WO2008011676A1

WO2008011676A1 - Fluid treatment apparatus and modular tank therefor

Info

Publication number: WO2008011676A1
Application number: PCT/AU2007/001038
Authority: WO
Inventors: Michael Andrew Atkinson; Christopher Paul Schuck
Original assignee: Aquaviro Holdings Pty Limited
Priority date: 2006-07-27
Filing date: 2007-07-27
Publication date: 2008-01-31
Also published as: AU2007278760A1; AU2007278760B2

Abstract

Fluid treatment apparatus (91) particularly for marine applications comprising a modular tank having a plurality of hollow tank modules (92, 93, 94), each defining a fluid treatment chamber of a fluid treatment unit (95, 96,97) respectively. Respective fluid treatment means (117, 122, 123, 144, 147) are associated with the modular tank modules for treatment of fluid in each module and pump modules (98,98', 98') are provided in the tank modules (92,93,94) for pumping fluid through through the fluid treatment means (117, 122, 123, 144, 147).

Description

FLUID TREATMENT APPARATUS AND

MODULAR TANK THEREFOR Technical Field

This invention relates to a fluid treatment apparatus and modular tank therefor and in particular to a fluid treatment apparatus and modular tank for use in treating wastewater such as sewage. The fluid treatment apparatus and modular tank have particular application for treating sewage in marine applications but may be applied to other applications. Background Art To minimize the impact of untreated sewage on the marine environment, it is now a legislated requirement that marine vessels be fitted with holding tanks for sewage or alternatively a sewage treatment unit for onboard treatment of wastes. Often, holding tanks are required to be specifically designed to suit particular vessels and this generally proves to be an expensive proposition. To overcome this problem, bladder-type holding tanks are used however these types of tank are not suitable to use in many situations.

A number of different systems are available for onboard treatment of waste. Many of the systems use a simple electrode unit for treatment of sewage wastes however often these systems are ineffective. The result is that supposedly treated sewage which is able to be discharged has nol been sufficiently treated. As a consequence, the marine environment can be damaged. The tanks used in these systems are usually required to be multi-compartmented tanks however the tanks which are currently available either do not fulfill this requirement or are expensive. Summary of the Invention

The present invention aims to provide a fluid treatment apparatus and a modular tank for use in the fluid treatment apparatus. The present invention is particularly suited to the treatment of sewage in a marine environment but may be used in other applications. The present invention in a Anther aspect aims to provide a method for discharging treated fluids and in particular to a method of discharging treated fluids in the above treatment apparatus in a marine environment. Other objects and advantages of the invention will become apparent from the following description.

The present invention thus provides in one preferred aspect, fluid treatment apparatus comprising a modular tank having a plurality of hollow tank modules, each defining a fluid treatment chamber of a fluid treatment unit, and respective fluid treatment means associated with respective modules of said modular tank for treatment of fluid in each module, each said fluid treatment means being adapted to be mounted to or adjacent a said tank module.

In one form, the fluid treatment means may be mounted to a side or top of a tank module. In this form, a pump module may be associated with each tank module for pumping fluid therefrom or for pumping fluid through the fluid treatment means. Preferably the tank modules have an upper port suitably a circular port for receiving a pump module therein. A pump module suitably includes an upper support member suitably a planar member and a lower support member suitably a generally planar member suspended from the upper member. The lower member which is smaller than the port such that it may be inserted into the port so as to be capable of being submerged in fluid in the tank module and with upper member secured detachable to the upper side of the tank module. Preferably the lower member supports the one or more pumps. The upper member may also include one or more outlet connectors connected to the one or more pumps respectively, Preferably a hollow lubular member connects and extends between the upper and lower members. Suitably the hollow tubular member communicates at its lower end with the interior of the tank module and pressure sensing means are provided at the upper end of the tubular member to sense pressure increase in the tubular member consequent upon the level of fluid in the tank module and thus hollow tubular member rising.

The fluid treatment means supported by a tank module may comprise ozone treatment means for introducing ozone into fluid in the tank. A pump of a pump module may circulate fluid from the tank module through the ozone treatment means. The ozone treatment means may comprise a venturi connected to a source of ozone. The fluid treatment means in another form may comprise a UV treatment means for exposing fluid to be treated to UV light, the UV treatment means including one or more UV lamps. A UV treatment means may be provided in scries with an ozone treatment means. A pump of the pump module may circulate fluid from the tank module through the UV treatment means. A fluid treatment means may also include one or more solids filters through which fluid to be treated may be pumped by a pump of a pump module. A solids filter may comprise a chamber having a solids filter material therein through which fluid is pumped by the pump means. In one embodiment, a solids filter material may comprise a fabric filter in the form of a filter sock. In another embodiment, the solids filter material may comprise a filter membrane.

Preferably a fluid treatment apparatus of the above described type includes a primary, secondary and tertiary treatment units, each having a respective tank module, each provided with a pump module. A primary unit may include a macerator for breaking up solids in the tank module. The macerator may be supported on a pump module.

A secondary unit may include an ozone treatment unit and the pump module may include a first pump for circulating fluid through the ozone treatment unit A secondary unit may also include a solids filter and the pump module may include a second pump for pumping fluid through the solids filter.

