JPH01500537A - Method and device for measuring cyanide - Google Patents

Abstract

A system for measuring cyanides in a sample employs a photoillumination component for producing ultraviolet radiation to dissociate cyanides contained in an alkaline sample. The system includes filtering components interposed between the photoillumination components and an alkaline sample to be tested for passing lower frequency ultraviolet radiation to produce an irradiated sample in which cyanides have been dissociated, while blocking high frequency ultraviolet radiation to inhibit thiocyanate dissociation. Thin-film distillation components are included for separating cyanide from the irradiated sample to produce recovered cyanide for measurement purposes, and measuring components are provide for receiving the recovered cyanide generating a recordable signal indicative of recovered cyanide quantity.

Description

[Detailed description of the invention] The present invention generally relates to a method and apparatus for determining the amount of cyanide in a sample. Ru. In particular, the present invention relates to the above apparatus and method with improved cyanide separation capabilities.

Background technology Toxic compounds called cyanides are a threat to health and the environment. human These compounds are extremely harmful to aquatic life, not to mention environmental damage. This form of environmental pollution occurs and enters the environment through various routes. It is important to understand and control this. Measure cyanide in a given sample is an important step in the environmental remediation process.

Existing types and types of analytical methods applied to determine cyanide Among the corresponding devices, the most significant result is automated systems. For example, Publication No. 4.265,857 and Ann Arbor Michigan, L. ibrary or Congress Catalog Card lio, 7 6-50991j SBN O25040185-1 Ann Arbor 5c + Chenis published by ieence Publishers, Inc. Also the title of try of Vastewater Technology+ See references. These are incorporated into this disclosure for reference.

Takemote t1 anus 4-500537 (2) ”Chemistry Or Wastewater Technology+ As described in Chapter 20 of The measurement process consists of a thin film distillation method, a chemical absorption method, and an ultraviolet method. , cyanide is dissociated in the separation process.

A typical ultraviolet device consists of a violet beam surrounded by a quartz coil through which the acidic sample to be tested passes. Equipped with an outside line lamp. This quartz coil has a wavelength that is generated by ultraviolet lamps. Several energy levels or steps of ultraviolet light between approximately 15 mμ and 400 mμ Pass all spectral lines. Due to this ultraviolet radiation, iron and copolymer Decomposes all cyanide complexes including bal) complexes. Cobal) complex is a wave It is dissociated by radiation with lengths of about 255 mμ and about 310 mμ. generated shear Hydrogen chloride gas is separated by thin film distillation, and then HCN gas is dissolved in sodium hydroxide. Absorb it in a liquid and measure the color. In this way, total cyan in many different samples Chemicals can be continuously and automatically detected and measured.

The quartz coil in the system's conventional irradiation equipment covers all or a small portion of the ultraviolet spectrum. It is completely transparent and therefore ultraviolet light can remove all the shear in acidic samples. Can decompose compound complexes. However, thiocyanate is also dissociated and therefore cyanogen Cyanide measurements are somewhat higher and inaccurate because they are detected along with oxides.

Therefore, thiocyanate dissociation is undesirable in many applications. The system of the present invention The anhydride detection measurement system is a satisfactory system for most applications. However, all compounds including strong cobalt complexes can be used without dissociating the thionanate. A cyanide measurement system that dissociates cyanide complexes is highly desirable.

Parking of inventions Therefore, the main objective of the present invention is to remove the presence of thiocyanates without detecting or indicating the presence of thiocyanates. A novel and improved method and apparatus for determining the amount of cyanide in a sample in a convenient and accurate manner Our goal is to provide the following.

Another object of the invention is to form cobalt and iron complexes without dissociating the thiocyanate. We present a new and improved method and device that enable the dissociation of strong cyanide complexes, including It is about providing.

