Method and device for detecting total sulfur in domestic sludge

Abstract

The embodiment of the invention provides a detection method and a detection device for total sulfur in domestic sludge. The detection method comprises the following steps: respectively weighing a to-be-detected domestic sludge sample and an Escherka reagent, putting the two into a crucible, and uniformly mixing; the crucible is placed in heating equipment to be subjected to staged temperature rising and heating; cooling after heating is finished, mashing a burnt material in the crucible, transferring the mashed burnt material into a beaker, continuously adding dilute nitric acid and distilled boiling water into the beaker, and carrying out boiling water bath; performing centrifugal motion on the beaker, extracting supernatant liquid in the beaker, and fixing the volume of the extracted supernatant liquid to a third volume; part of the solution with the third volume is extracted into a storage bottle, an yttrium element solution with the preset solubility is added into the storage bottle, deionized water is used for dilution to a preset scale, and then the total sulfur content is measured through a plasma emission spectrometer. The detection method disclosed by the embodiment of the invention is simple to operate, high in recovery rate and small in measurement interference.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the field of sludge detection technology, and specifically relate to a method and a device for detecting total sulfur in domestic sludge. Background Art

[0002] As a by-product of sewage treatment, the total sulfur content of domestic sludge directly affects the calorific value, odor control and heavy metal stability of sludge incineration. Currently, there is no specific method for determining total sulfur in domestic sludge, and the method for determining total sulfur in coal is generally used. The Aishkar method is an arbitration method for determining total sulfur in coal and is widely used in solid samples such as coal and soil. The sample is mixed with the Aishkar reagent and burned at high temperature to convert sulfur into sulfate. The sulfur content is then calculated through dissolution, precipitation, burning and weighing. However, the Aishkar method has the following problems when applied directly to domestic sludge:

[0003] (1) Low recovery rate: Domestic sludge contains a lot of organic matter, and high-temperature burning leads to the loss of sulfur in the organic matter.

[0004] (2) Serious interference: The content of chloride ions and heavy metal ions (such as Fe3+, Al3+) in domestic sludge far exceeds that in solid samples such as coal and soil. These elements will interfere with the determination of sulfur.

[0005] (3) Complicated operation: The Aishkar method for determining the total sulfur content in coal requires multiple washing, filtering, precipitation, and burning steps, which generally takes 24 to 48 hours and is inefficient. Summary of the Invention

[0006] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a method and a device for detecting total sulfur in domestic sludge.

[0007] In one aspect, an embodiment of the present disclosure provides a method for detecting total sulfur in domestic sludge, the detection method comprising:

[0008] Weigh a first weight of the domestic sludge sample to be tested and a second weight of the ASC reagent respectively, place the two in a crucible and mix them evenly;

[0009] Placing the crucible in a heating device, heating the crucible to a first temperature, burning the crucible and maintaining the temperature for a first preset time, and then continuously heating the crucible to a second temperature, burning the crucible and maintaining the temperature for a second preset time;

[0010] The crucible is removed from the heating device for cooling, and after cooling, the burned material in the crucible is crushed and transferred into a beaker, a first volume of dilute nitric acid and a second volume of distilled boiling water are added to the beaker, and the beaker is placed in a boiling water bath for a third preset time;

[0011] Placing the beaker in a centrifuge for centrifugal movement, extracting the supernatant in the beaker and adjusting the volume of the extracted supernatant to a third volume;

[0012] A portion of the third volume of solution is extracted into a storage bottle, and a yttrium element solution with a preset solubility is added to the storage bottle. After being diluted to a preset scale with deionized water, the total sulfur content is determined by a plasma emission spectrometer.

[0013] Optionally, the first weight is 0.5g~5g, the second weight is 3g~10g, the first temperature is 180℃~220℃, the first preset time is 25min~35min, the second temperature is 450℃~550℃, the second preset time is 1h~2.5h, the first volume is 5ml~15ml, the second volume is 40ml~60ml, the third preset time is 15min~25min, and the third volume is not less than 100ml.

