The first scientific paper on water
Analysis of water treatment technology
Nowadays, with the continuous development of society, the quality and safety of drinking water in people's lives are becoming more and more important, which puts forward higher requirements for water treatment technology. Based on the detailed analysis of the current basic situation of water treatment technology, this paper expounds the main water treatment technologies in depth, and makes a comprehensive analysis of the key contents and operational difficulties of water treatment technology, aiming at strengthening the application of this technology in practice, making a modest contribution to solving the problem of drinking water safety in urban and rural areas, and providing a higher guarantee for people's lives.
Water treatment; Technology; App application
Nowadays, with the continuous development of society, the quality and safety of people's drinking water is becoming more and more important, which puts forward higher requirements for water treatment technology. According to the basic situation of current water treatment technology, the main water treatment technology is elaborated in detail, and the key contents and operation difficulties of water treatment technology are comprehensively analyzed, so as to strengthen practical technology, make a modest contribution to drinking water safety in urban and rural areas, and provide higher guarantee for people's lives.
Keywords: water treatment; Technology; app; application
China Library ClassificationNo.: TU45 Document ID: A DocumentNo.: 2095-2104 (2012) 01-0020-02.
At present, in many places, due to perennial development and environmental pollution, the degree of water pollution is serious, which poses a great threat to the quality and safety of drinking water for local people. Therefore, in order to ensure the safety of drinking water, according to the national standards for drinking water, it is necessary to carry out a series of technical treatments on the water source to make it meet the relevant requirements and norms, reduce the problems of high fluorine, bitter salt, high arsenic and microbial diseases in the water source, and solve the quality problems that affect people's health and quality. In this paper, the water treatment technology is analyzed and discussed in detail from many angles, and the practical problems existing in it are deeply analyzed, so as to make this technology more widely used in people's daily life. According to the detailed analysis of technical characteristics and operation, it is concluded that various technologies are suitable for which environment, and the collected data are analyzed in detail according to actual use and operation. Comparing the advantages and disadvantages of different water treatment technologies will help water treatment technologies to be better applied in practice, provide better quality assurance for people's quality of life and make positive contributions to social development.
First, the analysis of the main water treatment technology
Generally speaking, ion exchange technology, membrane reverse osmosis technology, electrodialysis technology, composite multi-media filtration technology and electrocoagulation technology are commonly used in water treatment technology. Among these technologies, according to the actual use and operation, membrane reverse osmosis technology has the problem of high operation cost, which will increase the cost in the process of operation and use and is not conducive to solving practical problems. At the same time, electrodialysis technology also has the same problem. Although its operating cost is not very high in theory, the operating cost caused by different equipment in practical engineering will be higher. Due to the frequent replacement of media, ion exchange technology will cause complicated management and inconvenience in practical use and operation. The operating cost is determined according to the actual situation, and different media sources and replacement frequency will cause different costs. The other two technologies, electro-flocculation technology and composite multi-media filtration technology, are relatively new at present. This paper will analyze these two technologies in detail. Among them, electrocoagulation technology concentrates some advantages of electrochemical technology, and it also has the advantages of low operating cost and simple management. Composite multi-media filtration technology has overcome a series of shortcomings of other ion exchange technologies, and made many improvements in operating cost and operation. These two technologies are the two most widely used technologies today, not only because they can control the use cost well, but also because of their advantages in management and operation, which accords with the selection principle of water treatment technology today. Generally speaking, water treatment technology should follow several principles. First of all, the most important thing is to ensure the safety of drinking water and meet the corresponding requirements and specifications after relevant treatment. Second, technology needs to be safe and reliable, and mature technology, equipment and theory are comprehensive; Third, the operating cost should be low and the management should be convenient. Don't choose technologies and equipment that will cause great costs, and don't choose technologies that are more troublesome to manage, especially in some poor areas. We must strictly control the cost of technology and strictly grasp the complexity of technology. Finally, investment needs to be saved as much as possible. After meeting the above principles, we need a series of savings in technology investment, which is of great significance and role in maintaining economic development and ensuring economic benefits. According to the above description, we can have a more detailed understanding of the present situation of water treatment technology. Next, we will make an in-depth analysis of electro-flocculation technology and composite multi-media filtration technology, and compare the two technologies in many aspects through the results of data collection, in order to strengthen the application of water treatment technology in practice.
Second, the principle and process analysis of electrocoagulation technology
Electrocoagulation technology is an electrochemical technology, which concentrates some advantages of electrochemistry. It can effectively replace chemical reagents with electric energy, reduce economic cost, effectively remove heavy metals and suspended solids from water sources, and scientifically and reasonably remove pollutants such as emulsified organic matter. It is a new technology, which has been continuously improved in practical use and operation, and its effect has been recognized in many aspects. Electrocoagulation technology really started at the end of last century, but its theory was gradually established at the beginning of last century. Because of the immature equipment and less practice, it has not been widely used, and it was not until the end of last century that it was really improved and improved in practical use. Now this technology has made a great breakthrough. In Europe and America, it has become one of the main technologies of water treatment. At the same time, the economic cost and equipment management were reasonably controlled, and remarkable results were achieved. The main technologies and operations will be analyzed in detail below.
