CN114235523B - Method for detecting heavy metal element content of fly ash of household garbage power plant - Google Patents
Method for detecting heavy metal element content of fly ash of household garbage power plant Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 44
- 239000010881 fly ash Substances 0.000 title claims abstract description 34
- 229910001385 heavy metal Inorganic materials 0.000 title claims abstract description 27
- 239000010813 municipal solid waste Substances 0.000 title claims abstract description 25
- 238000002386 leaching Methods 0.000 claims abstract description 82
- 238000010790 dilution Methods 0.000 claims abstract description 47
- 239000012895 dilution Substances 0.000 claims abstract description 47
- 238000001514 detection method Methods 0.000 claims abstract description 37
- 238000012360 testing method Methods 0.000 claims abstract description 26
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 22
- 239000007788 liquid Substances 0.000 claims abstract description 18
- 239000013522 chelant Substances 0.000 claims abstract description 16
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims abstract description 15
- 238000011088 calibration curve Methods 0.000 claims abstract description 12
- 229960000583 acetic acid Drugs 0.000 claims abstract description 7
- 239000012362 glacial acetic acid Substances 0.000 claims abstract description 6
- 238000002360 preparation method Methods 0.000 claims abstract description 6
- 239000000523 sample Substances 0.000 claims description 78
- 239000000243 solution Substances 0.000 claims description 63
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 27
- 229910017604 nitric acid Inorganic materials 0.000 claims description 27
- 238000009616 inductively coupled plasma Methods 0.000 claims description 19
- 239000012086 standard solution Substances 0.000 claims description 19
- 239000003153 chemical reaction reagent Substances 0.000 claims description 15
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 claims description 15
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- 230000000694 effects Effects 0.000 claims description 10
- 238000010438 heat treatment Methods 0.000 claims description 9
- 239000012528 membrane Substances 0.000 claims description 9
- 230000007306 turnover Effects 0.000 claims description 9
- 238000005303 weighing Methods 0.000 claims description 9
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 8
- 238000002347 injection Methods 0.000 claims description 8
- 239000007924 injection Substances 0.000 claims description 8
- 229910052725 zinc Inorganic materials 0.000 claims description 8
- 239000011701 zinc Substances 0.000 claims description 8
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 7
- 229910052788 barium Inorganic materials 0.000 claims description 7
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims description 7
- 229910052790 beryllium Inorganic materials 0.000 claims description 7
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 claims description 7
- 229910052793 cadmium Inorganic materials 0.000 claims description 7
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 claims description 7
- 229910052804 chromium Inorganic materials 0.000 claims description 7
- 239000011651 chromium Substances 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 7
- 239000010949 copper Substances 0.000 claims description 7
- 238000007865 diluting Methods 0.000 claims description 7
- 239000011133 lead Substances 0.000 claims description 7
- 238000011068 loading method Methods 0.000 claims description 7
- 238000005259 measurement Methods 0.000 claims description 7
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 7
- 239000002253 acid Substances 0.000 claims description 6
- 238000012790 confirmation Methods 0.000 claims description 6
- 238000000605 extraction Methods 0.000 claims description 6
- KJFMBFZCATUALV-UHFFFAOYSA-N phenolphthalein Chemical compound C1=CC(O)=CC=C1C1(C=2C=CC(O)=CC=2)C2=CC=CC=C2C(=O)O1 KJFMBFZCATUALV-UHFFFAOYSA-N 0.000 claims description 6
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- -1 polytetrafluoroethylene Polymers 0.000 claims description 5
- 239000012496 blank sample Substances 0.000 claims description 4
- 238000013494 PH determination Methods 0.000 claims description 3
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- 238000004458 analytical method Methods 0.000 claims description 3
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- 239000000919 ceramic Substances 0.000 claims description 3
- 238000012937 correction Methods 0.000 claims description 3
- 230000029087 digestion Effects 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 3
- 238000011010 flushing procedure Methods 0.000 claims description 3
- 239000003365 glass fiber Substances 0.000 claims description 3
- 238000007603 infrared drying Methods 0.000 claims description 3
- STZCRXQWRGQSJD-GEEYTBSJSA-M methyl orange Chemical compound [Na+].C1=CC(N(C)C)=CC=C1\N=N\C1=CC=C(S([O-])(=O)=O)C=C1 STZCRXQWRGQSJD-GEEYTBSJSA-M 0.000 claims description 3
- 229940012189 methyl orange Drugs 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- 230000010355 oscillation Effects 0.000 claims description 3
- 230000020477 pH reduction Effects 0.000 claims description 3
- 239000002245 particle Substances 0.000 claims description 3
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 3
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- 239000007787 solid Substances 0.000 claims description 3
- 239000003814 drug Substances 0.000 abstract description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 abstract description 8
- 239000002699 waste material Substances 0.000 abstract description 5
- 229910052786 argon Inorganic materials 0.000 abstract description 4
- 239000000463 material Substances 0.000 abstract description 4
- 230000007547 defect Effects 0.000 abstract description 3
- 239000002910 solid waste Substances 0.000 description 4
- 229940079593 drug Drugs 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 230000002452 interceptive effect Effects 0.000 description 2
- 241001494115 Stomoxys calcitrans Species 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000007853 buffer solution Substances 0.000 description 1