A tertiary unit may include an ozonc treatment unit and a UV treatment unit and the pump module includes a first pump for circulating fluid through the ozone and UV treatment units. The tertiary unit may also include a carbon filter and the first pump may also circulate fluid through the carbon filter. The pump module of the tertiary unit may include a second pump for backwashing the solids filter of the secondary unit The pump module of the tertiary unit may also include a third pump for pumping treated fluid from the apparatus.

In another form, the fluid treatment means are in the form of fluid treatment modules which extend into a tank module for treatment of fluid in a chamber of a tank module. In this form, each fluid treatment module is a self-contained fluid treatment module.

Preferably each fluid treatment means comprises an elongated hollow body which may extend into a chamber in a hollow tank section, the elongated hollow body being detachably mounted to a tank module. The elongated hollow body houses means for treatment of fluid within the chamber of the tank section. Preferably the elongated hollow body extends from an end mount adapted to be mounted externally to the tank module such that the elongated hollow body extends into the chamber of the tank module. The end mount may comprise an end flange which may be secured to a wall of the tank module by any suitable fasteners. The tank module also has at least one opening through which the elongated hollow member may pass to extend into the

Chamber of the tank section.

Preferably communication means between the respective tank modules is provided by communication between the respective fluid treatment means externally of the modular tank system.

In one form the tank modules are aligned longitudinally and are defined by a single tank separated by one or more walls into the respective tank modules. The one or more walls may be defined by an intermediate baffle or baffles which separate the tank into adjacent tank modules.

Most preferably however the tank modules are separate but may be joined to form the modular tank. A tank module may include means at its end for securing the adjacent tank module. The securing means may comprise flanges at the end of the adjacent tank module. The flange may be defined by an end wall of a tajik section,

The flanges of adjacent tank modules may be may be juxtaposed and interconnected to join one lank module to the adjacent tank module. The flanges may be releasably interconnected such as by fasteners or the like. The flanges may be provided with corresponding openings through which the fasteners may be inserted to secure the flange to the baffle.

As an alternative, the tank module may be separate from each other and interconnection by any fluid connection means such as ducts or tubes which proved fluid communication between tank sections.

At least one access port may be provided into a compartment defined by a tank module on to provide access to the hollow interior of the tank module to enable insertion of a modular fluid treatment unit therein,

A modular fluid treatment unit may comprise one or more pumps where a compartment is required to hold liquid to be pumped.

Preferably tank modules used in the modular tanks described above may be of a hollow tubular configuration. Preferably however the tank modules are of substantially rectangular in cross section so that the upper wall thereof is substantially planar. The substantially planar upper wall most suitably contains the one or more ports into which the modular fluid treatment units may be inserted. Preferably at least the lower corners of the tank module are internally concavely curved to prevent build up of solid materials in the corners of the tank.

Preferably each tank module comprises opposite end wall member and one or more intermediate side wall members which define the top, bottom and opposite side walls of the tanks module and define with the end walls a fluid-containing chamber. Suitably the side wall member comprises a single flexible sheet like member. The opposite end walls may be provided with grooves which define the peripheral configuration of a tank module and which are adapted to receive opposite side edge portions of the side wall member. Preferably the opposite side edge portions are adhered within the grooves in opposite end wall members. Preferably the side wall member extends around the full periphery of the lank module with opposite end edges of the wall member abutting and being sealed to each other to define a closed chamber within a tank module. Preferably the opposite end edges abut each other at the top of the tank module. The modular tanks may be fabricated from plastics, glass reinforced plastics, metal or any other materials or combinations thereof.

The modular tank of the invention as described above is most suitably used in a fluid treatment process such as in a process for treating sewage. The modular tank of the invention however may be used in other applications.

When used for a fluid treatment process, the respective chambers defined in the respective tank modules of the modular tank may be used for carrying out different processes on liquid to be treated therein. A first chamber defined by a first tank module may be used for anaerobic treatment of liquid in the first chamber, A second chamber defined by a second tank module may be used for aerobic treatment of liquid within the second chamber. A third chamber defined by a third tank module may be used for sterilizing liquid within the third chamber. A fourth chamber defined by a fourth tank module may be used for holding liquid additive to be added to liquid being processed in the other chambers,

In each chamber, the fluid treatment process as described above may be effected by one or more modular fluid treatments units extending into a chamber through a port or ports therein. Thus the modular fluid treatment extending into the first chamber may comprise a housing which houses a filter through which liquid in the first chamber may be passed such as by pumping. The filter may comprise a filter clement in the housing and a pump for pumping liquid through the filter may be provided in the housing.

A second filter may be provided in a housing of a second modular fluid treatment unit to receive and filler fluid from the first fluid treatment unit. Preferably communication means such as one or more ducts communicate the first modular fluid treatment unit to the second modular fluid treatment unit, the communication means being externally of the tank sections. The second modular fluid treatment unit may include a restricted outlet leading back to the first chamber through which liquid pumped to the second filter may be circulated past the filter clement of the second filter. The circulating fluid may serve to maintain the filter element of the filter clean and further ensure circulation of fluid within the first chamber.