[0014] Optionally, the first weight is 1g, the second weight is 5g, the first temperature is 200℃, the first preset time is 30min, the second temperature is 500℃, the second preset time is 2h, the first volume is 10ml, the second volume is 50ml, the third preset time is 20min, and the third volume is 100ml.

[0015] Optionally, extracting a portion from the third volume of solution into the storage bottle includes extracting 5 ml of solution into the storage bottle, and adding a preset yttrium element solution into the storage bottle includes adding 1 ml of yttrium element solution with a solubility of 500 mg / L into the storage bottle, and the preset scale is 50 ml.

[0016] Optionally, the crucible is a porcelain crucible, and the heating device is a muffle furnace.

[0017] Optionally, crushing the burnt material in the crucible and transferring it into the beaker comprises crushing the burnt material in the crucible with a glass rod, washing the inner wall of the crucible with boiling water, and pouring all the washing liquid into the beaker.

[0018] Optionally, extracting the supernatant liquid from the beaker and adjusting the volume of the extracted supernatant liquid to a third volume includes directly extracting the third volume of the supernatant liquid if the volume of the supernatant liquid in the beaker is larger than the third volume; if the volume of the supernatant liquid in the beaker is smaller than the third volume, continuing to mix deionized water into the supernatant liquid after extracting the supernatant until the volume reaches the third volume.

[0019] Optionally, the measuring the total sulfur content by using a plasma emission spectrometer includes measuring the total sulfur content by using the plasma emission spectrometer at a wavelength of 182.03 nm.

[0020] Optionally, before weighing the domestic sludge sample to be tested, the detection method further comprises placing the domestic sludge in a mixing device for mixing to obtain the domestic sludge to be tested;

[0021] Placing the beaker in a centrifuge for centrifugal motion includes subjecting the beaker to centrifugal motion at a rotation speed of 6000 rpm to 10000 rpm in the centrifuge, and the time of the centrifugal motion is 15 min to 25 min.

[0022] On the other hand, an embodiment of the present disclosure provides a device for detecting total sulfur in domestic sludge, the detection device comprising:

[0023] a weighing and mixing module, for respectively weighing a first weight of the domestic sludge sample to be tested and a second weight of the Aesca reagent and placing the two in a crucible and mixing them evenly;

[0024] A heating module is used to place the crucible in a heating device, and to raise the temperature of the heating device to a first temperature for burning and maintain it for a first preset time, and then to raise the temperature to a second temperature for burning and maintain it for a second preset time;

[0025] an extraction and volume setting module, configured to remove the crucible from the heating device for cooling, crush the burnt material in the crucible after cooling, transfer the crushed material into a beaker, continue adding a first volume of dilute nitric acid and a second volume of distilled boiling water into the beaker, and place the beaker in a boiling water bath for a third preset time; place the beaker in a centrifuge for centrifugal motion, extract a supernatant in the beaker, and set the supernatant to a third volume;

[0026] The detection module is used to extract a portion of the solution from the third volume into a storage bottle, add a yttrium element solution of a preset solubility into the storage bottle, dilute it to a preset scale with deionized water, and then determine the total sulfur content by a plasma emission spectrometer.

[0027] The disclosed method and device for detecting total sulfur in sewage sludge are simple to operate, require fewer steps, and produce results in just 3-5 hours. They also offer a high recovery rate, using a staged incineration process to eliminate sulfur loss due to high-temperature volatilization. The final total sulfur determination is performed using a plasma emission spectrometer, minimizing interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a flowchart of a method for detecting total sulfur in domestic sludge according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0030] like Figure 1 As shown, a method for detecting total sulfur in domestic sludge includes S110, respectively weighing a first weight of a domestic sludge sample to be tested and a second weight of an ASC reagent and placing the two in a crucible and mixing them evenly.

[0031] Specifically, before performing this step, the domestic sludge is placed in a mixing device and thoroughly mixed for 30 minutes to obtain a specific domestic sludge sample to be tested. Then, a first weight of the domestic sludge sample to be tested and a second weight of the Aesca reagent are weighed and placed in a crucible and mixed evenly. The first weight can be set to 0.5g to 5g, and the second weight can be set to 3g to 10g. Specifically, 1g of the domestic sludge sample to be tested and 5g of the Aesca reagent are weighed and placed in a porcelain crucible and mixed evenly.

