GB2437931A

GB2437931A - Treating contaminated waste

Info

Publication number: GB2437931A
Application number: GB0704390A
Authority: GB
Inventors: Alan Evett; Stewart Risk
Original assignee: CALASH Ltd
Current assignee: CALASH Ltd
Priority date: 2006-03-07
Filing date: 2007-03-07
Publication date: 2007-11-14
Also published as: GB0604542D0; GB0704390D0

Abstract

A method and apparatus for treatment of waste material, for example waste material from an earth drilling operation. The waste material includes solids, fluids and contaminants, and is separated into a first material stream containing solids, and a second material stream containing fluids. Fluids are driven from the first material stream into the second for a fluid treatment process, which may include treatment to remove free oil, oil/water emulsions, dissolved hydrocarbons and heavy metals. The treatment process allows the treated solids and treated fluid to be discharged into the environment. The invention may be implemented on an offshore facility or marine vessel to allow on site treatment of drilling waste and discharge of treated material into the environment. Preferably contaminant monitoring and control systems are provided.

Description

1 Material Treatment Apparatus and Method 3 The present invention

relates to treatment apparatus and 4 methods for disposal of material in the environment. The invention relates particularly to the treatment of debris 6 containing a solid and a fluid phase, and more 7 particularly to the treatment of drilling waste produced 8 by oil or gas recovery or exploration processes, 9 including drill cuttings, produced sands, water, scale, and other byproducts.

12 As part of oil or gas recovery or exploration processes it is necessary to dispose of waste fluids and solids, ::::.l4 for example in the drilling of wells. Typically drill fluid or drilling mud is provided to the wellbore to S. * .. * * 16 assist the drill bit in cutting through rock formations.

**....

17 The fluid is usually pumped into the well from a rig * 18 through the centre of a drill or tubing string, and is * S. 19 returned back to the surface from the well in the annular S * **S.

space between the weilbore wall and an outer surface of 21 the drill string.

1 As the rock is cut by the drill bit, solid drill cuttings 2 are produced, typically comprising rock cuttings and 3 debris. The drill cuttings are flushed out together with 4 the drill fluid, which may also include produced sand water, scale, and other byproducts. The drill fluid 6 mixes with fluids from geological formations at depth, 7 and thus the fluid returned is impure and is typically 8 contaminated with various hydrocarbons and other 9 substances. In addition, the drill fluid has a specific composition chosen according to the type of rock being 11 drilled. In some cases, particular chemicals are 12 introduced for assisting the drilling. Thus, impure 13 drill fluid that is returned to the rig from the well is 14 not readily re-used in the well and must be handled accordingly.

17 Existing systems for handling return drill fluid 18 typically involve storing the returned fluid on the rig 19 until it can be transported away to a treatment facility.

It is known in the art to separate drill cuttings from 21 the fluid ready for transportation. Systems also exist 22 for separating out drill cuttings and discharging the i.,23 cuttings into the environment from the rig. Further, drill fluid that has been separated from the cuttings is sometimes re-used in the welibore. ** 4a

* .. S * 26 There are a number of drawbacks associated with these *.. 28 existing systems. Storage and subsequent transportation *.,, 29 is costly. It is also inconvenient and costly to spend S...

time loading transport vehicles.

1 Another problem is that storage can be a significant 2 health and safety hazard as the drill fluid may contain 3 harmful or flammable substances at the work site.

It would be desirable to discharge treated materials and 6 their by-products, solid or fluid, into the environment 7 to ease the burdens of storage and transportation.

8 However, discharge of solids and fluid materials may lead 9 to unacceptable levels of contamination in the environment.

12 It is an object of the present invention to obviate or at 13 least mitigate drawbacks and deficiencies of prior art 14 methods and apparatus.

16 It is a further object of at least one aspect of the 17 present invention to provide apparatus for on site 18 treatment of drill cuttings and drill fluid.

Other objects will become apparent from the description 21 below.

.23 According to a first aspect of the invention there is ".24 provided material treatment apparatus comprising: -a separator unit configured to receive material from 0S an industrial process, the material comprising fluids, solids and a contaminant, the separator unit 28 being operable to divert solids from the material 29 into a first material stream and diverts fluids from 6 * *6*6 the material into a second material stream; 31 -a drying unit operable to drive off fluids from the 32 first material stream and comprising an outlet to 1 channel the driven off fluids into the second 2 material stream; 3 -a treatment device configured to reduce a level of 4 the contaminant in the second material stream and produce a treated fluid stream; and 6 -means for discharging the first material stream and 7 the treated fluid stream into the environment.

9 In this context, the word "stream" is intended to reflect a movement or transport of material, and does imply a 11 fluid component or flow of material as such.

13 The material may be obtained from an earth drilling 14 operation. The material may comprise drilling fluid, solid drill cuttings, and one or more contaminants. The 16 contaminants may be hydrocarbons. The hydrocarbons may 17 be ETEX hydrocarbons.

19 The apparatus may comprise a contaminant monitor configured to be disposed at or nearby the discharged 21 material and operable to monitor a level of contaminant 22 in the environment and provide an indication of :. 23 contaminant level. * 4. * ** * S * S_S

The contaminant monitor is preferably adapted to measure S. fs * 26 the level of contaminant in the environment. 27

* 28 Preferably, the contaminant monitor is configured to * S. 29 transmit a measuring signal for producing a measurable response from the contaminant.

32 Preferably, the contaminant monitor comprises an 33 excitation source for transmitting the measuring signal.

2 The excitation source may be adapted to transmit light 3 for illuminating the contaminant. The excitation source 4 may be one of a laser light source, an infra-red (IR) light source and an ultra-violet (UV) light source.

7 The excitation source may be adapted to transmit acoustic 8 energy. The contaminant monitor may be a mass 9 spectrometer.

11 Preferably, the contaminant monitor is configured to 12 measure a signal from the environment. The contaminant 13 monitor may comprise a sensor configured to receive the 14 reflected signal. Preferably, the sensor is further configured to measure the level of contaminant.

17 The reflected signal may comprise a light signal.

19 The sensor may be an optical sensor for sensing light energy. The optical sensor may be adapted to measure 21 fluorescence from the contaminant.

23 The sensor may be configured to measure a sound signal.

24 The sensor may be an acoustic sensor operable to measure :. 25 a sound signal level corresponding to a level of the * 26 contaminant. II..

*s.. 27 28 The material may be discharged into a body of * 29 environmental water. *

31 The contaminant monitor may be adapted to receive a test *. 32 volume of the environmental water. The contaminant *.S.

