Dosing device

Classification and characteristics of agents for water treatment dosing unit
Water treatment agents are necessary chemicals in the process of industrial water, domestic water and wastewater treatment. By using these chemicals, water can reach the necessary quality requirements. Its primary effect is to control scale and sludge composition, reduce foam, reduce erosion of water contact data, remove suspended solids and toxic substances in water, deodorization, decolorization and softening water quality. At present, due to the rapid increase of water consumption in the world, various environmental protection laws (water purification laws) have been formulated one after another, and the requirements are increasingly stringent, so the various efficient water disposal agents have increased rapidly. In our country, the contradiction with the increasingly serious water capital crisis is that the production ability of water disposal agents is very low and the quality can not be guaranteed. Therefore, it is urgent to speed up the development of water disposal agents, an environmental protection material property in our country.
Water Disposal Agent Flocculant, Corrosion Inhibitor, Scale Inhibitor, Algaecide, Defoamer, Cleaner, Dehydrating Agent, Decolorizing Agent, Phosphorus Removal Agent and Ion Exchange Resin, etc. This paper will introduce systematically the flocculants and biocides.
The pharmaceuticals for water treatment and dosing devices in China were introduced into large chemical fertilizer plants in the 1970s and gradually developed. Since then, a series of water treatment agents have been developed by ourselves. The main types of water treatment agents in China are scale inhibitor, corrosion inhibitor, bactericide and algae killer, defoamer, organic flocculant and so on.
The medicament of water treatment dosing device can be divided into three main categories:
1. Sewage treatment chemicals
Two, industrial circulating water treatment dosing device pharmacy
Three. Oil-water separation agent
Commonly used water treatment additives are scale inhibitor, corrosion inhibitor, bactericide and algae killer (water treatment bactericide), defoamer, decolorizer, flocculant, coagulant, phosphorus removal agent and other water treatment agents. Sodium hexametaphosphate is also a water treatment agent.
Four. Green water treatment dosing device.
Reagent, water quality testing agent and water quality testing instrument for water treatment dosing device
Pharmaceutical characteristics of the new water treatment dosing device:
1, the reaction speed is fast, the treatment of ordinary industrial wastewater takes only half an hour to a few hours.
2. It has a wide range of effects on organic pollutants, and has a good degradation effect on refractory organic pollutants.
3. Simple process, less investment, long service life, convenient operation and maintenance, ideal treatment effect, less consumption of micro-electrolytic reactants.
4. After micro-electrolysis treatment, the wastewater will form original ferrous or iron ions in the water, which has better coagulation effect than ordinary coagulants. Without adding coagulants such as iron salts, COD removal rate is high, and it will not cause secondary pollution to the water.
5. It has good coagulation effect, can effectively remove chroma and COD, and greatly improve the biodegradability of wastewater.
6. The method can achieve the effect of phosphorus removal by chemical precipitation, and can also remove heavy metals by reduction.
7. Analyzing the opportunities faced by the pharmaceutical development of water treatment dosing devices in China, this paper expounds the application status of environmental protection water treatment dosing devices, and holds that on the solid basis of continuous innovation of coagulation theory, the pharmaceutical of water treatment dosing devices will be added to green water treatment devices, multi-component compound water treatment dosing devices and nano-materials. The direction of the new high efficiency water treatment and dosing device has developed rapidly.
Natural mineral wastewater treatment agent is a new product made from composite aluminosilicate non-metallic mineral as main raw material and treated by special technology. It is essentially different from chemical synthetic water treatment agent. It has two kinds of state: paste and powder. Its property is acidic, its PH value is 3-4, its specific gravity is 1.5-1.6, its specific gravity is 1.2-1.3, and its color is gray to dark gray.
Natural mineral wastewater treatment agents have five characteristics: adsorption, ion exchange, catalytic cracking, chemical conversion and physiological fertility.
Application advantages:
1, the most important advantage is that it can manage all kinds of refractory, especially toxic sewage.
2, remove a little floatation;
3, flocculation and sedimentation rate is fast, sediment moisture content is low, density is high, dehydration is good, easy to press filter treatment;
4. Sewage treatment facilities and processes are simple and easy to operate, which greatly reduces the one-time investment in engineering construction, while operating costs are not high.
5. Sludge from sewage treatment can be used as a fertilizer additive to increase efficiency, because the mineral raw material is a heavy fertilizer additive. Thus thoroughly eliminating the two pollution.
