HG/T 20590-1997 Technical regulations for design of wastewater treatment in sulfuric acid and phosphate fertilizer industries
Some standard content:
Industry Standard of the People's Republic of China
HG/T-20590 -- 97
Design Technical Regulation for the Treatinent of-Wastewateifrom Sulpharie:Acid &- Phosphatie Fertilizer Industries199706--16 Issued 1997--0801 Implementation Ministry of Chemical Industry of the People's Republic of China
Ministry of Chemical Industry Document
Chemical Construction Development (1997) No. 360
Notice on the Issuance of Three Industry Standards Including "Technical Regulations for Design of Wastewater Treatment in Sulfuric Acid and Phosphate Fertilizer Industries" To all provincial, autonomous region, municipality directly under the Central Government, and independently planned cities, and all relevant units:
Organized by the Water Supply and Drainage Design Technology Center of the Ministry of Chemical Industry and edited by the Design Institute of Nanhua Group and other units, the three industry standards including "Technical Regulations for Design of Wastewater Treatment in Sulfuric Acid and Phosphate Fertilizer Industries" have been approved as recommended industry standards after review. The standard name, number and implementation date are as follows:
Standard name
Main Compilation unit
Implementation date
"Technical regulations for treatment design of sulphuric acid and phosphate fertilizer industrial wastewater HG/T20590971997.8.1"
"General drawing of L92 fan countercurrent cooling tower HG/T21580-971997.5.1"
"General drawing of 2.4m fan countercurrent drum HG/T21614-97 wind-type high turbidity, high temperature, anti-corrosion cooling tower"
Nanhua Group Design
China Global Chemical Engineering Corporation
The Third Design Institute of the Ministry of Chemical Industry
The three standards are managed by the Water Supply and Drainage Design Technology Center of the Ministry of Chemical Industry, and published and distributed by the Engineering Construction Standard Editing Center of the Ministry of Chemical Industry. Ministry of Chemical Industry
June 16, 1997
Industry Standard of the People's Republic of China
Design Technical Regulations for Wastewater Treatment of Sulfuric Acid and Phosphate Fertilizer Industries
HG/T 20590--97
Editing unit: Nanhua Group Design Institute
Approving department: Ministry of Chemical Industry
Implementation period: August 1, 1997 Engineering Construction Standard Editing Center of Ministry of Chemical Industry
1997 Beijing
Sulfuric acid industrial wastewater treatment
Phosphate fertilizer industrial wastewater treatment
Main equipment for sulfuric acid and phosphate fertilizer industrial wastewater treatment, neutralizing agent and lime milk preparation
6 Sulfuric acid and phosphate fertilizer industrial wastewater treatment station
Appendix A Explanation of terms used in this regulation
Explanation of clauses
(6)
(9)
1 General provisions
1.0.1 This regulation mainly stipulates the sulfuric acid and phosphate fertilizer industrial wastewater treatment process, equipment, selection and preparation of neutralizing agents, and design of wastewater treatment stations. 1.0.2 These regulations apply to the design of industrial wastewater treatment for new construction, expansion, reconstruction and technological transformation projects of sulfuric acid and phosphate fertilizer industries.
1.0.3 For expansion, reconstruction and technological transformation projects, full use should be made of existing buildings (structures) and treatment equipment and other facilities.
1.0.4 When designing the treatment of wastewater from sulfuric acid and phosphate fertilizer industries, close cooperation with process professionals should be carried out to adopt clean production processes to increase the reuse rate of water, reduce the amount of wastewater discharged and the pollution of water bodies, and save water resources. 1.0.5 The various treatment methods listed in these regulations have certain applicable conditions. When designing, they should be determined based on the amount of wastewater, water quality, combined with the specific conditions of the project and national and local environmental protection regulations, and determined after technical and economic comparison.
1.0.6 For the dilute sulfuric acid produced in the sulfuric acid industry and the fluorosilicic acid produced in the phosphate fertilizer industry, the comprehensive utilization plan should be considered first. The wastewater and waste liquid generated after comprehensive utilization will be treated again. The dilute sulfuric acid and fluorosilicic acid that cannot be comprehensively utilized should be treated and discharged after meeting the discharge standards.