Means may be provided for communicating the second water treatment module with the chamber of a second tank module such that fluid filter in the second filter is supplied to the chamber of the second tank module. Such communication means may comprise a duct or ducts externally of the tank modules, The second filter suitable comprises a large particulate filter however in some embodiments this second filter is not employed and the pump in the first fluid treatment module simply pumps fluid from the first chamber to the second tank module chamber. At least a third modular fluid treatment unit may be associated with the second tank module and extend into the chamber therein. The third modular fluid treatment unit may include a filter through which liquid in the second tank module chamber may be passed such as by pumping. The filter may be provided in the housing of the further modular fluid treatment unit The filter may comprise a submerged membrane filter in the housing further modular tluid treatment unit. A pump for pumping liquid through the filter may be providing in a housing of a fourth modular fluid treatment unit extending into the second tank module chamber. The fourth modular fluid treatment unit suitably communicates with the third modular fluid treatment unit through means such as ducts or pipes externally of the tank modules whereby the pump in the fourth modular treatment unit may pump fluid through the filter in the third modular fluid treatment unit. The filter may include a restricted outlet leading back into the second tank module chamber. The restricted outlet may be associated with means to introduce external air into the liquid in the second tank module chamber. Such means may comprise a venturi through which air is drawn into the second chamber.

A third tank module may include means to sterilize liquid in the chamber of the third tank module. The sterilizing means may be provided in a housing of a fifth fluid treatment module which extends into the chamber of the third tank section. The sterilizing means may include electrodes within the housing of the fifth fluid treatment module. An outlet of the third fluid treatment module in the second chamber may be connected externally of the tank modules to the chamber of the third tank module whereby permeate fluid from the filter in the third fluid treatment module may be directed to the chamber of the third tank module.

The third tank module may also include a sixth water treatment module having a housing incorporating a pump, the housing extending into a port in the third tank module into the chamber of the third tank module. The sixth water treatment module may be connected externally to the fifth water treatment module whereby fluid may be pumped selectively through the sterilizing means. The pump in the sixth water treatment module may also be used for pumping treated fluid out of the third tank module.

The fourth tank module may define a chamber for holding a liquid additive for use in the fluid treatment process. The chamber of tbe fourth tank module may communicate with the venturi in the third fluid treatment unit to enable liquid additive to be selectively introduced through the venturi into the chamber of the second tank module.

Where required, water treatment units which house the pumps may include level sensors to control the operation of the pumps in accordance with the level of liquid sensed in the chambers of the respective tank modules. Selected water treatment units may be provided with heating means for selectively heating liquid in the chambers.

A further modular water treatment unit for use in association with a tank module may include means for exposing fluid to be treated to ozone. The present invention in further preferred aspect aims to provide a method of controlling the discharge of treated fluid from fluid treatment apparatus, in particular marine based sewage treatment apparatus, said method including the steps of monitoring the geographical location of said treatment apparatus, and preventing the discharge of treated fluid from said treatment apparatus if said apparatus is not in a location prescribed for discharge of said treated fluid.

Typically a controller is associated with the treatment apparatus for controlling discharge from the apparatus and a geographical positioning system is connected to or provided in the controller whereby the controller can determine the geographical position of the apparatus and thereby control discharge from the apparatus. Remote monitoring apparatus may be provided for remotely monitoring operation of the apparatus and the components thereof. Brief Description of the Drawings

In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein :-

Fig. 1 illustrates in end view a modular tank for use in fluid treatment apparatus according to an embodiment of the present invention; Fig. 2 is a side view of the modular tank of Fig. 1 showing one of the water treatment cartridges removed from the modular tank;

Figs. 3 and 4 illustrates the manner in which the tank sections of the modular tank are constructed;

Fig. 5 illustrates schematically typical fluid treatment apparatus according to the invention;

Fig. 6 illustrates schematically an ozone generator unit for use in a fluid treatment process according to the present invention;

Fig. 7 (a) and (b) illustrate schematically in sectional and end views a UV clarifier cartridge for use in the fluid treatment process according to the invention; Fig. 8 illustrates schematically the ozone generator unit of Fig. 6 in combination with the UV clarifier cartridge and an activated carbon filter for use in a fluid treatment process;

Fig, 9 illustrates a further embodiment of fluid treatment apparatus of the invention; Fig. 10 illustrates schematically the fluid treatment apparatus of Fig.9;

Fig. 11 is a view from one side of a pump module for use in the fluid treatment apparatus;

Fig. 12 is a sectional view of a sock filler for use in the fluid treatment apparatus of Fig. 9; Fig. 13 is a block diagram of a control system for monitoring and controlling operation of the fluid treatment apparatus including control of discharge therefrom. Detailed Description of the Preferred Embodiment

