GB2155459A - Chlorine dioxide production - Google Patents

Abstract

Apparatus suitable for the production of chlorine dioxide solution of predeterminable concentration and volume comprises a reaction chamber 10 and a dilution chamber 20 and valve means 11, 12 and 21. The solution may be made by injecting the compounds through valve means 11 into the chamber 10 wherein reaction occurs while the chamber is closed by, for instance, valve 12, and after the reaction is complete the valve 12 is opened to allow the chlorine dioxide gas to become absorbed in diluent that has previously been introduced into dilution chamber 20 through valve 21, which is then closed. After absorption is complete valve 21 may be opened and the dilute solution discharged from the apparatus. <IMAGE>

Description

SPECIFICATION Chlorine dioxide production The invention relates to a method and a portable apparatus for producing reproducible pre-determinable quantities and concentrations of a solution chlorine dioxide gas, having particular utility in on-site field applications for sampling the effects of known concentrations of chlorine dioxide relative to adverse bacterial and algae growth, and the like, as well as sulphide related problems.

Chlorine dioxide is utilised in a variety of processes including a large amount of bactericidal applications, especially in the fields of water treatment and odour abatement. The usage of chlorine dioxide is continuing to grow for many reasons.

Prior art procedures for the preparation of chlorine dioxide may generally be placed within one of two general classifications. First, the typical "tube" or "conduit" procedure provides a continuous reaction of the additives along a conduit or flow stream. In such a procedure, the additives are introduced at points along the conduit and are continuously mixed with the diluent flowing therethrough. In this procedure, chlorine dioxide in diluted form is produced at ambient pressure. Secondly, chlorine dioxide typically may be prepared in a "batch" procedure in which an open reaction chamber, such as a flask, which is not under pressure, is utilised for receipt and reaction of the carbon dioxide precursor materials. Chlorine dioxide gas which is produced in the flask issues out of the flask and is fed into a reservoir where it is instantaneously diluted with a given diluent.In the "batch" process, the produced chlorine dioxide conentration is continuously variable because the total produced gs quantity may not be completely captured within the end product.

Due to the unstable nature of gaseous chlorine dioxide when compressed, it is necessary to produce chlorine dioxide on site rather than produce it at a plant and ship it for usage when needed. Accordingly, in U.S. Patent No.4,247,531, there is disclosed a device which is exemplary of the "tube" or "conduit" means for producing chlorine dioxide. In the '531 patent, the reactants are introduced into a chamber or "conduit" which is interconnected with a venturi or other source of vacuum through which water is introduced into the reaction chamber. The diluent is produced at another end of the chamber opposed from the water source and the source of precursor injection. Also exemplary of the "tube" or "conduit" type of procedure utilised to prepare chlorine dioxide is that as is disclosed in U.S.Patent No.4,247,531 ,which teaches a process wherein the generated chlorine dioxide is transferred from the reaction zone to another location by eduction of the chlorine dioxide by the movement of a diluting fluid through a venturi.

When chlorine dioxide is used in the pulp and paper, petroleum, and municipal water industries for various biocidal, sulphide removal, and water purification applications, it is also necessary to produce the chlorine dioxide on-site, as opposed to production at a plant, primarily because, as explained above, of the unstable nature of chlorine dioxide gas. Such applications generally require prior evaluations in order to establish the comparative effectiveness with respect to competitive products, and to provide an estimate of some initial dosage level. Such evaluations also typically require a specimen of chlorine dioxide to be available at a known activity level. Furthermore, these solutions require cumbersome shipping times and usually have a limited shelf life.

In applications wherein it is desired to provide prior evaluation of the effectiveness of given dosage levels of chlorine dioxide, it is not practical to utilise chlorine dioxide produced through typical prior art "tube" or "conduit" or "batch" processes, because the routine supply of test samples requires wasteful chemical expenditures during start up and shut down of such processes if the equipment is not in constant use.