In the water treatment industry, not only all kinds of water treatment equipment are widely used, but also the medicines of water treatment and dosing devices have made great contributions to various industries. Drugs used in water treatment dosing devices include corrosion and scale inhibitors, flocculants, decolorizers, fungicides, phosphorus removal agents, cleaning agents, etc. Each agent has its own functions and characteristics.

flocculant
The molecular formula of flocculant is: +CH2-CHn, which belongs to linear polymer with molecular weight ranging from 4 million to 20 million. The flocculant can treat domestic sewage by high efficient mixed flocculation and degradation bacteria separated from municipal domestic sewage, and ensure that the removal rate of COD and BOD in sewage reaches 100%.
Corrosion and scale inhibitor
Corrosion and scale inhibitor, as its name implies, is a kind of water treatment dosing device which can alleviate scaling and corrosion of circulating water equipment such as boilers. The agent is made of alkaline substance and organic compound, and a corrosion inhibitor is added to prevent the heated surface from being corroded. The alkaline substance in the reagent reacts with calcium and magnesium salts in water to form water slag in the boiler through chemical reaction. After precipitation, the alkaline substance is discharged out of the boiler through the function of sewage discharge, which reduces the concentration of calcium and magnesium ions in the water and prevents scale formation in the boiler.
Cleaning agent
Cleaning agent is a volatile solvent which can dissolve the osmotic fluid, and is used to remove the excess osmotic fluid on the surface of the workpiece being examined. Some cleaning agents are specially designed to remove metal hydroxides, calcium carbonate and other similar fouling adhering to the surface of polyamide, polysulfone and film components. Before cleaning agent, check the cleaning tank, pipeline and security filter and install the new filter element.
Bactericide
Bactericide, see the name will see its role. Bactericide is a kind of medicine that destroys bacteria, microorganism and other harmful bacteria. Internationally, it is commonly used as a general agent for the prevention and treatment of all kinds of pathogenic microorganisms. Fungicides do not cause hazards to the system such as bromine, iodine, peroxide or peracetic acid.
1, sterilization, disinfection: water disinfection methods can be divided into two kinds of chemical and physical. Physical disinfection methods include heating method, ultraviolet ray method, ultrasonic method, chemical method includes chlorination method, ozone method, heavy metal ion method and other oxidant method.
2, magnetization: the use of magnetic field effect on water treatment, known as the magnetization of water treatment.
3. Precision filtration technology: microporous filter core and membrane made of special material can intercept particles and bacteria in water by uniform pore size, so that they can not be removed and intercepted through filter core and membrane. Precision filtration can filter micron sized (mu m) or nanometer sized (nm) particulates and bacteria. It is also widely used in advanced treatment of water.
4, ultrafiltration technology: ultrafiltration is a membrane separation technology. Under certain pressure (pressure is 0.07-0.7 Mpa, maximum not exceeding 1.05 Mpa), water flows on the membrane surface, water and dissolved salts are tiny particles in other electrolytes, which can permeate the ultrafiltration membrane, while particles with large molecular weight and colloidal substances are blocked by the ultrafiltration membrane, so that some particles in the water can be separated. Ultrafiltration membrane pore size is determined by interception test of substances with a certain molecular weight and expressed by the molecular weight value.
5, ozone: it is a blue gas with special fishy smell at room temperature, and its molecular formula is O3. Ozone is an allotrope of oxygen, which can be decomposed into single oxygen atoms at room temperature, while single oxygen atoms are highly oxidized. Ozone can oxidize and denaturate the proteins of bacteria and fungi, and make electrolytes lose their function. It can kill bacterial propagators and spores, viruses, fungi, etc. It can also destroy botulinum toxin. Ozone can remove and kill toxic substances and bacteria in air, water and food. Ozone can remove odors and is widely used in food. In the process of sterilization, sterilization, etc. Ozone only produces non-toxic oxides in the process of disinfection and sterilization. The excess ozone is finally reduced to oxygen. There is no residue in the disinfected articles. Ozone can be directly used for food disinfection and sterilization.
