Method and device for automatic dissolution and conversion of colloidal iron in water samples

Abstract

The present invention belongs to the field of analysis and detection technology, and relates to a method and device for automatically dissolving and converting colloidal iron in a water sample, comprising the following steps: 1) adding a water-soluble catalyst to a water sample containing colloidal iron to obtain a mixed water sample containing colloidal iron; 2) the mixed water sample containing colloidal iron flows through an optical oxidizer (4), and under the action of the catalyst and optical oxidation, the colloidal iron in the mixed water sample is converted into dissolved iron; the volume-to-mass ratio of the water sample containing colloidal iron to the water-soluble catalyst is 60-100 ml:1 g; the water-soluble catalyst is composed of persulfate, additive, nitrate and water in a mass ratio of 4:2:4:90. The present invention can realize rapid and automatic dissolution and conversion of colloidal iron in a water sample, has a fast dissolution and conversion speed, low pollution, a high degree of automation, can accelerate the measurement speed of total iron, and reduce manual operation.

Description

Technical Field

[0001] The invention belongs to the technical field of analysis and detection, and relates to a method and a device for automatically dissolving and transforming colloidal iron in a water sample. Background Art

[0002] Currently, when testing for total iron in power plant water vapor, the iron in this vapor is mostly in the form of colloidal iron. Therefore, before sampling and testing, the colloidal iron must first be converted to a dissolved state before measurement. This typically requires adding acid or an oxidant and then boiling the colloidal iron to convert it into dissolved iron. Only then can the accurate total iron content be measured using atomic absorption or spectrophotometry. However, since the colloidal iron must first be converted into dissolved iron before testing, the addition of acid or an oxidant and the boiling process are environmentally polluting and complex. The measurement process is labor-intensive and time-consuming. In particular, during unit shutdown and startup, the inability of the colloidal iron to quickly convert into dissolved iron causes a significant lag in total iron measurement results. This makes it impossible to monitor the total iron content in the effluent water in a timely manner to guide adjustments to water conditions, hindering energy conservation and consumption reduction in power plants. Summary of the Invention

[0003] In order to solve the technical problems existing in existing iron detection, the present invention provides a method and device for automatically dissolving and converting colloidal iron in water samples. The present invention can realize the rapid and automatic dissolution and conversion of colloidal iron in water samples, with a fast dissolution and conversion speed, low pollution, high degree of automation, and can accelerate the measurement speed of total iron and reduce manual operation.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for automatically dissolving and converting colloidal iron in a water sample comprises the following steps:

[0006] 1) adding a water-soluble catalyst to a water sample containing colloidal iron to obtain a mixed water sample containing colloidal iron;

[0007] 2) The mixed water sample containing colloidal iron flows through the optical oxidizer. Under the action of the catalyst and optical oxidation, the colloidal iron in the mixed water sample is converted into dissolved iron.

[0008] Furthermore, in step 1), the volume-to-mass ratio of the water sample containing colloidal iron to the water-soluble catalyst is 60-100 ml:1 g.

[0009] Furthermore, the water-soluble catalyst is composed of persulfate, additive, nitrate and water in a mass ratio of 4:2:4:90.

[0010] Furthermore, the persulfate is (NH4)2S2O8; the additive is NH4Ac; and the nitrate is NH4NO3.

[0011] Furthermore, in step 2), the mixed water sample containing colloidal iron is pumped into the optical oxidizer at a flow rate of 1 to 10 mL / min.

[0012] Furthermore, in step 2), the process volume of the optical oxidizer is 5 mL to 10 mL; and the temperature of the dissolved iron-containing water sample coming out of the optical oxidizer is 35 to 50°C.

[0013] An automatic dissolution and conversion device for a method of automatically dissolving and converting colloidal iron in a water sample comprises a pump, a water sample mixer, a reagent storage tank, an optical oxidizer, and a dissolving water sample bottle; a water inlet, a reagent addition port, and a water outlet are respectively provided on the water sample mixer and are all connected to the interior of the water sample mixer; the pump is connected to the water inlet; the reagent storage tank is connected to the reagent addition port; and the water outlet is connected to the dissolving water sample bottle via the optical oxidizer.

[0014] Furthermore, the optical oxidizer is an online oxidizer.

