric salts are ferric saccharate, ferric ammonium citrate, ferric citrate, ferric sulfate, ferric chloride, as well as mixtures of these ferric salts. Other bio-available sources of iron particularly suitable for fortifying water of the present invention include certain iron-sugar-carboxylate complexes. In these iron-sugar-carboxylate complexes, the carboxylate provides the counter ion for the ferrous (preferred) or ferric iron. The USRDA for iron generally ranges from 10 mg per 6 kg female or male to 18 mg per 54 to 58 kg female, depending somewhat on age. The iron fortified water prepared using the device of the present invention typically contains at least about 1 ppm of iron compound, sufficient to deliver about 10% of USRDA of iron per litre of water to account for iron that is available from other dietary sources, assuming a reasonably balanced diet is available.

The dietary supplement may also be selected from other nutrients, for example vitamin C, vitamin E, vitamin A, niacin, vitamin B6, vitamin B2, vitamin D2, vitamin B12, folate, zinc, electrolytes such as salts of sodium, potassium or magnesium and mixtures thereof. The typical values for most healthy adults are generally: vitamin C (60 mg), vitamin A (2000 lU/day) vitamin B2 (1 .7 mg), niacin (20 mg), vitamin B6 (2.0 mg), folic acid (0.2 mg/day), vitamin D2 (400 lU/day), vitamin B12 (0.001 mg/day) magnesium (300 mg), zinc (1 1 mg/day) and vitamin E (30 international units). The adequate intake value of sodium is generally 1 .5 g and for potassium is generally 4.7 g. Commercially available vitamin A sources may also be incorporated into the benefit agent tablet. Vitamin A can be provided, for example, as vitamin A palmitate (retinol palmitate), vitamin A acetate and/or as beta-carotene. It can be as an oil, as a beadlet or may be encapsulated. As used herein, "vitamin A" includes vitamin A, β-carotene, retinol palmitate and retinol acetate. Commercially available sources of vitamin B2 (riboflavin) can be used herein.

Nutritionally supplemental amounts of other vitamins for incorporation into the water include, but are not limited to, vitamins B6 and B12, folate, niacin and vitamins D2 (ergocalciferol) and E. Preferred salt for vitamin B12 is 5,6 DNB cyanocobalamide and for folate is folic acid. Sodium salts can be selected from sodium chloride, sodium ascorbate, sodium citrate, sodium ferric pyrophosphate, sodium gluconate, sodium phosphate, sodium pyrophosphate or mixtures thereof. Potassium salts can be selected from potassium chloride, potassium gluconate, potassium glycerophosphate, potassium iodide or mixtures thereof. Magnesium salts can be selected from magnesium gluconate, magnesium phosphate, magnesium sulfate or mixtures thereof. Zinc salts can be selected from zinc oxide, zinc gluconate, zinc sulfate or mixtures thereof.

Preferably, the benefit agent tablet provides the water with 10 to 20% of the USRDA or adequate intake value for these vitamins, minerals or electrolytes.

Other vitamins, minerals and electrolytes can also be incorporated into the water depending on the nutritional needs of the consumers to which the water product is directed.

Other ingredients in the benefit agent tablet

The benefit agent tablet may optionally include a sweetener. Such sweetening agents are added to the water to mask a metallic taste or after-taste caused by the minerals or vitamins. Suitable particulate sugars can be granulated or powdered, and can include sucrose, fructose, dextrose, maltose, corn maltodextrin, lactose and mixtures thereof. Most preferred is sucrose. Artificial sweeteners may also be used. Often gums, pectins and other thickeners are used with artificial sweeteners. Mixtures of sugars and artificial sweeteners may also be used.

The benefit agent tablet can optionally include a flavouring agent. The flavouring agent may be of any natural or synthetically prepared fruit or botanical flavours or with mixtures of botanical flavours and fruit juice blends. Suitable natural or artificial fruit flavours include lemon, orange, grapefruit, strawberry, banana, pear, kiwi, grape, apple, mango, pineapple, passion fruit, raspberry and mixtures thereof. Suitable botanical flavours include Jamaica, marigold, chrysanthemum, tea, chamomile, ginger, valerian, yohimbe, hops, eriodictyon, ginseng, bilberry, rice, red wine, mango, peony, lemon lavender, walnut, gentiam, cinnamon, aloe, peppermint and mixtures thereof. When present the flavouring agent is from 0.01 wt% to 10 wt%, preferably from 0.02 wt% to 8 wt%. The actual amount of flavouring agent will depend on the type of flavouring agent used and the amount of flavour desired in the treated water. Most preferred flavouring agent is peppermint flavour. The benefit agent tablet composition preferably includes a filler. Suitable fillers include sparingly soluble salts of calcium and magnesium, natural gums and polysaccharides. Examples of fillers include starch, calcium chloride, calcium carbonate, gum arabic, gum ghatti, inulin, carboxy methyl cellulose, vinyl pyrollidone-vinyl acetate copolymers. Use of the cartridge in water purification devices:

It is preferable to use the cartridge in water purification devices having reverse osmosis or ultra-filtration systems, ultraviolet based systems for providing

microbiological purity of input water in which the inlet water pressure is upto 20psig. Use of the cartridge having a benefit agent in the form of halogen based tablets in a reverse osmosis or ultraviolet based water purification system ensures high levels of microbiological purity. The inlet of the cartridge according to the invention can also be connected directly to the faucet to ensure killing of microbes present in the input water. If the benefit agent is a dietary supplement tablet it is preferable to connect the inlet of the cartridge to the faucet that dispenses purified water and the treated water exiting the outlet of the cartridge will have known amounts of dietary supplement dissolved in purified water.

The cartridge of the present invention may also be integrated into a storage type water purification device. The cartridge may also be provided with a storage tank when connected directly to the source of water. The inlet of the cartridge is preferably provided with a valve for maintaining the air column in the compartment when the cartridge of the present invention is integrated into a storage type water purification device or when the cartridge is provided with a downstream storage tank. The valve preferably closes the flow of water through the inlet when the storage tank downstream the cartridge reaches an optimum level, the closing of the valve is preferably actuated by the level of water in the storage tank.

It is also preferred to use the cartridge of the present invention in a gravity fed water purification device having a filtration unit for separating particulate and soluble material from the input water and then passing it through the cartridge where the benefit agent is preferably a biocide tablet and then through a retention chamber for retaining the biocide treated water for a predetermined period of time before exiting the water purification system through a scavenger means adapted to separate the dispensed biocide from the exit water. If the benefit agent is a dietary supplement tablet it is also preferable to connect the inlet of the cartridge, to the faucet that dispenses purified water and the treated water exiting the outlet of the cartridge will have known amounts of dietary supplements dissolved in purified water.

Brief description of the Drawings

Figure 1 is a sectional view of one embodiment of the cartridge in accordance with the invention. Figure 2 is a sectional view of a second embodiment of the cartridge in accordance with the invention.

Detailed Description of the Drawings Figure 1 is a sectional view of an embodiment of the cartridge. The cartridge has an inlet (1 ) which is in fluid communication with a vertical passage (3). The inlet of the cartridge is inline with the vertical passage. The vertical passage extends upwardly towards a benefit agent tablet leading the water entering through the inlet to the exposed face of a benefit agent tablet (7) such that the vertical passage is spatially separated from the tablet. The benefit agent tablet (7) is housed in a housing (6) of an air tight lid (5). The air tight lid closes the mouth of a compartment (4) that is coaxially positioned to the vertical passage (3) and is in fluid communication with the vertical passage (3) and an outlet (2) of the cartridge. The tablet is encased in a polymeric sleeve (8) which surrounds the tablet leaving a face of the tablet exposed to the vertical passage and also holds the tablet at the highest position in the lid (5) in an inverted or hanging position. The air tight lid (5) keeps the compartment air tight because it is preferable that in operation the water in the compartment is separated from the exposed face of the benefit agent tablet (7) by an air column so that the water in the compartment does not submerge the benefit agent tablet but preferably allows only a jet of water from the vertical passage to contact the exposed face of the tablet to allow the water to carry with it the dissolved benefit agent which collects in the compartment from where it can be dispensed through the outlet (2).

The inlet (1 ) of the cartridge is connectable to a faucet of a source of water and when the faucet is opened the water enters the cartridge through the inlet and rises upwardly in the vertical passage (3) towards the benefit agent tablet and a jet of water touches the exposed face of the benefit agent tablet (7) and dissolves a portion of the tablet (7) and the water carrying the dissolved benefit agent flows into the compartment (4) and leaves the compartment from the outlet (2).

