How to treat sewage?

Commonly used products in sewage treatment include quartz sand filter, anthracite filter, polyaluminum chloride, activated carbon, honeycomb inclined tube filler, fiber ball filter, garnet sand and so on.

Polyacrylamide product introduction: Polyacrylamide (PAM) is a water-soluble polymer, which is insoluble in most organic solvents and has good flocculation property, which can reduce the friction resistance between liquids. According to ionic characteristics, PAM can be divided into four types: nonionic, anionic, cationic and amphoteric.

Product characteristics

1, Flocculation: PAM can flocculate suspended solids through electric neutralization and bridging adsorption.

2. Adhesion: It can be adhered by mechanical, physical and chemical actions.

3. Resistance reduction: PAM can effectively reduce the friction resistance of fluid, and adding a small amount of PAM to water can reduce the resistance by 50-80%.

4. Thickening: PAM has thickening effect under neutral and acidic conditions, and PAM is easy to hydrolyze when the PH value is above 10. Thickening will be more obvious when it is semi-reticular.

explain

1, the dosage of cationic polyacrylamide for coal washing can be set at 30 kg ~ 1 10 kg, and the dosage should be increased. It is reasonable to set the quantity at 100 kg to 300 kg, and the water used for electroplating wastewater industry and general industry generally does not exceed 50 kg. Note: (The consumption of these industries is per 1000 tons of wastewater)!

2. The application of polyacrylamide in textile industry.

If the main process adopts biochemical method, that is, the excess sludge is dehydrated (which may contain some primary sludge), only cationic PAM is needed as sludge dehydrating agent.

If the main process adopts physical and chemical methods, such as one-time strengthening, loading magnetic separation and other processes, it is generally added between kilograms first; The consumption of wastewater in chemical industry is generally between 50-120kg; The wastewater from bleaching and dyeing industry and papermaking industry is the most difficult to be treated by PAC, then anionic flocculant is added, and finally cationic flocculant is added for dehydration. The specific dosage depends on the quality of sewage.

There are also many sewage treatment stations that can directly add PAC or other inorganic flocculants for sludge dewatering, which are widely used in plate-and-frame filter presses, especially in electronic factories or small sewage treatment stations.

When PAM is used as sludge dewatering agent, the ratio of PAM to water is generally between 0. 1%-0.2%. After being dissolved into colloidal liquid, it is added into sludge for mixing treatment.

The ratio with sludge is generally 5%- 10%, and some are lower, depending on the concentration of sludge. It is best to determine the best dosage and use model through on-site beaker experiment. Different sludge, different chemicals, different equipment and different management levels have different treatment effects.

3. Cationic polyacrylamide is used as sludge dehydrating agent in sewage treatment plant. In the process of communication with customers, customers often ask about the dosage of sludge dehydrating agent in the process of sludge dehydration in sewage treatment. In order to know the dosage of sludge dehydrating agent relatively accurately, we must first know these parameters, such as sludge moisture content, mud cake moisture content, sludge amount, dosage and dosage concentration.

Sludge moisture content: the percentage of water contained in sludge to the total sludge weight is called sludge moisture content.

Water content of mud cake: the percentage of water content of mud cake to the total weight of sludge is called water content of mud cake.

It is also calculated by the following formula:

1, dose mg/L= dose mass/treated water volume/dose concentration.

2. Treatment water consumption = treatment water m3/h* consumption g/m3.

3. Dry sludge quantity = treated water quantity *( 1- sludge moisture content) /( 1- mud cake moisture content)

4. Dosage of dry mud per ton g/m3= dosage/dry mud quantity

The error of the above calculation results may be relatively large, which is only for reference in sewage disposal operation. The actual drug consumption should be tested on the actual computer.

Flocculant, a water treatment agent for sewage treatment.

There are many kinds of sewage treatment chemicals, the most commonly used is flocculant, which can be divided into inorganic and organic.

Inorganic flocculant

Inorganic flocculants can be divided into low molecular weight and high molecular weight according to molecular weight.

I. Low molecular inorganic flocculant

The most widely used inorganic flocculants are iron and aluminum metal salts. The mainstream inorganic coagulants in the market are ferric chloride, ferrous sulfate and aluminum sulfate.

The molecular formula of ferric chloride is (FeCl3 6H20).