[0015] Furthermore, the operating wavelength of the optical oxidizer is 280 to 500 nm; the power of the optical oxidizer is 30 to 100 W.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention adds a catalytic agent to the water sample and uses an optical oxidizer. Under the dual effects of the catalytic agent and optical oxidation, the colloidal iron in the water sample is automatically converted into dissolved iron. The dissolution speed is fast, and the dissolution rate can reach more than 96%. It greatly improves the iron measurement speed and ensures that the water condition can be adjusted in time.

[0018] 2. The catalyst provided by the present invention is composed of persulfate, additives, nitrate and water in a mass ratio of 4:2:4:90. Under the action of the catalyst, colloidal iron is rapidly dissolved and converted through optical oxidation, achieving automatic dissolution of the colloidal iron and significantly improving the detection efficiency of iron.

[0019] 3. The catalyst provided by the present invention is water-soluble, and the persulfate is (NH4)2S2O8; the additive is NH4Ac; and the nitrate is NH4NO3, so that the colloidal iron conversion and dissolution process is less polluting and faster.

[0020] 4. The present invention uses the optical oxidation effect of the optical oxidizer to quickly and automatically convert colloidal iron in water into dissolved iron, reducing manual workload and improving the degree of automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the automatic dissolution device provided by the present invention;

[0022] in:

[0023] 1—Pump; 2—Water sample mixer; 3—Reagent storage tank; 4—Optical oxidizer; 5—Dissolved water sample bottle. DETAILED DESCRIPTION

[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Example

[0026] See also Figure 1 The automatic dissolution device provided in this embodiment includes a pump 1, a water sample mixer 2, a reagent storage tank 3, an optical oxidizer 4, and a dissolving water sample bottle 5.

[0027] In this embodiment, a water inlet, a reagent addition port and a water outlet are respectively provided on the water sample mixer 2 and are all connected to the interior of the water sample mixer 2; the pump 1 is connected to the water inlet; the reagent storage tank 3 is connected to the reagent addition port; the water outlet is connected to the dissolved water sample bottle 5 through the optical oxidizer 4.

[0028] Furthermore, the optical oxidizer 4 is an online oxidizer, the operating wavelength of the optical oxidizer 4 is 280 to 500 nm, and the power of the optical oxidizer 4 can be arbitrarily selected within 30 to 100 W, and is selected according to the processing volume of the water sample.

[0029] The optical oxidizer 4 includes a housing, a coil, and a light source, each disposed within the housing. One end of the coil serves as the water inlet, and the other as the water outlet. Two light sources are located on the inner wall of the housing, each illuminating the water inlet and outlet, respectively, to facilitate photo-oxidation of the water sample flowing through the inlet and outlet. Both the coil and the housing are made of quartz.

[0030] The present embodiment provides a method for automatically dissolving and converting colloidal iron in a water sample, wherein the method comprises the following steps:

[0031] 1) adding a water-soluble catalyst to a water sample containing colloidal iron to obtain a mixed water sample containing colloidal iron;

[0032] In this step, the volume-to-mass ratio of the water sample containing colloidal iron to the water-soluble catalyst is 60 ml:1 g (the volume-to-mass ratio does not exceed 100:1).

[0033] 2) The mixed water sample containing colloidal iron flows through the optical oxidizer 4. Under the action of the catalyst and optical oxidation, the colloidal iron in the mixed water sample is converted into dissolved iron.

[0034] In this step, the mixed water sample containing colloidal iron is pumped into the optical oxidizer 4 at a flow rate of 1 mL / min (maximum flow rate is 10 mL / min); the flow volume of the optical oxidizer 4 is 5 mL, and the maximum flow volume is 10 mL; the temperature of the water sample containing dissolved iron exiting the optical oxidizer 4 is 35°C, and the maximum does not exceed 50°C.

[0035] The process volume refers to the volume of the water sample in the coil inside the optical oxidizer 4 when the water sample is oxidized and dissolved by the optical oxidizer 4, that is, the volume of the pipeline inside the optical oxidizer 4.

[0036] The water-soluble catalyst provided in this embodiment is composed of persulfate, additive, nitrate and water in a mass ratio of 4:2:4:90, and has a good catalytic effect.

[0037] Furthermore, the persulfate is (NH4)2S2O8; the additive is NH4Ac; and the nitrate is NH4NO3, which has low pollution and fast dissolution speed.

[0038] The following takes the dissolution of colloidal iron in a specific water sample as an example.