Some laboratory apparatuses can be altered to provide given and known quantitites of chlorine dioxide for sample and evaluation purposes, as described above. However, these apparatuses are usually custom made and require expensive labour charges for their construction and are not typically suitable for on sight continuous and convenience field evaluation purposes. Such field evaluations are preferred to laboratory activity because of extraneous variables due to transportation of samples to the laboratory from the field, and there is a need to work with fresh samples of chlorine dioxide in actual field situations.

Most chlorine dioxide generators and methods of their use require concentrated precursor solutions. This usually results in production of chlorine dioxide gas which is not in solution. Closed vessels typically generate large pressures, which may be hazardous and promote large losses of products when the sealed vessels are opened to allow addition of diluent.

The present invention provides portable apparatus that solves these problems and a convenient method for providing a chlorine dioxide solution of predeterminable concentration and volume.

In the invention a chlorine dioxide slolution is made by reacting in a closed reaction chamber reactants that will generate chlorine dioxide and then connecting the reaction chamber to a dilution chamber containing diluent for chlorine dioxide and absorbing the chlorine dioxide into the diluent to form the solution of predetermined concentration and volume, and discharging the solution from the dilution chamber. The dilution chamber is, apart from its connection to the reaction chamber, closed during the absorption. The dilution chamber should receive the chlorine dioxide directly from the reaction chamber preferably substantially only upon complete reaction of the reactant compounds.The compounds are chosen such that they can and do react together to yield chlorine dioxide in the absence of the diluent but, when the two chambers are connected there is immediate and substantially complete absorption of the chlorine dioxide into the diluent in the dilution chamber, to form the solution. This absorption can be facilitated by agitatingly manipulating the apparatus to induce complete mixing of the chlorine dioxide and the diluent. The diluent is often water.

The method is preferably conducted using apparatus wherein the closed reaction chamber is selectively isolatable from the atmosphere, there are means communicable with the reaction chamber for introducing the reactant compounds into the chamber, the dilution chamber is selectively communicable with and extends from the reaction chamber for receipt of diluent and receipt of chlorine dioxide directly from the reaction chamber only upon complete reaction of the reacting compounds, and in which there are first valve means between the reaction chamber and the dilution chamber manipulatable between open and closed positions and which when closed isolate the chambers and when open permit absorption of the chlorine dioxide gas into diluent in the dilution chamber, means communicating with the dilution chamber for introducing the diluent into that chamber, and second valve means communicable with the dilution chamber and manipulatable between open and closed positions for introduction of the diluent into the dilution chamber and for removal of dilute chlorine dioxide solution when in the open position, and for isolating the dilution chamber from the atmosphere when in the closed position.

The invention also includes a portable apparatus for producing reproducible, pre-determinable quantities and concentrations of a solution of chlorine dioxide, comprising; (1) a closed reaction chamber selectively isolatable from the atmosphere and for production and retention of a pre-determinable volumetric amount of chlorine dioxide gas; (2) means communicable with the reaction chamber for introducing reactant compounds, which when reacted together in the absence of diluent yield chlorine dioxide, into the reaction chamber; (3) a dilution chamber selectively communicable with and extending from the reaction chamber for receipt of diluent therein and receipt of chlorine dioxide directly from the reaction chamber only upon complete reaction of the reacting compounds;; (4) first valve means between the reaction chamber and the dilution chamber manipulatable between open and closed positions, the first valve means when in the closed position isolating the reaction chamberfrom the dilution chamber and when in the open position permitting absorption of the produced chlorine dioxide gas into diluent in the dilution chamber; (5) means communicating with the dilution chamber for introducing a liquid chlorine dioxide diluent therein; and (6) second valve means communicable with the dilution chamber and manipulatable between open and closed positions for introduction of the chlorine dioxide liquid diluent into the dilution chamber and for removal of diluted chlorine dioxide solution when in open position and for isolating the silution chamber from atmosphere when in closed position.The means communicating with the reaction chamber for introducing the reactant compounds may comprise third valve means wherein means are provided on one end of the third valve means for selective sealing engagement of one end of a syringe for injection of the reactant compounds through the third valve means into the reaction chamber.

