GB2439047A

GB2439047A - Granular deodorant for refuse and compost composition comprising humic substance, such as peat, on structural carrier

Info

Publication number: GB2439047A
Application number: GB0611735A
Authority: GB
Inventors: Maria Prunty; David Seaby
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-06-14
Filing date: 2006-06-14
Publication date: 2007-12-19
Also published as: GB0611735D0

Abstract

A granular deodorant, for use in refuse bins or for scattering on refuse, comprises a humic substance on a structural carrier. The humic substance may be humus, humin, humic acid, fulvic acid or (preferably) peat. The structural carrier may be natural or synthetic, and is preferably fibrous. It includes cellulose, fibrous waste from anaerobic digestion, pulverised bark, chopped coir, chopped wood waste, chopped rock wool, pumice (especially expanded pumice) or (most preferably) peat of a different type to that used as the humic substance, such as a mixture of semidried moss peat (mainly comprising partially decomposed sphagnum moss) and moist, friable, strongly degraded, deep-dug wood peat (mainly comprising natural humic substances). The deodorant composition may optionally contain a natural or synthetic deodorant, limestone, sugar-beet-lime, plant nutrients (such that the deodorant may also serve as a compost), a scent (e.g. coffee, vanilla or citrus), a hygroscopic material (e.g. ground seaweed) or odour-eating organisms. The deodorant composition absorbs odours and also refuse bin liquor.

Description

A GRANULAR DEODORANT I COMPOST

This invention relates to a granular, peat-based, deodorant for scattering into or onto refuse, for example in disposal bins. In such bins the aim is to absorb bad odours and also the foul liquors that tend to collect at the bottom of such bins. Another possible use is on landfill sites, for example in a situation where bad odours have spiralled out of control and are resulting in serious complaints. Being peat-based, a minor dual-purpose use for this material is as a re potting compost for houseplants.

Bins for waste disposal, particularly if made of plastic (such as the household wheeled bin) are prone to smell very unpleasant. Annually, councils receive a huge number of complaints about odours from such bins. Typically, these containers have a large internal surface area of plastic. This soon becomes scored, thus retaining dirt. Furthermore, odours appear to attach to such plastic surfaces.

As an example, a woman buys a fresh fish and the offal from it is placed in a plastic bag in a bin. Even if this bin is emptied after only a few days, that offal will still have largely liquefied due to bacterial action. Some fishy liquor may drip out of the bag and seep to the bottom of the bin. Or it may be spilled out of the bag during the tipping of the bin. Unless that bin is deodorised, it is likely stink for months.

Such a smell may have has several levels of nuisance value. The bin sits out, possibly in the sun and may be passed by tradesmen, neighbours and guests. It is also likely to attract flies and vermin.

In a commercial example, a hotel is busy during the summer. This could be a long hot continental' summer. The hotel has several bins; all of them tend to smell because of the large amount of fish and meat waste that is disposed of in them. An unpleasant smell may negatively influence the hotel's popularity, or it may lead to serious complaints; the warmer the conditions, the worse the problem. This is due to bacterial multiplication being more rapid in warmer weather. The kitchen-staff is greeted by a stink every time one of them goes to open a bin.

Putting bleach in a bin has little effect on the level of smell, and such a measure is to be avoided on health and safety grounds. Spraying air freshener into a bin is not usually effective because the source of smell is too large to be easily neutralised. There are however tradesmen who do provide the service of power washing bins on a contract basis. Bins are also usually made with tight fitting lids in order to help retain smell.

But this fails when the bin is opened, or if the lid is faulty.

Due to the modern emphasis on recycling, there are now bins specifically used for collecting organic domestic plus garden waste (provided it is all suitable for making into compost). But, having several bins, each of which is used for a different type of waste, has resulted in longer delays between emptying. A weekly cycle has possibly become a two-week cycle. Furthermore, should a collection be missed, then, a bin may not be emptied for a month, or even more. This has greatly increased the likelihood that bad smells will develop. Thus, the use of a granular deodorant based on peat, as described in the present invention below, is particularly apt where the bin's contents are destined to become compost anyway. The granular bin deodorant described here has been formulated to be suitable to have an alternative use as a re-potting compost, for example suitable for houseplants.

It has been shown by survey and by experiment that the most unpleasant bin smells are caused by bacterial action degrading meat, or in particular, fish or urine. Many putrefaction bacteria have strong unpleasant odours. (For some people even the smell of fresh fish offal is offensive). When disposable nappies (diapers) containing urine and faeces are placed in bins the urea in the urine is very quickly broken down to release ammonia -a gas that has a very pungent odour.