33 monitor may comprise a test chamber configured to receive 1 a test volume of environmental water. In forms of the 2 invention comprising an excitation source, the excitation 3 source may be configured to transmit a measuring signal 4 to the test volume. In forms of the invention comprising a sensor, the sensor may be configured to measure a 6 measuring signal reflected from the test volume.

8 Preferably, the contaminant monitor is configured to 9 float on the body of environmental water. Thus, the contaminant monitor may comprise a marine buoy. In forms 11 of the invention comprising a test chamber, the test 12 chamber may be located on a central axis of the buoy.

13 The contaminant monitor may be fitted to a marine vessel 14 or ship.

16 Preferably, the contaminant monitor is operable to 17 calculate a concentration of the contaminant.

19 Preferably, the contaminant monitor is operable to transmit an alert signal according to a level of 21 contaminant. Preferably, the contaminant monitor 22 comprises a transmitter operable to transmit the alert 23 signal. The alert signal may be an electronic signal for 24 transmission to a remote location via the transmitter.

The electronic signal may be one or more of a digital : 26 signal and an analogue signal. The alert signal may be S.,.

S

". 27 an audible alarm.

* S. 5 * . * 29 Preferably, the apparatus may be configured to filter S.....

residual solids from the second material stream. The *:*:.* 31 apparatus may be configured to backf lush filtered solids *. 32 into the first material stream. a...

1 The treatment device may be configured to oxidise the 2 contaminant in the second material stream. More 3 specifically, the treatment device may comprise 4 electrolysis apparatus operable to reduce a contaminant in the second material stream.

7 The contaminant may comprise at least one of a free 8 contaminant and a dissolved contaminant.

Alternatively or in addition, the treatment device may be 11 configured to reduce a hydrocarbon contaminant in the 12 second material stream.

14 Alternatively or in addition, the treatment device may be configured to separate free oil from the second material 16 stream.

18 Alternatively or in addition, the device may comprise a 19 coalescing unit operable to reduce free oil in the second material stream by attracting oil droplets to a surface 21 of the coalescing unit.

23 Preferably, the treatment device is configured to remove 24 oil/water emulsions from the second material stream. The treatment device may comprise an emulsion removal unit * 26 for removing oil/water emulsions. * *

:.:,28 The emulsion removal unit may comprise a filter. The * 29 filter may be configured to adsorb or absorb an emulsion ****** from the second material stream. The filter may-comprise *:*:.* 31 solid media to adsorb or absorb an emulsion from the *. 32 second material stream. The media may be charcoal or *.S.

33 Fuller's earth, or other suitable filtration media. The 1 media may be recyclable and reusable. The media may be 2 removable from the emulsion removal unit.

4 The apparatus may be adapted to receive the media in the dryer unit. In this way, the dryer unit is operable to 6 drive off fluids, i.e. the water and oil components of 7 the emulsion, to leave behind the solid media. The solid 8 media can then be used in a subsequent filtering 9 operation. The emulsion, having been broken by the drying unit, enters the second material stream water for 11 subsequent treatment.

13 The apparatus thus provides a system with low or zero 14 volume waste by products.

16 The apparatus may comprise a storage vessel for storing 17 the free oil separated from the fluid.

19 The water treatment apparatus may be configured for portability, e.g. for transport and installation at 21 different sites.

23 The treatment apparatus may be configured for operation 24 in a mineral recovery process. The mineral recovery :. 25 process may be a hydrocarbon recovery process. * ****

*..27 Alternatively or in addition, the treatment apparatus may further comprise a treatment device controller operable * 29 in dependence upon the indication of contaminant level to change an extent to which the treatment apparatus reduces *:*:.* 31 the level of contaminant in the second material stream. * .32

1 More specifically, the treatment device controller may be 2 manually operable by a user of the treatment apparatus.

4 Alternatively or in addition, the dryer may comprise a microwave heating device operable to heat the solids.

7 According to a second aspect of the present invention 8 there is provided a method of treating material from an 9 industrial process, the method comprising the steps of: 11 -receiving material from an industrial process, the 12 material comprising fluids, solids and a 13 contaminant; 14 -diverting solids from the material into a first material stream and diverting fluids from the 16 material into a second material stream; 17 -driving off fluids from the first material stream 18 and channelling the driven off fluids into the 19 second material stream; -reducing a level of the contaminant in the second 21 material stream to produce a treated fluid stream; 22 and 23 -discharging the first material stream and the 24 treated fluid stream into the environment. * *

* 26 Embodiments of the second aspect of the present invention may comprise one or more features according to the first 28 aspect of the present invention. * 29

In this context, the word "stream" is intended to reflect 31 a movement or transport of material, and does imply a *. 32 fluid component or flow of material as such. ** S.

1 The method may comprise the step of receiving material 2 from an earth drilling operation. The material may 3 comprise drilling fluid, solid drill cuttings, and one or 4 more contaminants. The contaminants may be hydrocarbons.

The hydrocarbons may be BTEX hydrocarbons.

7 The method may comprise the additional step of monitoring 8 contaminants in the environment and provide an indication 9 of contaminant level.

11 The material may be discharged into a body of 12 environmental water.

14 Preferably, the method includes the step of filtering residual solids from the second material stream. The 16 method may include the additional step of backflushing 17 filtered solids into the first material stream.

19 Preferably, the method includes the step of oxidising the contaminant in the second material stream.

22 Preferably, the method includes the step of reducing a 23 hydrocarbon contaminant in the second material stream.

:. 25 Preferably, the method includes the step of separating * 26 free oil from the second material stream. ****

S

28 Alternatively or in addition, the method includes the * ** S * S * 29 step of attracting oil droplets to a surface of a coalescing unit.

*::::* 32 Preferably, the method includes the step of removing 33 oil/water emulsions from the second material stream.

2 Preferably, the method includes the step of adsorbing or 3 absorbing an emulsion from the second material stream.

4 The method may include the step of recycling or reusing media from a filter. The media may be removable from the 6 emulsion removal unit.

8 Preferably, the method includes the step of receiving the 9 media in the dryer unit. In this way, the dryer unit is operable to drive off fluids, that is the water and oil 11 components of the emulsion, to leave behind the solid 12 media. The solid media can then be used in a subsequent 13 filtering operation. The emulsion, having been broken by 14 the drying unit, enters the second material stream water for subsequent treatment.

17 The apparatus thus provides a system with low or zero 18 volume waste by products.

The method may be a part of a mineral recovery process.

