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Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. HJ 1222-2021: Solid waste-Determination of water content and dry matter-Gravimetric method Status: Valid
Basic dataStandard ID: HJ 1222-2021 (HJ1222-2021)Description (Translated English): Solid waste-Determination of water content and dry matter-Gravimetric method Sector / Industry: Environmental Protection Industry Standard Word Count Estimation: 7,776 Issuing agency(ies): Ministry of Ecology and Environment HJ 1222-2021: Solid waste-Determination of water content and dry matter-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.(Solid waste - Determination of moisture and dry matter content - Gravimetric method) National Ecological Environment Standard of the People's Republic of China Determination of moisture and dry matter content of solid waste gravimetric method Solid waste-Determination of water content and dry matter -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 Instruments and equipment...2 6 samples...2 7 Analysis steps...2 8 Result calculation and representation...3 9 Precision...3 10 Quality Assurance and Quality Control...3 11 Waste disposal...4 12 Notes...4 Gravimetric method for determination of moisture and dry matter content of solid waste Warning. When measuring toxic and harmful samples, avoid skin contact or inhalation through mouth and nose, and measures such as ventilation and exhaust should be taken during the test to avoid Prevent contamination of the laboratory environment or other samples. When measuring, attention should be paid to the flammability and explosiveness of the sample to avoid fire. 1 Scope of applicationThis standard specifies the gravimetric method for the determination of moisture and dry matter content in solid waste. This standard is applicable to the determination of moisture and dry matter content in common solid wastes, but not applicable to high volatile organic compounds, flammable and explosive Determination of moisture and dry matter content in solid waste samples.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/T 20 Technical Specification for Sampling and Sample Preparation of Industrial Solid Waste HJ 298 Technical Specification for Hazardous Waste Identification3 Terms and DefinitionsThe following terms and definitions apply to this standard. 3.1 water content water content (OH2w) Under the specified conditions, the mass fraction of the water evaporated from the solid waste accounts for the total mass of the sample. 3.2 dry matter content (dmw) The mass fraction of dry residues in solid waste under specified conditions. 3.3 constant weight constant mass After the samples were dried, the cooled samples were weighed continuously for 2 times at 4 h intervals, and the difference between before and after did not exceed the final measured quality. 1% of the weight, the weight at this time is the constant weight. Note. When microwave drying method or infrared drying method is selected, under the condition that the sample is continuously dried and weighed by the moisture analyzer, the mass difference before and after within 10 s does not exceed the final measured mass. 0.01% of the weight, the weight at this time is the constant weight.4 Principles of the methodThe solid waste samples were dried at 105 °C ± 5 °C to constant weight, and the moisture and dry matter contents were calculated based on the difference in sample mass before and after drying. Expressed as a quality score.5 Instruments and equipment5.1 Oven. The temperature range is 105 ℃±5 ℃. 5.2 Microwave moisture analyzer. the actual division value of the balance is less than or equal to 0.000 1 g, and the temperature range is 100 °C ± 10 °C. 5.3 Infrared moisture analyzer. the actual scale division value of the balance is ≤0.000 1 g, and the temperature range is 100 °C ± 10 °C. 5.4 Desiccant. It is equipped with anhydrous color-changing silica gel. 5.5 Analytical balance. the actual division value is less than or equal to 0.01 g. 5.6 Container with lid. waterproof material and does not absorb moisture, volume ≥ 100 ml. 5.7 Common laboratory instruments and equipment.6 samples6.1 Sample Collection and Storage Sample collection and preservation shall be carried out in accordance with the relevant regulations of HJ/T 20 and HJ 298.Moisture and dry matter content should be performed as soon as possible after sample collection. quantity measurement. 6.2 Specimen Preparation In general, it can be directly sampled for determination. Sample preparation can also be performed in accordance with selected disposal specifications, evaluation specifications or analytical method standards. Execute on request.7 Analysis steps7.1 Oven drying method Dry the container with lid (5.6) and the lid at 105 ℃ ± 5 ℃ for 1 h, cool slightly, cover the lid, and then put it in the desiccator (5.4) to cool But (about 45 min), weigh the mass m0 of the container with the lid (accurate to 0.01 g). Flatten 25 g to 50 g solid waste samples with a sample scoop Put it into the weighed container with lid (5.6), cover the container, weigh the total mass m1 (accurate to 0.01 g), put it in the oven (5.1), beat it. Open the lid of the container and dry to constant weight at 105 ℃±5 ℃. Cover the container, put it in the desiccator (5.4) to cool (about 45 min), take out Weigh the total mass m2 (accurate to 0.01 g) of the container with the lid and the dried sample immediately afterwards. Note. For samples with high moisture content, the samples can be dried for 12 h, and then weighed at 4 h intervals. 