HJ 1221-2021 English PDFUS$219.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. HJ 1221-2021: Ambient air - Determination of dustfall - Gravimetric method Status: Valid
Basic dataStandard ID: HJ 1221-2021 (HJ1221-2021)Description (Translated English): Ambient air - Determination of dustfall - Gravimetric method Sector / Industry: Environmental Protection Industry Standard Word Count Estimation: 9,935 Issuing agency(ies): Ministry of Ecology and Environment HJ 1221-2021: Ambient air - Determination of dustfall - Gravimetric method---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.(Ambient air - Determination of dust fall - gravimetric method) National Ecological Environment Standard of the People's Republic of China Gravimetric Method for Determination of Ambient Air Dust Ambient air-Determination of dustfall-Gravimetric method This electronic version is the official standard text, which is reviewed and typeset by the Environmental Standards Institute of the Ministry of Ecology and Environment. Published on 2021-12-16 2022-06-01 Implementation Released by the Ministry of Ecology and Environment directory Foreword...ii 1 Scope...1 2 Normative references...1 3 Terms and Definitions...1 4 Principles of the method...1 5 Interference and cancellation...1 6 Reagents and materials...1 7 Instruments and equipment...2 8 samples...2 9 Analysis steps...3 10 Result calculation and representation...3 11 Accuracy...4 12 Quality Assurance and Quality Control...4 13 Notes...4 Appendix A (informative appendix) Determination of combustibles in total dustfall...5 Gravimetric Method for Determination of Ambient Air Dust Warning. The ethylene glycol used in the experiment is a toxic chemical and precautions should be taken during the experiment. 1 Scope of applicationThis standard specifies the gravimetric method for the determination of dust fall in ambient air. This standard applies to the determination of dust fall in ambient air. The detection limit of the method for dust fall measured in this standard is 0.3 t/km2 ∙30 d, and the lower detection limit is 1.2 t/km2 ∙30 d.2 Normative referencesThis standard refers to the following documents or clauses thereof. For dated references, only the dated version applies to this standard. For undated references, the latest edition (including all amendments) applies to this standard. HJ 194 Technical Specification for Manual Monitoring of Ambient Air Quality3 Terms and DefinitionsThe following terms and definitions apply to this standard. 3.1 dustfall Particles that naturally settle in the dust collection tank by gravity under air ambient conditions.4 Principles of the methodThe particles that can settle in the air are settled in the dust collecting tank filled with ethylene glycol aqueous solution as the collecting liquid. After evaporation, drying and weighing, Calculate the amount of dust fall.5 Interference and cancellationLeaves, dead branches, bird droppings, insects, tidbits, etc. will interfere with the measurement and should be removed before the sample measurement.6 Reagents and MaterialsUnless otherwise stated, analytical reagents that meet national standards are used in the analysis, and the experimental water is distilled water or water of equivalent purity. 6.1 Ethylene glycol (C2H6O2). 6.2 Aqueous glycol solution. Ethylene glycol (6.1) and water were mixed in a volume ratio of 1.1.7 Instruments and equipment7.1 Dust collection cylinder. cylindrical cylinder with inner diameter of 15 cm ± 0.5 cm and height of 30 cm, made of plexiglass, glass or ceramics, with a flat bottom. The inner wall is smooth. If worn, it should be replaced immediately. 7.2 Metal or nylon sieve. aperture 1 mm. 7.3 Soft silicone scraper. 7.4 Porcelain crucible. 100 ml. 7.5 Electric heating plate..2000W～4000W. 7.6 Oven. 7.7 Electronic analytical balance. the actual division value is 0.1 mg. 7.8 Common laboratory instruments and equipment.8 samples8.1 Setting of sampling points 8.1.1 The layout of monitoring points shall meet the relevant technical requirements for the layout of monitoring points in HJ 194. 8.1.2 When selecting sampling points, priority should be given to the places where the dust collection cylinder is not easily damaged, and the operator should also consider the easy replacement of the dust collection cylinder. It is generally set on the roof of the building, and obvious signs should be set up around the sampling point to prevent accidental entry. 8.1.3 The dust collecting tank should be placed at a height of 8m to 15m from the ground, that is, the 3rd to 5th floors of ordinary residences. In the same area, each sampling point collects dust The height of the cylinders should be as consistent as possible. On the premise of ensuring that the monitoring points are spatially representative, if the radius around the selected monitoring point is The average height of buildings within the range of 300 m to 500 m is more than 25 m, and when the height setting requirements cannot be met, the dust collector can be placed at a height of Select within the range of 20 m to 30 m. If it is placed on the roof, the distance between the mouth of the dust collector and the surface of the building wall, roof and other supports should be greater than 1 m to avoid the influence of dust on the support. 