A further object of the present invention is to provide an improved method and apparatus which requires only modification of existing systems. The aim is to provide a

In summary, the above and other objects of the present invention are to solve the problems of cyanide in a liquid sample. This can be achieved by providing a new and improved system for measuring

The above system irradiates the sample only through low frequency ultraviolet light, which includes It decomposes the cyanide complexes in the In order to suppress the dissociation of the It is equipped with a filtering component.

A thin film distillation component is provided to separate cyanide from the irradiated sample and remove the cyanide. Collect and measure. In addition, we receive the recovered cyanide and present it as thioneane-1. Provide a measuring component that generates a recordable signal, indicating the recovery of cyanide insects. Ru.

Therefore, the method and apparatus of the present invention do not have the disadvantages of the prior art. The filter is about 1 It blocks ultraviolet light in the range of 50 mμ and about 290 mμ, and , but allows longer UV wavelengths to pass through.

By increasing the p)I of the sample, the strong cobalt cyanide complex can be completely decomposed.

In conventionally known systems in this regard, the sample is acidic; Because the pull is irradiated with a quartz irradiation device without a filtering function, the cyanide complex is completely removed. as well as releasing undesirable thiocyanates. However, the filter When combined with treatment irradiation, thiocyanate-1 can be dissociated even in alkaline samples. The cyanide complex decomposes completely without any decomposition. In this way, existing systems More advantageous cyanide measurements can be made by simply changing the system.

Brief description of the drawing Below, one embodiment of the present invention will be explained in detail with respect to the attached page 1. As a result, the above objectives and features of the present invention and other objectives and features of the present invention become clear, and the present invention You should be able to understand the invention best.

FIG. 1 partially schematically depicts a cyanide measurement system constructed in accordance with the present invention. , is a block diagram, and FIG. 2 is a schematic diagram showing the ultraviolet irradiation device of the system in FIG. is a schematic diagram, and FIG. 3 shows the detection and determination of thiocyanate in a sample according to the present invention. 1 is a block diagram of a multi-channel system; FIG.

Kaisotsubo Isu 1 (Bu 4i Futakami) Referring to the drawings, and in particular to FIG. The chemical substance measurement system 10 is comprised of a series of Used to determine the total amount of different cyanides present in different water samples It is something to do. Overall, the system 10 includes a pumped water sump. The separation section includes a light irradiation device 11A that decomposes the cyanide complex in the sample. Thin The membrane distillation device 11B separates cyanide from the irradiated sample and converts it into cyanide for measurement. collect things. In the absorption section 11C, the hydrogen cyanide gas generated from the sample is converted into hydroxyl. It is absorbed by chlorinated lithium. In the measuring section 11D, the sample from the absorption section IIC is measured. Automatically measures cyanide.

Segmented flow pump 12 transfers samples and reagents to system IO population 1 2A-12N and 12P to outlets 13.15-2j. (Usually for preservation Al MF11 [;4-500537 (3) The sample (potassic) is sent to the sample mixing coil 25 via the inlet 13. and mixed with an appropriate amount of nitrogen to create a segmented flow of a series of water samples to be tested. It is used as a carrier for Water can be used in place of nitrogen in system 10.

Light irradiation device! 1. A takes the form of a filtered UV irradiation device 30, which is connected to the coil 2 A series of segmented samples flowing from 5 are irradiated with ultraviolet light to Dissociates cyanide complexes contained. The irradiation device 30 It emits light in a very limited area, that is, ultraviolet rays with wavelengths of approximately 290 mμ and approximately 400 mμ. cyanide from the cyanide complex without dissociating the thiocyanate. Let go.

The irradiation sample that continuously flows from the outlet of the irradiation device 30 is sent through the pipe 15. and pressurized air received via line 16.

The continuous thin film evaporator 11B receives the aerated acidic sample and removes shear from the sample. Separate the compounds. The evaporator 11B is disclosed in detail in the above-mentioned US patent publication. There is. Thin film evaporator 11.8 produces continuous segments from the acidified sample). Hydrogen cyanide gas is released as a chemical flow along with some water. Condenses and cyanates Hydrogen gas is absorbed by the absorption section IC.