Referring to the drawings and firstly to Fig. 1 and 2, there is illustrated a modular tank 10 for use in fluid treatment apparatus according to an embodiment of the invention. The tank 10 comprises in this instance three interconnected tank modules 11, each tank module 11 as shown also in Figs. 3 and 4 being of a generally rectangular cross section and includes opposite substantially rectangular planar end wall members J 2 which preferably are formed of plastics. The side walls of the tank module 11 are defined by a flexible sheet plastics member 13 of a width defining the required volume of the tank section 11. The end wall members 12 are provided on their opposing inner sides with endless grooves 14 which defines the external shape of the tank module 1] and which are of a width such that a side edge portion IS of the sheet plastics member 13 may be received therein. To fabricate the tank module 11, opposite side edges portions 15 of the sheet member 13 are located in the opposite grooves 14 in the end wall members 12 and secured and sealed therein by a suitable adhesive and preferably a UV curing adhesive. The length of the sheet member 13 is such that the free ends 16 and 17 of the sheet member 13 abut each other as .shown in Pig. 4 when the sheet member 13 is assembled with the opposite end wail members 12. The abutting ends 16 and 17 are also joined and sealed together such as by welding or an adhesive such as a UV curing adhesive as above. It will be further noted that the abutting ends 16 and 17 form a join line which is at the top of the tank module 11. The endless grooves 14 in the end members 12 have a substantially linear upper transverse portion 18 such that the top wall 19 of the tank module Il is substantially planar to facilitate mounting of various fluid treatment components. The comers of the grooves 14 however are curved so a$ to allow the sheet member 13 to curve from the sides to the top and bottom of the tank section 11, the internal curve in the comers of the tank module 11 preventing treatable materials collecting in the corners of the tank module 11 and facilitating cleaning thereof, Whilst the modular tank 10 described with reference to Figs. 1 and 2 is shown to have three separate tank modυlcl 1, the modular tank 10 may be formed with the tank modules integral or permanently joined in which case the abutting wall members 12 may be replaced by single wall members whicb separate the tank 10 into three tank module 11. Various ports, such as the circular ports 20 and 21 (see Fig, 4) are provided in the top wall 19 of the tank module 11 where required according to the fluid treatment or handling unit to be inserted into the tank module 11.

The modular tank 10 of Figs. 1 and 2 comprises three tank modules 11 arranged in an end-to-end relationship relative to each other with the respective end wall members 12 of adjacent tank modules 11 abutting each other. The end wall members 12 may be held in abutment by means of any suitable fasteners passed through aligned openings 22 in the abutting end wall members 12 outwardly of the sheet side wall member 13. The openings 21 are provided at spaced locations around the end wall members 12 and the fasteners which secure the end wall members 12 together are suitably quick connect and release fasteners to enable the tank modules 11 to be readily assembled or disconnected. This facilitates assembly of the tank 10 in a confined location such as in a boat as each tank modulel 1 can be positioned prior to interconnection to the adjacent tank modules 11.

Thus the modular lank 10 of the invention allows the assembly of raulti- compartmented tanks for various process needs. Such tanks can be constructed on a flexible, modular, simple and cost-effective basis.

In an alternative configuration, the tank modules 11 may be separate from each other and interconnected as required. This allows the placement of each tank modulel 1 in different locations where space permits.

The ports 20 and 21 as indicated are provided where required to permit the insertion of pumps, sensors, filters and other ancillary components of fluid treatment or handling apparatus within a tank module 1 1 of the modular tank 10. In the embodiment of Pig. 2, one tank module 11 of the tank 10 is provided with a circular opening 23 to receive a fluid treatment or handling module or cartridge 24 which includes a hollow tubular housing 25 of slightly smaller diameter than the opening 23 and an end cap 26 which in use seats on top walJ 19 of the tank module 11 and may be secured- in position (as indicated by the dotted outline in Fig. 1) by spaced screws or other fasteners. The tubular housing 25 may accommodate any components to be supported with the tank module 11 for treatment or handling of fluid in the tank module 11. Communication between the respective tank modules 11 however is provided externally of the tank modules 11 and via the fluid treatment modules or cartridges 25 in the respective tank modules 11. Thus a fluid treatment or handling module 25 may be readily mounted to a tank module 11 to extend into the chamber therein or removed for servicing purposes. The end tank module ) 1 containing the opening 23 in this case is provided with an inlet fitting 27 for introduction of fluid to be treated. Further fittings 28 are provided for connection of the end tank module 11 to a vacuum or for flushing and for venting the tank module 11. In some cases a mounting plate or panel 29 may be secured to the top of a tank module 11, the mounting plate or panel 29 providing stiffening and support to the top of the tank module 11 and can contain a series of smaller openings as well as the larger openings where required to receive fluid handling or treating modules or cartridges which extend into the chamber of the tank module 11. A modular tank system formed as above may advantageously be used in a process for treating sewage as in the embodiment illustrated in Fig. 5. The modular tank in this embodiment includes four joined tank modules 30, 31, 32 and 33 which are of the same construction as the tank modules 11 but which can be of different volumes. The tank module 30 has an inlet 34 for fluid to be processed and a first and second fluid treatment or handling modules or cartridges 35 and 36 extending into the tank module 30 through ports formed in the top wall of the tank module 30. The cartridge 35 has a tubular body 35' which houses a variable speed pump 37 which includes a macerator and filter screen 38 whilst the tubular body 39 of the module or cartridge 36 houses a filter 40. The outlet of the pump 37 is connected to the inlet to the filter 40 via an external connecting line or pipe 41 extending between the respective modules 35 and 36. The outlet from me filter 40 is connected by external line 42 from the module 36 to the tank module 31. The module 36 in this embodiment includes fluid level detection probes 43 to delect level of fluid within the tank module30 to control operation of the pump 37. The level detection probes 43 alternatively may be provided in a separate module inserted into the tank module30 through a separate port

Operation of the pump 37 at varying speeds controls the functioning of the tank module 30. Thus at a low flow rate, fluid is pumped by the pump 37 past the filter 40 to scour the filter 40 with cross-flow fluid to keep it clear of clogging build up with that fluid thereafter exiting back into the tank module 30 through a calibrated outlet 44 in the module 36 to provide beneficial circulation of the fluid within the tank module 30. Operation of the pump 37 at a high flow rate circulates fluid between the module 30 and module 31. This occurs because the backpressure caused by the high pressure against the calibrated outlet 44 forces fluid through the filter 40 and thus into the tank module 31 via line or pipe 42.