[0039] 10mL of water sample to be dissolved (mainly in the form of colloidal iron) enters the water sample mixer 2 through the water inlet, and at the same time, 0.1g of catalyst is added to the water sample mixer 2 from the reagent storage tank 3. After being evenly mixed in the water sample mixer 2, it enters the optical oxidizer 4 at a certain flow rate. In the optical oxidizer 4, light irradiation reaction is carried out at a wavelength of (280-500) nm. The colloidal iron is completely converted into dissolved iron in this process and enters the dissolved water sample bottle 5 connected to the optical oxidizer 4. The water sample in the dissolved water sample bottle 5 is used for atomic absorption or spectrophotometric measurement.

[0040] During implementation, 10 mL of water sample to be dissolved (mainly in the form of colloidal iron) is pumped into the water sample mixer 2 from the water inlet through pump 1, and 0.1 g of catalyst is introduced into the water sample mixer 2 from the reagent storage tank 3 through the reagent addition port. 10 mL of water sample to be dissolved and 0.1 g of catalyst are stirred and mixed in the water sample mixer 2 to form a mixed water sample. The mixed water sample enters the optical oxidizer 4 through the water outlet at a flow rate of 1 mL / min. The process volume in the optical oxidizer 4 is 10 mL. After being irradiated with light by the optical oxidizer 4, a photooxidation reaction occurs. Under the catalytic action of the reagent and the optical oxidation action, the colloidal iron in the water sample to be dissolved is converted into dissolved iron, and the dissolution rate can reach more than 96%; the water sample after the colloidal iron is dissolved (the temperature is 35° C.) flows from the optical oxidizer 4 into the dissolved water sample bottle 5, and the water sample in the dissolved water sample bottle 5 is used for atomic absorption or spectrophotometric measurement.

[0041] The present invention uses the dual effects of catalytic oxidation and optical oxidation to dissolve and transform colloidal iron in water samples in real time. The dissolution speed is fast, which facilitates the detection of total iron and provides a basis for timely adjustment of water conditions to ensure the smooth operation of the production system. In addition, the catalytic agent does not generate pollution during oxidation and dissolution, which is energy-saving and environmentally friendly.

Claims

1. A method for automatically dissolving and converting colloidal iron in a water sample, characterized in that: The following steps are involved: 1) adding a water-soluble catalyst to a water sample containing colloidal iron to obtain a mixed water sample containing colloidal iron; 2) The mixed water sample containing colloidal iron flows through the optical oxidizer (4), and under the action of the catalyst and optical oxidation, the colloidal iron in the mixed water sample is converted into dissolved iron; In step 1), the volume mass ratio of the water sample containing colloidal iron to the water-soluble catalyst is (60-100) ml:1 g; The water-soluble catalyst is composed of persulfate, additives, nitrate and water in a mass ratio of 4:2:4:90; The persulfate is (NH4)2S2O8; the additive is NH4Ac; and the nitrate is NH4NO3.

2. The method for automatically dissolving and converting colloidal iron in water samples according to claim 1, wherein: In the step 2), the mixed water sample containing colloidal iron is pumped into the optical oxidizer (4) at a flow rate of 1-10 mL / min.

3. The method for automatically dissolving and converting colloidal iron in water samples according to claim 2, characterized in that: In the step 2), the process volume of the optical oxidizer (4) is 5 mL to 10 mL; the temperature of the dissolved iron-containing water sample coming out of the optical oxidizer (4) is 35 to 50°C.

4. An automatic dissolution and conversion device for the automatic dissolution and conversion method of colloidal iron in water samples as claimed in claim 3, characterized in that: The automatic dissolution conversion device comprises a pump (1), a water sample mixer (2), a reagent storage tank (3), an optical oxidizer (4) and a dissolving water sample bottle (5); a water inlet, a reagent addition port and a water outlet are respectively provided on the water sample mixer (2) and are all connected to the interior of the water sample mixer (2); the pump (1) is connected to the water inlet; the reagent storage tank (3) is connected to the reagent addition port; and the water outlet is connected to the dissolving water sample bottle (5) via the optical oxidizer (4).

5. The automatic dissolution and conversion device according to claim 4, characterized in that: The optical oxidizer (4) is an online oxidizer.

6. The automatic dissolution and conversion device according to claim 4, characterized in that: The operating wavelength of the optical oxidizer (4) is 280-500 nm; the power of the optical oxidizer (4) is 30-100 W.

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