Electrocoagulation technology generates an electric field between steel plates through DC excitation. After the water to be treated enters the gap between the steel plates, a part of the steel plates being electrified will be consumed and enter the water source. At the same time, ionic and nonionic pollutants in the electric field will react with ionization products in the electric field after being acted by the electric field, and the water consumed in the electric field will also join the reaction. Various ions interact with each other to form some solid particles in the most stable form, which are gradually precipitated in the water flow to achieve the purpose of purifying water. This is the main working principle of electrocoagulation technology. In the electro-flocculation process, water enters the homogenization tank from the well, and the role of the homogenization tank is to balance the water in the water pump, well control the difference between it and the water flow in the electro-flocculation reactor, and strictly ensure the reaction. Then the water flows into the reactor. Generally speaking, the two reactors are connected together. Water is pumped into the reactor from the homogenization tank, and steel plates are placed inside, which can react with ionized ions in the water, thus achieving the purpose and effect of pretreatment. At the bottom of the reactor, there is an inclined cavity. The function of this cavity is to attract the heavier particles in the water flow and treat some pollutants still existing in the water flow, such as mill scale. Because of their great mass, these substances will gradually sink into the cavity and will not advance with the water flow. Then, the water will pass through the sludge storage equipment, defoaming tank, sedimentation tank, sand filter, etc. in turn, where pollutants will be further treated, and a series of technological processes will be completed to remove particles, dust and sediment in the water, so as to achieve the best water treatment effect. From the actual use and operation, the effect of electrocoagulation technology is relatively good, and good use effect has been achieved under the condition of reasonable control of cost and equipment management.
Third, the principle and process analysis of composite multi-media filtration technology
Through a series of physical treatment of water source, the composite multi-media filtration treatment technology meets the requirements of environmental protection and low energy consumption, and does not use chemical agents. While meeting the requirements and standards of water source treatment, the cost has also been well controlled, and only less backwashing water is needed in the whole treatment process. Therefore, it has been recognized in many aspects in practical use, and the technology is relatively mature and widely used. In the composite multi-media filtration treatment technology, due to the application of a series of modern automatic treatment systems, it is more convenient to monitor the water source in real time, read and operate more conveniently, and have strong maintainability. The whole process is relatively simple, and at the same time, the cost is low. This is a modern technology.
In the composite multi-media filtration treatment technology, water first enters the booster pump, which pumps the water into the water treatment system pool for preliminary treatment according to the requirements of flow and pressure, and then the water flows through the automatic backwashing media processor, which can well filter the sediment and deposits in the water flow. Then the filtered water flows into the backwashing activated carbon adsorber, and according to the use of coconut shell activated carbon, the odor in the water flow is effectively treated. Then, water flows through arsenic removal device, scale inhibitor, water ultraviolet disinfection inlet, etc. The arsenic, iron, manganese and other media in the water are treated in series in order to remove the scale in the water, and the water flow is decomposed and disinfected by ozone, so as to further remove the pollutants in the water and achieve the best water treatment effect. The above process is the main process flow of composite multi-media filtration treatment technology.
Fourth, data analysis and effect comparison
According to the detailed analysis of the operation effect in a certain area and the comparison of the collected data, it can be found that the harmful substances in the water are obviously reduced after adopting this water treatment technology, which has a good treatment effect on pollutants. At the same time, according to the data comparison between electro-flocculation technology and composite multi-media filtration technology, we can see that the two technologies have their own advantages. Firstly, flocculation technology is compared with multi-media filtration technology. It is mature in use and operation, low in cost and convenient in management. The service life and maintenance degree of the equipment are better than that of the multi-media filtration treatment technology. However, electrocoagulation technology also has its own shortcomings, such as high one-time investment, which is not suitable for poor areas.
Verb (abbreviation of verb) conclusion
To sum up, we can have a more detailed understanding of the main water treatment technologies at present. Through the detailed description of electro-flocculation technology and multi-media filtration treatment technology, we can master the working principle and process flow of related technologies in more detail, strengthen the practical use and operation of related technologies, strengthen the effect of water treatment technology, further reduce costs, strengthen management, treat water sources in the best way, and provide the best quality guarantee for people's lives.
refer to
Ye Rui. Analysis of water treatment technology and process flow J. Principles and technology of hydropower, June 2005.
