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GB 51441-2022: (Engineering Design Standards for Electronic Industry Wastewater Treatment)
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(Engineering Design Standards for Electronic Industry Wastewater Treatment)
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GB 51441-2022
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Standard similar to GB 51441-2022 GB/T 50082 GB/T 51446 Basic data | Standard ID | GB 51441-2022 (GB51441-2022) | | Description (Translated English) | (Engineering Design Standards for Electronic Industry Wastewater Treatment) | | Sector / Industry | National Standard | | Word Count Estimation | 82,898 | | Date of Issue | 2022-10-31 | | Date of Implementation | 2023-02-01 | | Issuing agency(ies) | Ministry of Housing and Urban-Rural Development of the People's Republic of China; State Administration for Market Regulation | GB 51441-2022: (Engineering Design Standards for Electronic Industry Wastewater Treatment)---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.
1 General
1.0.1 This standard is formulated in order to standardize the design of waste water treatment projects in the electronics industry, to achieve safety and applicability, advanced technology, reasonable economy, energy saving and environmental protection.
1.0.2 This standard is applicable to the design of newly built, rebuilt and expanded electronics industry wastewater treatment projects. The electronic industry wastewater treatment project shall be designed, constructed and put into operation at the same time as the main project.
1.0.3 The design of the electronic industry wastewater treatment project shall not only comply with the provisions of this standard, but also comply with the provisions of the current relevant national standards.
2 Terms and Abbreviations
2.1 Terminology
2.1.1 acidic & alkaline wastewater
Acidic or alkaline wastewater discharged during the production process.
2.1.2 Grinding & sawing wastewater
Wastewater containing solid particles or suspended matter discharged from the production process of grinding, cutting, etc.
2.1.3 chemical mechanical planarization (CMP) wastewater
Wastewater containing solid particles or suspended matter discharged from the chemical mechanical polishing production process.
2.1.4 fluoride wastewater
Wastewater containing fluoride ions and their compounds discharged during the production process.
2.1.5 Phosphorus wastewater phosphorus wastewater
Wastewater containing phosphoric acid, phosphate, metaphosphate, polyphosphate and organic phosphate discharged during the production process.
2.1.6 Arsenic wastewater arsenic wastewater
Wastewater containing various arsenic compounds discharged from the production process.
2.1.7 organic waste water
Wastewater containing organic matter discharged from the production process.
2.1.8 inorganic waste water
The wastewater discharged during the production process only contains compounds such as inorganic salts and does not contain organic compounds.
2.1.9 heavy metal containing waste water
Wastewater containing cadmium, chromium, lead, nickel, silver, copper, zinc and other metal ions, complexes and their compounds discharged during the production process. According to the heavy metal elements contained in the wastewater, it is also called cadmium-containing wastewater, chromium-containing wastewater, lead-containing wastewater, nickel-containing wastewater, silver-containing wastewater, copper-containing wastewater, zinc-containing wastewater, etc.
2.1.10 physical & chemical treatment
Wastewater is treated by physical and chemical methods. The physical and chemical treatment process of electronic wastewater mainly includes chemical reaction, coagulation precipitation, adsorption, ion exchange, filtration, evaporation and concentration and other methods.
2.1.11 biochemical treatment biochemical treatment
Using the metabolism of microorganisms to convert dissolved and colloidal organic pollutants in sewage into harmless substances to achieve purification, including aerobic treatment and anaerobic treatment.
2.1.12 reclaim water
Wastewater can be used directly or after proper treatment to meet certain water quality indicators and meet certain use requirements.
2.1.13 Gas stripping＆oxidation process for ammonia wastewater
A wastewater treatment method that strips ammonia in ammonia nitrogen wastewater and oxidizes it into nitrogen by catalytic oxidation.
2.1.14 Sequencing batch reactor coagulating sedimentation process
In the same reactor, the coagulation-sedimentation wastewater treatment method consists of five basic processes of water intake, reaction, sedimentation, drainage and standby in chronological order.
2.2 Abbreviations
3 basic rules
3.0.1 The process selection of wastewater treatment projects should follow the principles of comprehensive treatment, recycling, energy saving and emission reduction, and total volume control. Under the condition of reasonable technology and economy, the recyclable substances in water resources and waste water should be fully recycled.