21 The method may be a hydrocarbon recovery process.

23 The method may include the additional step of inspecting 24 a level of a contaminant prior to discharge.

"26 Alternatively or in addition, the treatment apparatus may further comprise a treatment device controller operable :.:..28 in dependence upon the indication of contaminant level to * 29 change an extent to which the treatment apparatus reduces ****.

I

the level of contaminant in the second material stream.

*:*:.* 31 *::::* 32 More specifically, the treatment device controller may be 33 manually operable by a user of the treatment apparatus.

2 Alternatively or in addition, the dryer may comprise a 3 microwave heating device operable to heat the solids.

According to a third aspect of the present invention 6 there is provided material treatment apparatus 7 comprising: 9 -treatment apparatus configured to receive material from an industrial process, the material 11 comprising fluids, solids and a contaminant, and 12 to reduce a level of the contaminant in the 13 received water, the treatment apparatus being 14 configured to discharge the treated material into the environment; and 16 -a contaminant monitor configured to be disposed at 17 or nearby the discharged treated material, wherein 18 the contaminant monitor comprises a luminescence 19 sensor operable to monitor a level of the contaminant in the environment and provide an 21 indication of contaminant level.

23 Preferably, the water treatment apparatus may be 24 configured to receive a plurality of indications of contaminant level and operable to perform a statistical : *.*26 analysis of the plurality of received indications. The *S.. * I

**.. 27 water treatment apparatus may further comprise a I:: 28 processor for performing the analysis. * 29 I....

The indication of contaminant level may correspond to a 31 concentration of contaminant in a volume of environmental ::::* 32 water. Preferably, the contaminant monitor is operable to 33 calculate a concentration of the contaminant.

2 The water treatment apparatus may be adapted to compare 3 the indication of contaminant level with a threshold 4 value.

6 Preferably, the contaminant monitor may comprise a 7 comparator operable to perform the comparison with the 8 threshold value. The contaminant monitor may be operable 9 to transmit an alert signal in dependence upon the comparison with the threshold value. Preferably, the 11 contaminant monitor is fitted with a transmitter for 12 transmitting the alert signal.

14 Embodiments of the third aspect of the present invention may comprise one or more features of the first or second 16 aspect of the present invention.

18 According to a fourth aspect of the invention there is 19 provided a method of treating water from an industrial process, comprising the steps of: 21 -receiving water comprising a contaminant from an 22 industrial process; 23 -treating the received water to reduce a level of 24 the contaminant in the received water; :. 25 -discharging the treated water into environmental * 26 water; S.. * S

27 -monitoring a level of the contaminant in the 28 environrnent.al water at or nearby the discharged * 29 treated water; and ****, -providing an indication of the contaminant level *:*:.* 31 by monitoring a level of the contaminant in the 32 environmental water with a luminescence sensor. *...

1 Embodiments of the fourth aspect of the present invention 2 may comprise one or more features of the preceding 3 aspects of the present invention.

According to a fifth aspect of the present invention 6 there is provided a marine vessel comprising a treatment 7 apparatus according to the first, third or fifth aspect 8 of the present invention.

According to a further aspect of the present invention 11 there is provided water treatment apparatus comprising: 12 -treatment apparatus configured to receive water, 13 which comprises a contaminant, from an industrial 14 process and to reduce a level of the contaminant in the received water, the treatment apparatus 16 being configured to discharge the treated water 17 into the environment.

19 More specifically, the water treatment apparatus may further comprise a contaminant monitor configured to be 21 disposed at or nearby the discharged Created water, the 22 contaminant monitor being operable to monitor a level of 23 the contaminant in the environmental water and provide an 24 indication of contaminant level.

26 Embodiments of the further aspect of the present "**27 invention may comprise one or more features of the first *.::28 to fifth aspects of the present invention. * 29 _ #1s

There will now be described, by way of example only, 31 embodiments of the invention with reference to the *: 32 following drawings, of which: 1 Figure 1 is a cross-sectional representation of a drill 2 fluid treatment apparatus according to an embodiment of 3 the invention; Figure 2A is a schematic representation of drill fluid 6 treatment apparatus in accordance with a further 7 embodiment of the invention; 9 Figure 2B is a schematic cross-sectional representation of a filter and back flush unit according to the 11 embodiment of Figure 2A; 13 Figure 2C is a schematic cross-sectional representation 14 of a free oil separator unit according to the embodiment of Figures 2A and 23; 17 Figure 2D is a schematic cross-sectional representation 18 of an emulsion removal skid according to the embodiment 19 of Figures, 2A, 2B and 2C; 21 Figure 2E is a schematic cross-sectional representation 22 of an electrolysis skid according to the embodiment of 23 Figures 2A, 2B, 2C and 2D; :. 25 Figure 3 is a schematic cross-sectional representation of * 26 a contaminant level monitoring unit according to an S...

s.. 27 embodiment of the invention; * .* . * * 29 Figure 4 is a chart of an alert transmission process *5 according to an embodiment of the invention; and

I -I.

1 Figure 5 is a schematic drawing of a drill fluid 2 treatment apparatus deployed for use on site in 3 accordance with an embodiment of the invention.

With reference firstly to Figure 1, a first embodiment of 6 the invention is described with the application to 7 treatment of waste from drilling operations in oil and 8 gas wells. The treatment apparatus is generally shown by 9 reference numeral 100, and provides treatment of waste material for safe discharge of solids and fluids into the 11 environment. The present system provides treatment of 12 both the fluid and solid components of the waste 13 material.

The apparatus 100 comprises an initial separation tank 16 102 for separation of solid drill cuttings from fluids, 17 which by volume form between 5% and 100% of the debris.

18 Untreated drill fluid or drilling mud is received by the 19 initial tank from a source of cuttings, which may be a rig, a storage container, a further cuttings treatment 21 system, the seabed, or a vessel, via an inlet 104. The 22 separated solids 106 in the tank in general are 23 contaminated with residual hydrocarbons as a result of 24 being transported out of the well with the drill fluid.

., 26 The fluids are drained off into a fluid stream and may be **S.

27 passed through a filter (not shown) functioning to back * * 28 flush any remaining solids back into the tank, and * S. 29 subsequently passed through the solid treatment stream. **Ss* * 30

* 31 The treatment apparatus further comprises a transport * *.

**. 32 system 108, such as a conveyor belt, for transporting the *I*.

33 contaminated solid material to a heating chamber 110 for 1 treatment. In the heating chamber 110 the material is 2 heated by microwave radiation 112, for example by the 3 process described in one or more of WO 2007/007068, 4 US 3,777,095 or US 4,551,437 although other suitable heating methods could be employed. Heating causes water 6 and the hydrocarbon contaminants to vapourise, and the 7 vapours are channelled out of the tank via a suitably 8 located outlet 114. This leaves the solid in the tank 9 relatively dry, having for example less than 5% to 10% fluid, and substantially free of fluid contaminants.

