Question 1: What is reclaimed water? It has been nearly 20 years since the term reclaimed water was first used in China in the early 1980s. It has now been recognized by industry insiders and even some people in water-scarce cities and regions. It was originally called "middle water", coming from Japan, because its water quality and its facilities were between water and sewers. With the introduction of foreign reclaimed water technology, experimental research on domestic pilot projects, advancement of reclaimed water engineering facility construction, development of reclaimed water treatment equipment, research and development of reclaimed water application technology and the establishment and implementation of relevant norms and regulations, gradually A complete set of engineering technologies is formed, just like "water supply" and "drainage", which is called gray water.
Reclaimed water is named after the connotation of water supply and drainage. The translated terms include reclaimed water, reclaimed waterway, recycled water, miscellaneous water, etc. We call it reclaimed water (RECLAIMEDWATER), which refers to buildings, In terms of supporting facilities in the building community, they are also called gray water facilities.
Reclaimed Water refers to non-potable water that has been treated to meet the prescribed water quality standards and can be used in domestic, municipal, environmental and other fields.
Recycling water (recycling water) The Ministry of Construction has formulated a classification standard for recycled water reuse. The definition of recycled water is: "Refers to water that is reused after secondary treatment and advanced treatment of sewage and wastewater. When secondary treatment When the treated effluent meets specific reuse requirements and has been reused, the secondary treated effluent can also be called reclaimed water. "Obviously, reclaimed water is reclaimed water.
The Reclaimed Water System is an organic combination of engineering facilities such as the collection, storage, treatment and supply of reclaimed water. It is one of the functional supporting facilities of a building or building community. .
Reclaimed Water System for Building: Reclaimed Water System for Building has different names due to different scopes. Reclaimed Water System for Buildings is a reclaimed water system established in one or several buildings. ; The gray water in the community is a gray water system established in the community. Community mainly refers to residential communities, but also includes concentrated building areas such as schools and government compounds, collectively referred to as building communities. Water in buildings is the general term for water in buildings and water in communities.
The reclaimed water design is based on making full use of the stability of microorganisms to treat organic wastewater, and uses secondary oxidation treatment to treat bathing wastewater. Practice has proven that modified rotifers grown in bathing wastewater at low concentrations of B0D5 have good treatment effects on low-concentration bathing wastewater, and their stability and impact resistance have been verified. The use of this process can also save a lot of physical and chemical processes in bathing wastewater treatment, such as saving the coagulation section and the activated carbon protection section, thereby reducing the dosage of coagulant and reducing labor intensity. As a reclaimed water protective agent, activated carbon can reduce the concentration of organic matter in the water. Existing in large amounts, the activated carbon will quickly harden and become ineffective. The activated carbon needs to be replaced, and the cost of activated carbon is relatively high, which results in economic waste and increased labor intensity. From the above analysis, it can be seen that the water treatment process at the current stage should adopt a method that is mainly biochemical and supplemented by physical chemistry. The key to biochemistry lies in the load of organic matter in the filler and the improvement of oxygen utilization. Better oxide fillers It is a new Japanese technology honeycomb filler BOD5 reaching 2.2KG. BOD5/M3 filler, and the overall volume is 1/3 smaller. The oxidizer adopts equipment produced by Chuanyuan, Taiwan, with high gas blasting efficiency and low noise.
"Reclaimed water" is named after Japan. There are many interpretations of the definition of "reclaimed water". It is called "reclaimed water" in sewage engineering and "recycled water" in factories. It is generally distinguished by water quality. sign. It mainly refers to non-potable water that can be reused within a certain range after urban sewage or domestic sewage has been treated to meet certain water quality standards. In the United States, Japan, Israel and other countries, a large amount of gray water is used for toilet flushing, garden and farmland irrigation, road cleaning, car washing, urban fountains, cooling equipment replenishment water, etc.
Our country is a country that is short of water resources, but there are currently no special projects or special funds for reclaimed water utilization. It is just policy guidance. The amount of reclaimed water used in each city is determined based on the degree of water shortage in the city.
Water after urban sewage has been deeply purified by treatment facilities (including water after secondary treatment and further in-depth treatment in sewage treatment plants) and concentrated bathing water, vegetable washing water, etc. in large buildings and living communities. Treated water) is collectively referred to as "reclaimed water". The water quality is between tap water (upwater) and sewage discharged into the pipe (sewer), hence the name "...gt; gt;
Question 2: What is "intermediate water" in water supply and drainage projects? 2.0.6 The intermediate water system of building
uses the building's cooling water, bathing drainage, toilet drainage, laundry drainage, etc. as water sources , after physical and chemical treatment, it is used in water supply systems for toilet flushing, greening, car washing, road sprinkling, air conditioning cooling and water features
in buildings. water system.