The segmented sample flowing from the outlet of the thin film evaporator is absorbed into the absorption section 11C. In the collecting coil 50-, it is mixed with lithium hydroxide from the pipe 17. This point As described in more detail in the above-mentioned literature, simultaneously with sodium hydroxide, Hydrogen cyanide gas is forced through the coil along with water to remove the cyanide in each sample. Recover hydrogen. The sample from the output [] of the absorption coil 50 is collected by the pump 12. The sample is sent back to the sample mixing coil 55 via the junction 18 and mixed with a suitable buffer. , segment by air.

The outlet sample of the sample mixing coil 55 is passed through the pipe 19 at the mixing coil 57. The chloramine-T is mixed with the chloramine-T of Mix with the color reagent.

The outlet of the mixing coil 57 is connected to a colorimeter 65 via a mixing coil 60, and connected to a piping 66. connected to pump 12 which drives the system through and pumps the sample out of line 2I do.

The colorimeter is connected to a printer 75 that provides a recordable signal indicating the amount of cyanide recovered. The output signal is sent to the input terminal of the recorder 70.

Thus, the method and apparatus of the present invention are free from interference with thiocyanate-1. It dissociates all cyanide complexes, including cobalt complexes. In the present invention , a novel method that suppresses thiocyanate decomposition by filtering specific ultraviolet energy levels. This can be achieved by using an alkaline sample together with a modified ultraviolet device. Achieved 4-ru.

After irradiation rather than before irradiation, the acid mixture sent via line 15 Acidifying the sample removes the cobalt complex without decomposing the thiocyanate. Decomposition of any strong cyanide complexes is a feature of the present invention.

Next, consider the filtered ultraviolet ray irradiation device 30 with respect to the device 30 in FIG. No A UV lamp 32 is installed vertically within a transparent metal housing 31 to emit a full spectrum of violet light. Generates an outside line. A transparent glass tube 33 surrounding the ultraviolet lamp 32 is connected to the first and second tubes. It is supported vertically by rings 34 and 35). These rings 34 and 35 a are supported by a plurality of support rods 36 and support screens 37, respectively.

Ultraviolet lamp 32 with transparent glass coil 38 by a plurality of upright support rods 39 surround. In this position, the segmented sample flowing through the glass coil 38 is irradiated with ultraviolet rays, and the device 30 is cooled by a fan 40.

The glass tube 33 is made of transparent glass and has a wavelength between about 290 mμ and about 400 mμ. It acts as a filter, allowing UV rays with shorter wavelengths to pass through, but blocking UV rays with shorter wavelengths. child As a result, except for a small portion of the strong cobalt complex dissociated, cyanide including iron complexes Dissociate all compound complexes. Using alkaline samples instead of acidified samples When irradiated, even cobalt complexes decompose.

In operation, the sample is passed through the glass tube 38 and the sample is irradiated to absorb thiocyanate. Dissociates cyanide without dissociating.

FIG. 3 shows a multi-channel system 100 for detecting thiocyanates in a sample. FIG.

In one channel, glass system 10 is used to remove the complete cyanide. generates the output signal shown. The second channel is, as described in said document, Equipped with a conventional quartz system +10, it is not only a complete cyanide but also the same quartz system. Thiocyanate from the pull is also shown.

The sample is connected through a piping lot, the reagent is connected through a piping 102, and this Quartz tJV cyanide system +10 and glass UV cyanide system l Connects to the inlet of O. System 110 is a system similar to system 10, A conventional quartz irradiation device (not shown) can be used instead of the filtered ultraviolet irradiation device 30. is used to generate a full spectrum of ultraviolet radiation, thereby identifying all cyan in each sample. and thiocyanate-1.