3.0.2 When the main project is constructed in stages, the wastewater treatment project shall be uniformly planned, rationally arranged and implemented in stages according to the final scale.
3.0.3 Wastewater treatment should adopt a technological process with mature technology, safety and reliability, and convenient operation and maintenance. Scientifically, rationally, actively and prudently select proven and effective new technologies, new processes, new materials and new equipment.
3.0.4 Wastewater treatment requirements should be determined according to the requirements of the environmental impact assessment report approval, and pollutant discharge should meet the corresponding national, industry or local pollutant discharge standards.
3.0.5 The selection of technological process shall consider the influence of natural factors such as region, geography, geology, meteorology, earthquake and flood.
3.0.6 The influent water quality of the wastewater treatment project should be determined according to the actual measurement data or the operating practices of similar enterprises.
3.0.7 When there is no mature experience for reference in the treatment process of the wastewater treatment project, the treatment process and design parameters can be determined through experiments or based on similar water quality operation experience.
3.0.8 Wastewater treatment projects should be collected and treated by classification and quality according to the project scale and water quality characteristics in accordance with the principles of cleaning and diversion, and separation of concentration and light.
3.0.9 For the storage and treatment of waste water treatment devices and structures containing volatile toxic, harmful, flammable and odorous gases, the exhaust gas shall be collected and disposed of properly.
3.0.10 The pipes of the electronic industry wastewater treatment system shall be clearly marked according to different media.
4 Wastewater Treatment Process
4.1 General provisions
4.1.1 The technological process shall be determined through technical and economical comparison, taking into account factors such as initial investment, operating cost, service life, resource occupation and energy consumption.
4.1.2 The wastewater treatment project should be equipped with an online monitoring system.
4.1.3 Waste gas, waste residue and other pollutants that may be generated during operation shall be properly disposed of in the process design of wastewater treatment engineering.
4.1.4 The waste water treatment station shall be equipped with an emergency pool, and its volume should not be less than the 6h average total discharge of the largest stream of waste water.
4.1.5 When coagulation-sedimentation method is used to treat wastewater and the volume of wastewater is less than 50m³/d, sequential batch coagulation-sedimentation method should be used for treatment.
4.2 Water quantity and quality
4.2.1 In the early stage of wastewater treatment project design, detailed investigation and analysis and demonstration should be carried out on the water quantity and quality of wastewater.
4.2.2 The determination of the treatment capacity of the wastewater treatment project shall comply with the following regulations.
1 When conditions permit, the water quantity and quality should be determined according to the measured values, and a certain margin should be left according to the process requirements;
2 When there is no actual measured value, the pollutants and pollution load should be determined according to the same type of enterprises, or estimated according to the wastewater volume and water quality per unit product, and coordinate with the current national regulations on industrial water consumption.
4.2.3 The design flow rate of the wastewater treatment system should be determined according to the following principles.
1 When there is no adjustment facility in front of the treatment system, the design flow should be designed according to the maximum hourly wastewater flow;
2 When there are adjustment facilities in front of the treatment system, the design flow should be designed according to the average hourly wastewater flow.
4.2.4 For wastewater treatment systems with large changes in water volume and water quality, facilities for adjusting water volume and water quality should be installed. The design of the regulating tank should meet the following requirements.
1.The volume of the regulating tank should be determined according to the range of wastewater volume and water quality changes and the required adjustment degree, and should meet the regulation requirements of all wastewater for more than one cycle of water volume and water quality changes;
2 The regulating tank should be equipped with a stirring system, and measures such as capping, ventilation, deodorization, explosion protection and sludge discharge should be considered according to the characteristics of the wastewater.
4.2.5 The drainage volume of the wastewater treatment project shall meet the limitation requirements of the overall engineering drainage volume.
4.3 Treatment process design
4.3.1 The treatment of acid-base wastewater should meet the following requirements.
1 The reaction pool of the acid-base wastewater treatment system should not be less than the second stage;
2 The waste water that finally enters the acid-base wastewater treatment system should enter the system evenly;
3 When the waste water from each stream enters the acid-base wastewater treatment system, it should be pretreated by neutralizing the waste acid-base.