Features: The formed alum flower has good sedimentation, the effect of treating low-temperature water or low-turbidity water is better than that of aluminum salt, and the applicable pH value range is wider, but the treated water has higher chromaticity than aluminum series and is corrosive.

The molecular formula of ferrous sulfate is (FeS04 H20).

Features: Free Fe2+ can only form the simplest mononuclear complex, and the coagulation effect is not as good as that of iron salt.

The molecular formula of aluminum sulfate is Al2(S04)3.

Features: Aluminum sulfate is the most used flocculant in wastewater treatment, which is convenient to use and has good flocculation effect;

Disadvantages: when the water temperature is low, hydrolysis is difficult and the flocs formed are loose; Its effective pH range is very narrow.

BenQ (Al2 (Al2 (s04) 3k2S04 24h20) is similar to aluminum sulfate.

Second, polymer inorganic flocculant

Inorganic polymer flocculant is the most widely used flocculant because of its good coagulation effect and low price. According to the degree of ions, it can be divided into cationic and anionic types.

Cationic type: polymeric aluminum chloride, polymeric aluminum sulfate, polymeric aluminum phosphate, polymeric ferric sulfate, polymeric aluminum ferric chloride, etc.

There are few kinds of anionic inorganic flocculants, and polysilicic acid is the mainstream in 20 13.

flocculating agent

edit

Three-dimensional elastic packaging

1. In the production process of elastic wool, adding hydrophilic and bio-friendly additives and some nutrient slow-release elements can better promote the growth and metabolism of microorganisms and increase microbial biomass.

2. The four grooves in the green environment-friendly cross wire and the special-shaped wire can effectively resist the water scouring in the horizontal direction (in and out of the water flow) and the vertical direction (generated by aeration), so that the strains are easy to parasitize and reproduce in the initial stage of film formation, and the defect that the surface of circular cilia is smooth and difficult to form a film is overcome; The edges and corners of wool have better cutting effect on bubbles, which improves the utilization rate of dissolved oxygen and reduces the power consumption of oxygen exposure.

3. The elastic filler has long service life, good oxygenation performance, quick start-up and film hanging, easy film stripping and updating, simple operation and management, corrosion resistance, no blockage and no caking.

job operation

edit

Divided by function

Sewage treatment can be divided into physical method, biological method and chemical method according to its function.

① Physical method: Insolubles in sewage are mainly separated by physical action, and their chemical properties are not changed during treatment. Commonly used are gravity separation, centrifugal separation, reverse osmosis, air flotation and so on. The physical treatment of structures is simple and economical, and it is used in villages and towns with large water volume, strong self-purification ability and low requirements for sewage treatment.

② Biological method: The dissolved or colloidal organic matter in sewage is decomposed and oxidized into stable inorganic matter by using the metabolic function of microorganisms, so that the sewage can be purified. Activated sludge process and biofilm process are commonly used. The treatment degree of biological method is higher than physical method.

(3) Chemical method: it is a method to treat or recover dissolved or colloidal substances in sewage through chemical reaction, which is mostly used in industrial wastewater. Coagulation, neutralization, redox and ion exchange are commonly used methods. Chemical treatment has good treatment effect and high cost, and it is mostly used as the effluent after biochemical treatment for further treatment to improve the effluent quality.

Depending on the degree of treatment

Sewage treatment can be divided into primary treatment, secondary treatment and tertiary treatment according to the treatment degree.

Primary treatment is mainly to remove suspended solids from sewage, and physical methods are commonly used. After primary treatment, the BOD removal rate of wastewater is only 20%, which is still not suitable for discharge and needs secondary treatment. The main task of secondary treatment is to remove a large number of colloids and dissolved organic substances from sewage, and the removal rate of BOD is 80% ~ 90%. Generally, the sewage after secondary treatment can meet the discharge standard, and the commonly used methods are activated sludge method and biofilm method. The purpose of tertiary treatment is to further remove some special pollutants, such as fluoride and phosphorus, which belongs to advanced treatment and commonly used chemical methods.

Selection of sewage process flow requires 1. To improve the existing primary treatment process to enhance the treatment effect, we should make full use of the existing treatment facilities according to the actual situation, reform the structure or operation mode of septic tanks and contact tanks widely used in existing hospitals, and add some facilities when necessary to improve the treatment effect as much as possible to meet the discharge standards of hospital sewage treatment.