8.1.4 The support of the dust collecting tank should be stable and firm to prevent it from swinging or being blown down by the wind. 8.1.5 When setting up spots in forest areas, parks and other places where birds gather, you can, as needed, without affecting sample collection and human safety. Birds are repelled by means of sound waves, light waves, and installation of anti-bird devices. 8.2 Preparations Before placing the dust collection tank at the sampling point, add 120 ml of ethylene glycol aqueous solution (6.2), and in areas with arid and high evaporation, ethylene glycol can be added as appropriate The amount of alcohol solution added. After adding the solution, cover the cylinder mouth with plastic wrap to prevent dust and record it. 8.3 Collection of samples Remove the plastic wrap when placing the tank, record the location, tank number, and release time (month, day, hour). Regularly replace the dust collector on a monthly basis (28 d ~ 31 d) cylinder, the sampling and recording time should be accurate to 0.1 d. When taking the tank, check the location and number of the tank, and record the time of taking the tank (month, day, hour), and keep it fresh. The membrane covers the cylinder mouth to prevent dust and bring it back to the laboratory. In the rainy summer and winter snowy seasons, you should pay attention to the accumulation of water or snow in the tank. If the snow overflows, the tank should be replaced with a new one in time, and the collected samples should be combined for determination. During the sample collection process, if the height of the collected liquid in the tank is less than 0.3 cm, Aqueous glycol solution (6.2) should be appropriately supplemented. 8.4 Sample Storage The sample should be analyzed as soon as possible after collection. If it cannot be analyzed within 24 hours, the sample should be transferred according to step 9.2.1, and an appropriate amount of ethylene glycol should be added. (6.1), and cover the mouth of the beaker with plastic wrap, and measure within 7 days.9 Analysis steps9.1 Preparation of the porcelain crucible Wash and number the porcelain crucible (7.4), dry it in an oven at 105 °C ± 5 °C for 3 h, take it out and put it in a desiccator, cool it to room temperature, Weigh with an electronic analytical balance (7.7), bake for 50 min, cool to room temperature, and weigh again until constant weight (the difference between the two weights is less than 0.4 mg), After constant weight, take the mean value of the last 2 weighing values as m0. 9.2 Determination of dust fall samples 9.2.1 Measure the inner diameter of the dust collecting cylinder (measure at least 3 places in different directions, take the arithmetic mean, accurate to 0.1 cm), and then use a smooth Take out the foreign objects such as leaves and insects that fall into the tank with the tweezers, and rinse the dust particles attached to the foreign objects with water, and then discard the foreign objects. Scrape the tank wall with a soft silicone scraper (7.3), pass the solution and dust particles in the tank through a metal or nylon sieve (7.2), and transfer all into 500 ml In the beaker, rinse the foreign matter trapped on the sieve and the soft silicone scraper repeatedly with water. Discard foreign objects. 9.2.2 Slowly heat and evaporate the collected liquid in the beaker on an electric hot plate to concentrate the volume to 10 ml to 20 ml. After cooling, rinse the beaker with water. and use a soft silicone scraper (7.3) to scrape off the dust particles on the wall of the cup, and transfer all the solution and dust particles to a constant weight porcelain crucible (7.4) , put it on an electric hot plate and slowly heat it to near dryness (to prevent collapse and splash when the solution is small), then put it in an oven to dry at 105 ℃ ± 5 ℃, press 9.1 Method Weigh to constant weight, and take the mean value of the last two weighing values as m1 after constant weight. 9.3 Blank test Add the same batch of ethylene glycol aqueous solution (6.2) with the same total amount during the sampling operation and sample storage, and add it to a 500 ml beaker. according to Prepare a laboratory blank sample in the same procedure as in 9.2.2.After weighing to a constant weight, subtract the weight m0 of the porcelain crucible to obtain m2. 9.4 Determination of blank spiked samples Weigh the quality control samples, add the same batch of ethylene glycol aqueous solution (6.2) with the same total amount to the dust collection tank during sampling operation and sample storage. Follow the same procedure as in 9.2 for determination of laboratory blank spikes. 10 Result calculation and presentation 10.1 Result calculation The total amount of dustfall is calculated according to formula (1). 30--one sampling period, in 30 d; 104--g/cm2 is converted to unit conversion factor of t/km2. 