7.2 Microwave drying method According to the operation instructions of the microwave moisture analyzer (5.2), set the instrument parameters (including power and end point determination mode, etc.), and the temperature range is 105℃±5℃. Use a sample spoon to take an appropriate amount of sample (select the appropriate sample size according to the requirements of the instrument, the recommended sample size range is 1.00 g～ 3.00 g) Spread on the sample tray of the instrument, cover the instrument, run the measurement program and read. Note. For samples with poor uniformity, at least 3 parallel samples should be measured, and the results are expressed as the arithmetic mean. 7.3 Infrared drying method According to the operating instructions of the infrared moisture analyzer (5.3), set the parameters of the instrument, and the temperature range is 105 °C ± 5 °C. Take a sample with a spoon (Choose the appropriate sample weight according to the requirements of the instrument, the recommended sample weight is about 3 g), lay it flat on the sample injection tray of the instrument, and cover the instrument cover, run the assay and read. Note. For samples with poor uniformity, at least 3 parallel samples should be measured, and the results are expressed as the arithmetic mean.8 Result calculation and representation8.1 Result calculation The moisture content OH2w and dry matter content dmw in the sample are calculated according to formula (1) and formula (2) respectively. 8.2 Result representation The measurement result shall be retained to the integer, and when the measurement result is less than 1%, it shall be expressed as "< 1%".9 PrecisionSeven verification laboratories used the oven drying method to test the waste incineration residue samples with a moisture content of about 9%, and the process samples with a moisture content of about 69%. Sludge samples from industrial sewage treatment plants and sludge samples from domestic sewage treatment plants with a moisture content of about 85% were tested for 6 replicates. in the laboratory The relative standard deviations ranged from 1.7% to 8.0%, 0.08% to 1.0%, and 0.15% to 0.50%, respectively; the inter-laboratory relative standard deviations were 0.70% to 0.70%. 11%, and the repeatability limit was 0.69% to 1.2%. 2 verification laboratories used microwave drying method for waste incineration residue samples with a moisture content of about 9%, and work samples with a moisture content of about 69%. Sludge samples from industrial sewage treatment plants and sludge samples from domestic sewage treatment plants with a moisture content of about 85% were tested for 6 replicates. in the laboratory The relative standard deviations ranged from 1.8% to 2.2%, 0.42% to 0.73%, and 0.78% to 1.0%, respectively. 1 verification laboratory used infrared drying method for waste incineration residue samples with a moisture content of about 9%, and work samples with a moisture content of about 69%. Sludge samples from industrial sewage treatment plants and sludge samples from domestic sewage treatment plants with a moisture content of about 85% were tested for 6 replicates. in the laboratory The relative standard deviations were 1.2%, 0.31%, and 0.20%, respectively. 10 Quality Assurance and Quality Control 10.1 The sampling process is carried out in strict accordance with the relevant regulations of HJ/T 20 to fully ensure the uniformity of the samples. 10.2 According to the nature of the samples, the number of samples collected should be increased as appropriate to improve the representativeness of the samples. The precision of the measurement results should be less than or equal to 25%, otherwise it should be increased. The number of replicates of the sample. 10.3 When this method is used for arbitration, each sample shall be measured 3 times in parallel, and the arithmetic mean of the measurement results shall be taken. 11 Waste Disposal Hazardous wastes involved in the experiment should be properly collected to avoid mixed collection of incompatible wastes. Hazardous waste shall be stored and disposed of. 12 Notes 12.1 The material of all utensils in contact with the sample should not have any reaction with the sample to be tested, not destroy the representativeness of the sample, and not change the composition of the sample. 12.2 During the experiment, the fine particles of the sample in the container with the lid should be prevented from being blown out by the airflow or wind. 12.3 When using microwave drying method or infrared drying method, it is necessary to carry out in-lab verification and compare it with the data of oven drying method to ensure the precision. The degree and relative deviation between the two methods meet the standard requirements of this method. 12.4 Considering the fire safety factor, if the temperature rises too fast, it may lead to the rapid volatilization of organic matter and flashback and flashback, resulting in the formation of open flames on the surface. Therefore, an oven is recommended The heating rate of the drying method shall not exceed 5 °C/min. 12.5 The instruments and equipment to be used must be within the validity period of the verification or calibration certificate and meet the accuracy requirements of the instruments and equipment in this method. use. ...... |