The apparatus may be hand-carried, is lightweight, its construction being stable, and, most importantly, fixed and pre-determinable quantities of chlorine dioxide solutions in which the activity of chlorine dioxide is known and can be reproduced on a repeatable basis, is provided.

The preferred apparatus comprises a closed reaction chamber selectively isolatable from atmosphere for production and retention of a pre-determinable volumetric amount of chlorine dioxide. Means are provided which are communicable with the reaction chamber for introducing reacting compounds, which when reacted together yield chlorine dioxide in the absence of dilution water, into the reaction chamber. A dilution chamber is selectively communicable with and extending from the reaction chamber.First valve means are provided between the reaction chamber and the dilution chamber and are manipulatable between open and closed positions, the first valve means when in the closed position isolating the rection chamber from the dilution chamber, and when in the open position subsequent to complete production of chlorine dioxide in the reaction chamber permitting immediate and substantially complete absorption of the produced chlorine dioxide into a diluent in the dilution chamber. Means are provided for communication with the dilution chamber for introducing a liquid chlorine dioxide diluent therein.Second valve means are provided which are communicable with the dilution chamber and are manipulatable between open and closed positions for introduction of the chlorine dioxide liquid diluent into the dilution chamber and for removal of chlorine dioxide solution when in open position, and for isolating the dilution chamber from atmsophere when in closed position.

The invention can be utilised with numerous types of reacting compounds which when reacted together yeild chlorine dioxide in the absence of dilution water. For example, binary and tertiary reacting compounds can be utilised. Binary precursor systems basically involve the use of metallic chlorites or chlorates with some acid or oxidising chemical. Examples of metallic chlorites are; Mx(C102)y, where M is a metal and x andy are subscripts which provide for the proper stoichiometry. Metallic chlorates having the formula: Mx(ClO3)y, wherein M, x andy are as described above, may also be utilised. Numerous acides, such as hydrochloric, sulphuric, oxalic, hypochlorous, and the like, mae selected for reaction. Oxidizers, such as ozone, chlorine gas, sodium persulphate and acetic anhydride solutions, and the like, may be incorporated into the invention. Tertiary systems which would include use of metallic chlorites or chlorates as well as the acids, described above, together with chlorine gas or sulphur dioxide gas, may also be used to produced chlorine dioxide in the invention.

The method of preparing on-site repeatable known quantities of chlorine dioxide diluent is provided which utilises the apparatus as described above. The dilution chamber is isolated from the reaction chamber by manipulating the first valve means to a closed position. Reacting compounds, which when reacted together yield chlorine dioxide in the absence of dilution water are introduced into the reaction chamber in predeterminable quantities to produce a predeterminable volumetric amount of chlorine dioxide while the reaction chamber is isolated from atmosphere. A predeterminable amount of liquid diluent is introduced into the dilution chamber to produce a predeterminable concentration of dilute solution of chlorine dioxide.The first valve means is manipulated to open position upon substantially complete reaction of the reactants in the reaction chamber to instantaneously communicate all of the produced chlorine dioxide in the reaction chamber and to be absorbed within the diluent liquid. The produced chlorine dioxide solution is removed from the dilution chamber upon manipulation of the second valve means to open position. Alternatively, the dilution chamber may be first isolated from the reaction chamber and diluent placed therein.Thereafter, the reactants may be placed into the reaction chamber for production of chlorine dioxide under pressure therein and the valve between the dilution chamber and the reaction chamber manipulated to open position after a known time, which is pre-calculatable, and subsequent to complete reacion of the reactants in the reaction chamber to produce a known amount of chlorine dioxide. Thereafter, the chlorine dioxide is intermixed with the diluent by manipulation of the valve means between the dilution chamber and the reaction chamber.