6. Ion exchange: The so-called ion exchange is the isoelectric reaction of ions in water and ions on ion exchange resins. The ion exchange reaction can be exemplified by H + cation exchange resin HR and Na + exchange reaction in water: HR + Na + = Na + + H + can be seen from the formula above: in the ion exchange reaction, cations (such as Na) in water are transferred to the resin, while exchangeable H on the ion exchange resin is transferred to the water. The process of Na transferring from water to resin is the process of ion replacement. The process of exchanging H from resin to water is called dissociation process. Therefore, due to the results of the process of dissociation and displacement, Na and H exchange positions. This change is called ion exchange.
7. Ultraviolet: When the mercury lamp is ignited, it can emit ultraviolet radiation with wavelength of 1400-4900 nm (1nm = 10-10m). This kind of light can penetrate the cell wall of bacteria, kill microorganisms and achieve the purpose of disinfection and sterilization. Ultraviolet wavelengths at 2600nm are the best. Ultraviolet disinfection is mainly applied to small quantities of drinking water. Its characteristics are: strong killing ability, short contact time, simple equipment, convenient operation and management, colorless, tasteless and non-toxic water after treatment, and will not increase the chloride ions like chlorine when disinfecting.
8, adsorption water purification technology: mainly refers to activated carbon adsorption technology such as adsorption capacity. In this paper, the characteristics of activated carbon are briefly introduced. Activated carbon is widely used in the purification, dehydrogenation, degreasing and deodorization of drinking water, food industry, chemical industry, electric power and other industrial water. Usually, 63%-86% colloidal substances can be removed, about 50% of iron and organic matter of 47%-60%.
Common medicament
Polyaluminium chloride
Polyaluminium chloride is an inorganic polymer coagulant, because of the framework of hydroxyl ion.
Application characteristics
Compared with other inorganic flocculants, polymeric ferric sulfate has the following characteristics:
1. New, high quality and high efficiency ferric salt inorganic polymer flocculants.
2. Good coagulation performance, dense alum and fast settling speed.
3. Water purification effect is excellent, water quality is good, no harmful substances such as aluminium, chlorine and heavy metal ions, no water phase transfer of iron ions, non-toxic, harmless, safe and reliable;
4. Removal of turbidity, decolorization, deoiling, dehydration, sterilization, deodorization, algae removal, removal of COD, BOD and heavy metal ions in water have significant effects.
5. The suitable range of PH value is 4-11, and the optimum range of PH value is 6-9. After purification, the change range of PH value and total alkalinity of raw water is small, and the corrosiveness of treatment equipment is small.
6. The purification effect of micro-polluted, algae-containing, low temperature and low turbidity raw water is remarkable, especially for high turbidity raw water.
7, less dosage, low cost, and processing cost can save 20%-50%.
Characteristics of oily wastewater treatment:
Flocculation technology is widely used in the treatment of oily wastewater because of its strong adaptability, removal of emulsified oil and dissolved oil, and some complex macromolecule organic matter which is difficult to biodegrade. Commonly used flocculants are inorganic flocculant, organic flocculant and composite flocculant three main categories.
Low molecular weight inorganic flocculants, such as polyaluminium chloride and polyferric sulfate, are widely used in inorganic polymer flocculants because of their good treatment effect, low cost, low dosage and high efficiency.
polyacrylamide
Polyacrylamide (PAM) is a water-soluble macromolecule polymer, insoluble in most organic solvents, with good flocculation, which can reduce friction resistance between liquids. According to ionic characteristics, PAM can be divided into four types: non-ionic, anionic, cationic and amphoteric.
Principle of action
1. Principle of flocculation: When PAM is used in flocculation, it is related to the surface properties of flocculated species, especially the potential, viscosity, turbidity and PH value of suspension. The potential on the surface of particles is the reason why particles are inhibited by adding PAM with opposite surface charge, which can reduce the potential and agglomerate.
2. Adsorption bridging: PAM molecular chains are fixed on different particle surfaces, and polymer bridges are formed between particles, which make particles form aggregates and settle down.
3, surface adsorption: the adsorption of polar group particles on PAM molecules.
4. Enhancement: PAM molecular chains and dispersed phases connect dispersed phases through various mechanical, physical, chemical and other functions, forming a network, thus playing an enhanced role.
Application scope
1, in the process of papermaking as retention aid, reinforcing agent.
2. Water treatment as coagulant, flocculant and sludge dehydrant.
3. Oil drilling and production as dewatering agent and oil displacement agent.
4. PAM is also widely used in thickening, stabilizing colloid, drag reduction, bonding, film formation, biomedical materials and so on.