Background of the Invention [002] Use of ultraviolet (UV) radiation for disinfecting fluids such as water is well known in the art. Exposure to UV radiation alters and causes irreparable damage to cellular material (DNA) in most microorganisms and render them incapable of reproducing. As the microorganisms are not able to reproduce, they are considered inactivated and liquids containing such inactivated microorganisms may be considered disinfected. Water containing microorganisms such as bacteria, viruses, molds, and algae are commonly disinfected using UV radiation. To effectively disinfect water containing such microorganisms using UV radiation, the LJV radiation exposed to the microorganism needs to be of sufficient intensity and for a sufficient duration. Disinfection can also be achieved using either high-intensity UV radiation for a short of duration of time or low-intensity UV radiation for a proportionally longer duration of time.

[003] UV radiation is most effective for inactivation of microorganisms in the far UV region of the electromagnetic spectrum, between 230 and 290 nm which generally corresponds to the absorbance spectrum of nucleic acids. Optimum UV radiation wavelengths for inactivation of microorganisms appear to be in the range of 255 to 265 nm. Common commercial sources of LTV radiation are UV lamps such as mercury vapor lamps. These UV lamps are available in"low-pressure"and "medium pressure"configurations. The advantage of low-pressure lamps are in their near monochromatic output of UV radiation of wavelength 254nm, which is ideal for disinfection purposes. However, the output intensity of low pressure lamps are generally lower than that of medium pressure lamps. Typically single unit of medium pressure lamp is used to treat 10 to 2000 gallon per minute of fluid, depending on the type of fluid and characteristics of the fluid.

[004] There are some concerns affecting the performance of existing UV treatment systems. One such concern is the penetration of the LJV radiation in water. Any particles present in water tend to interfere with the transmission of UV radiation and effectively shield any microorganisms in the water from the UV radiation. This disadvantageously decreases the efficiency of existing UV treatment systems. This condition of having suspended particles in water is known as turbidity. In general, UV radiation is not wholly effective in disinfecting water exhibiting high turbidity even when intensity of UV radiation is increased.

[005] To overcome this concern with turbidity of water, prior art treatment systems typically employ UV irradiation in conjunction with pre-treatment systems that employ solid-liquid separation processes such as screening, filtration or centrifugal separation. These solid-liquid separation processes remove particles which would otherwise interfere with the disinfection of water when using LJV radiation. The solid-liquid separation processes usually precedes the LJV irradiation. However this inevitably increases the footprint of the whole treatment system. The footprint of a filtration based pre-treatment system can be much larger if the liquid flow rate is high. Treatment of high flow rate, highly turbid waters using UV systems therefore poses technical challenges when it comes to development of compact UV disinfection systems.

[006] Turbidity of water also affects the UV lamps directly by way of deposit formation on the UV lamps. The UV lamps used for disinfection of water are typically sheathed in quartz sleeves and placed directly in the water stream. The LTV lamps may be configured in symmetrical arrays and in a variety of orientations to optimize exposure of UV radiation to the water.

[007] Regular maintenance of the quartz sleeves of the LJV lamps allow for consistent and efficient transmission of UV radiation to the water. This is important for water exhibiting high turbidity and high iron or manganese content.

An example is highly turbid sea water. When treating highly turbid sea water, fouling of the quartz sleeves of the LJV lamps occurs regularly from the formation of deposits on the quartz sleeves of the UV lamps. With time, the efficiency of the UV lamps can be severely affected when more deposits are formed on the quartz sleeves effectively shielding the water from the UV radiation, thus necessitating lamp cleaning. However, such maintenance often requires the shutting down of the entire system while the quartz sleeves are being cleaned. This is inefficient and adds to the total cost incurred from the shutdown.

[008] Existing W treatment systems typically incorporate automatic or continuous-operating cleaning devices as an integral part of the W system to overcome this problem. Other UV treatment systems also employ W radiation in combination with carbon filtration, reverse osmosis and other chemicals to reduce fouling of the quartz sleeves of the UV lamps.

[009] It can thus be seen that the treatment of highly turbid water poses some serious concerns with existing water treatment systems utilizing UV radiation. Thus, there remains a need for a UV treatment system having a compact footprint for treating highly turbid liquids having reduced pre-treatment processes, reduced maintenance time and cost,.

Summary of the Invention [0010] The present invention seeks to provide a system and method for disinfection of turbid fluids by electromagnetic radiation particularly using ultra violet radiation while at the same time undergoing separation of particles from the fluid [0011] Accordingly, in one aspect, the present invention provides, an apparatus for treating a turbid fluid, comprising: a hydrocyclone for separating the turbid fluid into a substantially liquid portion and a substantially solid portion; and a UV radiator for irradiating the turbid fluid with LTV radiation; wherein the W radiator irradiates the turbid fluid while the turbid fluid is being separated into the substantially liquid portion and the substantially solid portion.