The module 31 receives through a port therein a further pump module or cartridge 45 of similar form to the module 35 housing a further variable speed pump 46 controlled, by level sensors 47. The outlet of the pump 46 is connected through an external connecting line or pipe 48 to a further filter module 49 which houses a submerged membrane cartridge filter 50. An air entraining venturi device 51 in the module 49 directs fluid back to the tank module 31, the venturi device 51 being selectively connected to the atmosphere through an external solenoid valve 52.

The outlet of the filter 50 is connected via an external line or pipe 53 and via a solenoid valve 54 to tank module 33. By operating the pump 46 at a low speed, fluid in the tank module 3 Hs aerated by the air entraining venturi device 51. When the pump 46 is operated at a high speed, fluid is forced through the submerged membrane cartridge filter 50 to exit as permeate fluid which passes through solenoid valve 54 (when opened) into tank module 33. The pump 46 also provides a beneficial circulation of flow throughout the tank module 31 when fluid is pumped through the venturi device 51.

The tank module 33 also houses a further pump module or cartridge 55 which houses a further variable speed pump 56. Also housed in pump cartridge 55 are fluid level detection probes 57 to aid in the control of the pump 56 and a temperature controlled heater 58 which is set to maintain the optimum temperature of fluid within the tank module 33. Similar heaters may also be provided in the pump modules 35 and 45. The outlet of the pump 56 is connected via an external connecting line to a further module or cartridge 59 housing sterilization apparatus 60 which includes electrodes. The outlet of the pump 56 is also connected to solenoid valve 61 which controls an outlet for treated fluid pumped from the tank module 33. .

By operating the pump 56 at a low speed, fluid flow is provided through the sterilisation apparatus 60 and back into the tank module 33. By operating the pump 56 at a high speed, fluid can be backwashed through the submerged membrane cartridge 50 by opening of the solenoid valve 54. Further treated fluid, through operation of the solenoid valve 61 can be pumped out for disposal, for additional treatment or for further use.

The tank module 32 provides a reservoir for liquid additives for use during the fluid treatment process and has a module or cartridge 62 which includes an outlet controlled by a solenoid valve 63 which communicates externally with the venturi device 51. By sequenced operation of the solenoid valves 52 and 63, the vacuum formed by the air entraining venturi device 51 draws liquid additive out of the tank module 32 thereby allowing the liquid additive to be specifically dosed during the treatment process. The cartridge 62 also houses fluid level detection probes 64 to monitor the level of the liquid within the tank module 32. The fluid processing system described with reference to Fig. 5, is most suitably used in a sewage treatment plant in marine or other applications with the tank module30 comprising a chamber containing bacteria for anaerobic treatment of sewage, the tank module 31 comprising a chamber containing bacteria for aerobic treatment of sewage, and the tank modυle 33 comprising a sterilization chamber.

Each module or cartridge for use in the modular tank 29 may be of the configuration of the module or cartridge 24 of Fig. 2 so that they may be simply mounted to the respective tank modules and interconnected as required by the external pipe lines or detached from each other for servicing as required. This is facilitated as all connections between the tank modules and fluid treatment or handling modules are provided externally. The modules or cartridges 24 may be of different sizes depending upon the fluid treatment component to be supported. It will be also appreciated that a fluid processing system may be provided with aαy number of tank modules and selected fluid treatment or handling modules as is required in the processing system.

Referring now to Figs. 6 to 8, there is illustrated further fluid treatment or handling modules which may be used with a modular tank as described and in a fluid treatment process typically in a quaternary treatment process and involving the use of ozone for treatment purposes. The cartridges 65 and 66. of Figs. 6 to 8 comprise a UV clarifier cartridge 65 and an activated carbon treatment cartridge 66 which can be inserted through respective ports in a tank module in a modular tank as above in a similar manner to the cartridge or module 24 illustrated in Fig. 2. Water for passage to the cartridges 65 and 66 is initially treated in an ozone generator unit 61 shown in Fig. 6 comprising an outer tubular body 68 closed by opposite end members 69 and having a inner coaxial fluid flow tube 70 extending into the body 68 and having an inlet end 71 and is supported by spaced discs 72. The initial How path of the fluid through the tube 70 acts to transfer waste heat from the electrically active parts of the ozone generator unit 67. An intermediate coaxial tube 73 surrounds and forms a cavity 74 with the fluid carrying tube 70. An ozone generator plasma field coil 75 surrounds the intermediate tube 73. Oxygen is either drawn in, by venturi action or pumped in through inlet port 75 which communicates with the cavity 74 through a disc 72 and as the oxygen passes through cavity 74, it is converted to ozone. An integral eductor 76 combines the fluid passing through the tube 70 with the generated ozone with the resultant fluid stream treated with ozone exiting through an outlet end 77 from the eductor 76. The clarifier cartridge 65 includes an outer tubular housing 78 closed by end plates or members 79 and 80 at opposite ends and having an outlet tube 81 supported coaxially within the housing 77 by means of an internal annular apertured support member 82 and to me end plate 80. A quartz tube 83 coaxially surrounds the outlet tube 81 and a plurality of circumferentially spaced UV lamps 84 are provided in the cavity between the tubes 81 and 83. An additional coaxial outer tube 85 is provided adjacent the housing 77, the tube 85 being coated with a photocatalytic preparation. An inlet 86 for fluid to be treated is connected to the region between the tube 85 and tube 83 and arranged tangentially such that fluid flowing therein is caused to flow in a predominantly circumferential direction around a tube 83. The incoming fluid thus flows between tubes 85 and 83 being exposed to ultraviolet light from the lamps 84, the effects of which are enhanced by the phoiocatylytic action of the coated tube 85. The fluid passes through the apertured support member 82 into the end of the tubular member 81 for flow along the member 81 and exit therefrom in a direction opposite to the incoming flow.