Primary strengthening treatment

1, process description

Sewage treatment in general hospitals (non-infected wards) can adopt the process of "pretreatment → primary intensive treatment → disinfection". Particles carrying viruses and germs are removed by coagulation and sedimentation (filtration), which improves the disinfection effect and reduces the dosage of disinfectant, thus avoiding the adverse impact of excessive dosage of disinfectant on the environment. Hospital sewage enters the regulating pool through septic tank, with automatic grille in front of the regulating pool and lifting pump in the regulating pool. Sewage enters coagulation sedimentation tank for coagulation sedimentation after lifting, and the effluent from sedimentation tank enters contact tank for disinfection, and the effluent from contact tank is discharged up to standard.

The garbage generated by the sewage treatment station, such as sludge and grid slag in the regulating tank, coagulation sedimentation tank and contact tank, is disinfected and transported outside. Sterilization can be carried out by pasteurizing steam or adding lime.

2, process characteristics

Strengthening the treatment effect by primary intensive treatment can improve the treatment effect, remove particles carrying viruses and germs, improve the further disinfection effect and reduce the dosage of disinfectant. Among them, the existing primary treatment process can make full use of existing facilities and reduce investment costs.

3. Scope of application

The first-level enhanced treatment can enhance the treatment effect, which is suitable for the treated effluent to finally enter the general hospital of the second-level urban sewage treatment plant.

Secondary treatment process

1, process description

The secondary treatment process is "regulating tank → biological oxidation → contact disinfection". Hospital sewage enters the regulating pool through septic tank. An automatic grille is arranged in front of the regulating pool. The regulating tank is equipped with a lift pump. The sewage enters the aerobic tank for biological treatment after lifting, and the effluent from the aerobic tank enters the contact tank for disinfection, and the effluent reaches the standard and is discharged.

Garbage generated by sewage treatment station, such as sludge and grid residue in regulating tank, biochemical treatment tank and contact tank, is transported abroad for incineration after centralized disinfection. Sterilization can be carried out by pasteurizing steam or adding lime.

Secondary treatment process (sewage from non-infectious diseases and infectious diseases)

Sewage and feces in infectious disease hospitals are collected separately, which is very cheap. Domestic sewage directly enters the pre-disinfection pool for disinfection and then enters the adjustment pool. The patient's feces should be disinfected or treated separately before entering the septic tank through the sewer. All structures must be operated in a closed environment, ventilated by a unified ventilation system, and the waste gas is discharged after disinfection. Ultraviolet disinfection system can be used for disinfection.

2, process characteristics

Aerobic biochemical treatment unit removes organic pollutants such as CODcr and BOD5, and aerobic biochemical treatment can choose contact oxidation, activated sludge and high-efficiency aerobic treatment processes, such as membrane bioreactor and biological aerated filter. Adopting an efficient aerobic treatment process with filtration function can reduce the concentration of suspended solids and is beneficial to subsequent disinfection.

3. Scope of application

It is suitable for sewage treatment in infectious disease hospitals (including general hospitals with infectious wards) and general hospitals discharged into natural water bodies.

process technology

edit

Modern sewage treatment technology can be divided into primary, secondary and tertiary treatment according to the degree of treatment. Generally, the degree of sewage treatment depends on the water quality and the direction of water treatment.

Primary treatment

It mainly removes suspended solid pollutants from sewage, and most physical treatment methods can only meet the requirements of primary treatment. After primary treatment, BOD can generally be removed by about 30%, which can not meet the discharge standard. Primary treatment belongs to the pretreatment of secondary treatment.

Secondary treatment

It mainly removes colloid and dissolved organic pollutants (BOD, COD) in sewage, and the removal rate can reach above 90%, which makes the organic pollutants meet the discharge standard, and the removal rate of suspended solids can reach 95%, with good effluent effect.

Three-stage treatment

Further treatment of refractory organic matter, nitrogen and phosphorus and other soluble inorganic substances that can lead to eutrophication of water body. The main methods include biological nitrogen and phosphorus removal, coagulation and sedimentation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis.

The whole process is as follows: the raw sewage passing through the coarse grid is lifted by the sewage lifting pump, passes through the grid or screen, and then enters the grit chamber; Sewage separated from sand and water enters the primary sedimentation tank, which is primary treatment (i.e. physical treatment); The effluent from the primary sedimentation tank enters biological treatment equipment, including activated sludge process and biofilm process (the reactors of activated sludge process include aeration tank and oxidation ditch, etc.). ). Biofilm method includes biofilter, biological turntable, biological contact oxidation method and biological fluidized bed). The effluent from biological treatment equipment enters the secondary sedimentation tank, and the effluent from the secondary sedimentation tank is discharged after disinfection or enters the tertiary treatment. The primary treatment ends here as secondary treatment, and the tertiary treatment includes biological nitrogen and phosphorus removal, coagulation and precipitation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis. Part of the sludge in the secondary sedimentation tank flows back to the primary sedimentation tank or biological treatment equipment, and part of it enters the sludge concentration tank and then enters the sludge digestion tank. After dehydration and drying equipment, the sludge is finally utilized.

conventional process

edit

factory effluent

Method for treating industrial sewage

A method for treating industrial sewage belongs to the technical field of sewage treatment. Introducing the sewage into the water collecting tank, adjusting the pH value of the grid at the end of the water collecting tank, lifting the sewage to the first-class pressure dissolving tank by a first-class dissolving pump, and simultaneously sucking air and coagulation decolorant, so that the first-class saturated dissolved air water in the first-class pressure dissolving tank is suddenly released to the first-class air flotation tank to form the first-class treated water; The primary treated water overflows into the buffer pool, then the primary treated water is lifted into the secondary pressure dissolved air tank by a secondary dissolved air pump to control the pH, and at the same time, air and coagulation decolorant are inhaled, so that the secondary saturated dissolved air water in the secondary pressure dissolved air tank is suddenly released into the secondary air flotation tank to form secondary treated water, which overflows into the sedimentation tank and is discharged after sedimentation; The floating mud in the primary and secondary air flotation tanks enters the floating mud tank, and is pressed into a filter cake, and the filtrate is returned to the water collection tank. The removal rates of CODcr, decolorization, SS and BOD5 are 80-90%, 95% and 90% and 75-80% respectively, which meet the first-class discharge standard of GB 8978- 1996. Biogas power generation is a comprehensive utilization technology of new energy which integrates environmental protection and energy saving. It uses the biogas produced by anaerobic fermentation of industrial sewage to drive the biogas generator set to generate electricity, and can make full use of the residual heat of the generator set to produce biogas, so that the comprehensive thermal efficiency reaches about 80%, which is much higher than the general power generation efficiency of 30~40%. The economic benefit of users is remarkable, and it is a good method to treat industrial sewage.

Domestic sewage articles

1. Rural domestic sewage treatment methods

Domestic sewage → septic tank → anaerobic pond → constructed wetland (canna, scallion, calamus and other plants with developed roots and strong absorption capacity) is treated by "filtration", which is mainly suitable for the treatment of scattered domestic sewage in rural areas. After completion, the operating cost is basically zero, and the service life exceeds 10 years.

2. Urban domestic sewage treatment methods

Transport urban domestic sewage to the rural areas around the city, and use the vast land in rural areas to purify urban domestic sewage. This will be a good way once and for all. Take large and medium-sized cities that supply domestic tap water 100W cubic meter daily as an example: the cost of ordinary sewage treatment facilities is 1000 yuan/cubic meter. The construction cost is 65.438+0 billion yuan, and the annual operating cost is 654.38+000 w m3/day × 365× 0.5 yuan/m3 = 65.438+0.8 billion yuan/m3, and the annual operating cost of soil purification method is 654.38+000 w m3/day× 365× 0.6 million yuan/m3.

3. A new domestic sewage treatment technology: decentralized treatment.

The decentralized biological comprehensive treatment system for domestic sewage is a new, economical and environmentally friendly domestic sewage treatment system. The system has the advantages of low equipment investment, low operation cost and simple installation. Bioaugmentation technology is used to efficiently degrade pollutants, realize local treatment of domestic sewage and achieve the purpose of recycling water resources. As an effective supplement to traditional sewage treatment plants, the system has been widely used in urban residential quarters, hotels, tourist attractions, new rural communities and other fields.

Decentralized sewage treatment technology has the characteristics of small equipment area, no need to lay pipe network and high equipment integration, so the proportion of capital construction cost and civil engineering cost in the overall investment is relatively small, only about 30%, and about 70% of the investment is mainly used for the procurement and installation of sewage treatment equipment.