[0012] In another aspect, the present invention provides, an apparatus for treating a turbid fluid, comprising: a separator for separating the turbid fluid into a substantially liquid portion and a substantially solid portion; and a disinfecting radiator for providing a source of disinfecting radiation; wherein the disinfecting radiator irradiates the turbid fluid while the turbid fluid is being separated into the substantially liquid portion and the substantially solid portion [0013] In a further aspect, the present invention provides, a method for treating a turbid fluid, comprising the steps: introducing the turbid fluid into a hydrocyclone forming a first liquid vortex; irradiating the first liquid vortex with ultra-violet radiation while separating the first liquid vortex into a substantially liquid portion and a substantially solid portion; discharging the substantially solid portion out of the hydrocyclone; forming a second liquid vortex from the substantially liquid portion; irradiating the second liquid vortex with ultra-violet radiation; and discharging the second liquid vortex out of the hydrocyclone.

Brief Description of the Drawings l0014] A preferred embodiment of the present invention will now be more fully described, with reference to the drawings of which: l0015] FIG. 1 illustrates an apparatus in accordance with the present invention.

[0016] FIG. 2 illustrates a hydrocyclone in accordance with FIG. 1 ; [0017] FIG. 3 illustrates a flowchart of an aspect of the method in accordance with the present invention; Detailed description of the Drawings l0018] Referring to Fig. 1, an apparatus 5 in accordance with the present invention comprising a hydrocyclone 10 and a disinfecting radiator which in the present embodiment is a helical ultra-violet lamp 22. The hydrocyclone 10 further comprises a main body 12, an inlet 14 for receiving a turbid fluid, an underflow outlet 16 for discharging a substantially solid portion of the turbid fluid, a vortex finder 18, and an overflow outlet 20 for discharging a substantially liquid portion of the turbid fluid. The helical ultra-violet (UV) lamp 22 comprises a plurality of loops and is disposed inside the main body 12 of the hydrocyclone 10.

[0019] Hydrocyclones 10 are suitable for separation of solids from liquids of turbid fluids in continuous systems. The concept behind the workings of the hydrocyclone 10 is the use of centrifugal force and specific gravity to separate any particles and solids from a turbid fluid. Referring to Fig. l and Fig. 2, the inlet 14 introduces a turbid fluid into the main body 12 of the hydrocyclone 10 causing the turbid fluid to flow in a swirling manner towards the outlet 16 of the hydrocyclone 12. This swirling flow of the turbid fluid within the main body 12 results in the forming of a first fluid vortex 26. Centrifugal force generated by the swirling flow of the first fluid vortex 26 causes the substantially solid portion of the turbid fluid to separate from the substantially liquid portion of the turbid fluid.

[0020] The substantially solid portion of the turbid fluid comprises of any particles which move outwards from a central axis of the main body 12 and flow with the first fluid vortex 26 towards the outlet 16 of the hydrocyclone 10. As the particles move away from the central axis of the main body 12, the substantially liquid portion of the turbid liquid moves towards the central axis of the main body 12. The particles are discharged from the main body 12 through the underflow outlet 16 together with the substantially solid portion of the turbid fluid.

[0021] The substantially liquid portion of the turbid fluid is forced to reverse its direction of flow and instead of flowing towards the underflow outlet 16, now flows towards the vortex finder 18. This reversal of flow is caused by a combination of factors such as the blockage of the underflow outlet 16, the movement of the substantially liquid portion of the turbid fluid towards the central axis and the presence of the vortex finder 18. This reversal of flow further results in the forming of a second liquid vortex 28 from the substantially liquid portion of the turbid fluid. The second liquid vortex 28 flows within the first liquid vortex 26 towards the vortex finder 18 and is discharged through the overflow outlet 20. l0022] The present invention incorporates a disinfecting radiator such as the helical UV lamp 22 into the hydrocyclone 12. Referring to Fig. 1, the helical UV lamp 22 is mounted within the main body 12 of the hydrocyclone 10 and in the present embodiment is shaped like a spiral. The plurality of loops are decreasing in their respective diameters, such that a first loop of the helical UV lamp 22 is broader than a last loop of the helical UV lamp 22. The helical LTV lamp 22 is mounted such that the first loop of the helical UV lamp is nearer the vortex finder 18 while the last loop of the helical UV lamp is nearer the underflow outlet 16. The shape of the helical UV lamp is designed and calculated so as to not interfere with the flow of the first liquid vortex within the main body 12 of the hydrocyclone 10. In fact, the addition of the helical UV lamp 22 in the main body 12 of the hydrocyclone 10 advantageously aids in the smooth formation of the first liquid vortex 26 by reducing the turbulence of the turbid fluid as it enters the main body 12. The shape of the helical UV lamp 22 is also designed and calculated so as not to interfere with the flow of the second liquid vortex 28. In fact, the addition of the helical UV lamp 22 in the main body 12 of the hydrocyclone 10 advantageously aids in the formation of the second liquid vortex 26 as the helical UV lamp 22 guides the substantially liquid portion of the turbid fluid into the vortex finder 18. The helical UV lamp 22 thus advantageously aids in the formation of the first liquid vortex 26 and the second liquid vortex 28 which ultimately enhances the separation performance of the hydrocyclone 10. l0023] In addition to providing better separation performance, the helical UV lamp 22 further irradiates the turbid liquid in the main body 12 of the hydrocyclone 10. The method of the present invention advantageously comprises the steps of performing solid-liquid separation of the turbid fluid into a substantially liquid portion and a substantially solid portion while at the same time disinfecting the substantially liquid portion by UV irradiation.