12 In alternative embodiments, other techniques are used to 13 remove contaminants from the solids, including use of a 14 centrifuge or a solvent treatment step to flush contaminants from the solid. These techniques could be 16 used alone or in additional to a heat treatment step.

18 The vapour derived from the heating is channelled to a 19 condensation tank 116, including cooling means, thus turning the vapour into condensed fluid 118. The 21 distilled fluid may comprise water contaminated with 22 soluble hydrocarbons, and! or free oil. The condensed 23 fluid is then passed to the fluid treatment unit 120.

The drill fluid in the initial separation tank is 26 filtered and channelled from the separation tank 102 for a...

.*. 27 fluid treatment. The condensed fluid from the *, 28 condensation tank 116 is combined with "separated" fluid * S. * 29 channelled directly from the separation tank and is fed **SS** * 30 into a fluid treatment unit 120. The fluid treatment . * 31 unit 120 comprises equipment dependent on the material * *.

*. 32 being treated, and may comprise a series of treatment *.S.

33 units each performing a different process.

2 Treated fluid is then discharged into the ocean via an 3 outlet skid 122. Cleaned solid material is discharged 4 into the ocean environment via a skid 124. In other embodiments the discharge may be transported for 6 discharge elsewhere e.g. on-land.

8 The treatment apparatus 100 is preferably configured such 9 that it may be used on an offshore or onland rig, ship or other plant requiring the treatment of drill fluid and 11 cuttings, and may be a portable unit that can be moved 12 and installed at a site as required.

14 With reference now to Figures 2A to 2E, in another embodiment of the invention, there is generally shown 16 dual drill cutting and a drill fluid treatment apparatus 17 at reference numeral 200.

19 This apparatus 200 shares components with the embodiment of Figure 1, with like-components given like reference 21 numerals. However, in this embodiment an initial 22 separation tank 103 is a split tank and is linked to a 23 filter and back flush unit 202. In this case, the 24 separation tank 103 provides an initial separation of solid drill cuttings from the drill fluid. The solid .,, 26 material separated in the tank is transported to the *S..

*,*. 27 heating unit 110 as in the previously-described 28 embodiment.

* S. * 5S In this case, drill fluid from the initial separation * 31 tank 103 is channelled to the dual filter back flush unit * *.

" 32 202. Typically, the fluid will carry some solid material S...

33 with it and into the unit 202. The filter and back flush 1 unit 202 comprises two filters 204a, 204b that are 2 independently operable to filter out solid material 206a, 3 206b. Each filter 204a, 204b filters out solid material 4 from the drill fluid.

6 Each filter is fitted with a pressure gauge 203a, 203b 7 for measuring the pressure differential across the 8 filter. These pressure measurements are used to 9 determine which of the filters shall receive and filter the drill fluid. For example, as the first filter 204a 11 becomes blocked up with solid filtrate, the unit 202 is 12 configured with flow control valves 208 that switch to 13 the second filter 204b to continue filtration. The first 14 filter may then be unblocked by flushing out the solid filtrate.

17 In this case, fluid that is passed through the 18 operational filter 204b is used to flush through the 19 second filter 204a to remove the solid filtrate from the filter and flush it back into the initial separation tank 21 103. The flow of fluid in the present example is 22 generally indicated by arrows 207.

24 By running the drill fluid through such a dual filter and back flush unit 202, the efficiency of solid/fluid n.,. 26 separation is maximised. Various other filter/back flush *.S.

27 systems could be employed as known in the art.

* ** 28 * 29 As in the case of Figure 1, the apparatus 200 provides for the treatment of solids and fluids, with the solids * 31 being transported to a heating chamber 110 and the fluids 32 entering a fluid treatment stream. As with the 33 embodiment of Figure 1, fluids vaporised from the heating 1 process are condensed at condensation tank 116 and 2 recombined with the fluid stream for subsequent 3 treatment.

The assembly 200 further comprises a free oil removal 6 skid 212. Fluid 210 from the separation tank combined 7 with condensed fluid 118 is fedinto the free oil removal 8 skid 212. The skid 212 comprises oil water separator 9 equipment for removing free oil from the combined fluid.

In this case, the equipment includes a gravity oil-water 11 separator unit 214. A typical gravity oil-water 12 separator takes advantage of the relative difference in 13 density of oil and water such that oil droplets 216 rise 14 through water allowing the oil to be captured using a skimming device as known in the art. The equipment may 16 also include a coalescing unit 218 formed of a material 17 suitable for attracting small oil droplets to the surface 18 of the material. The small oil droplets that accumulate 19 on the surface of the coalescing material agglomerate to form larger droplets, which then rise through the water 21 for removal.

23 It will be appreciated that other apparatus may be 24 employed for performing the separation of the free oil from the fluid. S. * . * S.. *5*.

*. 27 Free oil that has been removed is stored for subsequent ** * 28 use by any suitable means, for example a barrel 222. The * ** . 29 remaining fluid is channelled out of the skid 212 via an * 30 outlet 220. This fluid typically comprises oil/water *. * 31 emulsions deriving from the fluid phase of the material * *. 32 and dissolved hydrocarbons. ***.

1 The apparatus 200 includes an emulsion removal skid 224 2 for further treatment of the fluid passed through the 3 free oil removal skid 212. The emulsion removal skid 224 4 includes a bone charcoal filter 226 for removing hydrocarbon emulsions 228 from the fluid. The filter 226 6 may be formed from various other materials as known in 7 the art, for example, wood charcoal or Fuller's earth.

8 The filter preferably includes filtration media for 9 filtering heavy metals from the fluid stream, although it will be appreciated that such filtration media may 11 alternatively be provided as part of separate apparatus 12 in a prior or subsequent filtration step.

14 Oil/ water emulsions 228 collected in the filter media are removed from the fluid are fed back into the heating 16 unit 110. This is done by physical removal of the media 17 from the filter 226 and placing it in the heating 18 chamber. In the heating unit the emulsions will be 19 broken by vaporisation. Upon heating, the hydrocarbon and water components will form vapour at different 21 temperatures. Subsequently, the hydrocarbon and water 22 vapours are condensed in the condenser unit. The 23 condensed fluid then becomes treated in the free oil 24 removal unit 212 where free hydrocarbons are removed. In this way, the emulsions 228 are cycled back through the .,, 26 heating system until they are broken up and the oil can *S..