As shown in Fig, 8, the ozone generator and treatment unit 67 is connected to the UV clarifier cartridge 65, being oriented substantially radially or tangenlially relative to the cartridge 65 with the outlet 77 of the unit 67 connected to the inlet 86 to the cartridge 65 in the manner. In. addition, the outlet end of the lube 81 is connected to the carbon filter cartridge 66. The carbon filter cartridge 66 includes an outer housing 87, a coaxial inlet tube 88 supported in the housing 87 and opening to a lower part of the housing 87 with the region between the inlet tube 88 and housing 87 containing activated carbon 89.

The outlet of the tube 81 is connected through connecting line 89 to the inlet tube

88 of the cartridge 66 so that fluid treated in the cartridge 65 passes into the cartridge 66 where it passes through the bed of biologically activated carbon 89 and exits through outlet 90 to achieve a highly advanced fluid treatment process.

Referring to Pigs. 9 and 10, there is illustrated a further embodiment of fluid treatment apparatus 91 according to the invention which includes three tank modules 92, 93 and 94, which are similar in construction to the module 11 of Figs. 3 and 4 as used in the fluid treatment tank 10 of Fig, 1. The tank modules 92, 93 and 94 comprise tank modules for primary, secondary and tertiary treatment units 95, 96 and 97 respectively of a fluid to be treated typically sewage. Each tank module 92, 93 and 94 supports a pump module 98 details of which are also shown in Fig. 10 which illustrates the pump module

98 is used in the primary treatment unit 95. The pump module 98 includes a circular top plate or cap 99, a hollow leg 100 which depends downwardly from the centre of the cap

99 and a bottom plate 101 which carriers a least one submergible pump 102. The pump module 98 is inserted into a central opening 103 in the top of the tank module 92 and is secured in position by circumferenlially spaced screws such that the one or more pumps 102 is suspended within the tank module 92. The pump module 98 for the primary treatment unit 95 includes a single pump 102 and a macerator pump 104 to break up solids introduced into the tank module 92. A pressure sensor switch 105 is mounted to the cap 99 and communicates with the interior of the hollow leg 100. The leg 100 has openings 106 at its lower end such that as the fluid level in the tank module 92 rises, the level of liquid in the leg 100 also rises resulting in an increase in pressure in the leg 100 which is sensed by the pressure sensor switch 105. The end cap 99 also carries an outlet connector 107 by a pipe 108 to the outlet of the pump 102.

An inlet 109 is provided at the upper end of the tank module 92 for connection to a source of fluid to be treated which is typically sewage. The tank module 92 also carries a carbon air filter 110 which communicates with the upper end of the module 92 for treatment of gases within the module 92 above the liquid level therein.

The tank module 92 also carries an electronic control unit 111 which controls operation of the pump 102 and macerator pump 104 and which is also connected to the pressure sensor 105. A timer 112 is also provided on the module 92 to record the total time of operation of the pump 102. Similar timers 112 are provided on the other modules

93 and 94.

The tank module 93 of the secondary treatment unit 96 also supports a pump module 98' which in this case carries two submergible pumps 113 and 114 comprising a circulation pump and a discharge pump respectively, the outlets of which are connected to respective outlet connectors 1 15 and 116 on the cap 99\ The connector 116 is connected to a pair of ozone treatment units 117 each of which includes a ventυri 11$ which is provided to introduce ozone into liquid flowing through the Venturis 118 via ducts 119 connected to an ozone generator 120 mounted on the side of the tank module 94, The outlets of the Venturis 1 18 are connected back to the tank module 93 through an upper wall thereof as at 121. Operation of the pump 113 will thus cause liquid in the tank module 93 to be circulated through the Venturis 118 for introduction of ozone and for flow back into the module 93.

The outlet connector 116 of the discharge pump 114 is connected to a first solids filter 122, the outlet of which is connected to a second solids filter 123, each being detachable mounted by suitably brackets to a side of the module 93. The first solids filter 122 is a sock filter comprising as shown in Fig. 12, a sealed elongated tubular housing 124 having a central inlet tube 125, a tubular filter material 126 formed for example of geotextile-like fabric or other filter fabric secured at is upper end to the upper wall of the housing 121 to surround the inlet tube 125 and anchored to the lower end of the lower wall of the housing 124. An upright outlet pipe 127 is positioned adjacent the filter material 126 and is connected at its lower end to an outlet 125, the upper end of the pipe 127 acting as a weir over which fluid flows after passing through the filter material 126 as indicated by the arrows in Fig. 12.