The output of system 110 is the total dissociated cyanide and thiocyanate in each sample. The electrical signal is +13 indicating the current. The output of system 10 is thionanate (SCN ) is an electrical signal 114 indicative of dissociated cyanide.

These two types of signals are generated by the output of a colorimeter, such as colorimeter 65 in Figure 1. You can also let Other conventional techniques may be applied to generate the signal. These beliefs No. 1 is a suitable means for generating an electrical output signal 131 indicative of the difference between human input signals 113 and 114. Conventional subtraction circuit 130 is coupled thereto. In this way, the output signal 131 is The amount of thiocyanate (SCN) in the test sample is shown.

Thus, the method and apparatus of the present invention provides a complete measurement of cyanide and, if desired, It is convenient for measuring thiocyanate.

A quartz tube (not shown) is used in place of the glass tube 33 and nitrogen is added to the acid mixture before irradiation. Quartz system 110 differs from system 1.0 only in additional respects.

Thus, there are only minor differences between the two systems.

Therefore, signal 131 is the difference between the two measurements taken by the two channels. This indicates the thiocyanate contained in each sample tested.

A complex method for measuring thiocyanate is that the color and turbidity of the sample do not interfere with the measured value. There are advantages to the channel type measurement method. The traditional direct thiocyanate colorimetric method is If the sample has color or turbidity, it will be subject to these interferences. The automatic system of the present invention If thiocyanate is not present, all of the strong cyanide complex (strong cobalt) Advantageously, total cyanide can be measured, including completely (even the root complex).

Although specific embodiments of the present invention have been disclosed for deaf persons, Various changes are possible and practicable within the spirit and scope of It is intended that For example, excluding the tube 33 and only the glass coil 38 Ultraviolet light can also be filtered, such as by using a filter with a filter. Therefore , there is no color gamut to limit the invention to the precise description disclosed herein.

Claims (8)

[Claims] 1. In equipment that measures cyanide in samples, ultraviolet light is generated to light irradiation means for dissociating cyanide contained in the potash sample; Irradiate the sample through low-frequency ultraviolet light to dissociate cyanide, but not through high-frequency ultraviolet light. In order to block external radiation and suppress the dissociation of thiocinate, the light irradiation means and the sample are filtering means provided between the sample and the test sample; Thin film distillation to separate cyanide from irradiated samples and recover cyanide for measurement means, and A meter that receives the recovered cyanide and produces a recordable signal indicating the amount of cyanide recovered. fixed means, The above measuring device consisting of: 2. The device according to claim 1, wherein the light irradiation means comprises an ultraviolet lamp. . 3. Claims in which the filtering means comprises a glass tube provided around the light irradiation means. Apparatus according to paragraph 1. 4. The filtering means is a glass coil installed around the light irradiation means and passing through the sample to be tested. 2. The apparatus of claim 1, comprising: a. 5. A method of measuring cyanide in a sample uses a photoirradiation component to Generates external radiation to dissociate cyanide contained in alkaline samples, and A filter is installed between the stage and the alkaline sample to be tested to allow low frequency ultraviolet light to pass through. irradiate the sample to dissociate cyanide but block high-frequency ultraviolet light. to suppress the dissociation of thiocyanate and separate cyanide from the irradiated sample for measurement. collect regular cyanide, and Measure the recovered cyanide and generate a recordable signal indicating the amount of cyanide recovered , The above method consists of: 6. Furthermore, by acidifying the irradiated sample and thin-film distillation of the acidified sample, The method according to claim 5. 7. The claim further comprises absorbing HCN from the product of thin film distillation. The method described in Section 6. 8. In a method for determining thiocyanate in a sample, cyanide and thiocyanate using a quartz ultraviolet irradiation device with the components to be measured. generate a first signal indicating the amount of recovery; A second signal indicating the amount of cyanide recovered using a glass irradiation device with the component to be measured a subtraction circuit responsive to the recordable first and second signals; generating a recordable signal indicative of the difference between the first and second signals using The above method consists of: