JPS60252262A - Method for measuring hydrogen sulfide - Google Patents

Abstract

PURPOSE:To measure continuously hydrogen sulfide with high accuracy with respect to the gas obtd. by briging an aq. soln. of hydrogen sulfide into contact with air, gaseous nitogen or carbon dioxide. CONSTITUTION:A required amt. of acid is added to the sample supplied from a metering pump 1 and thereafter the sample enters a diffuser S where the sample contacts with the air or gaseous nitrogen supplied at a specified rate to form the diffusion gas contg. hydrogen sulfide. Temp. controllers 5, 6 control the diffusion temp. and a condenser 7 condenses the moisture in the diffusion gas. The gas emitted from the condenser 7 enters a hydrogen sulfide detector D where the hydrogen sulfide is detected. The measured value having good accuracy is thus obtd. by the simple operation from the aq. soln. of low concn. contg. the hydrogen sulfide in the form of single substance, hydrosulfide ion or sulfide ion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention deals with aqueous solutions containing hydrogen sulfide in the form of molecules, hydrogen sulfide ions, sulfide ions, etc. Concerning how to measure.

Manufacturing of chemical factories] -: For the measurement of hydrogen sulfide contained in culm solutions, factory wastewater, etc., whether the method for analyzing hydrogen sulfide in waste waste has been applied mutatis mutandis. 12, the quadrisection formula l] also requires a lot of manpower and time at θ.
And continuous data cannot be merged. Furthermore, it has been pointed out that when the pH of the sample is low, hydrogen sulfide is likely to escape during the analysis process, making it difficult to obtain sufficient analysis accuracy.

The present invention was made with the aim of improving the accuracy of continuous 1-S simultaneous measurement of hydrogen sulfide θ] f ([1-constant) in various aqueous solutions (including hydrogen sulfide θ). 676 aiM7 fraction (3
This is based on the fact that it has a large Henry constant of 5°C) and can be separated as a scrap by a simple /f operation. In this method, the hydrogen sulfide concentration is several 10-(
1,01m9//l. It is suitable for measuring samples with extremely low L5 levels, and can therefore provide very useful data for process management and wastewater management.

In the method of the invention, a sample containing hydrogen sulfide is first brought into contact with clean scum free of hydrogen sulfide, and the hydrogen sulfide is selectively diffused into the gas phase. At this time, air or nitrogen gas is most commonly used as the dregs, but depending on the use, carbonic acid dregs may also be used. Hydrogen sulfide σ
In order to perform the quantitative dissipation, firstly, the pl, l of the aqueous solution is
It is necessary to maintain the condition in which all hydrogen sulfide exists in the molecular form, and therefore, the p■■ of the sample is changed to I'j, and the required amount of acid is added in advance to bring the pI-] to 41CJ. When to use 7F, which is non-volatile and has an oxidizing effect.
It needs to be a strong acid, and for practical purposes, dilute acid is most suitable.

In addition, if test r1 is slightly alkaline, even if carbonate scum is added for a month, pl4 will decrease and the same effect will be obtained? I can do it by being able to do it. The next necessary condition is the temperature for dissipation.The higher the degree of crystallinity, the easier the dispersion, but if the evaporation of water increases and the selectivity decreases, or if it condenses. Do not cause re-dissolution of hydrogen sulfide and cause errors.
No impact! It is necessary to set the value to an appropriate value in order to obtain the desired value. This temperature is preferably 30 DEG-45 DEG C. when the dissipation is carried out under atmospheric pressure, and if the pressure is reduced by -4.degree., a lower temperature is selected accordingly.

Next, the obtained hydrogen sulfide-containing residue is introduced into the sample diffuser 1j through a detector, and the hydrogen sulfide contained therein is continuously determined. A detector and a detector (~) are suitable for the coulometry type or the flame photometry type according to JTSB7952, but by adding an operation to acidify hydrogen sulfide to sulfur dioxide, the ultraviolet fluorescence type according to 5. ] TE K, o 103 solution conduction method can also be used.A coulometry-type detector electrolytically oxidizes hydrogen sulfide in an aqueous solution of potassium bromide acidified with sulfuric acid, and detects the energy necessary to maintain a predetermined redox potential. It is used to detect electrolytic current. All detectors are designed for continuous measurement and can obtain continuous recording charts. The usage classification of each detector is roughly as follows. One method of coulometry when the hydrogen sulfide concentration in the sample is too high
(I) elementary concentration in the sample 2 (I) 2m T flame y (
', degree method 0.1''-0, OQ 2 // In case, measure appropriately diluted.

Figure 1 shows the basic configuration for carrying out the present invention. In the figure, 8 is a hydrogen sulfide release device, 1 to 7 are devices in the 1st category, and 1 is a detection device. It is a vessel. Is a diffuser or a packed tower like Mukai Sushi's most suitable?
1'f II↓θ) type gas-liquid contact device is also available. Quantitatively quantify the release of hydrogen sulfide in a full moon? T
5 If the specific surface area is 10cIVm
It is necessary to fill 10 CTT 11'7''l of 10 CTT 11'7''l height, and the $ 01 supply rate with σ] is 2
~6ml/cm-mis air, liquid, ratio is 50-200 (
It is appropriate to use the volume ratio).

As shown in the figure, the sample is supplied from a metering pump.1) The acid is added to the sample, and then enters the diffuser, where it is supplied at a constant rate. [7] Forming a dissipated scum containing hydrogen sulfide. 56 is a πM moderator for dissipated gas quality, and 7 is a condenser for moisture in the dissipated gas. The gas that exits step 7 is detected for hydrogen sulfide in step (■).

Now, the Iko 1 speed of the test Fl is al11/, /gaku, the flow rate of the waste is b Nl/mrn, and the detector indication I16 is cvol.
When expressed as ppm, the hydrogen sulfide concentration in the sample is X (m9/l)
can be calculated from the following equation for a range where C is relatively small.

As is clear from the above explanation, the measuring method of the present invention does not contain hydrogen sulfide alone, in the form of hydrogen sulfide ions, sulfide ions, etc.;
It is possible to obtain continuous and highly accurate measurement values by simple operation, and is expected to be highly effective in practical use.

The following examples are provided to illustrate the method of the invention.

Example 1 The measuring device used in this example was assembled according to Figure 1, and the stripping tower had an inner diameter of 26 m5 and an overall height of 5 m.
5 (-In glass), 79+ is equipped with a material introduction tube and a gas discharge tube, and the bottom is equipped with an air introduction tube. 0
．． 3rnrn - Ratio table 1'Tii product 2 Q crI/
This was filled to a height of 40 mm with a glass coil made of ``Romell IJ''.Furthermore, the tower was equipped with a heater for preheating at the sample introduction part, and a humidity fiber was installed on the outside of the tower. Adopt things [Also.

1. Sulfurize the device once a month. Continuation of hydrogen sulfide in IJum aqueous solution ii! ll determination was carried out. That is, a solution containing 0.0909 of -Wi sodium hydrate (Na, S-9B2) in 1 liter was prepared, and its hydrogen sulfide concentration was analyzed by the methylene blue method, and the result was 12.1 η/l.

Which liquid disfigures V=Jj 41- for E'11)'1.
"A ・4N a to a concentration of 1 m-mol/7"
The above continuous measuring device VC8,00
Supply 1~ at a rate of m1/m = simultaneous addition of dilute sulfuric acid (co, o: cN) at a rate of 2 ml/mvl.

Also, by using an air pump, 1. ooNl/mvl of air was introduced. Free? 111Ja degree kept at 3'';'C 2
When the time was measured, the hydrogen sulfide concentration 10 minutes after the start of the measurement was 119±02 m9/71, which was in good agreement with the value analyzed in advance.

Example 2 Hydrogen sulfide in condensate water collected from a geothermal power plant was measured using the same equipment as used in Example 1. The properties of the condensate were a temperature of 38°C, a pI (4,6), and an expected concentration of hydrogen sulfide of around 5m9/1.Measurement conditions 7 - The conditions were as in Example except that the concentration of dilute sulfuric acid was ○oo5~. The result of continuous measurement over about 2 hours is 498~
It showed a constant value of 5.11 m9/7 [Also, for r, the analysis value by the methylene blue method carried out in parallel at incremental intervals was 4γfy - 5.06 my/i, which was quite variable. is.

[Brief explanation of drawings]

FIG. 1 shows the basic configuration for carrying out the measuring method of the present invention. S... Diffusion device ■... Metering pump for sample supply 2... Constant rate pump for acid supply? ... Air pump 4 ... Gas flow meter 5 ... Temperature controller 6 ... Temperature controller 7 ... Condenser ■) ... Hydrogen sulfide Detector patent applicant Kawa 1) Director of the Agency of Industrial Science and Technology - Ichino September 1983 IS
No. 2, Title of the invention Hydrogen sulfide) fill method 3, Supplementary IJ
:Relationship with each case Patent applicant

Claims (1)

[Claims] The aqueous solution is brought into contact with air, nitrogen scum, or carbon dioxide scum, while maintaining the hydrogen ion concentration in a state in which the hydrogen sulfide contained in the aqueous solution is substantially present in molecular form. 1. A method for continuous measurement of rh hydrogen sulfide in an aqueous solution, characterized by selectively dissipating hydrogen sulfide therein into a gas phase and detecting hydrogen sulfide in the resulting gas.