[0024] Referring to Fig. 3, an aspect of the method in accordance with the present invention starts with the step of : introducing 110 the turbid fluid into the hydrocyclone 10 forming the first liquid vortex 26. Next, the first liquid vortex 26 is irradiated 115 with ultra violet radiation while undergoing solid-liquid separation resulting in the substantially solid portion and the substantially liquid portion of the turbid liquid. The substantially solid portion of the turbid fluid is then discharged 120 from the hydrocyclone 12 via the underflow outlet 18. Next, the second liquid vortex 28 is formed 125 from the substantially liquid portion of the turbid fluid. The second liquid vortex 28 is guided by the helical UV lamp 22 and the vortex finder 18 to be irradiated 130 by UV radiation from the helical W lamp.

The second liquid vortex 28 which is formed from the substantially liquid portion of the first liquid vortex 26 is then discharged 135 from the hydrocyclone via the overflow outlet 20. The second liquid vortex 28 comprises primarily of the substantially liquid portion of the turbid fluid and upon being discharged from the overflow outlet 20 can be considered to be treated liquid or disinfected liquid.

[0025] The present invention advantageously reduces the overall size and footprint of a turbid fluid treatment apparatus by combining apparatuses for separation with that of disinfection. Further, there is an increase in exposure of the turbid fluid to the UV radiation as the turbid fluid is exposed to the UV radiation as the first liquid vortex 26 and then again as the second liquid vortex 28.

[0026] The present invention also advantageously allows the helical UV lamp 22 to be self cleaning. Due to the continuous flow of the turbid fluid within the hydrocyclone 12, there is little opportunity for any particles to settle and deposit on to any surfaces of the helical UV lamp 22. [0027] To further aid in the efficiency of the helical UV lamp 22, the helical UV lamp 22 has a Teflon sleeve or a quartz sleeve coated with Teflon AF fluropolymer. The sleeve would be of substantially similar shape as the helical UV lamp 22 with similar plurality of loops. The advantages of using such sleeves is in the inherent characteristics of the Teflon material. Teflon possesses very high optical clarity and allows optimal UV transmission (about 95%), which would greatly enhance the efficiency of the helical W lamp 22. Furthermore, Teflon has the lowest coefficient of friction of any solid material which results in a non-stick characteristic that advantageously allows the helical UV lamp 22 to be easily maintained and cleaned. Teflon is also resistant to chemical reactions and is thus advantageously compatible with aggressive oxidizing agents and additive chemicals used in the treatment and disinfection of fluids.

[0028] Particularly, such oxidizing and additive chemicals may be added into the turbid fluid prior to the turbid fluid being disinfected in the apparatus 5 of the present invention. This can increase the efficiency of the apparatus 5 of the present invention by reducing the number of organisms present in the turbid fluid when being irradiated by the disinfecting radiator such as the helical W lamp 22.

Other oxidizing and additive chemicals may also be added to the substantially solid portion of the turbid fluid after it is discharged from the apparatus 5. This can further disinfect the substantially solid portion of the turbid fluid by inactivating and destroying any organisms not inactivated by exposure to UV radiation in the apparatus 5. This will advantageously aid in the re-use of the substantially solid portion of the turbid fluid, that can be mixed back with the substantially liquid portion of the fluid after disinfection. As the substantially solid portion of the fluid forms only a small fraction of the total fluid volume, the chemical usage to disinfect this portion will be substantially lower.

[0029] It will be appreciated that various modifications and improvements can be made by a person skilled in the art without departing from the scope of the present invention. The description refers to a single hydrocyclone, however, it would also be entirely possible to arrange a plurality of hydrocyclones in an array where at least one or more or all of the hydrocyclones are equipped with a disinfecting radiator such as the helical UV lamp 22. Further, the description of the helical UV lamp 22 is that of a spiral shape. It would be entirely possible for the helical UV lamp to be cylindrically shaped and still not depart from the scope of the invention.