This invention is now illustrated by reference to the accompanying drawings, in which: Figure 1 is a dimensionalised schematic illustration, in cross-sectional view, of the device of the present invention.

Figure 2 is a view similar to that shown in Figure 1, but illustrating the convenient portability of the device as well as an alternative embodiment including means for injection of reactants into the reaction chamber, by the hand of a human operator.

Figure 3 is an illustration of the exterior of the device being hand agitated during the dilution step.

Now referring to Figure 1, the apparatus A basically consists of a reaction chamber 10 which is directly extendable from and communicatable with a dilution chamber 20. The interior of the dilution chamber 20 may be easily calculatable in order that when filled to a given amount, a known and repeatable dilution of the produced chlorine dioxide will be obtained therein. In a preferred embodiment, and in the embodiment utilised in the tests the results of which are shown in the examples below, the dilution chamber internal dimension was one inch by seven and three-quarters inches (2.5 x 19.5 cm).

A valve means 11, such as a flapper head, or rotational ball valve element, is shown as positioned and sealably associated in relation to the reaction chamber 10. The valve means 11 may be selectively manipulatable between open and closed positions. In a preferred embodiment, the valve means 11 comprises a housing 11 a with open end 23 for receipt of reactants therethrough.

Referring now to Figure 2, a particularly preferred method of use of the apparatus includes injection of the chlorine dioxide reactants into the reaction chamber 10 by utilisation of a convenient syringe S which is selectively sealingly engaged through the open end 23 of the housing 11 a of the valve means 11.

Pre-ascertainable amounts of the particular reactants are added, one after another, by use of one or more syringes S insertable into the open end 23. Upon sealing engagement of the end of the syringe S into the open end 23 of the housing 11 a, the valve means 11 is manipulated from closed to open position. Prior to removal of the syringe S from the housing 11 a, the valve means 11 is manipulated to closed position.

The apparatus A also provides valve means 12, which may be a butterfly, flapper, ball valve or other valve sealing element, with a hand operated manipulator 12a for manipulation of the valve between open and closed positions. The valve means 12 permits selective isolation between the reaction chamber 10 and the dilution chamber 20 when the valve means 12 is manipulated to the closed position. When the valve means 12 is manipulated to the open position, such as after complete reaction of the additives in the reaction chamber 10 to produce chlorine dioxide, the valve means 12 is manipulated to the open position to permit the diluent in the dilution chamber and the chlorine dioxide which is produced in the reaction chamber to mix and produce a known, predeterminable and repeatable volumetric amount of diluted chlorine dioxide solution.

The end of the dilution chamber 20 opposite that of the reaction chamber 10 has an open end 22 for discharge of the produced diluted chlorine dioxide solution, as well as for introduction into the dilution chamber 20 of the given amount of diluent. Valve means 21, which is similar in construction to valve means 12, contains manipulator 21a for selectively moving the valve means 21 between open and closed positions.

Of course, when valve means 21 is in the closed position the dilution chamber is sealingly isolated from the open end 22 of the apparatus A.

When it is desired to produce a known and fixed amount of chlorine dioxide diluent at an on sight location for purposes of evaluating the strength of the chlorine dioxide sample as a biocide, or the like, the apparatus A can be used to prepare aqueous chlorine dioxide solutions from acid-chlorate, acid-chlorite, hypochloriteacid-chlorite, chlorine-chlorite reactants. Preferably, a known and precalculatable amount of sodium chlorate or sodium chlorite is first introduced utilising the syringe S. A given amount of sodium chlorate or sodium chlorite first is placed ito the syringe S and transferred to the apparatus A by sealingly engaging the syringe S within the open end 23 of the valve means.Prior to injection of the sodium chlorate or sodium chlorite into the reaction chamber 10, the valve means 12 is manipulated to closed position and the valve means 11 is manipulated to open position. After injection of the sodium chlorate or sodium chlorite into the reaction chamber 10, the valve means 11 is closed and the syringe S removed therefrom. Thereafter, the syringe S is filled with a predeterminable or known amount of hydrochloric acid and again placed into sealing engagement with the valve means housing 11 a through the open end 23. The valve means 11 is manipulated to open position and the hydrochloric acid within the syringe S is injected into the reaction chamber 10.