Treatment of industrial water by micro-electrolysis

1, technical overview:

Micro-electrolysis technology, also known as internal electrolysis, is an ideal process for treating high concentration organic wastewater. In the absence of power supply, it electrolyzes wastewater by using the potential difference of 1.2V generated by micro-electrolysis materials filled in wastewater, thus achieving the purpose of degrading organic pollutants. When water is supplied to the system, countless micro-battery systems will be formed in the equipment, and an electric field will be formed in its action space. The new ecology [H] and Fe2+ generated in the treatment process can react with various components in the wastewater, such as destroying the chromophore or chromophore of colored substances in the colored wastewater, or even breaking the chain, thus achieving the effect of degradation and decoloration; The generated Fe2+ is further oxidized to Fe3+, and their hydrates have strong adsorption-flocculation activity, especially after adding alkali to adjust the pH value, ferrous hydroxide and ferric hydroxide colloidal flocculants are generated. Their adsorption capacity is much higher than that of iron hydroxide colloid obtained by hydrolysis of general drugs, and they can adsorb a large number of tiny particles, metal particles and organic macromolecules dispersed in water. Its working principle is based on the interaction of electrochemistry, redox, physical adsorption and flocculation precipitation to treat wastewater. This method has the advantages of wide application range, good treatment effect, low cost, convenient operation and maintenance, and no consumption of power resources. This process can greatly reduce COD and chromaticity, improve the biodegradability of wastewater, and has a good effect on the removal of ammonia nitrogen. Traditionally, the micro-electrolysis materials used in micro-electrolysis process are generally iron filings and charcoal, which need to be activated by acid and alkali before use and are easy to be passivated and hardened during use. Moreover, because iron and carbon are in physical contact, it is easy to form an isolation layer between them, which makes micro-electrolysis unable to continue and lose its function, resulting in frequent replacement of micro-electrolysis materials, which not only has a large workload, but also affects the effect and efficiency of wastewater treatment. In addition, the small surface area of traditional micro-electrolysis materials also makes wastewater treatment take a long time, which increases the investment cost per ton of water and seriously affects the utilization and popularization of micro-electrolysis technology.

2. Reaction formula:

Anode: Fe-2e → Fe2+E (Fe/Fe2+) = 0.44 V.

Cathode: 2h-+2e→ H2e (h-/H2) = 0.00 V.

When oxygen exists, the cathode reaction is as follows:

O2+4h﹢+4e→2h2o e(O2)= 1.23v

O2+2h2o+4e→4oh﹣e(o2/oh﹣)=0.4 1v

3. Technical features:

(1) The reaction speed is fast, and the general industrial wastewater only takes half an hour to several hours;

⑵ There are many kinds of organic pollutants, such as: refractory and degradable organic compounds containing even fluorine, carbon double bonds, nitro groups and halogen groups, with good degradation effect;

⑶ Simple technological process, long service life, low investment cost, convenient operation and maintenance, low operation cost and stable treatment effect. Only a small amount of microelectrolysis reagent is consumed in the treatment process. Microelectrolytes can be added directly without replacement or activation as long as they are added regularly.

(4) After micro-electrolysis treatment, the wastewater will form primary ferrous ions or iron ions in the water, which has better coagulation effect than ordinary coagulants, and does not need to add coagulants such as ferric salts, so that the COD removal rate is high and it will not cause secondary pollution to the water body;

5. Good coagulation effect, high removal rate of chroma and COD, and the same amount can greatly improve the biodegradability of wastewater;

This method can achieve the effect of chemical precipitation to remove phosphorus, and can also remove heavy metals through reduction;

(7) For the high-concentration organic wastewater treatment project that is not up to standard, this technology can be used as the pretreatment of wastewater of the established project, which can improve the biodegradability of wastewater while degrading COD and ensure the stable discharge of wastewater after treatment. Biochemical wastewater can also be advanced treated by micro-electrolysis or micro-electrolysis combined with biological filter bed process;

⑻ Each unit of this process can be used as a separate treatment method or as a pretreatment process for biological treatment, which is beneficial to sludge sedimentation and biofilm formation.

4. Applicable wastewater types:

This technology is especially aimed at the treatment of wastewater with high organic concentration, high toxicity, high chroma and difficult biochemical treatment, which can greatly reduce the chroma and COD of wastewater and improve the B/C ratio, that is, improve the biodegradability of wastewater; It can be widely used in the treatment of various industrial wastewater such as printing and dyeing, chemical industry, electroplating, pulping and papermaking, pharmacy, wool washing, pesticides, alcohol and so on. And treat water reuse project.