- 239000002738 chelating agent Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 150000002013 dioxins Chemical class 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 239000002920 hazardous waste Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 239000013582 standard series solution Substances 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/71—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
- G01N21/73—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited using plasma burners or torches
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- General Health & Medical Sciences (AREA)
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- Engineering & Computer Science (AREA)
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Abstract
A method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant only needs to prepare a medicament of glacial acetic acid in the leaching stage of the detection process, does not need to carry out complex operation for confirming the leaching agent, only draws a calibration curve once in the detection stage, has reasonable concentration gradient setting, can confirm the dilution multiple of suspected high-concentration samples before on-machine detection, can effectively simplify the preparation work of medicaments in HJ/T300-2007, does not need to carry out operation for confirming the leaching agent, and can effectively solve various defects of more types of standard samples, unreasonable concentration gradient of the calibration curve, long test time, high consumption of high-purity argon, high detection difficulty, environment pollution caused by high-concentration waste liquid and the like in the aspect of detecting the content of the heavy metal in the fly ash and chelate thereof of the garbage power plant. Compared with the prior art, the invention has obvious advantages in the aspects of sample testing period, material consumption, labor intensity, pollution control among samples, detection difficulty and the like.
Description
Technical Field
The invention relates to the technical field of solid waste detection, in particular to a method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant.
Background
The fly ash of the house refuse incineration plant contains more heavy metals and dioxins, which are listed in the national hazardous waste directory (2016 edition), and the fly ash must be safely and harmlessly treated in order to protect the environment. The current method is to mix chelating agent and fly ash to react to form stable fly ash chelate, and the leaching solution prepared according to the solid waste leaching toxicity leaching method acetic acid buffer solution method (HJ/T300-2007) has the concentration of harmful components lower than the limit value specified in the table 1 of the pollution control standard of the domestic garbage landfill (GB 16889-2008), and can enter the domestic garbage landfill for disposal. Therefore, the fly ash and heavy metal in the chelate generated in the garbage incineration process are required to be continuously detected so as to judge whether the requirements of the landfill are met.
At present, the method for detecting the heavy metal content in domestic garbage fly ash and chelate thereof mainly comprises two steps, wherein the first step is a leaching stage, HJ/T300-2007 is used for preparing heavy metal leaching liquid, the second step is a detection stage, 7.3.2 of an inductively coupled plasma emission spectrometry (HJ 781-2016) method for measuring 22 metal elements of solid waste is used for preparing leaching liquid into a sample, and then the subsequent steps of the method are adopted for detecting copper, zinc, lead, cadmium, nickel, beryllium, barium and total chromium.
However, the HJ/T300-2007 and HJ 781-2016 test ranges are solid waste classes and are not specifically established for the detection of heavy metals in waste fly ash and its chelates. For the HJ/T300-2007 method, the following problems exist in the process of testing the waste fly ash and its chelate: (1) a plurality of medicines are needed to be prepared, and medicines easy to prepare are involved, so that the medicine management requirement is high; (2) the leaching agent confirmation process is complicated, and each sample takes at least 20 minutes; (3) the overturning and oscillating process needs to be controlled at 23+/-2 ℃ and has higher requirements on laboratory environment. The HJ 781-2016 method has the following problems: (1) 4 calibration curves are required to be drawn, all samples are required to be measured on a machine for four times, the test time is long, high-purity argon is consumed more, the types of required standard substances are more, and manpower and material resources are wasted more; (2) the standard series solution reference concentration gradient given by the method is greatly different from the limit value in the table 1 of GB 16889-2008, and is not particularly suitable for measuring the heavy metals of the fly ash and the chelate thereof, taking zinc as an example: the method suggests that the maximum concentration point of the standard curve is 5ppm, the specified entrance limit value is 100ppm, and the actual sample is not equal to 0.01ppm-180ppm, so that the detection requirement of the actual sample can not be basically met. In addition, the existing detection method lacks means for rapidly screening suspected high-concentration samples in fly ash and chelate leachate thereof, the suspected high-concentration samples cannot be diluted in advance before sample injection, and only can be diluted and re-measured after sample injection, but as the sample concentration of all to-be-detected samples is unknown, if the sample concentration is higher, the sample injection system is polluted, and the sample injection needle and the sample injection pipeline need to be frequently cleaned or replaced; secondly, the salt accumulation rate of parts such as an atomizer, a torch tube, a cold cone and the like of the inductively coupled plasma emission spectrometer is accelerated, and the cleaning frequency is increased or the parts need to be directly replaced; and thirdly, the pollution possibility among samples is high, so that the detection results of the low-concentration samples and the blank samples on the batch of machine samples are influenced, the detection time and the detection difficulty are increased, or the test failure is directly caused.