[0032] S120, placing the crucible in a heating device, and heating the crucible to a first temperature for burning and maintaining the temperature for a first preset time, and then continuing to heat the crucible to a second temperature for burning and maintaining the temperature for a second preset time.

[0033] Specifically, in this step, a porcelain crucible containing 1g of the domestic sludge sample to be tested and 5g of the Aesculapius reagent is placed in a heating device, such as a muffle furnace. The muffle furnace is first slowly heated to a first temperature and maintained at the first temperature for a first predetermined time to ignite the domestic sludge sample and the Aesculapius reagent. The muffle furnace is then further heated to a second temperature and maintained at the second temperature for a second predetermined time to continue igniting the domestic sludge sample and the Aesculapius reagent.

[0034] The first temperature can be set to 180℃~220℃, the first preset time can be set to 25min~35min, the second temperature can be set to 450℃~550℃, and the second preset time can be set to 1h~2.5h. Specifically, slowly heat the muffle furnace to 200℃ and keep it at this temperature for 30min. Then continue to heat it to 500℃ and keep it at this temperature for 2h. This heating method is different from the direct high-temperature burning of the Aishka method. The staged low-temperature burning treatment method will not cause the loss of sulfur due to high-temperature volatilization. It should be noted that the direct mixing and burning of domestic sewage sludge with the Aishka reagent without drying will not affect the test results.

[0035] S130, taking the crucible out of the heating device and cooling it, crushing the burned material in the crucible after cooling and moving it into a beaker, adding a first volume of dilute nitric acid and a second volume of distilled boiling water into the beaker, and placing the beaker in a boiling water bath for a third preset time.

[0036] Specifically, in this step, first remove the crucible from the heating device and cool it to room temperature. Then use a glass rod to crush the burned material in the crucible and move it into a beaker. And use boiling water to rinse the inner wall of the crucible and pour all the rinsing liquid into the beaker to ensure that there is no ash residue left in the crucible. Then continue to add a first volume of dilute nitric acid and a second volume of distilled boiling water to the beaker. The first volume can be set to 5ml to 15ml, and the second volume can be set to 40ml to 60ml. Specifically, add 10ml of dilute nitric acid and 50ml of freshly boiled distilled water to the beaker. Put the beaker in a boiling water bath and heat it in the boiling water bath for a third preset time. The third preset time can be set to 15min to 25min, specifically using a boiling water bath for 20min.

[0037] S140, placing the beaker in a centrifuge for centrifugal motion, extracting the supernatant in the beaker and adjusting the volume of the extracted supernatant to a third volume.

[0038] Specifically, after heating the beaker in a boiling water bath, the beaker is placed in a high-speed centrifuge for centrifugal motion again. The beaker is subjected to high-speed centrifugal motion in the centrifuge at a speed of 6000 rpm to 10000 rpm. The centrifugal motion lasts for 15 minutes to 25 minutes, and specifically, the high-speed centrifugation can be performed for 20 minutes. After high-speed centrifugation, the supernatant in the beaker is extracted and fixed to a third volume. The third volume is not less than 100 ml. As an example, the third volume can be set to 100 ml.

[0039] Furthermore, extracting the supernatant from the beaker and adjusting the volume of the extracted supernatant to the third volume includes, if the volume of the supernatant in the beaker is larger than the third volume, directly extracting the third volume of the supernatant. If the volume of the supernatant in the beaker is smaller than the third volume, then, after extracting the supernatant, continuously mixing deionized water into the supernatant until the volume reaches the third volume.

[0040] S150, extracting a portion of the third volume of solution into a storage bottle, adding a yttrium element solution of a preset solubility into the storage bottle, diluting it to a preset scale with deionized water, and then measuring the total sulfur content by a plasma emission spectrometer.

[0041] Specifically, in this step, extracting a portion of the solution from the third volume into the storage bottle includes extracting 5 ml of the solution into the storage bottle, and adding the yttrium solution of a preset solubility into the storage bottle includes adding 1 ml of yttrium solution with a solubility of 500 mg / L into the storage bottle, where the preset scale is 50 ml. As a specific example, 5 ml of the solution from the third volume is extracted and added to a 50 ml storage bottle, and 1 ml of yttrium solution with a solubility of 500 mg / L is further added to the storage bottle. After diluting the solution to 50 ml with deionized water, the total sulfur content is measured using a plasma emission spectrometer at a wavelength of 182.03 nm.