Immediately thereafter, the valve means 11 is closed and the syringe S removed from the apparatus A. Since the volume of the reaction chamber is known, as well as the amount of the chlorate or chlorite placed therein, together with the amount of the hydrochloric acid utilised to promote the reaction, the time required for substantially complete reaction of the reactants to produce chlorine dioxide under pressure in the reaction chamber 10 is easily ascertained. Of course, hydrochloric acid can be added prior to the addition of sodium chlorite or sodium chlorate.

While the reaction is taking place in the reaction chamber 10, valve means 21 at the opposite end of the apparatus A may be manipulated to open position and a preascertainable known amount of diluent, such as tap water, or dionized water, may be inserted through the open end 22 into the dilution chamber 20 to obtain a fixed predeterminable dilution of chlorine dioxide solution. After injection of the diluent, the valve means 21 is manipulated to closed position by the manipulator 21a. Alternatively, the dilution chamber 20 can, of course, be filled with the proper amount of diluent prior to introduction of the reactants intlo the reaction chamber 10. If this sequence of steps is followed, the valve means 12 must, of course, be manipulated to closed position to isolate the diluent from the reaction chamber 10.

Upon the substantially complete reaction of the reactants in the reaction chamber 10 to produce the known quantity of chlorine dioxide, the valve means 12 is manipulated to open position by hand via the manipulator 12a, and the apparatus A shaked by hand, or otherwise, in any convenient motion, to permit and encourage mixture of the chlorine dioxide gas into the diluent within the dilution chamber 20. Typically, complete dilution can be effected in less than one minute or so. Thereafter, the valve means 21 is manipulated to open position and the diluted chlorine dioxide solution is removed from the apparatus A into a sample or other container for field or other convenient application.

One of the features and objectives of the present invention is the provision of an apparatus which may be used to provide repeated known quantities of chlorine dioxide solution. It can be seen that the amount of required reactants and the amount of the required diluent are easily pre-calculatable as well as the volumetric size of each of the reaction chamber 10 and the dilution chamber 20. With this information, any volumetric amount of a preselected activity of dilute chlorine dioxide solution may be prepared in the apparatus and, more importantly, may be repeatably prepared thereafter. The ease of application and repeatability of use of the apparatus is also demonstrated in the following examples.