Wang. Analysis of Rural Hydropower Water Treatment System and Technology Development in China, 2007(4)
Wang de Analysis on the Selection of Water Treatment Technology and the Use of Equipment M. Water Resources and Hydropower Information, 2006(5)
Scientific Papers on Water Part II
Virtual water and water safety
Abstract: Virtual water is a new concept in the field of water resources. In recent years, it has become a hot topic in international conferences related to water. This paper makes a preliminary discussion on virtual water and virtual water trade, and holds that virtual water, as unreal water, is realized through commodity trading or service, and virtual water trade is mainly manifested in grain trade and closely related to national security. The proposal of virtual water has changed some original ways of thinking, broadened the field of water resources research, established a new concept of water resources management, and finally provided a new way to solve the water shortage problem in arid areas.
Keywords: virtual water, virtual water trade, water security
First, virtual water and its characteristics
Virtual water is a new concept put forward by Professor Tony Allen of Institute of Asian and African Studies, University of London in the mid-1990s, which refers to the amount of water resources needed to produce goods and services. At present, virtual water is a hot topic discussed by experts and managers in the field of water resources in the world. The Third World Water Forum was held in Kyoto, Japan on March 18, 2003, right? Virtual water? Had a heated discussion.
Virtual water has three main characteristics: First, it is unreal. As the name implies, virtual water is not real water, but fictional water. Virtual? Does the product include a form? Can't see? Water, so virtual water is also called? Embedded in the water? And then what? Exogenous water? . ? Embedded in the water? It means that a specific product contains a certain amount of different forms of water. For example, to produce 1kg grain, irrigation needs 1 000 L water, 1kg beef consumption10.3 million l water, which is invisible virtual water behind the product. ? Exogenous water? It means that the water used by countries or regions importing virtual water is not from their own countries or regions. Second, social transactions. Virtual water is realized through commodity trading, that is, trade. Without commodity trading or services, there is no virtual water, which emphasizes the whole social transaction, not individual transactions. The more goods or services are traded, the more virtual water there is. Third, convenience. Due to the long transportation distance and high cost of physical water trade, this trade is usually unrealistic, and virtual water is used. Invisible? Compared with physical water resources, its convenient transportation makes trade a useful tool to alleviate the shortage of water resources.
Second, the virtual water trade and its role
Virtual water trade means that a country or region (usually a water-deficient country or region) buys water-intensive agricultural products or industrial products with high water consumption from another country or region (usually a water-rich country or region) through trade, so as to obtain water and food security and ensure national security. Virtual water trade is not a new thing, it is the product of commodity trading and the characteristic attribute of virtual water, and its history is as long as grain trade. At the same time, with the growth of trade, the number of virtual water is also growing steadily.
Virtual water trade is mainly manifested in agricultural products trade, especially grain trade. In a sense, the agricultural products trade between countries and regions is to import or export water resources in the form of virtual water. In the past, when people traded and served commodities, they didn't realize the virtual water behind commodities and its importance. With the growth of population, water resources in arid and semi-arid countries or regions are increasingly scarce, which leads to water crisis in these countries and regions. Water security problems cause food security and directly threaten national security. Therefore, in order to solve the problem of water security, some water-deficient countries have clearly realized the connection between the pressure of water resources and virtual water in the form of agricultural products trade, and are consciously conducting such import trade, such as Morocco, Jordan, Israel and Egypt.
Through trade, the relationship between the supply of grain in water-rich areas and the improvement of water shortage in water-deficient areas is established, so that water-deficient countries or regions can avoid looking for water and conduct a large number of grain trade with high virtual water content. Therefore, virtual water trade can alleviate the pressure of water resources in importing countries or regions and provide an economical and effective alternative water supply method for these countries and regions. Virtual water trade through appropriate and fair trade agreements is of positive significance for promoting water resources protection, improving global or regional food security and improving ecological environment in arid countries or regions. Invisible virtual water trade can also prevent the government and water experts from falling into endless arguments about water safety. However, virtual water trade also has negative effects, and there may be a tendency to ignore local water balance. For countries and regions that export virtual water, this trade will have an impact on their own environment (such as over-exploitation of local water resources and other natural resources). For countries and regions that import virtual water, virtual water trade will deprive farmers and their families of their livelihood if they can't provide other alternative crop cultivation or other employment methods.
Therefore, if virtual water trade is regarded as a policy, it is necessary to study the influence of virtual water trade on local nature, society, economy, environment, culture and politics and their interaction, and analyze the influence of virtual water on geopolitical importance.
Third,
Water security usually refers to having enough water resources to meet the material needs of human society, economic development and the maintenance of ecological environment. Water safety mainly includes water supply safety, flood control safety and water quality safety. Water shortage, floods and water pollution directly affect drinking water safety, health safety, food safety, economic safety, social safety and ecological safety. Water security related to virtual water is mainly water supply security.