[0042] The disclosed method for detecting total sulfur in sewage sludge is simple to operate, requires only a few steps, and produces results in just 3–5 hours. It also offers a high recovery rate, and the staged incineration process eliminates sulfur loss due to high-temperature volatilization. Furthermore, by adding an internal standard solution and measuring at a specific wavelength of 182.03 nm, interference from other elements is minimized.

[0043] As a specific example, the above detection method is used to select a domestic sludge for detection as follows:

[0044] Step 1: Place the domestic sludge sample in a mixing device and mix it thoroughly for 30 minutes. After mixing, weigh 1g of domestic sludge and 5g of ASC reagent in a porcelain crucible and mix them evenly. Place it in a muffle furnace and slowly heat it to 200℃ and keep it at this temperature for 30 minutes. Then heat it to 500℃ and keep it at this temperature for 2 hours. Take it out and cool it to room temperature.

[0045] Step 2: Use a glass rod to crush the burnt material in the crucible, then transfer it to a beaker. Rinse the inner wall of the crucible carefully with hot water to ensure that there is no ash residue. Add 10ml of dilute nitric acid and 50ml of freshly boiled distilled water. Heat in a boiling water bath for 20 minutes, place in a high-speed centrifuge, and centrifuge at high speed for 20 minutes. Take the supernatant and adjust the volume to 100ml.

[0046] Step 3: Take 5 ml of the above solution in a 50 ml volumetric flask, add 1 ml of yttrium element solution with a solubility of 500 mg / L, dilute to the scale with deionized water, and measure the total sulfur content of 3.6% using a plasma emission spectrometer at a wavelength of 182.03 nm.

[0047] On the other hand, an embodiment of the present disclosure provides a device for detecting total sulfur in domestic sludge, the device comprising:

[0048] The weighing and mixing module is used to respectively weigh a first weight of the domestic sludge sample to be tested and a second weight of the ASC reagent and place the two in a crucible and mix them evenly.

[0049] The heating module is used to place the crucible in a heating device, and to raise the temperature of the heating device to a first temperature for burning and maintaining it for a first preset time, and then continue to raise the temperature to a second temperature for burning and maintaining it for a second preset time.

[0050] The extraction and volume setting module is configured to remove the crucible from the heating device and cool it. After cooling, the burned material in the crucible is crushed and transferred to a beaker. A first volume of dilute nitric acid and a second volume of distilled boiling water are then added to the beaker, and the beaker is placed in a boiling water bath for a third predetermined time. The beaker is then centrifuged in a centrifuge, and the supernatant liquid in the beaker is extracted and the volume of the extracted supernatant liquid is set to a third volume.

[0051] The detection module is used to extract a portion of the solution from the third volume into a storage bottle, add a yttrium element solution of a preset solubility into the storage bottle, dilute it to a preset scale with deionized water, and then determine the total sulfur content by a plasma emission spectrometer.

[0052] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A method for detecting total sulfur in domestic sludge, characterized in that: The detection method comprises: Weigh a first weight of the domestic sludge sample to be tested and a second weight of the ASC reagent respectively, place the two in a crucible and mix them evenly; Placing the crucible in a heating device, heating the crucible to a first temperature, burning the crucible and maintaining the temperature for a first preset time, and then continuously heating the crucible to a second temperature, burning the crucible and maintaining the temperature for a second preset time; The crucible is removed from the heating device for cooling, and after cooling, the burned material in the crucible is crushed and transferred into a beaker, a first volume of dilute nitric acid and a second volume of distilled boiling water are added to the beaker, and the beaker is placed in a boiling water bath for a third preset time; Placing the beaker in a centrifuge for centrifugal movement, extracting the supernatant in the beaker and adjusting the volume of the extracted supernatant to a third volume; A portion of the third volume of solution is extracted into a storage bottle, and a yttrium element solution with a preset solubility is added to the storage bottle. After being diluted to a preset scale with deionized water, the total sulfur content is determined by a plasma emission spectrometer.

