Note: Descriptions are shown in the official language in which they were submitted.
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WATE~ P~IRIFICATION
Technical Field
The ~resent in~ention relates to the ~urification
of contaminated water, and in ~articular an im~ro~ed method
and a~paratus for ~hotocatalytic oxidation of water borne
chemical s~ecies, for exam~le, microtoxins, phenolic
com~ounds, and ~esticide and insecticide com~ounds.
Background Art
Photocatalytic oxidation (destruction and
G~ovàl) of water borne chemical s~ecies has been the
subject of considerable re3earch in recent years, and has
involved oxidisation of a wide range of water borne
chemical s~ecies where catalytic surfaces, represented by a
suspen~ion of ~owdered catalytic material contained in a
closed sy4tem through which the contaminated water
circulates, is exposed to a photoactivating light source,
or alternati~ely a ~tationery catalytic 4urface is ~rovided
over which the contaminated water ~asses whil~t being
exposed to a source of ~hotoacti~ating ultra~iolet light
which may be sunlight or an artificial ~ource of
ultra~iolet light.
Disclosure of the Invention
We have found that the destruction and ~e~o~al of
chemical s~ecies cont~;n~nts in water can be improved
markedly if a stationary catalytic surface formed by-a
metallic catalyst, and inclined at an angle down which the
cont~m;nated water flows, is exposed to sunlight or
artificially generated ultra~iolet light.
The in~ention therefore en~isages a method of
purifying water to destroy and remo~e chemical s~ecies,
wherein the water is ~assed down an inclined surface formed
by a metallic catalyst, wh~lst being exposed to ultra~iolet
light, the incl~ned surface also being such as to ~ro~ide
turbulence in the water.
The in~ention also en~isages an a~aratus for
purifying water to de~troy and remove chemical s~ecies,
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said ap~aratus com~rising means to provide an inclined
surface of metallic catalyst, and exposed to a source of
ultraviolet light, said inclined surface alsobeing such as
to ~rovide turbulence in the water.
Brief Descri~tion of the Drawinas
one ~referred embodiment of the invention will
now be described with reference to the accom~anying
drawings, in which:
Figure 1 i8 a schematic ~lan view of the
a~aratus of the ~referred embodiment and to carry out the
method of the ~referred embodiment.
Figure 2 is a schematic side elevational view of
the a~paratus of Figure 1, and
Figure 3 is an enlarged view of the catalytic
surface of the embodiment of Figures 1 and 2.
Best Mode for Carryin~ Out the Invention
Referring to the drawings, the a~paratus,
~enerally indicated as 10, comprises an inclined trough 11
which contains an undulating member 12 ~roviding a series
of transverse ridges, and consisting of an outer layer 13
of a metallic catalyst ~u~orted as a thin film on a
backing 14 of glass fibre matting or glass fibre weave, or
any other material which ~rovides a suitable backing. The
trough 11 terminates at its lower end above an o~en to~ed
tank 15 into which water gravitating down the trough on the
metallic catalyst surface is delivered. Water in the tank
15 is drawn through a transfer ~i~e 16 by a ~um~ 17 which
~um~s the water u~ through a su~ply pi~e 18, contA;n;ng a
flow control valve 19, to a heA~r manifold 20 from which
the water flows to the to~ of the trough 11 and down the
trough to the tank 15. The ridges ~rovided by the
undulating member 12 assisting generating turbulence in the
flow of water down the trough which assists the
~hotocatalytic oxidation of the chemical s~ecies in the
contaminated water, whilst if a single ~as8 down the trough
is not sufficient to destroy and remove the chemical
~MEN~EDSHEET
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s~ecies, the water ean be cireulated around the ~y~tem as
many t~mes as are neeessary to aehle~e the desired result.
In this ~referred embodiment of the invention a
lam~ 21 ~roviding a ~ource of ultra~iolet l~ght i8
~ositioned above and ~arallel to the trough, and extends
along substantially the full length of the trough.
Alternatively, or in addition, sunlight may be u ed to
provide a natural souree of ultraviolet light when water
~urifieation during daylight hours is acee~table.
In the ~referred embodiment a metallic cataly~t
of titanium dioxide antaese has been found to be an
effeetive metallie eatalyst, although other metallie
catalysts may be effective to the same or lesser extent.
~MENDED8HEET
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