... 27 be removed and stored. The filter media, dried during 28 the heating process, is ready for reuse in a subsequent * * 29 emulsion treatment step if required. * 30

* 31 In an alternative embodiment, the emulsion removal skid * ** , 32 may be provided with a heater to break the emulsion by *qS.

33 the application of heat.

2 The apparatus 200 includes a final electrolysis treatment 3 skid 230 for receiving fluid passed through the emulsion 4 removal unit 224. In this skid 230, fluid is subjected to electrolysis treatment. This purpose is to remove 6 dissolved hydrocarbons, such as BTEX or glycols, from the 7 fluid before discharge into the environment. Electrodes 8 232 are inserted into the fluid to cause ionisation of 9 the fluid such that organic compounds are broken up.

Once the fluid has been subjected to this treatment, the 11 drill fluid is substantially free of hydrocarbon 12 contaminants and is discharged into the ocean through a 13 suitable discharge skid.

In this manner, both the drill fluid and the drill 16 cuttings are treated and cleaned of contaminants suitable 17 for discharge of the cuttings and fluid into the 18 environment. This treatment is carried out on site where 19 the drill fluid and cuttings are received from the well.

The treated components are then discharged into the ocean 21 or land environment. In other embodiments, the cuttings 22 and fluid could be treated at another location, such as a 23 treatment vessel or a treatment facility in a yard.

The apparatus 200 further comprises a number of 26 inspection points 250, 252 and 254. At each inspection *. 27 point is located a sensor for monitoring levels of a 28 contaminant. At inspection point 250, a sensor is * ** S * 29 provided to detect the levels of contaminant in the solid material prior to discharge. If the contaminant levels * 31 are unacceptably high, the discharge of solid material * *.

*, 32 can be prevented. At inspection point 252, a sensor is **** 33 provided to detect the levels of contaminant in the fluid 1 from the emulsion removal skid 224 prior to discharge.

2 If the contaminant levels are acceptable, the fluid can 3 be discharged overboard. If the contaminant levels are 4 unacceptably high, the fluid will be channelled to the electrolysis treatment skid 230. Inspection point 254 6 monitors the level of contaminants in the fluid from 7 electrolysis treatment unit 230, and channels the fluid 8 for discharge or further electrolysis treatment as 9 appropriate.

11 The sensors will be chosen and configured for the 12 particular application and material to be treated. For 13 this example, the sensors detect the presence of 14 hydrocarbons by fluorescence monitoring techniques known in the art. The thresholds of acceptable/unacceptable 16 contaminant levels can be chosen depending on 17 environmental factors, such as discharge regulations or 18 specific location of discharge.

The apparatus 200 further includes a monitoring unit 240 21 for monitoring the ocean in the area near where the solid 22 and fluid have been discharged and identifying if the 23 discharge is harmfully contaminating the ocean. The unit 24 includes a transmitter 242 to transmit a signal 244 if the contaminant levels reach an unacceptable level. The n.,, 26 signal may be transmitted to different units 246 as a..

27 required, for example a treatment control unit for 28 alerting an operator or for shutting down the discharge : * 29 of waste material. ****. * 30

* 31 In conjunction with the inspection points 250, 252 and * ** " 32 254, the monitoring unit 240 can be used to provide *S*.

33 evidence of correct functioning of the material treatment 1 process in the event of high contaminant levels being 2 detected in the ocean. This allows the rig operator to 3 investigate alternative causes of contamination, e.g. 4 another rig process or discharge from a local facility or passing vessel.

7 Figure 3 illustrates an alternative example of how the 8 monitoring unit, shown generally at numeral 300 can be 9 implemented. In this embodiment, the unit 300 is incorporated into the body of a marine buoy 302.

11 Typically, the buoy is located in the ocean at a location 12 that may potentially be contaminated with hydrocarbons 13 resulting from discharge of drill fluid or cuttings into 14 the sea in the vicinity after treatment.

16 The monitoring unit 300 comprises a sample chamber 306 to 17 capture a volume of water 310 from near the sea surface 18 312 for analysis. The sample chamber has an end 320 that 19 is exposed to the sea allowing water to enter into and exit out of the chamber. This allows new water samples 21 from the sea surface local to the buoy to be circulated 22 into the chamber due to motion of the sea. In another 23 embodiment, the sample chamber may be temporarily exposed 24 to the sea surface, for example, by providing a closable :, 25 port that connects the sample chamber with the sea.

* S.. 26 S...

27 The unit 300 includes an illumination source 304 to 28 provide illumination of sea water in the sample chamber : .* 29 306. The illumination source 304 transmits tJV light, *...

which causes fluorescence of hydrocarbons present in the * 31 water. In other embodiments, the source could transmit * *.

32 IR or white light to the body of water. The illumination **se 33 source may be a narrow frequency band laser source for 1 producing other characteristic radiation from the 2 hydrocarbon contaminant.

4 The monitoring Unit is adapted to measure the reflected light. Optical windows 308 are positioned in the walls 6 of the chamber for sensing reflected fluorescence 314 of 7 hydrocarbons in the water. The optical window 308 8 comprises a photodiode 322 for sensing the fluorescence.

9 The photodiode 322 also acts to digitise the received light to digital data for processing by a processing 11 unit. In other cases, different transducers are fitted 12 to sense the appropriate radiation produced by the 13 hydrocarbon in response to excitation. In one 14 embodiment, acoustic radiation sources and receivers may be used to detect hydrocarbon. The optical window 308 is 16 positioned at a distance of around 2 to 8 cm below the 17 top surface of the water 306 in the chamber.

19 In order to ensure that the optical window is in the correct operating position, the sample chamber is located 21 on a central axis 324 of the buoy. This helps to keep 22 the height of water in the sample chamber stable.

24 The monitoring unit 300 includes a processing unit 326.

The processing unit 326 is configured to calculate n.,. 26 hydrocarbon concentration in the water sample contained .... 27 in the sample chamber based on the reflected radiation 28 sensed by the photodiode.

* *. I * 29 * II.

The monitoring unit also comprises a signal generator ** 31 unit 328 for producing an alert signal. This signal * 32 generator unit includes a transmitter 330 and is 33 configured to produce an alert signal 334 depending on 1 whether the measured hydrocarbon concentration exceeds or 2 meets a pre-prograrnined threshold value stored in a 3 storage unit 332. The alert signal is used to inform 4 various control units 336 of the state of contamination to trigger tests and checks of rig equipment. The 6 control units may be monitored by human operators at 7 different levels of site responsibility or could be 8 automated units for performing various levels of system 9 checks.