The second solids filter 120 comprises a housing 128 having an inlet 129 at its lower end, a spiral membrane filter 130 of known construction in the housing 128 and a pair of outlets 131 and 132 at its upper end. The outlet 131 is connected back to the tank module 93 to circulate liquid treated by the filters 122 and 123 back to the module 93 whilst the outlet 132 comprises an outlet for liquid treated in tbe secondary treatment unit 96.

To receive liquid from the primary treatment unit 95, an inlet connector 133 is provided in the upper wall of the tank module 93 which is connected by a pipe 134 to the outlet connector 107 from the primary treatment unit 95.

The tank module 93 also carries a control unit 135 similar to the control unit 111 which is connected to the pumps 113 and 114, the ozone generator 120, tbe pressure switch 105' for control of operation of the secondary treatment unit 96.

The tank module 94 of the tertiary treatment unit 97 also includes a pump module 98" which is similar to the previous pump modules 98 and 98' but which in this instance carries three submergible pumps 136, 137 and 138 comprising a back flush pump, a circulating pump and a discharge pump respectively. The pump 136 is connected to a connector 139 on the module cap 99" to which a pipe 140 from the outlet

132 of the solids filter 123 is connected. The pump 136 is operated periodically when water in the tank module 94 reaches a certain level for pumping treated water from the tank module 94 back through the filter 123 for backwashing and cleaning of the filter

130.

A second outlet connector 140 connected to the pump 136 is provided on the cap 99'" and is connected to a pair of venturis 141 arranged in parallel with each venturi 141 introducing ozone into the liquid flowing through the venturi 141 via ducts 142 connected to an ozone generator 143 mounted on the side of the tank module 94. The outlets of the Venturis 141 are connected to respective UV treatment units 144 which are of similar in principle to the UV treatment units 65 of Fig. 7 and which include a series of UV lamps to which liquid flowing the units 144 is exposed. The outlets of the units

144 are connected back to the tank module 94 at 145 so that the pump 137 circulates liquid in the tank module 94 through the Venturis 141 and UV treatment units 144.

The outlet connector 140 is also connected via a duct 146 to a carbon filter 147 mounted externally to the module 94. The outlet from the carbon filter 144 is connected via duct 148 back to the lank module 94, Thus liquid from the pump 137 is also circulated through the filter 147 back to the tank module 94,

A dean water outlet connector 149 on the end cap 99"'is connected to the pump

138 for discharge of treated liquid from the apparatus. The module 94 also carries as with the modules 92 and 93, a control unit 150 for controlling the pumps 136, 137 and

138, the ozone generator 143, and the UV units 144, the unit IS0 also being connected to the pressure sensor 105".

To equalise pressures between the respective tank modules 92, 93 and 94, breather tubes 151 are connected between the modules 92 and 93, and 93 and 94 respectively.

The control units 111, 135 and 150 of the respective treatment units 95, 96 and 97 are connected to a common control unit 152 which is programmed to control overall operation of the apparatus 91 and further to monitor operation of all components of the apparatus 91 to record for example, time of operation of a pump, current draw by respective components etc. The common control unit 152 has a transceiver which is connected to a GPRS and GPS aerial 153 sucb that all operation of the apparatus 91 can be monitored remotely. A similar arrangement can also be used in connection with the fluid treatment apparatus Fig. 5 to monitor the operat-on of the sewage treatment process in the tank 10. The monitored information can be accessed remotely via a GPRS or other communication link so that the operation of the fluid treatment process including the dumping of treated fluid can be monitored externally by authorities or other monitoring bodies.

When used on a boat in a sewage treatment application, it is necessary that the treated water outlet controlled by the valve 61 from the modular tank 10 in which the sewage is treated or the pump 138 of the embodiment of Fig, 10 only operate for discharge of treated water at prescribed geographical discharge areas as determined by government authorities. By use of the GPS position signals received from the aerial 153 operation of the discharge pump 56 and solenoid valve 61 in the embodiment of Fig. 5 and the pump 138 can be controlled to only allow discharge at prescribed locations. The control unit 151 can thus determine from the GPS signals, the geographical position of the boat and the control unit 151 can compare this geographical position information with the prescribed geographical areas allowed- for treated sewage discharge. If the boat is not in a prescribed discharge or dumping area, the control unit 152 will prevent the discharge of treated sewage by preventing for example opening of the valve 61 and/or operation of the discharge pumps 56 and 138.

The embodiments described above are only preferred embodiments of the invention and it will be appreciated that various different treatment processes can be used in the apparatus. Tn addition, components used i n the fluid treatment apparatuses of

Figs. 1 to 8 and 9 to 12 can be interchanged. The respective tank modules in the embodiments whilst illustrated as being positioned in juxtaposition with each other, may be separated from each other by increasing the lengths of the connecting ducts therebetween such that where used for example in confined locations as encountered on a boat, they may be positioned where required.