4.3.2 The treatment of fluorine-containing wastewater should meet the following requirements.
1 Fluorine-containing wastewater should be treated by chemical coagulation and sedimentation;
2 High-concentration fluorine-containing wastewater should be gradually and appropriately put into low-concentration fluoride-containing wastewater for treatment;
3 The fluorine-containing wastewater treatment system should be equipped with sludge return conditioning facilities;
4 The fluorine-containing wastewater treatment system should be equipped with an online fluoride ion monitor and be interlocked with the dosing of chemicals.
4.3.3 The treatment of phosphorus-containing wastewater should meet the following requirements.
1 Low-concentration phosphorus-containing wastewater should be treated by chemical coagulation and sedimentation;
2 High-concentration phosphorus-containing wastewater should be treated by two-stage chemical coagulation and sedimentation;
3 High-concentration phosphorus-containing wastewater should be gradually and appropriately put into low-concentration phosphorus-containing wastewater for treatment;
4 When comprehensive technology and economy are relatively feasible, phosphoric acid waste liquid should be outsourced for comprehensive treatment;
5 The phosphorus-containing wastewater treatment system should be equipped with sludge return conditioning facilities;
6 The phosphorus-containing wastewater treatment system should be equipped with a total phosphorus online monitor, which should be interlocked with the dosage of chemicals.
4.3.4 The treatment of CMP wastewater should meet the following requirements.
1 CMP wastewater should be treated by chemical coagulation sedimentation method;
2 The H2O2 contained in CMP wastewater should be pretreated separately before coagulation and sedimentation treatment;
3 CMP wastewater with different chemical properties should be collected separately and combined for disposal.
4.3.5 The treatment of ammonia-containing wastewater should meet the following requirements.
1 High-concentration ammonia-containing wastewater should be pretreated by stripping-absorption process before entering the next-level wastewater treatment system;
2 The stripping treatment system for high-concentration ammonia-containing wastewater should be equipped with heating measures and heat recovery measures;
3 When it is difficult to dispose of ammonium sulfate, high-concentration ammonia-containing wastewater can be treated by air stripping catalyst method;
4 Low-concentration ammonia-containing wastewater should be disposed of by breakpoint chlorination method or biological nitrification and denitrification process; when the breakpoint chlorine oxidation method is used to treat ammonia-containing wastewater, the pH value in the reaction tank should be controlled at about 4.
4.3.6 The treatment of arsenic-containing wastewater should meet the following requirements.
1 Arsenic-containing wastewater should be treated by chemical coagulation and sedimentation;
2 The grinding and cutting wastewater of gallium arsenide wafer should be separated and recovered by solid-liquid separation first, and then enter the subsequent treatment system;
3 The arsenic-containing wastewater sludge dewatering device should be set up separately.
4.3.7 The treatment of organic wastewater should meet the following requirements.
1 When the CODCr concentration of organic wastewater is greater than or equal to.2000mg/L, it is advisable to use chemical coagulation sedimentation method, air flotation method or anaerobic biological treatment system for pretreatment before entering the subsequent treatment system;
2 When the CODCr concentration of organic wastewater is less than.2000mg/L, biological treatment process should be adopted;
3 When the total nitrogen concentration in the wastewater exceeds the requirements of the discharge standard, the nitrification and denitrification denitrification process should be selected.
4.3.8 The treatment of heavy metal wastewater should meet the following requirements.
1 Heavy metal wastewater should be treated by chemical coagulation and sedimentation;
2 For heavy metal wastewater containing high concentrations of sulfate, NaOH should be used as the pH regulator;
3.For heavy metal wastewater containing complexing agents and chelating agents, it is advisable to carry out pretreatment to break the complex first, and then enter the heavy metal wastewater system for treatment;
4 For heavy metal wastewater containing H2O2, it is advisable to collect it separately and remove H2O2, then quantitatively inject it into the heavy metal wastewater for combined treatment;
5.High-concentration heavy metal wastewater should be collected separately. After heavy metal recovery and pretreatment, it should be quantitatively added to low-concentration heavy metal wastewater for treatment;
6 The heavy metal wastewater treatment system should be equipped with sludge return conditioning facilities;
7 The heavy metal wastewater treatment system should be equipped with an online heavy metal ion monitor and interlocked with chemical dosing.
4.3.9 The treatment of ammonia complex wastewater should meet the following requirements.
1 Ammonia-containing complex wastewater should be pretreated by sulfide precipitation method and breakpoint chlorination method;
2 When using the sulfide precipitation method to treat ammonia-complexed wastewater, heavy metal pollutants should be treated first and should not be mixed with other heavy metal wastewater. After treatment, ammonia-complexed wastewater should be treated with ammonia nitrogen pollutants;
3 When using the sulfide precipitation method to treat ammonia-containing complex wastewater, the wastewater should be treated under alkaline conditions, and technical measures to prevent excessive addition of sulfide chemicals should be designed;
4 When using the breakpoint chlorination method to treat ammonia-containing complex wastewater, it is advisable to treat the ammonia nitrogen pollutants first, and then import the heavy metal wastewater for subsequent treatment;
5 When the concentration of heavy metals in ammonia-containing complex wastewater is greater than 10g/L, after the reaction is completed, it should directly enter the filter press for full filtration, and then enter the subsequent treatment system after filtering out the water.
4.3.10 The treatment of printed circuit board chemical copper wastewater should meet the following requirements.
1 Chemical copper wastewater should be treated by ferrous sulfate method, calcium salt method, sodium borocyanide method and catalytic reduction method;
2 When the calcium salt method is used to treat chemical copper wastewater, calcium carbonate should not be used as a reactive agent.
4.3.11 The treatment of printed circuit board imaging and film removal waste liquid should meet the following requirements.
1 The imaging and film removal waste liquid should be pretreated by acidification and solid-liquid separation before subsequent treatment;
2 When acidification and solid-liquid separation are used to treat imaging and film removal waste liquid, it is advisable to use mechanical stirring and add an appropriate amount of defoamer;
3 The imaging waste liquid should be collected separately for acidification treatment and then combined with the film-removing waste liquid;
4 After the imaging waste liquid is pretreated by acidification and solid-liquid separation method, it is advisable to adopt biochemical treatment process for subsequent treatment.
4.4 Physical and chemical treatment
Ⅰ pH adjustment
4.4.1 When the pH value of wastewater cannot meet the requirements of the subsequent treatment system or discharge, pH adjustment treatment should be carried out.
4.4.2 The pH adjusting agent should give priority to the use of waste acid and alkali.
4.4.3 The pH adjustment facility shall have a stirring function, and graded adjustment may be considered. The single-stage residence time of wastewater should be 5min to 20min.
4.4.4 The mechanical stirring power of the pH adjustment system should be 2W/m³～4W/m³.
4.4.5 The dosing amount of pH adjustment agent should be determined through experiments or calculated according to the equivalent reaction according to the quality of wastewater and the type of agent to be added.
4.4.6 Dosing of chemicals for pH adjustment shall be controlled by automatic pH adjustment.
Ⅱ Coagulation and Flocculation
4.4.7 When chemical coagulation sedimentation method is used to treat electronics industrial wastewater, the following regulations shall be met.
1 The reaction time should be determined according to the characteristics of the wastewater, the chemical reaction requirements and the form of the reaction system, and should be controlled within 15 minutes to 30 minutes;
2 The average velocity gradient of the reaction pool should be 20s-1~70s-1, the GT value (the product of the velocity gradient and the reaction time) should be 104~105, and the velocity gradient and reaction flow rate should gradually decrease from large to small;
3 The reaction tank should be constructed in combination with the sedimentation tank or air flotation tank. When it is really necessary to connect with pipes, the flow velocity should be less than 0.15m/s;
4 The flow velocity of the perforated wall at the outlet of the reaction pool should be less than 0.10m/s;
5 The reaction pool should preferably adopt mechanical stirring;
6.The choice of chemical mixing method should be determined based on comprehensive analysis of wastewater volume, wastewater properties, pH value and water temperature;
7 The type selection of the reaction system should be determined through technical and economic comparison in combination with local conditions.
4.4.8 The setting of the chemical coagulation-sedimentation reaction system should meet the following requirements.
1.The reaction system should not be less than three sections, and each section should be equipped with a corresponding number of agitators;
2.The paddles can be divided into hand pull type and impeller type. The center line speed of the paddle should be 0.2m/s～0.5m/s, and the line speed of each section should be gradually reduced;
3 The top of the vertical shaft type upper paddle should be set at 0.3m below the water surface of the pool, the bottom of the lower paddle should be set at 0.3m~0.5m from the bottom of the pool, and the distance between the outer edge of the paddle and the side wall of the pool should not be greater than 0.25m ;
4 The total area of the paddles on each stirring shaft should be 10% to 20% of the cross-sectional area of the water flow, not more than 25%, and the width to length ratio of the paddles should be 1.15 to 1.10;
5 The reaction system should be equipped with measures to prevent short flow of waste water, and the vertical axis mechanical reaction tank should be equipped with fixed baffles on the pool wall;
6.The single cell of the reaction pool should be built into a square shape, the size of one side should be greater than 800mm, the depth of the pool should be 2.5m ~ 4.0m, and the maintenance platform should be set at the side of the pool.
4.4.9 The calculation of the coagulation reaction system should meet the following requirements.
1 The volume of the reaction pool should be calculated according to the following formula.
In the formula. V——the volume of each pool (m³);
Q——design water volume (m³/s);
t—response time (s), generally 900s~1800s.
2 The size of the reaction pool should be calculated according to the following formula, where L/B should not be greater than 1.5.
In the formula. L - the length of the reaction pool (m);
B - the width of the reaction pool (m);
H——The water depth of the reaction pool (m).
3 The number of revolutions of the agitator should be calculated according to the following formula.
In the formula. n0——rotation number of agitator (r/min);
v——linear velocity of the outer edge of the agitator (m/s);
D0 - diameter of the outer edge of the agitator (m).
4 The equivalent diameter of the reaction pool should be calculated according to the following formula.
When the reaction cell is rectangular, the equivalent diameter is.
In the formula. D—the equivalent diameter of the reaction pool (m).
5 The mixed effective power NQ should be calculated according to the following formula.
In the formula. NQ—the effective power of mixing and stirring (kW);
μ——dynamic viscosity of water (Pa·s);
tm - mixing time (s);
G—velocity gradient (s-1).
6 The diameter d of the agitator should be calculated according to the following formula.
In the formula. d——the diameter of the stirrer (m).
7 The linear velocity of the outer edge of the agitator should be set as v=2m/s～3m/s.
8 Stirrer power N should be calculated according to the following formula.
In the formula. N——Stirrer power (kW);
Cx——resistance coefficient, Cx=0.2～0.5;
ρ——the density of water (kg/m³);
ω——Agitator rotational angular velocity (rad/s);
n - the number of agitator blades;
l - the length of the agitator blade (m);
R——the radius of the stirrer (m);
g—gravitational acceleration (m/s2), take 9.8m/s2;
θ——the knuckle angle of the paddle board (°).
9 The motor power NA should be calculated according to the following formula.
In the formula. NA——motor power (kW);
K——Motor operating condition coefficient, when running continuously, take 1.2;
η——Total efficiency of mechanical transmission (%), η=0.5～0.7.
4.4.10 The selection of chemical agents should meet the following requirements.
1 When using the coagulation sedimentation process to treat wastewater, the type and quantity of chemicals to be added should be determined according to the wastewater quality such as pH, alkalinity, SS, etc., and the properties of pollutants such as relative molecular weight, molecular structure, density, concentration, hydrophobicity, etc.
2 Commonly used coagulants and their applicable conditions should comply with the provisions in Table 4.4.10.
Table 4.4.10 Commonly used coagulants and their applicable conditions
Continued Table 4.4.10
3 The applicable conditions of polyacrylamide (PAM) should meet the following requirements.
1) Polyacrylamide (PAM) is suitable for flocculation after the coagulation reaction of aluminum salt and iron salt is completed, and the dosage should not be less than 0.5mg/L;
2) Polyacrylamide (PAM) should be equipped with a special dissolving device, the dissolving time should be controlled within 45min~60min, the concentration of the agent should be less than 2%, the hydrolysis time should be 12h~24h, and the degree of hydrolysis should be 30%~40%;
3) Polyacrylamide (PAM) should not be used for more than 48 hours after dissolving and configuring;
4) Antifreeze measures should be considered for polyacrylamide (PAM) preservation and storage at room temperature.
