Technical advantages of a pipeline drinking water system The so-called direct drinking water, that is, the use of quality water supply, in the residential quarters or public buildings (such as hotels, schools, etc.) set up a water purification station, with tap water as the source water, after deep processing, processing and purification, in the original tap water In addition to the system, an independent high-quality water supply pipeline will be added to directly input the purified high-quality water to various households and water points for people to drink. Compared with the water in the bottle (barrel), the direct drinking water of the pipeline has more obvious industrial characteristics, which is an inevitable trend of the development of the times. At present, traditional tap water systems are facing multiple threats: Comparison of two kinds of direct drinking water treatment technologies 1 enhanced removal of dissolved organic matter in water; Tables 1 and 2 list common drinking water treatment technologies for pipelines. For different systems, the process selection and process setting should consider the water quality of the raw water and the water quality requirements of the effluent, and combine the economic (investment, operating costs), management and other factors to carry out scientific matching and optimization. design. Comparison of three kinds of pipe straight drinking water system pipes Good water quality requires excellent pipe to be transported, and secondary pollution is never allowed. Therefore, the requirements for straight drinking water system pipes can be summarized as follows: Economic Evaluation of Four Pipeline Direct Drinking Water System Take a high-rise commercial and residential building in Shenyang area (building area of ​​about 50,000 m2, 270 households) as an example: Five Shenyang City practices The promotion of the direct drinking water system is in line with the guidelines and policies put forward by General Secretary Jiang Zemin on "Developing the drinking water industry and improving the quality of drinking water". In this regard, the practice of Shenyang City is to set up the “Shenyang City Pipeline Direct Drinking Water Management Officeâ€, adopting the measures of standardization and development, and plans to popularize direct drinking water in the next few years. In the future, all new garden communities should be adopted. This type of water supply, especially in the mid- to high-end garden community, should be more so.
1. Whether it is surface water source or groundwater source, it has been deteriorating due to the deterioration of the overall environment, improper discharge of industrial wastewater and domestic sewage.
2. The traditional "coagulation-precipitation (or clarification)-filtration-chlorination disinfection" water treatment process is difficult to remove dissolved organic matter and low molecular substances in water, and some of these substances have "three" characteristic.
3. Traces of organic substances such as “Sanzhi†remaining in the water body, after chlorination, the harmfulness of the organic matter is enhanced, and the residual chlorine directly causes the tap water to feel unsatisfactory. 4. Due to the long history of urban water supply pipelines, various impurities and microorganisms adhere to the inner wall of the pipeline, and the possibility of secondary pollution is greater. In addition, the management of the reservoir, the pressurized pumping station, the roof tank and the secondary pipe network also have different effects on the quality of tap water.
In view of this, the pipeline drinking water system adopts adsorption, oxidation, biodegradation and membrane filtration in the water treatment process, and scientifically combines the deep treatment of the raw water, so that the effluent water quality fully complies with the “drinking water quality standard†( CJ94—1999). In the material selection and equipment use, the pipeline drinking water system adopts green environmental protection pipes such as random copolymer polypropylene (PP-R) pipe, cross-linked polyethylene (PEX) pipe, etc., valves, water tanks, etc. are made of stainless steel products, fundamentally Eliminate the occurrence of secondary pollution. In the water delivery mode, the continuous water supply system is continuously adjusted by adopting the microcomputer variable frequency constant pressure water supply equipment to circulate the water supply, thereby further ensuring the safety and reliability of the effluent water quality. project Activated carbon adsorption technology Membrane separation technology Ozone oxidation technology UV disinfection technology Ozone + activated carbon combined technology Biological activated carbon technology principle Adsorption is achieved by using a developed pore structure and a large specific surface area The impurities in the water are sieved by the micropores of the membrane. The water quality is changed and sterilized by oxidation, and the color and smell can be removed. Produces a photochemical reaction with the microbial life-center DNA, causing it to die or lose its ability to survive and reproduce. Ozone oxidation disinfection + activated carbon adsorption 1 biodegradation 2 physical adsorption Scope of application It has obvious removal effect on organic matter and hydrophobic organic matter with color, smell and molecular weight in 500-3000μ. broad Used as a pre-ozone oxidation (organic and inorganic) and post-ozone sterilization, disinfection, oxygen enrichment Disinfection broad broad Technical characteristics 1 microwell is the main adsorption zone.
2 Affected by the characteristics of organic matter: water, low solubility, weak polarity and easy to absorb. 1 water quality is related to the pore size of the membrane;
2 less investment or even do not add chemicals;
3 small footprint, easy to achieve automatic control. The reaction rate is related to the substances involved in the reaction, the concentration of ozone, and the contact time. 1 safe, reliable, easy to operate and manage;
2 economical and practical, no harmful products 1 improving and improving the adsorption performance of activated carbon;
2 extended the life cycle of activated carbon;
3 operating costs are reduced accordingly.