1.0.7 Wastewater treatment projects should be designed, constructed and put into production at the same time as the main project.
1.0.8 In addition to implementing these regulations, the design of wastewater treatment for sulfuric acid and phosphate fertilizer industries should also comply with the provisions of current relevant national standards and specifications. 1.0.9
Referenced standards
GB428284 "Pollutant Emission Standard for Sulfuric Acid Industry" GB4283--84 "Pollutant Emission Standard for Yellow Phosphorus Industry" GB4917-85 "Pollutant Emission Standard for General Calcium Industry" GB15580-95 "Water Pollutant Emission Standard for Phosphate Fertilizer Industry" 4
2 Wastewater Treatment for Sulfuric Acid Industry
2.1 General provisions
2.1.1 According to the different raw materials and purification processes of sulfuric acid production, before designing wastewater treatment, the conditions such as wastewater volume and water quality data should be determined in order to select a reasonable treatment method.
2.1.2 In order to save water resources, the first thing to consider is to return the treated wastewater to the purification process for recycling.
2.1.3 The main pollutants in sulfuric acid industrial wastewater are acidity, arsenic, fluorine and heavy metal ions. The wastewater treatment plan should focus on arsenic removal. If the arsenic content in the wastewater is not high, the acidity adjustment and fluorine removal should be the main focus.
2.1.4 When determining the wastewater treatment and neutralization process, the wastewater quality and discharge conditions should be mastered, and neutralization treatment, sludge sedimentation and other corresponding tests should be carried out to provide a technical basis for selecting an economically reasonable treatment plan.
2.2 Treatment methods, process design and calculation
2.2.1 Commonly used methods for sulfuric acid industrial wastewater treatment are: lime (or carbide slag) coagulation precipitation method. Applicable to wastewater with low arsenic content, using lime milk (or carbide slag) neutralization and coagulation precipitation treatment process. Lime (or carbide bay) iron salt coagulation precipitation method. Suitable for wastewater with high arsenic content, it is recommended to use lime milk (or carbide slag) for neutralization and add ferrous sulfate/coagulant coprecipitation treatment process.
Select the primary neutralization or secondary neutralization process, which can be determined based on experiments. If there is no data
When the secondary neutralization process is adopted, its process parameters are as follows: 2
First neutralization: bH: 3~~4.Fe/As: 2~4Second neutralization: bH: 7~~8.Fe/A4s: 20When the primary neutralization process is adopted, its process parameters are as follows: pH: 6~9; Fe/As: ≥10
Oxidation method. In order to improve the removal rate of arsenic, oxidizing agents such as bleaching powder, sodium hypochlorite, pyrolusite, etc. should be used to oxidize the trivalent arsenic in the wastewater into pentavalent arsenic. This method is often used in conjunction with the first two methods.
2.2.2 The process design of sulfuric acid industrial wastewater should be based on the wastewater volume, water quality and water quality requirements for treated effluent, sludge disposal methods, or reference to similar operating parameters, and select a reasonable process based on local conditions. 2.2.3 When lime is used as a neutralizing agent, its dosage is calculated as follows: NK?Ns/a (kg/h)
Wherein, N——lime dosage, kg/h;
Ns theoretically calculated dosage of lime, kg/h;
purity of lime % (calculated as CaO)
K--reaction unevenness coefficient, it is recommended to use 1.05~～1.15. The amount of sludge is calculated as follows:bZxz.net
N=-N+N+Q(SCd)(kg/h)
Wherein, N--sludge amount (thousand basis), kg/h; (2.2.3)
Na--amount of precipitate produced by neutralization reaction, kg/h, which can be found in the table of salt produced by neutralization of relevant chemical agents (unit acid amount): N--impurity content in neutralizing agent, kg/h; Q Wastewater volume, m2/h
S-Suspended solids content of wastewater before neutralization, kg/m: C-Amount of salt dissolved in water after neutralization, kg/m\d-Content of suspended solids carried away in drainage after sedimentation, kg/m. 3
Wastewater treatment in phosphate fertilizer industry
3.1-General provisions
3.1.1The wastewater treatment process should be determined according to factors such as the type of phosphate fertilizer, the adopted process flow and the quality of wastewater.
