AU2014100765B4 - Substrate for growing bacteria - Google Patents

Abstract

The invention discloses a substrate for growing bacteria for use in the treatment of water. The substrate is formed from a porous inorganic body that supports a nutrient source, which nutrients enhance the growth of bacteria both on the body and within pores of the body. The invention further discloses a suspension arrangement for suspending the substrate at various depths within the water.

Description

AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT (Original) APPLICATION NO: LODGED: COMPLETE SPECIFICATION LODGED: ACCEPTED: PUBLISHED: RELATED ART: NAME OF APPLICANTS: Aqua Bay Holdings Pty Ltd John Anthony Holland ACTUAL INVENTOR: John Anthony Holland ADDRESS FOR SERVICE: LORD AND COMPANY, Patent and Trade Mark Attorneys, of PO Box 530, West Perth, Western Australia, 6872, AUSTRALIA. INVENTION TITLE: SUBSTRATE FOR GROWING BACTERIA The following Statement is a full description of this invention including the best method of performing it known to me/us: TITLE SUBSTRATE FOR GROWING BACTERIA FIELD OF INVENTION [0001] The present invention relates to a substrate for growing bacteria. [0002] More particularly, the present invention relates to a substrate for growing bacteria for use in the treatment of water. BACKGROUND ART [0003] It is often found that static water, such as is found in natural pools, ponds and lakes, becomes polluted or contaminated with organic matter over time. This results in algae growth, cloudy water and increased sediment deposits. In addition aquariums, aquaculture enclosures, holding tanks and fish ponds can become polluted due to the accumulation of faeces, residues from overfeeding, decaying algae, plants or organic matter the release ammonia as they decompose or form nitrites which are toxic to fish and other forms of marine life. There are various manners for treating the contaminated water to remove the organic matter and ammonia which can include frequent water changes, recycling the water through a treatment plant having a filtration unit, the introduction of sterilising chemicals or the introduction of beneficial bacteria into the water. The use of the beneficial bacteria is preferable because it is economically more viable, requiring lower capital outlays that the installation of a treatment plant, and is also more environmentally friendly than chemical treatment. It is also largely self-regulating requiring less supervision. [0004] It is known to encourage the growth of naturally occurring beneficial bacteria within water by introducing nutrients into the water that support the development and growth of the bacteria. The nutrients are introduced in a suspended form within a liquid organic support, which then floats on the water surface. However, this does not allow the most effective treatment of the polluted water as the bacteria only grows on the surface of the liquid organic support and not within it, which limits the growth rate of the bacteria. Also, 2 due to the organic support floating on the water surface, the bacteria only grows at the water surface and then treats the water from the surface downwardly, i.e. there is no initial treatment of the water below the surface. [0005] It is an object of the invention to provide a substrate for bacteria, which will at least in part assist in overcoming these problems. SUMMARY OF INVENTION [0006] In accordance with one aspect of the present invention, there is provided a substrate for growing bacteria for use in the treatment of water, the substrate comprising: a porous inorganic body; and a nutrient source supported on and within the body; wherein the nutrient source enhances growth of bacteria on and within the body. [0007] The body may be constituted by one or more minerals selected from the group of calcium sulphate, calcium carbonate, natural or synthetic zeolite, sand, gravel, diamataceous earth and glass filter beads. [0008] The body may be in the form of granules that are contained within a porous sachet. [0009] The nutrient source may contain at least one of a carbon-, a sugar-, a phosphate-, an ammonium-, an agar-based substance and trace elements required for growth of the bacteria. [0010] In accordance with a further aspect of the present invention, there is provided a suspension arrangement for suspending the substrate as described herein within water, the suspension arrangement comprising: a buoyant member capable of floating in the water; an elongate cord extending from the buoyant member; and a porous plastic mesh structure joined to the elongate cord remote from the buoyant member; 3 wherein the mesh structure is adapted to house the substrate and to suspend the substrate at selective depths within the water. DETAILED DESCRIPTION OF THE EMBODIMENT [0011] The present invention will now be described, by way of example only, with reference to an embodiment thereof. [0012] It has been found that environmentally beneficial bacteria can be successfully cultivated in water to treat the water by introducing a suitable nutrient source into the water at any depth, on which nutrient source endogenous bacteria can grow. The nutrient source is provided on and within a solid porous inorganic body that forms a support substrate, thereby enabling the bacteria to grow both on and within the body. [0013] The body can be made from various minerals, such as calcium sulphate (otherwise known as gypsum plaster), calcium carbonate, natural or synthetic zeolite, sand, gravel, diamataceous earth or glass filter beads or any combination of these. The use of a zeolite, it itself being a microporous mineral, is advantageous because it greatly increases the internal surface area of the body and has a chemical affinity to attract ammonium providing a replaceable nutrient source for colonies of nitrifying or other beneficial bacteria. This permits the nutrient source to be spread and disperse over the greater surface area providing a larger area on which the bacteria can grow. [0014] The nutrient source for the bacteria can include, but is not limited to carbons, sugars, phosphates, ammonium, agars and other trace elements required for encouraging the growth of the bacteria. These nutrients can be dissolved or provided in a suspension within an oil that surface coats the body. In such instances it is necessary to emulsify the oil in a stable oil-in-water emulsion incorporating a surfactant to increase kinetic stability using a mechanical mixer, or blending the oil with food grade emulgents including, but not limited to lecithin or egg yolk, known to promote bacteria growth, to prevent the oil dispersing off the body to the water surface. Alternatively a water in oil emulsion may be provided incorporating stabilizing agents such as asphaltenes, resins, clays or calcium sulphate and others known to those skilled in the art. 4 [0015] The body can be provided in alternative forms. In a first form, the body is compressed or moulded by conventionally known methods into a porous block or tablet form of any shape. Alternatively, the body can be provided in a granulated powder-like form and be contained within a porous sachet, i.e. similar to a teabag. Optionally, open pore aquarium filter sponge, cotton pads, wool pads, synthetic fibres or activated carbon can be positioned in direct contact with the body and restrained thereto so that the bacteria can migrate across thereto from the body. Thereby a further enlarged surface area on which the bacteria can grow is available. [0016] In use, the body will be placed into water, such as in a pool, pond, lake, fountain, water feature, aquarium, aquaculture growing or holding tanks, or other enclosures. Although the porous body may initially contain a volume of air within its pores sufficient to cause the body to float on the water, the air will eventually become displaced by water seeping into the pores whereafter the body, having a greater density than water, will sink below the water surface. If left unsupported, the body will thus sink to the bottom of the pool, pond or lake and lie in the sludge / silt. However, the body can be supported at any desired depth within the water by attaching it directly to a buoyant float. [0017] Ideally the float will be part of a suspension arrangement wherein an elongate cord depends from the float and is attached at its distal end to a porous plastic mesh structure (preferably being similar to a commercially known type of onion bag or fish net). The porous body or sachet can then be easily replaceably housed within the mesh structure. By altering the length of the cord, the body can be suspended at selective depths within the water. This allows the bacteria to be "grown" on the surface of the water, in the sludge / silt at the bottom of the water or at any depth between these two extremes. [0018] Typically different strains of the beneficial bacteria grow at the different depths depending on the level of dissolved oxygen present in the surrounding water. Thus aerobic bacteria would tend to grow near the surface of the water or at shallow depths, whereas anaerobic bacteria would tend to grow at greater depths or within the sludge layer at the bottom due to an absence of oxygen. 5 [0019] The bacteria reduce or eradicate unwanted organic waste and lower the levels of nitrogen compounds in the water that can be toxic to fish and other marine organisms. In addition, the presence of the beneficial bacteria, apart from clearing cloudy water and reducing the sludge layer caused by decaying organic material, has been found to displace pathogenic bacteria in aquariums, fish farms, aquaculture, etc. This permits the greater effective use of artificial aquariums as larger numbers of fish can be contained therein without reducing water quality. It further increases the interval between water recycling steps, i.e. reducing the number of water changes, necessary to clear pollution caused by fish or prawn wastes. [0020] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. 6

Claims (4)

1. 2. A substrate as claimed in claim 1, in which the body is constituted by one or more minerals selected from the group of calcium sulphate, calcium carbonate, natural or synthetic zeolite, sand, gravel, clays, diamataceous earth and glass filter beads.
2. 3. A substrate as claimed in claim I or 2, in which the nutrient source contains at least one of a carbon-, a sugar-, a phosphate-, an ammonium-based substance and trace elements required tbr growth of the bacteria,
3. 4. A suspension arrangement for suspending a substrate within water, the suspension arrangement comprising: a buoyant member capable of floating in the water: an elongate cord extending from the buoyant member; a porous plastic mesh structure joined to the elongate cord remote from the buoyant member; and the substrate comprising a porous inorganic body and a nutrient source supported by the body, wherein the nutrient source enhances growth of bacteria on the body and within pores of the body wherein the mesh structure is adapted to house the substrate and to suspend the substrate at selective depths within the water,
4. 5. A suspension arrangement as claimed in claim 4, wherein the substrate is a substrate as claimed in any one of claims 1 to 3. 7