There are three reasons for the emergence of water security problems: first, water resources are irreplaceable, and water resources are indispensable basic resources for human survival and social development, so water resources are called basic natural resources; Second, the supply of water resources is limited. Water resources are scarce, and population growth is the most primitive driving force of water resources scarcity. Because it can't meet people's growing demand for water resources, there are problems of safe supply of water resources such as quantity and quality. Third, the integrity of water resources system, which is the internal relationship of an organic system. If the structure of water resources system is destroyed (such as water pollution), the function of water resources system will decline or even die out, thus causing water security problems.
Since the concept of virtual water was put forward, the theory of virtual water has been applied to some extent in water-deficient countries and regions. Some arid countries such as Jordan and Israel have consciously formulated planning policies to reduce the export of high-moisture products, especially crops. In fact, these countries have regarded virtual water as a very important and increasing water resource, and their water imports in the form of virtual water have far exceeded their virtual water exports. According to the estimation of relevant experts, the virtual water purchased by grain trade in the Middle East every year is equivalent to the annual runoff of the entire Nile. Therefore, by increasing virtual water, regional water resources can be balanced, the water shortage situation in water-deficient countries and regions can be alleviated, and the local water resources security can be guaranteed.
Fourth, virtual water and national security.
Water resources are basic natural resources and strategic economic resources. The emergence of global crises such as population, resources, environment and ecology has brought about a qualitative change in people's national security concept. Water resource security is not only a resource security issue, but also a major strategic security issue related to national economy, society and politics, which is directly related to national security and a key component affecting national security. For example, the dispute between Israel and its Arab neighbors on the Jordan River, the dispute between the United States and Canada on the Columbia River, the dispute between India and Pakistan on the Indus River and the Danube River across eight European countries have become acute national security issues.
As a necessity of human life, grain carries a lot of virtual water and is the largest commodity in current world trade. Because food production is inseparable from water, water security can also affect national security through food security. Drought countries and regions can export high-efficiency and low-consumption aquatic products and import food products produced by non-local water resources, and finally solve the problems of water shortage and food security in the form of trade. For countries or regions participating in virtual water trade, trade can enhance the interdependence of food security in these countries and regions, reduce direct conflicts caused by water or food problems between countries or regions, create lasting cooperative relations and safeguard national security.
Five, some enlightenment
1. The concept of virtual water has changed the way of thinking to solve problems.
The proposal of virtual water broke through the traditional concept and traditional way of thinking. This requires water conservancy workers to change from the original concept of taking water as the center to finding ways to solve the distribution and management of water resources outside water. Big water conservancy? Based on the concept and method of system, various influencing factors related to water problems are found out. Looking for measures to solve regional water problems outside the scope of water problems can better coordinate the relationship between population, resources and ecological environment.
2. Virtual water theory broadens the field of water resources research.
Traditional water resources generally study the characteristics, movement law and correlation of real water resources, right? Can't see? I know nothing about virtual water. Virtual water theory provides an innovative field for the study of water resources and water security. For example, the traditional water resources research and food security research are separated, and the virtual water theory makes them have a breakthrough, which provides a broader research space for researchers engaged in water resources research. In the future, we should mainly strengthen the research on the regional policy system of virtual water strategy, and study the relationship between virtual water and regional socio-economic development, strategic adjustment of industrial structure, food security and ecological environment security, which is of great significance for building a strategic system of water resources security.
3. Virtual water has established a new concept of water resources management.
At the national level, the sustainable utilization management of water resources should be carried out in the unit of river basin, and the role of river basin system in water resources management should be brought into play, so that water resources management will move from supply and demand management to socialized management. There should be three levels of water resources management. First of all, we should make full use of local water resources by saving water, changing living habits and ways, adjusting industrial structure and planting structure. Secondly, considering regional socio-economic development, water resources security and ecological environment security, regional water resources allocation is carried out; Finally, build a strategic system of water resources security, and realize global water resources utilization through virtual water trade and virtual water strategy.
4. Virtual water provides a new way to solve the problem of water shortage in arid areas of China.
Water resources are precious and scarce resources for human survival. The serious shortage of water resources in arid areas of North China and Northwest China has seriously restricted the regional socio-economic development and led to the serious deterioration of the regional ecological environment. The establishment of water resources security strategy has become an inevitable choice and an important strategic issue for the country's long-term stability and sustainable economic and social development. The implementation of virtual water strategy is conducive to the formulation of strategic safeguard measures and policies for water resources security in northwest China, to the development of northwest China, and to the ecological environment security and social and economic sustainable development in northwest China.
References:
Cheng, 1. New strategic thinking on water resources security of virtual water China. Journal of China Academy of Sciences, April 2003.
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