(1) dyes, printing and dyeing wastewater; Coking wastewater; Petrochemical wastewater;

-At the same time, the BOD/COD value of the treated water is significantly increased.

(2) Petroleum wastewater; Leather wastewater; Papermaking wastewater, wood processing wastewater;

-BOD/COD value of wastewater after water treatment is greatly improved.

(3) electroplating wastewater; Printing wastewater; Mining wastewater; Other wastewater containing heavy metals;

-Heavy metals can be removed from wastewater.

(4) organophosphorus agricultural wastewater; Organochlorine agricultural wastewater;

-Greatly improve the biodegradability of wastewater and remove phosphorus and sulfide.

Novel catalytically active micro-electrolysis filler

1, product overview:

A new type of micro-electrolytic filler with catalytic activity is jointly developed by scientific research institutes and produced by high potential difference metal alloy melting catalyst and high temperature micropore activation technology. It has the characteristics of iron-carbon integration, molten catalyst, microporous alloy structure, large specific surface area, light specific gravity, strong activity, high current density and high water efficiency. When it acts on wastewater, it can effectively remove COD, reduce chroma, improve biodegradability, and the treatment effect is stable, which can avoid the passivation and hardening of fillers in operation. This kind of filler is an important guarantee for the continuous micro-electrolysis reaction.

2. Technical features:

(1) The anode and cathode and the catalyst are integrated with iron and carbon through high-temperature melting, ensuring the lasting effect of "primary battery" effect. It will not be as easy to separate the anode and cathode as the physical mixing of iron and carbon, which will affect the reaction of the primary battery.

⑵ The filler is melted at high temperature to form a skeleton microporous alloy structure with large specific surface area, strong activity, no passivation and no hardening. The anode and cathode are matched according to different wastewater, which provides greater current density and better micro-electrolysis reaction effect for wastewater treatment. The reaction speed is fast, the general industrial wastewater only needs 30-60 minutes, and the long-term operation is stable and effective.

(3) Technical parameters:

Specific gravity: 1.0t/m3, specific surface area: 1.2m2/g, porosity: 65%, physical strength: ⊙ 1000kg/CM.

Chemical composition: iron 75-85%, carbon 10-20%, catalyst 5%.

(4) Specifications:

1cm*3cm (size can be customized)

Treatment facilities

The main ones are as follows:

centrifuge

Centrifuges are mainly used to separate solid particles from suspended liquids; Or separate two immiscible liquids with different densities in the emulsion (such as separating cream from milk); It can also be used to dehumidify liquids in solids, such as washing clothes with a washing machine; The special ultra-high speed tubular separator can also separate gas mixtures with different densities; Some settling centrifuges can also classify solid particles according to their density or particle size, and the settling speed of solid particles with different density or particle size in liquid is different.

sludge dehydrator

The sludge dewatering machine has the characteristics of automatic control operation, continuous production and stepless speed regulation, and is suitable for sludge dewatering in water supply and drainage, paper making, casting, leather, textile, chemical industry, food and other industries.

aeration machine

The aerator directly injects "micro bubbles" into untreated sewage through the diffusion impeller. Under the joint action of coagulant and flocculant, suspended solids undergo physical flocculation and chemical flocculation to form large suspended solid flocs, which float to the liquid surface to form scum under the floating action of bubbles, and are separated from water by a slag scraper; There is no need to clean the nozzle, and no blockage will occur. The equipment has good integrity, convenient installation, saving operation cost and occupying less land.

Drum filter

Microfiltration machine is a drum screen filtration device. The treated wastewater enters the drum along the axial direction and flows out through the screen along the radial direction, and impurities (fine suspended solids, fibers, paper pulp, etc. ) is trapped on the inner surface of the screen on the drum. When the impurities trapped on the filter screen are carried to the upper part by the roller, the pressure washing water is backwashed into the slag discharge tank to flow out. During operation, 2/5 of the drum diameter is exposed out of the water, and the rotating speed is 1-4r/min. The filtration speed of the screen can be 30- 120m/h, the washing water pressure is 0.5- 1.5kg/cm2, and the washing water volume is 0.5- 1.0% of the raw water output. The microfilter occupies a small area, has a large production capacity (250-36000m3/d) and is convenient to operate and manage. It has been successfully applied to water supply and wastewater treatment.