2. The method for detecting total sulfur in domestic sludge according to claim 1, wherein The first weight is 0.5g~5g, the second weight is 3g~10g, the first temperature is 180℃~220℃, the first preset time is 25min~35min, the second temperature is 450℃~550℃, the second preset time is 1h~2.5h, the first volume is 5ml~15ml, the second volume is 40ml~60ml, the third preset time is 15min~25min, and the third volume is not less than 100ml.

3. The method for detecting total sulfur in domestic sludge according to claim 2, wherein: The first weight is 1g, the second weight is 5g, the first temperature is 200℃, the first preset time is 30min, the second temperature is 500℃, the second preset time is 2h, the first volume is 10ml, the second volume is 50ml, the third preset time is 20min, and the third volume is 100ml.

4. The method for detecting total sulfur in domestic sludge according to claim 3, wherein: The step of extracting a portion of the solution from the third volume into the storage bottle includes extracting 5 ml of the solution into the storage bottle, and the step of adding a yttrium element solution of a preset solubility into the storage bottle includes adding 1 ml of a yttrium element solution of a solubility of 500 mg / L into the storage bottle, and the preset scale is 50 ml.

5. The method for detecting total sulfur in domestic sludge according to claim 1, characterized in that: The crucible is a porcelain crucible, and the heating device is a muffle furnace.

6. The method for detecting total sulfur in domestic sludge according to claim 1, characterized in that: The crushing of the burnt material in the crucible and transferring it into the beaker comprises crushing the burnt material in the crucible with a glass rod, washing the inner wall of the crucible with boiling water, and pouring all the washing liquid into the beaker.

7. The method for detecting total sulfur in domestic sludge according to claim 6, characterized in that: The step of extracting the supernatant liquid from the beaker and adjusting the volume of the extracted supernatant liquid to the third volume includes: if the volume of the supernatant liquid in the beaker is greater than the third volume, directly extracting the third volume of the supernatant liquid; if the volume of the supernatant liquid in the beaker is less than the third volume, continuing to mix deionized water into the supernatant liquid after extracting the supernatant until the volume reaches the third volume.

8. The method for detecting total sulfur in domestic sludge according to any one of claims 1 to 7, characterized in that: The measuring of the total sulfur content by using a plasma emission spectrometer includes measuring the total sulfur content by using the plasma emission spectrometer at a wavelength of 182.03 nm.

9. The method for detecting total sulfur in domestic sludge according to any one of claims 1 to 7, characterized in that: Before weighing the domestic sludge sample to be tested, the detection method further comprises placing the domestic sludge in a mixing device for mixing to obtain the domestic sludge to be tested; Placing the beaker in a centrifuge for centrifugal motion includes subjecting the beaker to centrifugal motion at a rotation speed of 6000 rpm to 10000 rpm in the centrifuge, and the time of the centrifugal motion is 15 min to 25 min.

10. A device for detecting total sulfur in domestic sludge, characterized in that: The detection device comprises: a weighing and mixing module, for respectively weighing a first weight of the domestic sludge sample to be tested and a second weight of the Aesca reagent and placing the two in a crucible and mixing them evenly; A heating module is used to place the crucible in a heating device, and to raise the temperature of the heating device to a first temperature for burning and maintain it for a first preset time, and then to raise the temperature to a second temperature for burning and maintain it for a second preset time; an extraction and volume setting module, configured to remove the crucible from the heating device for cooling, crush the burnt material in the crucible after cooling, transfer the crushed material into a beaker, continue adding a first volume of dilute nitric acid and a second volume of distilled boiling water into the beaker, and place the beaker in a boiling water bath for a third preset time; place the beaker in a centrifuge for centrifugal motion, extract a supernatant in the beaker, and set the supernatant to a third volume; The detection module is used to extract a portion of the solution from the third volume into a storage bottle, add a yttrium element solution of a preset solubility into the storage bottle, dilute it to a preset scale with deionized water, and then determine the total sulfur content by a plasma emission spectrometer.

Images