10.2 Result representation The number of digits after the decimal point of the determination result is consistent with the detection limit of the method, and a maximum of 3 significant digits are reserved. 11 Accuracy 11.1 Precision The 6 laboratories measured 6 dustfall samples of different quality collected from the same roof, and the 0.1000 g sample was relative to the standard deviation. The difference range is 0.4%～4.9%, the relative standard deviation range of 0.3000 g sample is 0.3%～2.2%, the relative standard deviation range of 0.7000 g sample Circumference is 0.4% to 2.1%. 11.2 Correctness 6 laboratories measured 6 dustfall samples of different quality collected from the same roof, and the 0.1000 g sample was measured with a blank plus Standard recovery rates ranged from 90.7% to 110%; for 0.3000 g samples, the blank spiked recovery rates ranged from 93.9% to 104%; for 0.7000 g samples The recovery rate of the blank spiked standard was determined in the range of 95.3% to 102%. 12 Quality Assurance and Quality Control 12.1 The preparation process of quality control samples in the laboratory. collect non-polluting or less polluted farmland soil (should use yellow soil, etc., avoid using red soil and forest soil with high organic matter), remove stones and wood by hand, air-dry and grind through a.200-mesh sieve to obtain a sample of about.200 g. product, spare. Before use, it should be dried at 105 ℃ ± 5 ℃ for constant weight, and then weighed. 12.2 At least 2 blank samples should be made for each batch of samples, and the measured value of the blank should be lower than 0.0100 g. 12.3 During the determination of each batch of samples, at least one internal laboratory quality control sample should be analyzed by blank addition, and the recovery rate is 90% to 110%. 13 Notes 13.1 The number of beakers, porcelain crucibles, etc. used for each sample should be consistent, and the cylinder number of the corresponding dust collector should be filled in in time. in the record sheet. 13.2 Porcelain crucibles in ovens and desiccators should be placed separately and not overlapped. 13.3 When the sample is concentrated in a porcelain crucible, do not wash the crucible with water, otherwise vigorous boiling will occur at the interface of ethylene glycol and water, causing the solution to boil. overflow. When the concentration is less than 20 ml, the heating temperature should be lowered and the porcelain crucible should be shaken continuously to make the dust fall on the wall of the porcelain crucible to avoid the sample splash out. 13.4 In areas with drought and high evaporation, it is impossible to guarantee that the whole sampling period is wet sampling. During sampling, a layer of diameter can be spread on the bottom of the dust collection tank. 12 mm glass beads, and the sampling method is described in the original recording. 13.5 See Appendix A for the operation steps for the determination of combustibles in total dustfall. 13.6 In addition to the heating method of the electric hot plate, the heating method of the water bath can also be selected. 13.7 Parallel samples can be collected upon request.Appendix A(informative appendix) Determination of combustibles in total dustfall A.1 Instruments and Equipment A.1.1 Muffle furnace. A.1.2 Instruments and equipment specified in text 7. A.2 Preparation of Porcelain Crucibles Put the porcelain crucible that has been weighed in 9.1 into the muffle furnace, burn at 600 °C for 2 h, and take it when the temperature in the furnace drops below 300 °C. out, placed in a desiccator, cooled to room temperature, and weighed. Then calcined at 600 °C for 1 h, cooled to room temperature, and weighed until constant weight. Then take the mean value of the last 2 weighing values as m4. A.3 Determination of combustibles in dust samples Put the porcelain crucible with the amount of dust-falling samples measured in 9.2 into the muffle furnace, burn at 600 °C for 3 h, and wait for the temperature in the furnace to drop below 300 °C Take it out, put it in a desiccator, cool it to room temperature, and weigh it. It was then fired at 600 °C for 1 h, cooled to room temperature, and weighed until constant weight. After constant weight, take the mean value of the last 2 weighing values as m3. A.4 Preparation of blank samples Put the porcelain crucible that has been weighed in 9.3 into the muffle furnace, weigh it to a constant weight according to A.2, and subtract the weight m4 of the porcelain crucible, which is m5. A.5 Result calculation The amount of combustibles in dustfall is calculated according to formula (A.1). A--the area of the cylinder port of the dust collector, cm2; t--sampling time (accurate to 0.1 d), d; 30--one sampling period, in 30 d; 104--g/cm2 is converted to unit conversion factor of t/km2. ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of HJ 1221-2021_English be delivered?Answer: Upon your order, we will start to translate HJ 1221-2021_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of HJ 1221-2021_English with my colleagues?Answer: Yes. 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