4 The coagulant can choose lime (CaO), sodium hydroxide (NaOH) and so on.
4.4.11 The selection and control of the dosing pump shall comply with the following regulations.
1 Dosing pump should use metering pump;
2 The dosing pump should have a spare, and should adopt the same model and specification;
3 Dosing of coagulant or coagulant aid should use automatic control dosing pump;
4 The solution dosing pipe should be equipped with a solution filter;
5.The material of the chemical dosing pump and system accessories should be compatible with the chemical properties of the dosing agent.
Ⅲ Sedimentation tank
4.4.12 The design of the sedimentation tank should meet the following requirements.
1 The design parameters of the sedimentation tank should be determined according to the test data or the operation data of the sedimentation tank similar to wastewater treatment. When there is no test condition and relevant data, the design parameters should be determined according to the provisions in Table 4.4.12.
Table 4.4.12 Settling Tank Design Parameters
2 The inclined plate spacing (or inclined tube diameter) of the inclined plate (tube) sedimentation tank should be 50mm~80mm, the inclined length should not be less than 1.0m, and the inclined angle should be 60°.
3 The mud discharge of inclined plate (pipe) sedimentation tank should meet the following requirements.
1) It is advisable to use mechanical mud discharge or mud discharge bucket;
2) The angle between the bucket wall and the horizontal plane of the sludge discharge bucket of the sedimentation tank should not be less than 55° for round buckets, and not less than 60° for square buckets. Each sludge bucket should be equipped with a separate sludge discharge pipe and sludge discharge valve.
4 The sloping plate (tube) sedimentation tank should be equipped with an automatic bottom cleaning device.
Ⅳ air flotation
4.4.13 The design of the air flotation system should meet the following requirements.
1 The air flotation system should be equipped with a water level control unit and have measures to adjust the water level;
2 The slag discharge cycle is determined by the amount of scum, and the cycle should be 0.5h to 2.0h. The moisture content of the scum can be designed according to 95% to 97%, and the slag thickness should be controlled at about 10cm;
3 The scum should be scraped off mechanically, and the driving speed of the scum scraper should be controlled within 5m/min.
Ⅴ Activated carbon adsorption
4.4.14 The design and selection of activated carbon adsorption system should meet the following requirements.
1 It is advisable to conduct static carbon selection and carbon column dynamic tests, and determine parameters such as the amount of carbon used, contact time, hydraulic load, and regeneration cycle according to the water quality to be treated and the requirements of subsequent processes;
2 The service life of activated carbon should be set as the control condition for regeneration when the target removal is close to exceeding the standard.
4.4.15 The design of the activated carbon adsorber should be determined through tests or operating experience under similar conditions. When no information is available, the following data should be used.
1 The influent turbidity should not be greater than 3NTU.
2 The design flow rate should be selected according to the following conditions.
1) When it is used to adsorb organic matter in water and is located between the multi-media filter and reverse osmosis, the flow rate should be 8m/h～10m/h;
2) When used to adsorb organic matter in water and located between ultrafiltration and reverse osmosis, the flow rate should be 10m/h~15m/h;
3) When used to adsorb residual chlorine in water, the flow rate should not be greater than 20m/h.
3 The loading height of activated carbon should meet the following requirements.
1) When used to adsorb organic matter in water, the loading height should not be less than 2m;
2) When used to absorb residual chlorine in water, the loading height should not be less than 1.5m.
4.4.16 The flushing of the activated carbon adsorber should meet the following requirements.
1 The regular flushing cycle should be 3d~5d, the flushing intensity should be 11L/(m²·s)~13L/(m²·s), the flushing time should be 8min~12min, and the expansion rate should be 15%~20%;
2 The period of regular high-flow flushing should be 30 days, the flushing intensity should be 15L/(m²·s)~18L/(m²·s), the flushing time should be 8min~12min, and the expansion rate should be 25%~35%;
3 The flushing water should be produced by an activated carbon adsorber, and flow adjustment and metering devices should be installed on the backwashing water pipe.
Ⅵ ion exchange
4.4.17 The design of the ion exchange system should meet the following requirements.
1 When the ion exchange method is used to treat sewage, it is advisable to...
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