3.1.2 For phosphate fertilizer devices where the treated wastewater can be returned to the process system for recycling, such as phosphoric acid, calcium magnesium phosphate, yellow phosphorus, etc., a recycling treatment method should be selected. For those that can be mostly recycled and a small part needs to be discharged, the recycling ratio should be increased. A small amount of discharged wastewater should be treated to meet the discharge standards before being discharged.
3.1.3 The process design of phosphate fertilizer industrial wastewater should be based on the type of phosphate fertilizer, the amount and quality of wastewater in the process, the water quality requirements of the treated drainage, and the sludge disposal method. Tests should be conducted or the operating parameters of similar plants should be referred to, and the treatment plan should be selected in combination with local conditions. 3.2 Scheme selection
3.2.1 For high-fluorine wastewater discharged from phosphoric acid, calcium carbonate and other devices, the primary or secondary neutralization scheme can be determined by referring to the empirical data or test data of the same type of wastewater treatment. When the neutralizing agent is lime, the H value control requirements are as follows: the primary neutralization scheme, control bH: 6~9 and then perform sedimentation (or coagulation sedimentation); the secondary neutralization scheme, the operating parameters are as follows: the first-stage neutralization controls H: 3-5, and the second-stage neutralization controls pH: 8.5~9. 3.2.2 For wastewater discharged from phosphoric acid, calcium carbonate, calcium carbonate and other devices, when the secondary neutralization scheme is adopted, the first-stage neutralization can choose limestone filtration neutralization or limestone powder neutralization. 3.2.3 Yellow phosphorus wastewater is returned to the process for reuse after limestone neutralization, coagulation and sedimentation, and cooling; in order to maintain the water balance of the process system, a small amount of wastewater is discharged, which should be further treated to meet the discharge standard before discharge.
When treating yellow phosphorus wastewater with lime (or carbide slag) for neutralization, H should be strictly controlled below 8.
3.2.5 When phosphate fertilizer industrial wastewater is neutralized with lime (or carbide slag), the amount of lime used is calculated as shown in Article 2.2.3 of this Regulation. The coefficient of uneven reaction should be 1.1~~1.2.3.2.6 The amount of sludge generated by the neutralization of phosphate fertilizer wastewater is calculated as shown in Article 2.2.4 of this Regulation.
4 Main equipment for the treatment of sulfuric acid and phosphate fertilizer industrial wastewater 4.1 Design and selection of neutralization equipment
4.1.1 The neutralization reaction of wastewater should be carried out in the neutralization equipment. The neutralization equipment should adopt a reinforced concrete structure neutralization tank or a steel-lined rubber neutralization tank. 4.1.2 The volume calculation of the neutralization tank (tank) should be designed according to the following parameters: The neutralization retention time of sulfuric acid industrial wastewater is 15 minutes. If the arsenic and fluorine content in the wastewater is high, it should be increased to 20~~30 minutes.
For the neutralization of phosphate fertilizer industrial wastewater, the retention time is 30 minutes. 4.1.3 The stirring of the neutralization tank (tank) can be carried out mechanically or with compressed air. When stirring with compressed air, the air pressure is 0.1~0.2MPa, and the amount of compressed air is 0.2m/min·m2 of wastewater.
When stirring mechanically, the stirring intensity is medium, and a single-blade or double-blade paddle mixer is used depending on the design of the neutralization tank (tank), and the linear speed is about 3m/s. 4.1.4 The number of neutralization tanks (tanks) should not be less than two, and no equipment is required. 4.1.5 When limestone is used for neutralization of yellow phosphorus wastewater, a horizontal drum neutralizer should be selected. The residence time of the neutralization reaction is 6~9min.
4.1.6 When limestone filtration is used for neutralization, fixed bed filtration or expansion filter filtration can be selected according to water quality or test results.
4.1.7 After the neutralization reaction, a crystal growing tank should be set up, and its design is the same as the neutralization tank. 4.2 Design of coagulation reaction tank
The coagulation reaction time is determined by the test, or it can be selected according to the experience data of the production plant. If there is no data, 3~~9min can be selected: if there is no crystal growing tank, 15~~30min can be selected.4.2.2 The coagulation reaction tank should adopt weak stirring intensity, and it is advisable to use paddle (or frame) stirring6
4.3 Design of sedimentation tank (tank)
In the treatment of sulfuric acid and phosphate fertilizer industrial wastewater, vertical flow or radial flow sedimentation tank (tank) should be adopted.