Example I Tests were conducted and results were evaluated in order to deterne successful production of chlorine dioxide utilising the apparatus A. The reaction chamber 10 had a dimension of 0.5 inch (13 mm) in diameter and 2.25 inches (57 mm) in length, and the dilution chamber 20 had a dimension of one inch (25 mm) by seven and three-quarters inch (190 mm). Thus, the interior volume of each of the reaction chamber 10 and the dilution chamber 20 was preascertainable prior to reaction. Six runs were made utilising the apparatus A of Figure 1, utilising 4.8 millilitres of hydrochloric acid. In three of the runs, 3.9 millilitres of sodium chlorate was utilised, with varying amounts of deionized water which was utilised as the diluent.In three of the tests, the sodium chlorate was replaced with 6.0 millilitres of sodium chlorite and varying amounts of dionized water was utilised as the diluent in the dilution chamber 20. The hydrochloric acid reactant was injected into the open end 23 of the housing 1 1a using the syringe S with the valve means 12 manipulated to closed position and the stated amount of dionized water introduced into the dilution chamber 20 and the valve means 21 thereafter manipulated to closed position. After injection of the stated amount of hydrochloric acid, the valve means 11 was closed and the syringe S removed from the housing 11 a. Thereafter, the stated amount of chlorate or chlorite was injected into the reaction chamber 10 through the open end 23, again using the syringe S. The percent of chlorine dioxide was calculated by used of ultraviolet spectroscopy at 360nm. The results of this test concluded that solutions of various concentrations of chlorine dioxide could be quickly and conveniently prepared utilising the apparatus A as well as that given the dimensions of the chambers 10 to 20, and the desired dilution of the produced carbon dioxide solution, the required amounts of hydrochloric acid, chlorate or chlorite, and diluent could be easily and quickly determined prior to reaction within the apparatus A.The results of this example are setforth in Table 1, below: TABLE 1 mL HCI mL Chlorate mL Chlorite mL Total Liquid % Chlorine Dioxide 4.8 3.9 - 153.1 0.25 4.8 3.9 - 79.0 0.34 4.8 3.9 9.0 9.0 2.9 2.0 - 6.0 152.0 0.25 2.0 - 6.0 78.0 0.53 2.0 - 6.0 8.0 4.0 Example Il The present example demonstrates the ability of the apparatus A incorporated into the present method to produce chlorine dioxide solution in known amounts with pre-determinable concentrations of chlorine dioxide on a repeatable basis. The apparatus used was as shown in Figure las well as that utilised in the testing described in Example 1.In thetest,the dilution chamber 20 contained 144 millilitres deionized dilution water. The reactants were introduced to the reaction chamber 10 as in Example I. In the first series of tests, 5 millilitres of hydrochloric acid was reacted with 4 millilitres of sodium chlorate. The percent chlorine dioxide was determined by ultraviolet spectroscopy at 360nm, and the percent chlorine was determined by the leuco crystal violet visible spectrophotometric method. Using each of these methods, the produced percent of chlorine dioxide was within 0.01 percent for each test, while the percent of chlorine produced was within 0.02 percent for each test.In a second, third and fourth series of tests were performed which clearly indicated that repeatable, reproducable fixed quantities of chlorine dioxide solution could be prepared utilising the apparatus and method of the present invention. The results of this series of tests are set forth in Table 2, below:: TABLE 2 mL HCI mL {ChloratelChloríte) % Chlorine Dioxide % Chlorine 5.0 4.0, chlorate 0.27 0.42 5.0 4.0, chlorate 0.28 0.44 5.0 4.0, chlorate 0.27 0.42 4.6 3.7, chlorate 0.23 0.33 4.6 3.7, chlorate 0.21 0.31 4.6 3.7, chlorate 0.22 0.32 1.0 3.0, chlorite 0.12 0.03 1.0 3.0, chlorite 0.13 0.028 1.0 3.0, chlorite 0.11 0.026 2.0 6.0, chlorite 0.25 0.03 2.0 6.0, chlorite 0.25 0.03 2.0 6.0, chlorite 0.26 0.04 Example 111 The present example demonstrates the ability of the method and apparatus of the present invention to generate chlorine dioxide from chlorate/chlorite precursor solutions containing various adjuvants. The apparatus utilised in the present example was as utilised for previous examples, and the adjuvants were inserted into the reaction chamber 10 as in the previous examples.The diluent inserted into the dilution chamber was dionized water. This series of tests clearly demonstrates that adjuvants, as set forth below, may be utilised to prepare chlorine dioxide in the apparatus on a repeatable predeterminable amount to obtain a given and known chlorine dioxide activity in solution. The results of this test are set forth in Table 3, below: TABLE 3 ml HCI ml Precursor Precursor % Chlorine % Chlorine Composition Dioxide 2.4 1.5 40% NaClO3 0.123 0.138 2.4 1.5 40%NaClO3, 0.15 0.161 1 %Na2CrO4 4.6 3.7 40% NaClO3, 0.21 0.25 1% Na2CrO4, 7%NaCI 1.9 1.55 28% NaClO3, 0.172 0.062 3% NaClO2 1.8 1.6 28% NaClO3, 0.213 0.085 3% NaClO2, 1% Na2CrO4 1.65 1.6 28% NaClO3, 0.232 0.084 3% NaClO2, 1% Na2CrO4, 7% NaCI 4.6 3.7 40%NaClO3, 0.38 0.158 7% NaClO2, 1% Na2CrO4