11 The alert signal 334 may be transmitted to a remote 12 location via radio transmission, other digital wireless 13 communication protocol, or could be an audible alarm 14 signal that can be heard by personnel in the field.

16 The monitoring unit 300 provides continuous monitoring of 17 contaminants and can alert personnel responsible for 18 waste discharges into the ocean environment of the state 19 of contamination. As before, the data from the monitoring unit 300 would be used in conjunction with the 21 data from the inspection ports 250, 252, 254 to verify 22 proper functioning of the material treatment process.

24 In other embodiments, the unit 300 might for example be fitted to a marine vessel. On a vessel, the monitoring n... 26 unit 300 includes an illumination source 304 for S...

.... 27 illuminating water in general proximity to the buoy. * 28 * 5*

* 29 In Figure 4, there is depicted at 400 a chart ****.

illustrating an example of how the transmission of an 5* . . * . . 31 alert signal from a monitoring unit 300 may be * *S " 32 configured. In this case, the monitoring unit 300 is 4*S, 33 programmed to transmit an alert signal if the hydrocarbon 1 contaminant level exceeds a pre-programmed level. In the 2 first instance, the monitoring unit transmits an alert 3 signal to the operator of the treatment apparatus 402.

4 In response to receiving the signal, the operator initiates a basic checking routine 404 of the apparatus 6 to ensure that the apparatus is operating correctly. In 7 an alternative embodiment, the checking routine is 8 automated. For example, the checks may include obtaining 9 readings concerning hydrocarbon levels in the drill fluid immediately prior to discharge.

12 If the contamination level remains above the acceptable 13 level despite the treatment apparatus functioning 14 properly, the alert is transmitted as a general alert to all personnel on site 406, e.g. the rig where the 16 treatment apparatus is employed. In response to this, a 17 series of detailed site wide checks 408 are initiated.

19 Further still, if the pollutant level remains unacceptable, the alert is transmitted to senior 21 personnel 410. The senior personnel 410 then initiate 22 shutdown processes 412 to prevent further contamination 23 from occurring.

The alert signal is first transmitted to a system ... 26 operator 402, and after conducting checks, the operator * *..

*... 27 unit 402 transmits the alert to personnel 406 and 28 subsequently the personnel 406 sends the alert to senior * ** S

I

29 personnel 410 according to the sequence I to III. S... * 30

31 Other arrangements may also be adopted, for example if 32 the pollution level is above a certain threshold the 33 units 406 or 410 may be alerted directly. Alternatively, 1 the monitoring unit 300 can be programmed to transmit an 2 alert directly to the unit 406 or 410 if the unit 402 3 fails to improve the contamination level after a pre- 4 determined period of time.

6 It will be appreciated that other alert arrangements for 7 ensuring that contamination levels are kept at an 8 acceptable level could be employed within the scope of 9 the present invention.

11 In a further embodiment, Figure 5 illustrates a drill 12 fluid and drill cutting treatment apparatus in use as 13 deployed at an offshore drilling site, and generally 14 shown at 500.

16 In this case, drill fluid and drill cutting treatment 17 apparatus as described above is deployed on an offshore 18 drilling rig 502. Drill cuttings and fluid retrieved 19 from the well 504 are treated and cleaned by apparatus 506 in the manner described with reference to the above 21 embodiments. Cleaned drill cuttings 510 and drill fluid 22 508 are discharged into the ocean 512. At least one 23 monitoring buoy 514 is deployed in the ocean in the 24 proximity of the rig. The buoy continuously measures the level of contamination at the sea surface at its

, 26 deployment locality. The contamination data are used to * 27 determine if the level of contamination is at an * 28 unacceptable level. Along with data from inspection *a * 29 ports (not shown), the system can confirm whether the *. *I unacceptable level of contamination is due to any- * 31 malfunction of the drill fluid and or drill cuttings. * S... DTD: 32 The buoy transmits an alert signal 516, which may be 33 received by the rig, if the contamination level is 1 unacceptably high. The alert signal is used to initiate 2 checks of equipment and shutdown of treatment apparatus 3 and/or well operations if appropriate.

The present invention provides a number of advantages.

6 The apparatus provides treatment and cleaning of both 7 drill fluid and cuttings for safe discharge into the 8 environment and removes the need to store hazardous drill 9 cuttings or drill fluid on site. This saves costs otherwise needed for transport and further treatment.

12 The monitoring unit, e.g. 300, measures environmental 13 contamination levels to ensure that discharge is safe and 14 is not harmful to the environment. This gives operators confidence in the treatment process and allows 16 performance to be evaluated.

18 The monitoring unit provides an alert system, which 19 allows rapid response to malfunctioning equipment.

21 Fluid resulting from the cleaning of cuttings is treated 22 together with separated drill fluid. The treatment 23 involves the separation of free oil, emulsion and 24 dissolved hydrocarbons. Oil/water emulsions are recycled through the heating system until the oil can be separated .,, 26 as free oil. This recycling of filtered components leads q *, 27 to minimal onsite storage. Only separated free oil is , 28 stored on site. This is re-useable. Other fluids are * .* * * * 29 made environmentally safe, e.g. water. * 30

* 31 The present unit may be assembled into an easy-to-use 32 compact portable unit for installation on site.

1 It will be appreciated in particular that the present 2 invention could be employed for treating fluid 3 contaminants and solid components in other effluent 4 streams, e.g., from manufacturing plants or refineries.

6 Various modifications and improvements may be made 7 without departing from the scope of the invention 8 described above.

U * . * *** *S.. * S a. *.

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Claims

1 Claims 3 1. A method of treating waste material from an 4 industrial

process, the method comprising the steps of: 6 a. receiving waste material from an industrial 7 process, the material comprising fluids, 8 solids and a contaminant; 9 b. diverting solids from the material into a first material stream and diverting fluids 11 from the material into a second material 12 stream; 13 c. driving fluids from the first material stream 14 and channelling the driven of f fluids into the second material stream; 16 d. reducing a level of the contaminant in the 17 second material stream to produce a treated 18 fluid stream; and 19 e. discharging the first material stream and the treated fluid stream into the environment.

22
2. The method as claimed in Claim 1 wherein the 23 material comprises solid drill cuttings and one or 24 more contaminants from an earth drilling operation.

26
3. The method as claimed in Claim 1 or Claim 2 wherein : 27 the one or more contaminants comprises a * *.S * * 28 hydrocarbon.