TDAF

Air flotation machine is a kind of equipment to remove suspended matter, grease and colloid from various industrial and urban sewage. The equipment is widely used in the treatment of industrial wastewater and urban sewage such as oil refining, chemical industry, brewing, slaughtering, electroplating, printing and dyeing.

According to the dissolved air way, it can be divided into: inflatable air flotation machine, dissolved air flotation machine and electrolytic air flotation machine. Its principle is to efficiently mix water-insoluble gas or two or more different liquids (the generated microbubbles have a particle size of 20-50 microns). Micro-bubbles are used as carriers to attach to impurity particles in water, and the particles are carried by bubbles to the surface to separate from water, thus achieving the purpose of solid-liquid separation.

ozonizer

Ozone is a strong oxidant, which can decompose organic macromolecules into small molecules, insoluble substances into soluble substances, degradable substances into degradable substances, and harmful substances into harmless substances, thus achieving the effect of sewage purification.

Product characteristics of ozone generator for sewage treatment

1, ozone is an excellent oxidant, which can completely decompose organic matter in sewage.

2. It can kill all pathogenic microorganisms with strong chlorine resistance, including viruses and spores.

3. In the process of sewage treatment, it is less affected by the PH value and temperature of sewage.

4. Ozone is decomposed into oxygen, which increases dissolved oxygen in water and improves water quality.

5. Ozone can decompose organic macromolecules that are difficult to degrade into small-molecule organic substances, thus improving the biodegradability of sewage.

6. Ozone will be completely decomposed in sewage, and the residue will not cause secondary pollution.

Treatment agent

edit

There are many kinds of sewage treatment agents, the most commonly used is flocculant, which can be divided into inorganic flocculant and organic flocculant.

Inorganic flocculant

Inorganic flocculants can be divided into low molecular weight and high molecular weight inorganic flocculants according to molecular weight.

Low molecular inorganic flocculant

The most widely used are iron-based and aluminum-based metal salts. The main products on the market are polyaluminum chloride, ferric chloride, ferrous sulfate and aluminum sulfate.

Polyaluminum chloride is a new type of mainstream inorganic polymer flocculant. Because it has higher efficiency than traditional inorganic chemicals in water treatment, it will be rapidly developed and widely used.

Molecular formula of ferric chloride (FeCl3 6H20)

Features: The formed alum flower has good sedimentation, the effect of treating low-temperature water or low-turbidity water is better than that of aluminum salt, and the applicable pH value range is wider, but the treated water has higher chromaticity than aluminum series and is corrosive.

The molecular formula of ferrous sulfate is (FeS04 H20).

Features: Free Fe2+ can only form the simplest mononuclear complex, and the coagulation effect is not as good as ferrous salt.

The molecular formula of aluminum sulfate is Al2(S04)3.

Features: It is the most used flocculant in wastewater treatment, with convenient use and good flocculation effect. When the water temperature is low, it is difficult to hydrolyze, and the floc formed is loose, and its effective pH range is narrow.

The action mechanism of Al2 (Al2 (s04) 3 K2S04 24h20 is similar to that of aluminum sulfate.

Polymer inorganic flocculant

Inorganic molecular flocculant is the most mainstream inorganic flocculant with good coagulation effect and low price. According to different ionic degrees, inorganic polymer flocculants can be divided into cationic and anionic types.

Cationic type: polymeric aluminum chloride, polymeric aluminum sulfate, polymeric aluminum phosphate, polymeric ferric sulfate, polymeric ferric chloride, polymeric ferric phosphate, polymeric ferrous sulfate, etc.

There are not many kinds of anionic inorganic flocculants, but polysilicic acid is the mainstream 20 13.

organic flocculant

Organic flocculants are divided into ionic and nonionic types.

Ionic organic flocculant can not only change the surface charge of particles, but also play a bridging role and cause flocculation. Such as polyacrylamide (also known as flocculant 3). Used to accelerate the rapid settlement of the concentrate in the thickener. Thereby reducing the water content of the concentrate and reducing the metal loss.

Generally, the molecular weight of organic flocculants is relatively large, reaching tens of thousands, hundreds of thousands or even millions, so adding a small amount can play a bridging role.