4.3.2 The design parameters of the sedimentation tank (tank) are selected according to the sludge sedimentation test, or they can be selected according to the sludge sedimentation performance data of the same type of production. Design of vertical flow sedimentation tank (pool)
The effective area of vertical flow sedimentation tank (pool) is calculated according to the following formula: A=Q/(3.6 · V)(m2)
Where A--effective sedimentation area of sedimentation tank (pool), m\: Q--design wastewater volume, m3/h;
V--rising flow velocity, mm/s
The relationship between rising flow velocity (V) and sludge settling velocity (U) is: V-UK(mm/s)
(4.3.3-1)
(4.3.3-2)
Sludge settling velocity, mm/s; when there is no data, 0.3~~0.5mm can be selected where U-
K--correction coefficient for uneven distribution of rising water flow in the sedimentation tank, which can be selected from 0.5~0.7.
The effective area of radial flow sedimentation tank (tank) is calculated as follows: A=Q/g(m2)
Where A-
-effective sedimentation area of sedimentation tank (tank), m2, Q-design wastewater volume, m/h;
-surface load, m2/(m2·h); when there is no data, 0.7~1.0m*/(m2.h) can be selected.
4.3.5 Two sedimentation tanks (tanks) should be set up, and no equipment is used. 7
Quasi-search and swing
4.4 Selection of sludge dewatering equipment
4.4.1For sewage treatment devices with less sludge, plate and frame or box filter press can be selected. For those with large sludge volume, belt filter press, folded belt vacuum drum dewatering machine, disc vacuum dewatering machine and other equipment can be selected.
4.4.2 The production capacity of various sludge dewatering equipment should be determined through sludge dewatering tests, or by using the manufacturer's experience data.
Search below3—1)
(4.3.3—2)
Sludge settling velocity, mm/s; when no data is available, 0.3~~0.5mm can be selected. Where U—
K is the correction coefficient for uneven distribution of rising water in the sedimentation tank, which can be selected from 0.5~0.7.
The effective area of radial flow sedimentation tank (tank) is calculated as follows: A=Q/g(m2)
where A-
-effective sedimentation area of sedimentation tank (tank), m2, Q-design wastewater volume, m/h;
-surface load, m2/(m2·h); when no data is available, 0.7~1.0m*/(m2.h).
4.3.5Two sedimentation tanks (tanks) should be set up, and no equipment is used. 7
准搜摆
4.4 Selection of sludge dewatering equipment
4.4.1 For sewage treatment devices with less sludge, plate-frame and box-type filter presses can be selected. For sewage treatment devices with large sludge volumes, belt filter presses, folded-belt vacuum drum dewatering machines, disc vacuum dewatering machines and other equipment can be selected.
4.4.2 The production capacity of various sludge dewatering equipment should be determined through sludge dewatering tests, or by using the manufacturer's experience data.
下搜搜3—1)
(4.3.3—2)
Sludge settling velocity, mm/s; when no data is available, 0.3~~0.5mm can be selected. Where U—
K is the correction coefficient for uneven distribution of rising water in the sedimentation tank, which can be selected from 0.5~0.7.
The effective area of radial flow sedimentation tank (tank) is calculated as follows: A=Q/g(m2)
where A-
-effective sedimentation area of sedimentation tank (tank), m2, Q-design wastewater volume, m/h;
-surface load, m2/(m2·h); when no data is available, 0.7~1.0m*/(m2.h).
4.3.5Two sedimentation tanks (tanks) should be set up, and no equipment is used. 7
准搜摆
4.4 Selection of sludge dewatering equipment
4.4.1 For sewage treatment devices with less sludge, plate-frame and box-type filter presses can be selected. For sewage treatment devices with large sludge volumes, belt filter presses, folded-belt vacuum drum dewatering machines, disc vacuum dewatering machines and other equipment can be selected.
4.4.2 The production capacity of various sludge dewatering equipment should be determined through sludge dewatering tests, or by using the manufacturer's experience data.
下搜搜
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