Disclosure of Invention
In order to solve the problems, the invention provides a method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant by referring to a relevant standard method and combining a large amount of test experience according to the composition characteristics of fly ash and chelate thereof of the household garbage power plant, wherein the method comprises the steps of directly adopting a leaching agent #2 in HJ/T300-2007 to prepare heavy metal leaching liquid, measuring the index value (pH value) of the hydrogen ion concentration of the leaching liquid by using a hydrogen ion activity meter, determining the dilution factor of a sample, treating the leaching liquid according to 7.3.2 in the method HJ 781-2016, diluting a suspected high-concentration sample to obtain a final loading sample, introducing a standard solution from low concentration to high concentration into an inductively coupled plasma emission spectrometer to measure the emission intensity according to the specification of an inductively coupled plasma emission spectrometer, taking the mass concentration of a series of target elements as an abscissa, taking the emission intensity value as an ordinate, establishing a calibration curve of the target element, and finally sequentially introducing the final loading sample into the inductively coupled plasma emission spectrometer to measure the emission intensity according to the calibration curve to calculate the content. According to the invention, only 1 medicament of glacial acetic acid is needed to be prepared in the leaching stage, complicated leaching agent confirmation operation is not needed, a calibration curve is drawn only once in the detection stage, the concentration gradient of the curve is reasonably arranged, the dilution multiple of a suspected high-concentration sample can be confirmed before on-machine detection, the preparation work of medicaments in HJ/T300-2007 can be effectively simplified, the leaching agent confirmation operation is not needed, and the defects that the HJ 781-2016 has a plurality of types of standard samples needed in the aspect of detecting the heavy metal content of the fly ash and chelate thereof in a garbage power plant, the concentration gradient of the calibration curve is unreasonable, the test time is long, the high-purity argon is consumed, the possibility of pollution among samples is high, the detection difficulty is high, the environment is polluted by high-concentration waste liquid can be effectively overcome. In contrast, the invention has obvious advantages in the aspects of sample testing period, material consumption, labor intensity, pollution control among samples, detection difficulty and the like.
The technical scheme adopted for solving the technical problems is as follows: the method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant is characterized by comprising the following steps of:
step 01, weighing 50-100 g of sample in a 100mL ceramic crucible, baking to constant weight at 105+/-2 ℃, and calculating the water content of the sample;
step 02, diluting 17.25mL of glacial acetic acid to 1L with reagent water, wherein the pH value of the prepared solution is 2.64+/-0.05, so as to prepare a leaching agent;
step 03, weighing 75-100 g of sample, placing the sample in a 2L extraction bottle, and according to the water content of the sample, according to the liquid-solid ratio of 20:1 (L: kg) calculating the required volume of the leaching agent, adding the leaching agent to prepare a leaching agent sample, observing whether bubbles emerge or not, if no bubbles exist, closing the bottle cap, and fixing on a turnover oscillation device; if the air bubbles exist, waiting for 10min and then carrying out subsequent operation; the extraction bottles filled with the sample and the leaching agent are placed on a turnover oscillator in sequence, the rotating speed of the turnover oscillator is set to be 30+/-2 rpm, and the time is set to be 18+/-2 h.