Claims (10)

1. A process in which a chlorine dioxide solution of predeterminable concentration and volume is made by reacting in a closed reaction chamber reactant compounds that will generate chlorine dioxide and, after the reaction, directly connecting the reaction chamberto a dilution chamber containing diluent for chlorine dioxide and absorbing the chlorine dioxide into the diluent to form the solution, and discharging the solution from the dilution chamber.

2. A process according to claim 1 in which the amount of the diluent and the amounts of each of the reactant compounds are predetermined.

3. A process according to claim 1 or claim 2 in which the absorption of the chlorine dioxide into the diluent is promoted by agitation of the reaction and dilution chambers.

4. A process according to any preceding claim in which the diluent is water.

5. A process according to any preceding claim conducted using portable apparatus comprising the reaction chamber which is closed and is selectively isolatable from the atmosphere, means communicable with the reaction chamber for introducing the reactant compounds into the chamber, the dilution chamber selectively communicable with and extending from the reaction chamber for receipt of diluent and receipt of chlorine dioxide directly from the reaction chamber only upon complete reaction of the reactant compounds, first valve means between the reaction chamber and the dilution chamber manipulatable between open and closed positions, the first valve means when in the closed position isolating the reaction chamber from the dilution chamber and when in the open position permitting absorption of the produced chlorine dioxide gas into diluent in the dilution chamber, means communicating with the dilution chamber for introducing a liquid chlorine dioxide diluent, and second valve means communicable with the dilution chamber and manipulatable between open and closed positions for introduction of the diluent into the dilution chamber and for removal of dilute chlorine dioxide solution when in the open position and for isolating the dilution chamber from the atmosphere when in the closed position.

6. A process according to claim 5 wherein the apparatus comprises third valve means and means on one end thereof for selective sealing engagement of one end of a syringe and wherein each reactant compound is injected into the reaction chamber by a syringe while the syringe is sealingly engaged against the said means on the end of the third valve means.

7. A process according to claim 1 substantially as herein described with reference to any of the accompanying drawings.

8. A portable apparatus for producing reproducible, pre-determinable quantities and concentrations of a solution of chlorine dioxide, comprising: (1) a closed reaction chamber selectively isolatable from the atmosphere and for production and retention of a pre-determinable volumetric amount of chlorine dioxide gas; (2) means communicable with the reaction chamber for introducing reactant compounds, which when reacted together in the absence of diluent yield chlorine dioxide, into the reaction chamber; (3) a dilution chamber selectively communicable with and extending from the reaction chamber for receipt of diluent therein and receipt of chlorine dioxide directly from the reaction chamber only upon complete reaction of the reacting compounds;; (4) first valve means between the reaction chamber and the dilution chamber manipulatable between open and closed positions, the first valve means when in the closed position isolating the reaction chamber from the dilution chamber and when in the open position to permitting absorption of the produced chlorine dioxide gas into diluent in the dilution chamber; (5) means communicating with the dilution chamber for introducing a liquid chlorine dioxide diluent therein; and (6) second valve means communicable with the dilution chamber and manipulatable between open and closed positions for introduction of the chlorine dioxide liquid diluent into the dilution chamber and for removal of diluted chlorine dioxide solution when in open position and for isolating the dilution chamber from atmosphere when in closed position.

9. Apparatus according to claim 8 wherein the means communicable with the reaction chamber for introducing the reactant compounds comprise third valve means and wherein there are means on one end of the third valve means for selective sealing engagement of one end of a syringe for injection of the reactant compounds through the third valve means and into the reaction chamber.

10. Apparatus according to claim 8 substantially as herein described with reference to any of the accompanying drawings.