It is already widely known that many strong odours bond strongly with humic substances. Then such odour molecules are no longer volatile and they cease to be a problem. For example ammonia forms ammonium hydroxide in the presence of moisture, this strong alkali bonds firmly with fulvic and humic acids. Humic substances include: humus, fulvic acid, humic acid, and humin, the latter is a major component of lignin. These molecules are sometimes known as polyphenolics or polyphenolic polymers. They are large complex molecules that have many bonding sites for both positively and negatively charged molecules (such as those causing odours) to attach to. One reason why the product', for which a patent is now sought, is effective, is because it is a rich source of such humic substances. The product' described in this invention largely comprises a damp, humin rich peat that has been spread out' over a structural material that is good at absorbing moisture, but besides the fibrous structure, may include fulvic and humic acid as well.

Peat is a common source of humic substances and occurs in a wide variety of types. Some peat is rich in humic acid, other types may be rich in humin. Moss peat' is largely the semi-decomposed remains of sphagnum moss (a plant that thrives in the wettest, most acidic, base deficient (oligotrophic), mineral-poor sites). Un decomposed Sphagnum moss is well known for its water absorbing properties. It has even been used as an absorbent wound dressing, and in past centuries it has been incorporated in nappies (diapers). Various types of peat, most often moss peat' (which is relatively young in age) have been used in filters, for both liquid and gas, their aim being to remove toxic material and in the case of air filters, to also remove bad odours. This process is sometimes known as biofiltratjon.

Biofiltration is said to largely rely on naturally occurring organisms that break down the odour molecules. Sometimes the stems of heather plants have been used in such filters, to aid their structure. But such filters do disintegrate over a period of years and have to be replaced. A new generation of manmade filters are replacing the older, peat and heather-stem filters. These new filters also retain life', but such organisms may have been selected and are then claimed to be more efficient at eating' or breaking down odours.

The patent application, applied for here, does not claim involvement of any new or selected organism but neither does it rule out incorporating one or more of them. It is not a filter with a rigid structure, through which water or gas is forced to flow, It is instead a granular product', made from a variety of peat types and/or other materials, each selected for its ability to neutralise' as wide a range of alkaline and/or acidic odours as possible.

The reason why, in this present patent application, it is deemed beneficial to deliberately combine at least two types of peat, is as follows: When semi-dry moss peat is light and springy, due to its content of un-decomposed fibrous material. It thus has an abundance of structure', although it is relatively low in polyphenolics when compared with older peat that is more decomposed. However, those polyphenolics that it does have are relatively strongly acidic. Thus the peat layers below moss peat are made up of progressively more and more degraded sphagnum (along with other degraded oligotrophic plants), and these lower layers are much richer in polyphenolics. When extracted from the bog, such peat usually has a very high moisture content (usually well over 90%). It is also sticky and it may be somewhat stringy due to the penetration of vegetation roots from above.

Furthermore, is not at all friable in structure. Such decomposed peat is thus not suitable for making a fine, granular product', one with a large surface area for absorbing odours.

On the other hand, there is a type of peat that comprises the remains of water plants, floating grasses, buirushes and also with a large proportion of remains of woody material (for example birch leaves twigs and stems). Such peat was once rich in lignin (although this has now broken down) and is very friable. It is sometimes found as a compressed layer below a raised sphagnum bog. In such a situation it may he several thousand years old. It is very degraded and is very rich in humic substances such as humin. Even when freshly extracted it is firm and solid to the touch, but it is nevertheless easily crumbled.

Typically, it has a water content of around 88% and a bulk density of approximately 1.04 (grams per cubic centimetre). But on air-drying, (unlike moss peat) it shrinks to a hard solid with approximately a quarter or less of its original volume. Furthermore, this shrinkage is largely irreversible. Thus on its own, it would not be suitable for making a granular deodorant from. It will be called here wood' peat (although this may not have been its principle constituent).

If this wood peat is mixed with moss peat (in the particular way described in the invention below) they can be made to combine'. The combination' peat then has properties that make it particularly suitable for the purposes outlined in this patent application. The necessary properties are as follows: close to having a naturally' suitable moisture content (without the need for much deliberate wetting or drying); a reasonably firm structure (one that does not appreciably shrink after it has lost some of its original water content); pleasant to handle; producing a minimal amount of soiling of the hands and containing both strongly acidic and weakly acidic humus.

However, in this invention it is envisaged that moss peat is not necessarily the sole carrier that is used to support the friable, humin rich, wood' peat as described above. Possible alternative carriers include: waste plant residues such as chopped coir and/or pulverised bark; expanded, graded, pumice; fibrous waste from an anaerobic digester; or even a renewable man made alternative such as chopped According to the present invention there is provided a granular deodorant for rubbish odours as claimed in the claims. It is designed to help deodorise domestic and commercial bins and may in some cases also have a secondary use as a houseplant potting compost. A further use is envisaged where a deodorant is urgently required for a rubbish tip. A specific embodiment of the invention will now be described by way of example. This and other embodiments of this invention may hereafter be called the product'.

In one particular product' two parts semi air-dried moss peat, as described above, having a moisture content of approximately 60% is violently mixed with 3 parts raw wood' peat, as describes above, this latter now having a moisture content of approximately 83% (having been somewhat dried after extraction, by storage in windrows). The two types of peat are loaded into the hopper of a machine that is dedicated to the mixing and breaking of peat.

A slow moving belt conveys the peat into the path of metal flails that are attached to a drum rotating at high speed. These flails fragment the moist wood' peat and at the same time force much of it to bind with the much lighter, drier moss peat. The resultant particles have the combined properties of both peat types.

For example, the combination's moisture content is now approximately 74%. This is still adequate moisture to absorb volatiles such as ammonia. But the particles are nevertheless dry' enough to soak up almost their own volume of bin liquor'. Shrinkage on partially air-drying of this mixture' is minimal, particularly if it is contrasted with that of the original wood' peat. Low shrinkage is important in the secondary, dual-purpose use of the product' as a re potting-compost.

The product' no longer comprises a high proportion of dusty particles (as would be the case if the granular deodorant had been merely semi-dry, milled, moss peat). The texture in the hand also becomes more pleasant, than with either of the ingredients alone. It is now soft, but it is not sticky. It is friable, granular, slightly moist, and is virtually non-soiling. It has sufficient weight to be easily scattered, but without fear that it will be blown away. However, it is not overly heavy to transport.

It looks attractive, particularly if the particles are graded in size to be say 3-6mm in diameter, for example.

This niix may be further mixed with finely ground magnesium limestone and/or sugar-beet-lime at a rate of say 5 grams per litre, for example. This brings the pH up to between 5 and 6. While mixing in this lime' it may be used as a vehicle' to aid the even mixing-in of a complete blend of plant nutrient minerals, at a suitable rate of for example (0.5 -O.75g per litre). The aim of these is to help sustain plant growth for several months. Furthermore, sugar-beet-lime is itself a rich source of minerals, particularly of trace elements. However, plant nutrients are not a vital ingredient of the product' for its main use.

Thus one reason for adding the limestone and the sugar-beet-lime is for the product's secondary use as a general-purpose compost, particularly for re potting houseplants. But a second and more important reason is that moist limestone and/or sugar-beet-lime provide alkaline sites to help neutralise acidic odours, such as H7S.

A further reason for adding plant nutrients, not only make the domestic product' dual purpose, it then becomes more attractive to the housewife. She may not wish to be seen buying something for neutralising refuse-bin odour. Thus, on one side of the sales package its potting compost use may he advertised, while on the other side are its use in helping to neutralise bin odours.

To aid scatter-ability spread-ability and its mopping up potential for bin liquor' the product' is screened, thus a majority of particles are graded' to lie in the range 3-6mm, for example.

In a specific example of the product' in use, the bottom of a bin is covered with a layer of deodorant granules to a depth of several millimetres. This provides a good surface area for absorbing smells, also a sufficient volume of deodorant is used to soak up traces of bin liquor.

It is found by experiment, that if the sides and base of the bin are wet, while making the first scattering, then a large active odour-absorbing layer is created. This can remain in place for a relatively long period of time, that helps to conserve the product'. It is also possible to scatter the product' into a partially filled bin. In this case the particles create an even larger odour absorbing layer'. Some particles will also fall to the bottom of the bin, aiding the uptake of liquor.

It is envisaged that a major use could be in domestic wheeled bins.

However, a bin may be of any size. A further extension of such a use is found where a rubbish dump has areas producing unacceptable amounts of odour. These may be dusted with product' granules to help absorb such odours.