Step 04, referring to general rules for determination of pH value of chemical reagent (GB/T9724-2007), measuring and recording the index value (pH value) of the concentration of hydrogen ions in the leaching solution by using a hydrogen ion activity meter;
step 05, calculating the dilution factor of the sample according to the index value (pH value) of the hydrogen ion concentration measured in the step 04; the pH value of the leaching solution is less than or equal to 6.00, and the dilution multiple is 20; the pH value of the leaching solution is less than 7.00 and the dilution factor is 10; the pH value of the leaching solution is more than or equal to 7.00 and less than 7.50, and the dilution factor is 5; the pH value of the leaching solution is more than or equal to 7.50, and the leaching solution is not diluted;
step 06, installing a glass fiber filter membrane or a microporous filter membrane with the aperture of 0.6-0.8 mu m on the filter, leaching the filter and the filter membrane by using 5% dilute nitric acid, discarding the leaching solution, filtering and collecting the leaching solution, acidifying the collected leaching solution to pH less than 2 by using GR-grade concentrated nitric acid, and preserving at the temperature of 4 ℃;
step 07, weighing 25.00mL of the leaching solution sample obtained in the step 06, putting the leaching solution sample into a 100mL polytetrafluoroethylene crucible, adding 5mL of GR grade concentrated nitric acid, heating and digesting for 1-2 h (h is an hour) at 180 ℃ on an electric plate, if particles or precipitates exist, adding 2mL of GR concentrated nitric acid, continuing heating and digesting until the solution is clear, leaching the crucible by using a proper amount of 1% dilute nitric acid solution, transferring all the leaching solution sample into a 25mL volumetric flask, using the 1% dilute nitric acid solution to fix the volume to a capacity marked line, and uniformly mixing to obtain the sample liquid for loading;
step 08, diluting the sample liquid according to the dilution factor required in the step 05 to prepare the sample liquid with the dilution factor, and keeping at least 20mL undiluted stock solution for standby or retesting;
step 09, optimizing test conditions according to the manufacturer specification of the inductively coupled plasma emission spectrometer, igniting the plasma after the correction of the detector, setting according to working parameters provided by the manufacturer, and starting preliminary measurement after the instrument is preheated until each index is stable;
step 10, preparing a series of standard solutions of elements to be detected by using standard solutions of copper, zinc, lead, cadmium, nickel, beryllium, barium and chromium in sequence, preparing a series of standard curves by using a 1% dilute nitric acid solution, wherein the concentration gradient is 0.1ppm, 0.2ppm, 0.5ppm, 1.0ppm, 2.0ppm, 5ppm and 10ppm; sequentially introducing standard solution into an inductively coupled plasma emission spectrometer from low to high, measuring emission intensity according to measurement conditions set by manufacturer specifications, and establishing a calibration curve of a target element by taking the mass concentration of the target element series as an abscissa and the emission intensity value as an ordinate;
step 11, flushing a sample injection system and an atomization system of the inductively coupled plasma emission spectrometer by using a 1% dilute nitric acid solution, observing that the blank value of the instrument is reduced to the minimum, starting to analyze a sample after an analysis signal is stable, and determining the blank sample according to the same operation steps and conditions;
step 12, outputting a result, namely a final detection result, by using the inductively coupled plasma emission spectrometer for a sample without dilution multiple; the sample with dilution multiple should input dilution multiple in the test sequence when editing the test method, the instrument output result is the final detection result; when the dilution factor is not input in the editing test method, the calculation should be performed according to the formula, wherein ρ is the calculation result, mg/L, ρ Measuring For the output result of the instrument, mg/L, n is dilution multiple, and dimensionless.
In the preferred scheme of the invention, when the total number of the fly ash and chelate samples thereof in the step 01 is less than or equal to 5, the water content measurement mode preferably adopts a microwave drying method or an infrared drying method, and the temperature condition is 105+/-5 ℃.
In a preferred embodiment of the invention, the hydrogen ion activity meter in step 04 meets the "0.02 level" requirement in 4.7 of the "laboratory pH meter calibration procedure" JJG 119-2005, and the electrode is used and maintained according to annex a of GB/T9724-2007 and calibrated periodically.
According to the preferred scheme of the invention, the hydrogen ion activity meter in the step 04 can be implemented by using wide pH test paper, precise pH test paper, litmus reagent, phenolphthalein reagent, methyl orange reagent or other methods capable of carrying out qualitative or semi-quantitative judgment on the pH value, and the determination of dilution factors is not influenced.
In a preferred embodiment of the present invention, step 04 and step 06 may be replaced by each other.
In the preferred scheme of the invention, after the dilution factors are determined together in step 04 and step 05, all measured values of the loading sample are in the range of the concentration curve or on the right side of the highest concentration point of the curve (the measured value is higher than the highest concentration point); if the detection value is on the right side of the highest concentration point, adopting the stock solution in the step 06 to dilute further, wherein the dilution multiple is diluted by 2 times further on the basis of the original; if the detection value is at the left side of the highest concentration point, adopting the sample reserved in the step 06 to directly go on the machine for detection.
According to the preferred scheme of the invention, the leaching solution in the step 06 is detected on the same day after preparation, and acidification is not needed.
According to the preferred scheme of the invention, the digestion operation in the step 07 can be further simplified into acid expelling operation, namely heating operation is only carried out, and redundant acidic substances in the leaching solution are removed, so that the influence on the result is not more than 1%, and the judgment of the chelate entrance standard is not influenced; if the atomizer, the atomizing chamber and the torch tube of the inductively coupled plasma emission spectrometer are replaced with acid-resistant components, the acid-dispelling operation is not performed, i.e., step 07 is not performed.