Figure 2 is a sectional view of a second embodiment of the cartridge. The cartridge has an inlet (1 ) which is in fluid communication with a vertical passage (3). The inlet of the cartridge is inline with the vertical passage. The vertical passage extends upwardly towards a benefit agent tablet (7) leading the water entering through the inlet to the exposed face of the benefit agent tablet (7) such that the vertical passage is spatially separated from the tablet. The benefit agent tablet (7) is housed in a housing (6) of an air tight lid (5). The air tight lid closes the mouth of a compartment (4) that is coaxially positioned to the vertical passage (3) and is in fluid communication with the vertical passage (3) and an outlet (2) of the cartridge. The benefit agent tablet rests on a base plate (9) situated at the opening of the housing (6). A movable support (10) is placed on top of the uppermost benefit agent tablet (7) in the housing. A bellow (1 1 ) is positioned between the fixed top end of the housing (6) and the uppermost benefit agent tablet (7). The movable support resting on top of the benefit agent tablet descends by the force of gravity as the benefit agent tablet is consumed. The bellow (1 1 ) provides additional force to ensure that the movable support descends as the tablets are consumed by urging against the movable support plate. The movable support has a plug means (12) for plugging the end of the vertical passage spatially separated from the tablet and stopping the water flow into the compartment when the benefit agent tablet is completely consumed. The air tight lid (5) keeps the

compartment air tight because it is preferable that in operation the water in the compartment is separated from the exposed face of the benefit agent tablet (7) by air so that the water in the compartment does not submerge the benefit agent tablet but preferably allows only the jet of water from the vertical passage to contact the exposed face of the tablet to allow the water to carry with it the dissolved benefit agent which collects in the compartment from where it can be dispensed through the outlet (2).

Examples

Example 1 :

A cartridge as shown in Figure 1 was taken. The inlet (1 ) of the cartridge was connected to the faucet of a tank of water to provide continuous supply of water. The vertical passage (3) of the cartridge was cylindrical with a radius of 2 mm and cross sectional area of 12.56 square millimeter. A benefit agent tablet (7) made of a biocide tablet comprising bromochloro dimethyl hydantoin (obtained from Lonza Inc., USA) and trichlorocyanuric acid (obtained Occidental Chemicals Corporation, Dallas, USA) in a ratio of 70:30 was placed in the housing of the air tight lid (5). The three sides of the tablet were tightly fitted into the polymeric sleeve (8) made of silicone and placed at the highest position of the housing (6).

The water from the faucet was allowed to enter the cartridge at 20 psig and 2 psig in two separate experiments. 2000 litres of water was passed through the cartridges in both the experiments while maintaining a flow rate of about 350 ml/minute at 20psig and about 120 ml/min at 2 psig. The level of chlorine in the treated water collected from the outlet (2) of the cartridge was measured after passing every 100 litres of water and the data are presented in Table 1.

Determination of available chlorine:

Material used- a) Potassium iodide: 100gm of potassium iodide was added to a beaker

and stirred until the potassium iodide was completely dissolved in

distilled water. The solution was transferred to a 1 litre volumetric

flask and the volume was made up to 1 litre to provide a 10%

(mass/volume) aqueous solution. The solution obtained was

colourless. Acetic acid: 6% (v/v) aqueous solution of acetic acid was prepared from 60ml_ of glacial acetic acid added to a 1 litre volumetric flask and the volume was made up to 1 litre with distilled water and shaked for uniform mixing.

Sodium thiosulphate: 0.001 N standardized sodium thiosulphate (Na ₂ S ₂ 0 ₃ ).

Starch indicator solution: Slurry of 1 .Ogram starch and 5ml_ water was prepared. The slurry was dissolved in 95ml_ boiling water and cooled to prepare a 1 % (mass/volume) aqueous solution of starch indicator solution. The solution was refrigerated when not in use and used within one week from preparation.

Procedure:

25ml_ of sample water was pipette out and transferred to an iodine flask. To the flask 10ml_ of acetic acid and 5 mL of potassium iodide were added. To this solution 1 to 2 mL of starch indicator solution was added and the colour of the solution changed to black. The solution was then titrated with sodium thiosulphate (0.001 N) solution to a colourless endpoint. The titration volume was recorded and the available chlorine was estimated formula

Available chlorine (ppm) = V x N x 100 x 10000 x 35.5

1000 x volume of water sample (mL) where,

Volume (mL) of water sample = 25

Volume (mL) of sodium thiosulphate = V

Normality of sodium thiosulphate = N Table 1

The data presented in Table 1 show that the dosing of the benefit agent (chlorine) using the cartridge of the present invention is consistent over the 2000 litres of water passed through the cartridge at pressures of 2 psig and 20 psig.