2 prolonging the regeneration cycle of activated carbon;
3 The effluent water quality is improved and the operating cost is reduced. insufficient 1 the price is higher;
2 to ensure the adsorption capacity must be regenerated or replaced at regular intervals 1 membrane is susceptible to contamination;
2 One-time investment and operating costs are high. 1 part of organic matter is not easily oxidized
2 easy to cause bacterial reproduction Due to the intensity of the light source and the life of the lamp, continuous sterilization cannot be achieved. Remarks Generally used in combination with ozone oxidation, biodegradation and other technologies. 1 The pore size of the membrane can be selected according to the particle size of the medium;
2 Try to control membrane fouling. Less used alone Usually placed in the regular treatment of clean water, commonly known as post-treatment. Not used in conjunction with pre-chlorination project Microfiltration (MF) Ultrafiltration (UF) Nanofiltration (NF) Reverse osmosis (RO) 1 membrane aperture Between 0.1μm and 2μm Between 0.001μm and 0.1μm 1nm～0.05μm <1nm 2 operating pressure 0.05MPa～0.3MPa 0.04MPa～0.4MPa 0.5MPa～1.0MPa 1MPa to 2MPa 3 Scope of application It is used as a post-treatment facility for pretreatment or activated carbon filtration as ultrafiltration, reverse osmosis or nanofiltration. Macromolecular organisms, suspended solids, bacteria, viruses and other microorganisms. Suitable for raw water with high hardness and low organic matter and low turbidity. Preparation of pure water 4 technical characteristics The utility model has the advantages of simple equipment, convenient operation, large water flow, low working pressure and high water production rate. Similar to microfiltration technology The raw water can be partially desalted and softened, removed, chroma, bacteria, dissolved organic matter and some metal ions. The water outlet has a good mouthfeel and is a membrane filtration technology suitable for use in the production of high quality drinking water. It can remove almost all impurities in water, including various suspended solids, colloids, dissolved organic matter, inorganic salts, bacteria, microorganisms and so on. 5 insufficient The separation effect of organic pollutants is poor. Similar to microfiltration technology Often with microfiltration or ultrafiltration as a pretreatment work pressure is higher, there is a certain water production rate. High working pressure; low water production rate; high energy consumption. 6 notes Microfiltration can generally be backwashed with water and chemical cleaning if necessary. Similar to microfiltration technology The pore size is between the ultrafiltration membrane and the reverse osmosis membrane Drinking water should be mineralized
It is safe and reliable, easy to construct, not easy to scale, excellent in hydraulic characteristics, long in service life, and has good cost performance.
It can be seen from Table 3 that the comprehensive performance of PP-R pipe and copper pipe is better, and the PP-R pipe is more advantageous from the economic point of view. Pipe project Pipe name Copper tube Random copolymer polypropylene
(PP-R) Polybutene
(PB) High density polyethylene (HDPE) Crosslinked polyethylene (PEX) Aluminum-plastic composite pipe Product specifications Have 20-125 20-110 Have 16-50 16-50 Hygienic performance better it is good it is good it is good it is good it is good Connection method mechanical Hot Melt mechanical Hot Melt mechanical mechanical Price ratio 2.7 1.0 2.0 0.85 1.3 1.6 Main scope of application Cold and hot water system Cold and hot water system; drinking water system Cold and hot water system; drinking water system Cold and hot water system; drinking water system; gas Cold and hot water system; geothermal Cold and hot water system Main piping method Both clear and dark Both clear and dark Dark compress Both clear and dark Both clear and dark Both clear and dark main feature Good pressure, low temperature and high temperature performance Heat resistant; good water quality; poor low temperature resistance High heat resistance Good low temperature resistance; good water quality Mainly used in geothermal systems Have certain rigidity and pressure resistance Construction safety it is good it is good better it is good better better Service life long Longer Longer Longer long Longer
The cost of direct drinking water equipment and materials for pipelines is about 11 yuan/m2, and the total cost (including construction labor costs, etc.) is about 18 yuan/m2. The system uses a nanofiltration membrane and other treatment technologies, calculated according to the water production rate of 70%, the water production cost is about 34 yuan / ton (the larger the scale, the lower the relative cost). According to the direct drinking water price of 200 yuan / ton, then the profit rate = (200-34) / 34 × 100% = 488%
It is worth noting that:
1. China is a country with severe water shortages. The water price of tap water will show an upward trend, which directly affects the manufacturing cost of direct drinking water. However, it does not mean that the price of direct drinking water will rise. The correct development direction of the direct drinking water system should be to seek benefits from scale.
2. At present, the price of drinking water is still far lower than the price of water in barrels (bottles). It is acceptable for most people who want to improve the quality of drinking water and hope that the price is not too high. But its profit margin is as high as 480%. It can be seen that the direct drinking water system contains huge business opportunities, and its promotion not only has social significance, but also has great economic significance.
3. The amount of water used for drinking water is only a small part of the amount of domestic water, and is currently limited to drinking, cooking and so on. How to expand the use of direct drinking water, such as for washing vegetables, bathing, washing underwear, etc., that is, how to guide and expand the consumption of drinking water is also a subject worth studying.
In order to regulate the market, the Shenyang Pipeline Direct Drinking Water Management Office has established a market access system, strictly checks and checks the layers, and provides trustworthy products and construction teams to the development and construction units to ensure that no direct drinking water is introduced into the newly built garden community. Stay hidden and suffering. The office also stipulates that the direct drinking water pumping stations of all residential quarters must be uniformly managed by the water supply company, and the direct drinking water management office of the pipelines authorizes the business offices of the districts to carry out franchising operations on behalf of the head office. Through the management of professional companies, ensure the quality of the direct drinking water system.
Design of residential pure water system
From: The First International Symposium on Water Environment in Residential Areas Weng Jun (Engineer)
"People eat food for the sky, food for the water first." Pipeline drinking water system once in China, it has inevitably attracted special attention. Although China's current direct drinking water system has relatively distinctive Chinese characteristics compared with foreign water supply, it promotes the commercialization of drinking water and reflects the development of the national economy and people's living standards from one aspect. The improvement has also confirmed the growing concern of the broad masses of the people for health.