In a preferred embodiment of the present invention, the standard solution of copper, zinc, lead, cadmium, nickel, beryllium, barium and chromium used in step 10 may be replaced by a multi-element mixed standard solution containing the 8 elements, but the multi-element mixed standard solution should not contain substances interfering with the 8 elements.
In a preferred embodiment of the present invention, the confirmation that the instrument blank value is minimized in step 11 is evaluated and confirmed by testing at least 3 1% nitric acid solution samples.
The beneficial effects of the invention are as follows: the invention provides a method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant, which is characterized in that only one medicament of glacial acetic acid is needed to be prepared in the leaching stage in the detection process, complicated operation of confirming the leaching agent is not needed, a calibration curve is only drawn once in the detection stage, the concentration gradient of the curve is reasonably arranged, the dilution multiple of suspected high-concentration samples can be confirmed before the on-machine detection, the preparation work of medicaments in HJ/T300-2007 can be effectively simplified, the operation of confirming the leaching agent is not needed, and the defects that the HJ 781-2016 needs more types of standard samples in the aspect of detecting the content of heavy metal in the fly ash and chelate thereof in the garbage power plant, the concentration gradient of the calibration curve is unreasonable, the testing time is long, the consumption of high purity argon is high, the possibility of pollution among samples is high, the detection difficulty is high, the environment is polluted by high-concentration waste liquid and the like can be effectively solved. In contrast, the invention has obvious advantages in the aspects of sample testing period, material consumption, labor intensity, pollution control among samples, detection difficulty and the like.
Detailed Description
A method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant comprises the following steps:
step 01, weighing 50-100 g of sample in a 100mL ceramic crucible, baking to constant weight at 105+/-2 ℃, and calculating the water content of the sample;
step 02, diluting 17.25mL of glacial acetic acid to 1L with reagent water, wherein the pH value of the prepared solution is 2.64+/-0.05, so as to prepare a leaching agent;
step 03, weighing 75-100 g of sample, placing the sample in a 2L extraction bottle, and according to the water content of the sample, according to the liquid-solid ratio of 20:1 (L: kg) calculating the required volume of the leaching agent, adding the leaching agent to prepare a leaching agent sample, observing whether bubbles emerge or not, if no bubbles exist, closing the bottle cap, and fixing on a turnover oscillation device; if the air bubbles exist, waiting for 10min and then carrying out subsequent operation; the extraction bottles filled with the sample and the leaching agent are placed on a turnover oscillator in sequence, the rotating speed of the turnover oscillator is set to be 30+/-2 rpm, and the time is set to be 18+/-2 h.
Step 04, referring to general rules for determination of pH value of chemical reagent (GB/T9724-2007), measuring and recording the index value (pH value) of the concentration of hydrogen ions in the leaching solution by using a hydrogen ion activity meter;
step 05, calculating the dilution factor of the sample according to the index value (pH value) of the hydrogen ion concentration measured in the step 04; the pH value of the leaching solution is less than or equal to 6.00, and the dilution multiple is 20; the pH value of the leaching solution is less than 7.00 and the dilution factor is 10; the pH value of the leaching solution is more than or equal to 7.00 and less than 7.50, and the dilution factor is 5; the pH value of the leaching solution is more than or equal to 7.50, and the leaching solution is not diluted;
step 06, installing a glass fiber filter membrane or a microporous filter membrane with the aperture of 0.6-0.8 mu m on the filter, leaching the filter and the filter membrane by using 5% dilute nitric acid, discarding the leaching solution, filtering and collecting the leaching solution, acidifying the collected leaching solution to pH less than 2 by using GR-grade concentrated nitric acid, and preserving at the temperature of 4 ℃;
step 07, weighing 25.00mL of the leaching solution sample obtained in the step 06, putting the leaching solution sample into a 100mL polytetrafluoroethylene crucible, adding 5mL of GR grade concentrated nitric acid, heating and digesting for 1-2 h (h is an hour) at 180 ℃ on an electric plate, if particles or precipitates exist, adding 2mL of GR concentrated nitric acid, continuing heating and digesting until the solution is clear, leaching the crucible by using a proper amount of 1% dilute nitric acid solution, transferring all the leaching solution sample into a 25mL volumetric flask, using the 1% dilute nitric acid solution to fix the volume to a capacity marked line, and uniformly mixing to obtain the sample liquid for loading;
