At present, there is no unified standard for the determination of the pH value of municipal solid waste in my country's sanitation industry. Since pH is a necessary parameter when using the composting method to harmlessly treat municipal solid waste, it is necessary to develop a pH determination method suitable for the characteristics of municipal solid waste. This standard combines the current analytical methods in environmental monitoring and soil physical and chemical testing, conducts comparative experiments and verification experiments in the laboratory to further modify and improve the analytical methods in view of the complexity and instability of the components of municipal solid waste, and compiles a method for determining the pH value of municipal solid waste. This standard specifies the method of determining the pH value of the extract by the glass electrode method after extracting the sample with a KCl solution. This standard is applicable to the determination of municipal solid waste samples. CJ/T 99-1999 Determination of pH value of municipal solid waste by glass electrode method CJ/T99-1999 Standard download decompression password: www.bzxz.net

Engineering construction standard full-text information system
Town construction industry standard of the People's Republic of China CJ/T 99—1999
Determination of H of municipal domestic refuse
Glass electrode method
Municipal domestic refuse-Determination of pHGlass electrode method
Published on November 24, 1999
Implementation on June 1, 2000
Ministry of Construction of the People's Republic of China
Engineering construction standard full-text information system
Engineering construction standard full-text information system
CJ/T99—1999
At present, there is no unified standard for the determination of pH of municipal domestic refuse in my country's sanitation industry. Since pH is a necessary parameter for harmless treatment of municipal domestic refuse by composting, it is necessary to formulate a pH determination method suitable for the characteristics of municipal domestic refuse. This standard combines the current analytical methods in environmental monitoring and soil physical and chemical testing, and conducts comparative experiments and verification experiments in the laboratory to further modify and improve the analytical methods in view of the complexity and instability of domestic waste components, and compiles the determination method of pH of urban domestic waste.
This standard is proposed by the Standard and Quota Research Institute of the Ministry of Construction. This standard is under the jurisdiction of the Shanghai Municipal Environmental Sanitation Administration, the technical unit responsible for urban environmental sanitation standards of the Ministry of Construction.
This standard was drafted by the Tianjin Environmental Sanitation Engineering Design Institute. The main drafters of this standard are: Han Zhimei and Zhang Fan. This standard is entrusted to the Tianjin Environmental Sanitation Engineering Design Institute for interpretation. Engineering Construction Standard Full-text Information System
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Engineering Construction Standard Full-text Information System
Town Construction Industry Standard of the People's Republic of China Municipal Domestic Refuse
Determination of pH
Glass Electrode Method
Municipal domestic refuseDetermination of pHGlass electrode method
1 Scope
CJ/T99——1999bzxZ.net
This standard specifies the method of determining the pH of the leaching solution by glass electrode method after extracting the sample with KCl solution.
This standard is applicable to the determination of municipal domestic refuse samples. Cited Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the following standards. CJ/T3039—1995 Sampling and physical analysis methods for municipal solid waste 3. Sample collection and preparation
3.1 The collection and preparation of samples shall be carried out in accordance with the provisions of CJ/T3039 to meet the 4-(1)b drying sample standard. The treatment process shall not exceed 24 hours. 3.2 The moisture content of municipal solid waste shall be determined in accordance with the provisions of C/T3039 to prepare for the conversion of sample determination results.
3.3 The storage of samples shall be carried out in accordance with the provisions of CJ/T3039. Approved by the Ministry of Construction of the People's Republic of China on November 24, 1999, and implemented on June 1, 2000. The full text information system of the engineering construction standard was implemented. 4 Principles. The glass electrode is used as the indicator electrode, and the saturated calomel electrode is used as the reference electrode to form a battery. When the electrode is inserted into the sample extract, a potential difference is generated between the two. Since the potential of the reference electrode is fixed, the size of the potential difference depends on the activity of hydrogen ions in the sample. The negative logarithm of the activity of hydrogen ions is the pH value. The pH meter used for sample detection can generally be accurate to 0.1 pH units, and precision instruments can be accurate to 0.01 pH units. In order to improve the accuracy of the measurement, the instrument needs to be calibrated with a pH standard buffer solution. 5 Reagents
5.1 pH standard solution (pH=4.008, 25℃) Accurately weigh 10.21g (accurate to 0.001g) of potassium hydrogen phthalate (KHC.H,O,) which has been dried at 105-130℃ for 2-3h and has reached a constant weight, dissolve it in an appropriate amount of water, and make up to 1000mL.
pH standard solution (pH=6.865, 25℃) Accurately weigh 3.388g of potassium dihydrogen phosphate (KH,PO,) and 3.531g (accurate to 0.001g) of disodium hydrogen phosphate (Na,HPO,) which have been dried at 105-130℃ for 2h and have reached a constant weight, dissolve them in an appropriate amount of water, and make up to 1000mL. 5.3 pH standard solution (pH = 9.18, 25 ℃) Accurately weigh 3.81 g (accurate to 0.001 g) of sodium borate (Na, B, 0·10H0) which has been dried at 105-130 ℃ for 2-3 h and has a constant weight, dissolve it in an appropriate amount of water, and make up to 1000 mL. The pH values ​​of the above three standard solutions change with temperature, as shown in Table 1. 2
Engineering Construction Standard Full-text Information System
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Engineering Construction Standard Full-text Information System
Temperature ℃
Potassium dihydrogen phthalate standard solution
Phosphate pH standard solution
Sodium borate pH standard solution
Bagged standard materials: Products that must be certified by the national metrology department and used according to the instructions 5.4
.
Note: The prepared standard solution should be stored in a polyethylene bottle or a hard glass bottle and sealed. It can be stored at room temperature for 1 month. The shelf life can be extended at 4°C. 0.1mol/L KCl solution
Weigh 17.45g of KCl that has been dried at 100~130℃ for 2~3h and has a constant weight, dissolve it in an appropriate amount of water, and make up to 1000mL.
5.6 Test water: The distilled water used in this standard must be boiled for several minutes before use, and the carbon dioxide must be removed and cooled before use.
a) Acidity meter (pH meter);
b) Glass electrode;
c) Saturated calomel electrode or silver-silver chloride electrode; d) 50mL beaker (polyethylene or polytetrafluoroethylene beaker) Engineering Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System
7 Operation steps
7.1 Prepare and check the instrument's electrodes and standard buffer solutions according to the instrument's instruction manual to see if they are normal. The glass electrode should be soaked in distilled water for 24 hours before use, and there should be an appropriate amount of potassium chloride crystals in the calomel electrode to ensure the saturation of the potassium chloride solution. 7.2 Before measurement, the instrument should be calibrated with pH=6.865 standard solution (5.2) and pH=9.18 standard solution (5.3) or pH=4.008 standard solution (5.1). 7.3 Weigh 5g of the domestic waste sample into a 50mL beaker, add 25mL of potassium chloride solution (5.5), stir with a glass rod for 1~2min and let stand for 30min. Stir for 0.5min every 5min, then operate according to the instructions of the pH meter. Read the pH value directly from the instrument after 1min.
When measuring pH, the solution should be stirred moderately to make the solution uniform and reach electrochemical equilibrium. When reading the data, it should be left still for a while to stabilize the reading. When replacing the standard solution or sample, the electrode should be fully rinsed with water, the water droplets on the electrode should be absorbed with filter paper, and then rinsed with the solution to be tested to eliminate mutual influence.
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