If further experimentation discovers certain bin odour/s that is/are not well absorbed by natural humic substances, but is/are absorbed by some other natural deodorant, such as fullers earth, or even by a chemical' deodorant, then the product' may have one or other of these latter deodorants added. Similarly, if it was found that odour eating' properties were to be enhanced by pasteurisation, followed by inoculation with harmless (but more efficient, selected odour eating organisms) then this may also be carried out.

Furthermore, if a scented material, such as coffee, citrus oil, lavender or vanilla, for example, were found to give the product' a pleasant positive scent (without this scent being itself absorbed) then this might be added to the product' as a trace of the pure compound. Or the scent might coi-ne from a vastly more substantial volume of milled waste from such a scented material's production process. For example coffee grounds might be added.

For ease of carrying, yet providing sufficient quantity for months of domestic bin use, the product' may for example, be packaged in five to twenty litre quantities, this amount being also sufficient to re-pot at least several average-size houseplants.

The package may be a re-seal-able plastic bag, as an aid to maintaining the product's' original moisture content. As another aid to maintaining moisture the product' may have a water attracting (hygroscopic) material added, such as, for example, powdered seaweed.

Claims

CLAIMS

1. A deodorising granular mixture, largely comprising humic substances on a fibrous structural carrier, for the purpose of deodorising refuse/rubbish, either in refuse bins or by scattering on said refuse/rubbish.

2. A deodorising granular mixture largely comprising natural humic substances on a fibrous structural carrier, such as cellulose, or fibrous waste from anaerobic digestion, for the purpose of deodorising refuse/rubbish, either in refuse bins or by scattering on said refuse/rubbish.

3. A deodorising granular mixture largely comprising natural humic substances on a natural structural carrier such as pulverised bark, for the purpose of deodorising refuse/rubbish, either in refuse bins or by scattering on said refuse/rubbish.

4. A deodorising granular mixture largely comprising natural humic substances on a natural structural carrier such as pumice or expanded pumice, for the purpose of deodorising refuse/rubbish, either in refuse bins or by scattering on said refuse/rubbish.

5. A deodorising granular mixture largely comprising natural humic substances on a synthetic structural carrier, for the purpose of deodorising refuse/rubbish, either in refuse bins or by scattering on said refuse/rubbish.

6. A deodorising granular mixture largely comprising natural humic substances, mainly based on a mixture of different types of peat, for the purpose of deodorising refuse/rubbish, either in refuse bins or by scattering on said refuse/rubbish.

7. A deodorising granular mixture as claimed in claims 1-6 mainly based on a peat mixture for the purpose of deodorising commercial refuse bins or skips after the mixture is scattered into them.

CLAIMS

8. A deodorising granular, mixture as claimed in any combination of clains 1 -7, in which the particle size is mainly in the range (3-6mm) 9. A deodorising granular mixture, as in any combination of claims 4-8 where the mix is of milled, semi dry moss peat and raw, friable, deep-dug wood' peat, the latter being very degraded, friable and with a high natural content of humic substances.

10. A deodorising granular mixture as in any combination of claims 1-9 also containing a natural or synthetic deodorant.

11. A deodorising granular mixture as in any combination of claims I -also containing ground limestone/magnesium limestone with or without sugar-beet-lime.

12. A deodorising granular mixture as in any combination of claims 1-11 in which the sugar-beet-lime has been deliberately formed into lumps so as not to raise the average pH too high to absorb alkaline odours.

13. A deodorising granular mixture as in any combination of claims 1-12 that also contains a balance of plant nutrients to give the product' dual purpose use, as a compost suitable for sustaining plant growth.

14. A deodorising granular mixture as claimed in any combination of claims I -1 3 also laden with an attractive scent such as coffee, citrus or vanilla for example, coming from a concentrate.

1 5. A deodorising granular mixture as claimed in any combination of claims 1 -1 3 also laden with an attractive scent such as coffee, or vanilla for example coming from the waste product of such production.

16. A deodorising granular mixture as claimed in any combination of claims I -1 5, also containing a hydroscopic material, for example ground seaweed. I,

CLAIMS

17. A deodorising granular mixture as claimed in any combination of claims 1-I 5 in which the mixture has been pasteurised and re-inoculated with harmless, odour eating' organisms.

18. A deodorising granular mixture as claimed in any combination of claims 1-16 in which the product' is sold in small, easily carried packets, with instructions for both of its dual purpose uses.

1 9. A deodorising granular mixture as claimed in claims I -1 7 in which the containing packet is a re-seal-able plastic bag with a a strip built in, or in which the packet is longer than its minimal length, in order to provide a fold over that can be closed with, for example, a spring clip.