step 08, diluting the sample liquid according to the dilution factor required in the step 05 to prepare the sample liquid with the dilution factor, and keeping at least 20mL undiluted stock solution for standby or retesting;
step 09, optimizing test conditions according to the manufacturer specification of the inductively coupled plasma emission spectrometer, igniting the plasma after the correction of the detector, setting according to working parameters provided by the manufacturer, and starting preliminary measurement after the instrument is preheated until each index is stable;
step 10, preparing a series of standard solutions of elements to be detected by using standard solutions of copper, zinc, lead, cadmium, nickel, beryllium, barium and chromium in sequence, preparing a series of standard curves by using a 1% dilute nitric acid solution, wherein the concentration gradient is 0.1ppm, 0.2ppm, 0.5ppm, 1.0ppm, 2.0ppm, 5ppm and 10ppm; sequentially introducing standard solution into an inductively coupled plasma emission spectrometer from low to high, measuring emission intensity according to measurement conditions set by manufacturer specifications, and establishing a calibration curve of a target element by taking the mass concentration of the target element series as an abscissa and the emission intensity value as an ordinate;
step 11, flushing a sample injection system and an atomization system of the inductively coupled plasma emission spectrometer by using a 1% dilute nitric acid solution, observing that the blank value of the instrument is reduced to the minimum, starting to analyze a sample after an analysis signal is stable, and determining the blank sample according to the same operation steps and conditions;
step 12, outputting a result, namely a final detection result, by using the inductively coupled plasma emission spectrometer for a sample without dilution multiple; the sample with dilution multiple should input dilution multiple in the test sequence when editing the test method, the instrument output result is the final detection result; when the dilution factor is not input in the editing test method, the calculation should be performed according to the formula, wherein ρ is the calculation result, mg/L, ρ Measuring For the output result of the instrument, mg/L, n is dilution multiple, and dimensionless.
Preferably, when the total number of the fly ash and the chelate samples thereof in the step 01 is less than or equal to 5, the water content is preferably measured by a microwave drying method or an infrared drying method, and the temperature condition is 105+/-5 ℃.
Preferably, the hydrogen ion activity meter in step 04 should meet the "0.02 level" requirement in 4.7 of the laboratory pH meter calibration procedure JJG 119-2005, and its electrodes should also be used and maintained and calibrated periodically in accordance with annex a of GB/T9724-2007.
Preferably, the hydrogen ion activity meter in the step 04 can be performed by using a wide range of pH test paper, precise pH test paper, litmus reagent, phenolphthalein reagent, methyl orange reagent or other methods capable of qualitatively or semi-quantitatively judging the pH value, and the determination of dilution factors is not affected.
Preferably, steps 04 and 06 may be replaced by each other.
Preferably, after determining the dilution factor in step 04 and step 05, all the measured values of the dilution of the loading sample are within the range of the concentration curve or on the right side of the highest concentration point of the curve (the measured value is higher than the highest concentration point); if the detection value is on the right side of the highest concentration point, adopting the stock solution in the step 06 to dilute further, wherein the dilution multiple is diluted by 2 times further on the basis of the original; if the detection value is at the left side of the highest concentration point, adopting the sample reserved in the step 06 to directly go on the machine for detection.
Preferably, the leachate in step 06 is detected on the same day after preparation, and acidification is not required.
Preferably, the digestion operation in the step 07 can be further simplified into acid expelling operation, namely heating operation is only carried out, and redundant acidic substances in the leaching solution are removed, so that the influence on the result is not more than 1%, and the judgment of the chelate entrance standard is not influenced; if the atomizer, the atomizing chamber and the torch tube of the inductively coupled plasma emission spectrometer are replaced with acid-resistant components, the acid-dispelling operation is not performed, i.e., step 07 is not performed.
Preferably, the standard solution of copper, zinc, lead, cadmium, nickel, beryllium, barium and chromium used in step 10 may be replaced by a multi-element mixed standard solution containing the 8 elements, but the multi-element mixed standard solution should not contain substances interfering with the 8 elements.
Preferably, the confirmation that the instrument blank value is minimized in step 11 is evaluated and confirmed by testing at least 3 1% nitric acid solution samples.