:.:. 29 *. 30
4. The method as claimed in any preceding claim 31 comprising the additional step of monitoring *.. 32 contaminants in the environment and providing an ,*. 33 indication of contaminant level.

2
5. The method as claimed in any preceding claim 3 comprising the additional step of discharging the 4 material into a body of environmental water.

6
6. The method as claimed in any preceding claim 7 comprising the additional step of filtering 8 residual solids from the second material stream.

7. The method as claimed in Claim 6 comprising the 11 additional step of backflushing filtered solids 12 into the first material stream.

14 8. The method as claimed in any preceding claim comprising the step of substantially removing a 16 soluble hydrocarbon from the second material 17 stream.

19 9. The method as claimed in any preceding claim comprising the additional step of oxidising the 21 contaminant in the second material stream.

23 10. The method as claimed in any preceding claim 24 comprising the additional step of separating free oil from the second material stream.

27 11. The method as claimed in Claim 10 comprising the *.. S additional step of attracting oil droplets to a surface of a coalescing unit. * 30

* IS..

31 12. The method as claimed in any preceding claim *.. 32 comprising the additional step of filtering heavy II..

S. metals from the second fluid stream.

2 13. The method as claimed in any preceding claim 3 comprising the additional step of removing an oil! 4 water emulsion from the second material stream.

6 14. The method as claimed in Claim 13 comprising the 7 additional step of adsorbing or absorbing an 8 emulsion from the second material stream.

15. The method as claimed in any preceding claim 11 comprising the additional step of recycling or 12 reusing media from a filter.

14 16. The method as claimed in Claim 14 comprising the additional step of adsorbing or absorbing an 16 emulsion from the second material stream using a 17 filter, and removing used media from the filter.

19 17. The method as claimed in Claim 16 comprising the additional step of treating the used media by 21 driving fluids from the media.

23 18. The method as claimed in Claim 17 comprising the 24 additional step of using the media in a subsequent filtering operation to adsorb or absorb an emulsion 26 from a material stream. * 27 **** * S

28 19. The method as claimed in Claim 14 comprising the :.:. 29 additional step of treating the used media to break *S*a. 30 an emulsion absorbed or adsorbed to the media to 31 create oil and water fluid components. * S * S I * I, Se.. 1.5.

1 20. The method as claimed in Claim 19 comprising the 2 additional step of channelling the oil and water 3 fluid components to the second material stream 4 water for subsequent treatment.

6 21. The method as claimed in any preceding claim 7 comprising the additional step of recovering 8 minerals from the first or second material streams.

22. The method as claimed in Claim 21 comprising the 11 additional step of recovering hydrocarbons from the 12 first or second material streams.

14 23. The method as claimed in any preceding claim wherein the step of driving fluids from the first 16 material stream is carried out by a drying unit.

18 24. The method as claimed in Claim 23 wherein the step 19 of driving fluids from the first material stream is carried out by heating the first material stream in 21 the drying unit.

23 25. The method as claimed in Claim 23 or Claim 24 24 wherein the step of driving fluids from the first material stream is carried out by a centrifuge 26 forming part of the drying unit. * 27

28 26. The method as claimed in any preceding claim comprising the additional step of treating the : 30 first material stream by applying solvents to 31 dissolve contaminants from the first fluid stream 32 and driving the solvent from the first material *s..

*** 33 stream.

2 27. The method as claimed in any preceding claim 3 comprising the additional step of inspecting a 4 level of a contaminant prior to discharge.

6 28. The method as claimed in Claim 27 comprising the 7 additional step of controlling an extent to which 8 the treatment apparatus reduces the level of 9 contaminant in the second material stream in dependence upon an indication of contaminant level.

12 29. The method as claimed in Claim 28 comprising the 13 step of manually controlling an extent to which the 14 treatment apparatus reduces the level of contaminant in the second material stream.

17 30. The method as claimed in Claim 28 comprising the 18 additional step of receiving in a processor a 19 plurality of indications of contaminant level and performing a statistical analysis of the plurality 21 of received indications.

23 31. The method as claimed in Claim 30 comprising the 24 additional step of calculating a concentration of the contaminant. :. 26

* 27 32. The method as claimed in any of Claims 28 to 31 S... * S

28 comprising the additional step of comparing the 29 indication of contaminant level with a threshold :..::. 30 value.

. 32 33. The method as claimed in Claim 32 comprising the *S..

 33 additional step of transmitting an alert signal in 1 dependence upon the comparison with the threshold 2 value.

4 34. The method as claimed in any preceding claim comprising the step of heating the first material 6 stream by irradiation with microwave radiation.

8 35. Apparatus for treating waste material from an 9 industrial process, the apparatus comprising: a separator unit configured to receive waste 11 material comprising fluids, solids and a 12 contaminant, the separator unit being operable to 13 divert solids from the material into a first 14 material stream and to divert fluids from the material into a second material stream; 16 a drying unit operable to drive fluids from the 17 first material stream; 18 a conduit to channel the driven off fluids into the 19 second material stream; a treatment device configured to reduce a level of 21 the contaminant in the second material stream and 22 produce a treated fluid stream; and 23 means for discharging the first material stream and 24 the treated fluid stream into the environment.

26 36. Apparatus as claimed in Claim 35 wherein the * 27 material comprises solid drill cuttings and one or *e.* * * 28 more contaminants from an earth drilling operation.

:.:. 29 37. Apparatus as claimed in Claim 35 or Claim 36 31 wherein the one or more contaminants comprises a v..' 32 hydrocarbon.

* S 33 *a*I 1 38. Apparatus as claimed in any of Claims 35 to 37 2 further comprising a contaminant monitor configured 3 to be disposed at or nearby the discharged 4 material, the contaminant monitor operable to monitor a level of contaminant in the environment 6 and provide an indication of contaminant level.

8 39. Apparatus as claimed in Claim 38 wherein the 9 contaminant monitor is configured to transmit a measuring signal for producing a measurable 11 response from the contaminant.

13 40. Apparatus as claimed in Claim 39 wherein the 14 contaminant monitor comprises an excitation source for transmitting the measuring signal.

17 41. Apparatus as claimed in Claim 39 or Claim 40 18 comprising an optical sensor adapted to measure 19 fluorescence from the contaminant.

21 42. Apparatus as claimed in any of Claims 39 to 41 22 comprising a sensor configured to measure a 23 reflected signal from the contaminant.

43. Apparatus as claimed in any of Claims 38 to 42 26 wherein the contaminant monitor is adapted to : 27 receive a test volume of environmental water. S... * S

:.:. 29 44. Apparatus as claimed in Claim 43 wherein an 30 excitation source is configured to transmit a 31 measuring signal to the test volume. * S * * S * S. S...