The terms "comprising" or "comprises" or derivatives thereof as used throughout the specification and claims are taken to specify the presence of the stated features, integers and components referred to but not preclude the presence or addition of one or more other feature/s, integer/s, component/s or group thereof. Whilst the above has been given by way of illustrative embodiment of the invention, all such variations and modifications thereto as would be apparent to persons skilled in the ait are deemed to fall within the broad scope and ambit of the invention as herein defined in the appended claims.

Claims

1. Fluid treatment apparatus comprising a modular tank having a plurality of hollow tank modules, each defining a fluid treatment chamber of a fluid treatment unit, and respective fluid treatment means associated with respective modules of said modular tank for treatment of fluid in each module, each said fluid treatment means being adapted to be mounted to or adjacent a said tank module.

2, Fluid treatment apparatus as claimed in claim 1 wherein said fluid treatment means is mounted to a tank module and wherein a pump module is associated with each said tank module tor pumping fluid therefrom or for pumping fluid through the fluid treatment means.

3. Fluid treatment apparatus as claimed in claim 2 wherein said tank module has an upper port for receiving a pump module therein.

4. Fluid treatment apparatus as claimed in claim 3 wherein said pump module includes an upper support member and a lower support member suspended from the upper member, said lower member being adapted to be inserted into said port with the upper member secured detachable to the upper side of the tank module, said lower member supporting one or more pumps.

5. Fluid treatment apparatus as claimed in claim 4 wherein said upper member carries one or more outlet connectors connected to the one or more pumps respectively.

6. Fluid treatment apparatus as claimed in claim 4 or claim 5 wherein a hollow tubular member connects and extends between the upper and lower planar members, said hollow tubular member communicating at its lower end with the interior of the tank module and wherein pressure sensing means are provided at the upper end of the tubular member to sense pressure in said tubular member.

7. Fluid treatment apparatus as claimed in any claims 3 to 6 and comprising a primary, secondary and tertiary treatment units, each having a respective tank module, each provided with a pump module.

8. Fluid treatment apparatus as claimed in claim 7 wherein said primary unit include a maccrator for breaking up solids in the tank module, said macerator being be supported on a pump module.

9. Fluid treatment apparatus as claimed in claim 7 or claim 8 wherein said secondary unit includes a ozone treatment unit and wherein said pump module of said secondary unit includes a first pump for circulating fluid through the ozone treatment unit.

10. Fluid treatment apparatus as claimed in claim 9 wherein said secondary unit includes a solids filter and wherein said pump module includes a second pump for pumping fluid through the solids filter.

11. Fluid treatment apparatus as claimed in claim 10 wherein said tertiary unit includes an ozone treatment unit and a UV treatment unit and wherein said pump module of said tertiary unit includes a first pump for circulating fluid through the ozone and UV treatment units.

12. Fluid treatment apparatus as claimed irt claim 11 wherein said tertiary unit include a carbon filter wherein said first pump is adapted to circulate fluid through the carbon filter.

13. Fluid treatment apparatus as claimed in claim 11 or claim 12 wherein said pump module of the tertiary unit includes a second pump for backwashing the solids filter of the secondary unit.

14. Fluid treatment apparatus as claimed in claim 13 wherein said pump module of said tertiary unit includes a thi rd pump for pumping treated fluid from the apparatus.

15. Fluid treatment apparatus as claimed in claim 1 wherein said fluid treatment means are in the form of fluid treatment modules which extend into a tank module through a port therein for treatment of fluid in a chamber of a tank module.

16. Fluid treatment apparatus as claimed in any one of claims 3 to 15 wherein said tank module is substantially rectangular in cross section such that the upper wall thereof is substantially planar, said planar upper wall having a said port for receipt of a said pump module or fluid treatment module.

17. Fluid treatment apparatus as claimed in claim 16 wherein at least the lower comers of said tank module are internally concavely curved.

18. Fluid treatment apparatus as claimed in claim 17 wherein said tank module comprises opposite end wall member and one or more intermediate side wall members which defines the top, bottom and opposite side walls of the tanks module and define with the end walls a fluid containing chamber.

19. Fluid treatment apparatus as claimed in claim 18 wherein said side wall member comprises a single flexible sheet like member and wherein said opposite end walls are be provided with, grooves which define the peripheral configuration of a tank module and which are adapted to receive opposite side edge portions of the side wall member.

20. Fluid treatment apparatus as claimed in claim 19 wherein said side wall member extends around the full periphery of the lank module with opposite end edges of the wall member abutting and being sealed to each other to define a closed chamber within a tank module.

21. Fluid treatment apparatus as claimed in any one of the preceding claims and including a controller for controlling discharge from the apparatus and a geographical positioning system is connected to or provided in the controller whereby the controller can determine the geographical position of the apparatus and thereby control discharge from the apparatus.

22. Fluid treatment apparatus as claimed in any one of the preceding claims and including remote monitoring apparatus for remotely monitoring operation of said apparatus and the components thereof.

23. A method of controlling the discharge of treated fluid from fluid treatment apparatus of the type defined in any one of claims 1 to 20, said method including the steps of monitoring the geographical location of said treatment apparatus, and preventing the discharge of treated fluid from said treatment apparatus if said apparatus is not in a location prescribed for discharge of said treated fluid.