Claims (9)
1. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant is characterized by comprising the following steps of:
step 01, weighing 50-100 g of sample in a 100mL ceramic crucible, baking to constant weight at 105+/-2 ℃, and calculating the water content of the sample;
step 02, diluting 17.25mL of glacial acetic acid to 1L with reagent water, wherein the pH value of the prepared solution is 2.64+/-0.05, so as to prepare a leaching agent;
step 03, weighing 75-100 g of sample, placing the sample in a 2L extraction bottle, and according to the water content of the sample, according to the liquid-solid ratio of 20:1, calculating the required volume of the leaching agent, adding the leaching agent to prepare a leaching liquid sample, observing whether bubbles emerge or not, and if no bubbles exist, closing the bottle cap and then fixing on a turnover oscillation device; if the air bubbles exist, waiting for 10min and then carrying out subsequent operation; sequentially placing the extraction bottles filled with the sample and the leaching agent on a turnover oscillator, wherein the rotating speed of the turnover oscillator is set to be 30+/-2 rpm, and the time is set to be 18+/-2 h;
step 04, referring to general rules for determination of pH value of chemical reagent (GB/T9724-2007), measuring and recording the index value of hydrogen ion concentration of the leaching solution by using a hydrogen ion activity meter to obtain the pH value;
step 05, calculating the dilution factor of the sample according to the index number of the hydrogen ion concentration measured in the step 04; the pH value of the leaching solution is less than or equal to 6.00, and the dilution multiple is 20; the pH value of the leaching solution is less than 7.00 and the dilution factor is 10; the pH value of the leaching solution is more than or equal to 7.00 and less than 7.50, and the dilution factor is 5; the pH value of the leaching solution is more than or equal to 7.50, and the leaching solution is not diluted;
step 06, installing a glass fiber filter membrane or a microporous filter membrane with the aperture of 0.6-0.8 mu m on the filter, leaching the filter and the filter membrane by using 5% dilute nitric acid, discarding the leaching solution, filtering and collecting the leaching solution, acidifying the collected leaching solution to pH less than 2 by using GR-grade concentrated nitric acid, and preserving at the temperature of 4 ℃;
step 07, weighing 25.00mL of the leaching solution sample obtained in the step 06, putting the leaching solution sample into a 100mL polytetrafluoroethylene crucible, adding 5mL of GR grade concentrated nitric acid, heating and digesting for 1-2 h at 180 ℃ on an electric plate for hours, if particles or precipitates exist, adding 2mL of GR concentrated nitric acid, continuing heating and digesting until the solution is clear, leaching the crucible by using a proper amount of 1% dilute nitric acid solution, transferring all the leaching solution sample into a 25mL volumetric flask, using the 1% dilute nitric acid solution to fix the volume to a capacity marked line, and uniformly mixing to obtain the sample liquid for loading the machine;
step 08, diluting the sample liquid according to the dilution factor required in the step 05 to prepare the sample liquid with the dilution factor, and keeping at least 20mL undiluted stock solution for standby or retesting;
step 09, optimizing test conditions, igniting plasma after the correction of the detector, setting according to working parameters provided by manufacturers, and starting preliminary measurement after the instrument is preheated until each index is stable;
step 10, preparing a series of standard solutions of elements to be detected by using standard solutions of copper, zinc, lead, cadmium, nickel, beryllium, barium and chromium in sequence, preparing a series of standard curves by using a 1% dilute nitric acid solution, wherein the concentration gradient is 0.1ppm, 0.2ppm, 0.5ppm, 1.0ppm, 2.0ppm, 5ppm and 10ppm; sequentially introducing standard solution into an inductively coupled plasma emission spectrometer from low to high, measuring emission intensity according to measurement conditions set by manufacturer specifications, and establishing a calibration curve of a target element by taking the mass concentration of the target element series as an abscissa and the emission intensity value as an ordinate;
step 11, flushing a sample injection system and an atomization system of the inductively coupled plasma emission spectrometer by using a 1% dilute nitric acid solution, observing that the blank value of the instrument is reduced to the minimum, starting to analyze a sample after an analysis signal is stable, and determining the blank sample according to the same operation steps and conditions;
step 12, outputting a result, namely a final detection result, by using the inductively coupled plasma emission spectrometer for a sample without dilution multiple; the sample with dilution multiple should input dilution multiple in the test sequence when editing the test method, the instrument output result is the final detection result; when the dilution factor is not input in the editing test method, the calculation should be performed according to the formula, wherein ρ is the calculation result, mg/L, ρ Measuring Output for instrumentAs a result, mg/L, n is dilution multiple, dimensionless;
step 04 and step 05 jointly determine dilution factors, and then dilute the sample to be tested, wherein all measured values are in a concentration curve range or on the right side of the highest concentration point of the curve, and the measured value is higher than the highest concentration point; if the detection value is on the right side of the highest concentration point, adopting the stock solution in the step 06 to dilute further, wherein the dilution multiple is diluted by 2 times further on the basis of the original; if the detection value is at the left side of the highest concentration point, adopting the sample reserved in the step 06 to directly go on the machine for detection.
2. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant according to claim 1, which is characterized in that,
and (3) when the total number of the fly ash and chelate samples thereof in the step (01) is less than or equal to 5, a microwave drying method or an infrared drying method is adopted in a water content measuring mode, and the temperature condition is 105+/-5 ℃.
3. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant according to claim 1, which is characterized in that,
the hydrogen ion activity meter in step 04 should meet the "0.02 level" requirement in 4.7 of the laboratory pH meter calibration procedure JJG 119-2005, and its electrodes should also be used and maintained and calibrated periodically according to annex a of GB/T9724-2007.
4. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant according to claim 1, which is characterized in that,
the hydrogen ion activity meter in the step 04 can be carried out by using wide pH test paper, precise pH test paper, litmus reagent, phenolphthalein reagent, methyl orange reagent or other methods capable of carrying out qualitative or semi-quantitative judgment on the pH value, and the determination of dilution multiple is not affected.
5. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant according to claim 1, which is characterized in that,
step 04 and step 06 may be interchanged.
6. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant according to claim 1, which is characterized in that,
and (3) detecting the leaching solution in the step (06) on the same day after the preparation is finished, and no acidification is needed.
7. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant according to claim 1, which is characterized in that,
the digestion operation in the step 07 can be further simplified into acid expelling operation, namely heating operation is only carried out, redundant acidic substances in the leaching solution are removed, the influence on the result is not more than 1%, and the judgment of the chelate entrance standard is not influenced; if the atomizer, the atomizing chamber and the torch tube of the inductively coupled plasma emission spectrometer are replaced with acid-resistant components, the acid-dispelling operation is not performed, i.e., step 07 is not performed.
8. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant according to claim 1, which is characterized in that,
in the step 10, the standard solution of copper, zinc, lead, cadmium, nickel, beryllium, barium and chromium can be replaced by the multi-element mixed standard solution containing 8 elements, but the multi-element mixed standard solution should not contain substances which interfere with the 8 elements.
9. The method for detecting the content of heavy metal elements in fly ash of a household garbage incineration power plant according to claim 1, which is characterized in that,
the confirmation that the instrument blank value was minimized in step 11 was evaluated and confirmed by testing at least 3 1% nitric acid solution samples.
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| CN114610086B (en) * | 2022-04-08 | 2024-06-14 | 深圳能源环保股份有限公司 | PH value-based waste incineration fly ash treatment method, device and storage medium |
| CN116558918B (en) * | 2023-04-27 | 2024-02-23 | 上海海关机电产品检测技术中心 | Method for simultaneously measuring Pb, cd, cr, hg, br content in electronic and electric products based on ICP-MS |
| CN116754349B (en) * | 2023-08-16 | 2023-11-21 | 四川赛科检测技术有限公司 | ICP-OES-based digestion method for lithium sulfide impurity elements and content determination method thereof |
| CN117470618A (en) * | 2023-12-28 | 2024-01-30 | 中国科学院烟台海岸带研究所 | Ultrafiltration separation detection method for colloidal iron in seawater |
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| CN103926236A (en) * | 2014-04-04 | 2014-07-16 | 攀钢集团攀枝花钢铁研究院有限公司 | Combined method for measuring content of impurity elements and matrix element niobium in niobium-iron alloy |
| CN107202865A (en) * | 2017-05-12 | 2017-09-26 | 上海大学 | Heavy metal stabilizing and the quick determination method of toxicity in domestic garbage incineration flyash |
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| CN101092665B (en) * | 2007-07-26 | 2010-06-02 | 北京科技大学 | Treating flying ash from burning garbage, and method for recovering heavy metal from the ash |
| CN102169091B (en) * | 2011-05-23 | 2012-06-06 | 同济大学 | Method for analyzing and measuring typical metal in circuit board of discarded electrical equipment |
| WO2018133046A1 (en) * | 2017-01-20 | 2018-07-26 | 深圳市能源环保有限公司 | Waste incineration fly ash deacidifying and chelating agent and preparation method therefor |
| CN109834109A (en) * | 2019-04-01 | 2019-06-04 | 河南师范大学 | The recycling processing method of heavy metal in a kind of domestic garbage incineration flyash |
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| CN103926236A (en) * | 2014-04-04 | 2014-07-16 | 攀钢集团攀枝花钢铁研究院有限公司 | Combined method for measuring content of impurity elements and matrix element niobium in niobium-iron alloy |
| CN107202865A (en) * | 2017-05-12 | 2017-09-26 | 上海大学 | Heavy metal stabilizing and the quick determination method of toxicity in domestic garbage incineration flyash |
| CN111198180A (en) * | 2020-01-13 | 2020-05-26 | 杨俊� | Method for rapidly determining talcum powder in food through microwave digestion-ICP-OES |
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