1 45. Apparatus as claimed in Claim 43 or 44 wherein a 2 sensor is configured to measure a reflected signal 3 from the test volume.

46. Apparatus as claimed in any of Claims 38 to 45 6 wherein the contaminant monitor is configured to 7 float on a body of environmental water.

9 47. Apparatus as claimed in Claim 46 wherein the contaminant monitor is located on a buoy, and a 11 test chamber is located on a central axis of the 12 buoy.

14 48. Apparatus as claimed in any of Claims 38 to 47 wherein the contaminant monitor is fitted to a 16 marine vessel or ship.

18 49. Apparatus as claimed in any of Claims 38 to 48 19 wherein the contaminant monitor is operable to transmit an alert signal according to a level of 21 contaminant.

23 50. Apparatus as claimed in Claim 49 wherein the alert 24 signal is an electronic signal for transmission to a remote location via a transmitter.

S

"27 51. Apparatus as claimed in any of Claims 35 to 50 * S.. * .

28 comprising a filter for filtering residual solids :.:. 29 from the second material stream. * 30 *.,

31 52. Apparatus as claimed in Claim 51 comprising means *... 32 for back-flushing filtered solids into the first *S** 33 material stream.

2 53. Apparatus as claimed in any of Claims 35 to 52 3 wherein the treatment device is configured to 4 oxidise the contaminant in the second material stream.

7 54. Apparatus as claimed in any of Claims 35 to 53 8 wherein the treatment device comprises electrolysis 9 apparatus operable to reduce a contaminant in the second material stream.

12 55. Apparatus as claimed in any of Claims 35 to 54 13 wherein the treatment device is configured to 14 reduce a level of a free contaminant.

16 56. Apparatus as claimed in any of Claims 35 to 55 17 wherein the treatment device is configured to 18 reduce a level of a dissolved contaminant.

57. Apparatus as claimed in any of Claims 35 to 56 21 wherein the treatment device is configured to 22 separate free oil from the second material stream.

24 58. Apparatus as claimed in Claim 57 wherein the treatment device comprises a coalescing unit 26 operable to reduce free oil in the second material : . 27 stream by attracting oil droplets to a surface of *I*S * * 28 the coalescing unit.

* .* S *..:.. 30 59. Apparatus as claimed in any of Claims 35 to 58 31 wherein the treatment device is configured to * . 32 remove oil/ water emulsions from the second * 33 material stream.

2 60. Apparatus as claimed in Claim 59 wherein the 3 treatment device comprises a filter for removing 4 oil! water emulsions.

6 61. Apparatus as claimed in Claim 60 wherein the filter 7 is configured to adsorb or absorb an emulsion from 8 the second material stream.

62. Apparatus as claimed in Claim 61 wherein the filter 11 comprises solid media to adsorb or absorb an 12 emulsion from the second material stream.

14 63. Apparatus as claimed in Claim 62 wherein the media is charcoal or Fuller's earth.

17 64. Apparatus as claimed in Claim 62 or Claim 63 18 wherein the media is removable from the filter.

65. Apparatus as claimed in any of Claims 62 to 64 21 further adapted to receive the media in the dryer 22 unit.

24 66. Apparatus as claimed in any of Claims 35 to 65 configured for transport and installation at :. 26 multiple sites. * 27 S.,. * .

 28 67. Apparatus as claimed in any of Claims 38 to 66 :.:. 29 further comprising a treatment device controller * a *..:. 30 operable in dependence upon the indication of 3]. contaminant level to change an extent to which the *.. 32 apparatus reduces the level of contaminant in the ** 33 second material stream.

2 68. Apparatus as claimed in Claim 67 wherein the 3 treatment device controller is manually operable by 4 a user of the apparatus.

6 69. Apparatus as claimed in any of Claims 35 to 68 7 wherein the dryer unit comprises a microwave 8 heating device operable to heat the first material 9 stream.

11 70. Apparatus for treating waste material from an 12 industrial process, the apparatus comprising: 13 treatment apparatus configured to receive material 14 from an industrial process, the material comprising fluids, solids and a contaminant, and to reduce a 16 level of the contaminant in the received water, the 17 treatment apparatus being configured to discharge 18 the treated material into the environment; and 19 a contaminant monitor configured to be disposed at or nearby the discharged treated material, wherein 21 the contaminant monitor comprises a luminescence 22 sensor operable to monitor a level of the 23 contaminant in the environment and provide an 24 indication of contaminant level.

26 71. Apparatus as claimed in Claim 70, configured to * 27 receive a plurality of indications of contaminant e*.* * * 28 level arid operable to perform a statistical :.:. 29 analysis of the plurality of received indications. * * * 30 ***.*

31 72. Apparatus as claimed in Claim 71 further comprising *:.. 32 a processor for performing the analysis.

I S...

1 73. Apparatus as claimed in any of Claims 70 to 72 2 wherein the contaminant monitor is operable to 3 calculate a concentration of the contaminant.

74. Apparatus as claimed in any of Claims 70 to 73 6 adapted to compare the indication of contaminant 7 level with a threshold value.

9 75. Apparatus as claimed in Claim 74 wherein the contaminant monitor comprises a comparator operable 11 to perform the comparison with the threshold value.

13 76. Apparatus as claimed in any of Claims 70 to 75 14 wherein the contaminant monitor is operable to transmit an alert signal in dependence upon the 16 comparison with the threshold value.

18 77. Apparatus as claimed in any of Claims 70 to 76 19 further comprising the features of the apparatus of any of Claims 35 to 69. 2].

22 78. A method of treating water from an industrial 23 process, comprising the steps of: 24 a. receiving water comprising a contaminant from an industrial process; :. 26 b. treating the received water to reduce a level * 27 of the contaminant in the received water; ***S * * 28 c. discharging the treated water into :.:. 29 environmental water; * * d. monitoring a level of the contaminant ii the 31 environmental water at or nearby the 32 discharged treated water; and S * S...

1 e. providing an indication of the contaminant 2 level by monitoring a level of the contaminant 3 in the enviromnental water with a luminescence 4 sensor.

6 79. The method as claimed in Claim 78 further 7 comprising the features of the methods of any of 8 Claims 1 to 34.

80. A marine vessel comprising apparatus according to 11 any of Claims 35 to 77.

13 81. An offshore facility comprising apparatus according 14 to any of Claims 35 to 77. * _.. S... * * a.. a.

* .* . S *

S S. a * .. a e as..