Question 3: What does medium water and high water mean? 1. The water level below 8 is ultra-low water. The water level below 1.85 is low water. The water level between 1.89 and 1.85 is medium-low water. 1.90 to A water level of 1.99 is gray water, a water level of 2.00 to 2.05 is high water, and a water level above 2.06 is ultra-high water.
Question 4: What does reclaimed water mean? The term "intermediate water" is relative to upper water (water supply) and lower water (drainage). The reclaimed water reuse technology refers to the centralized treatment of residential waste (sewage) water
biological contact oxidation method
(bathing, washing, laundry, kitchen, toilet) to achieve Certain standards are reused for greening watering in the community, vehicle washing, road washing, household toilet washing, etc., thereby achieving the purpose of saving water.
Wastewater reuse is usually confused with reclaimed water reuse, but it is different. Wastewater reuse refers to the reuse of industrial wastewater to the production line through the UF RO process. For recycling, the recovery rate is relatively lower than 75. Not used for greening watering, vehicle washing, road washing, household toilet washing, etc.
Recycled water: Both of the following can be called recycled water, but generally manufacturers will combine them to increase the recovery rate.
1. Classification by use
There are three treatment methods for gray water due to different uses
1. One is to treat it to drinking water standards and directly Reuse it in daily life, that is, realize the direct recycling of water resources. This treatment method is suitable for areas with extreme shortage of water resources, but the investment is high and the process is complicated;
2. The other is to use it Treatment to non-drinking water standards is mainly used for water that does not come into direct contact with the human body, such as toilet flushing, floor and car cleaning, greening watering, fire fighting, general industrial water, etc. This is the usual reclaimed water treatment method.
3. In industry, reclaimed water reuse technology can be used to reprocess industrial sewage that meets discharge standards. Generally, softeners, RO, EDI/mixed beds and other equipment are added to make it softened water. , purified water, ultrapure water level, can be recycled and reused in industry to achieve the purpose of saving capital and protecting the environment.
2. Classification according to treatment methods
According to treatment methods, gray water treatment processes are generally divided into 3 types:
1. Physical treatment method:
Membrane filtration method is suitable for situations where water quality changes greatly.
The characteristics of this process are: the device is compact, easy to operate, and is less affected by load changes.
The membrane filtration method is that under the action of external force, the separated solution flows along the surface of the filter membrane at a certain flow rate. The solvent, low molecular weight substances, and inorganic ions in the solution pass through the filter membrane from the high-pressure side into the low-pressure side. side and is discharged as filtrate; while polymer substances, colloidal particles and microorganisms in the solution are retained by the ultrafiltration membrane, and the solution is concentrated and discharged in a concentrated form.
2. Physical and chemical methods:
Suitable for situations where sewage quality changes significantly. Commonly used methods include: sand filtration, activated carbon adsorption, flotation, coagulation and sedimentation, etc. The characteristics of this process are: it uses hollow fiber ultrafilters for processing, advanced technology, compact structure, small footprint, intermittent system operation, and simple management.
3. Biological treatment method
is suitable for sewage with high organic content. Generally, biological treatment methods such as activated sludge method, contact oxidation method (as shown in the figure), and biological turntable are used. It can be used alone or in combination with several biological treatment methods, such as contact oxidation biological filter; biological filter activated carbon adsorption; rotating disc sand filtration and other processes. This process has the advantages of strong adaptability to hydraulic load changes, low sludge production, and easy maintenance and management.
At present, due to excessive and uncontrolled development of water resources in some countries and regions, and poor awareness of environmental protection, surface water and groundwater have been polluted to varying degrees. The supply of fresh water with good water quality is limited; secondly, the fresh water sources to be developed are far away from centralized water supply points, and the one-time investment cost is high, so some water-scarce areas are unable to expand water supply capacity. To the extent that it is not for drinking, the concept of gray water is introduced here. Reclaimed water refers to the reuse of high-quality miscellaneous drainage (excluding feces and kitchen drainage), miscellaneous drainage (excluding fecal sewage) and domestic sewage (waste) water used by people in life and production after collection and regeneration treatment. It is used as miscellaneous water for floor cleaning, watering flowers, car washing, air conditioning cooling, flushing toilets, fire fighting, etc. that does not come into direct contact with the human body. Because its water quality index is lower than the drinking water quality standard in urban water supply, but higher than the discharge standard of sewage allowed to be discharged into surface water bodies, that is, its water quality is between the domestic drinking water quality and the allowed sewage discharge water quality standard, so it is named " middle water".
Reclaimed water development and reuse technology has developed rapidly and has been widely used in the United States, Japan, India, the United Kingdom and other countries (especially Japan). These countries have determined the reclaimed water reuse technology suitable for their national conditions and strength based on the characteristics of their own countries and regions, making the reclaimed water reuse technology more and more perfect. In China, this technology has been valued by governments at all levels and relevant departments, and a lot of theoretical research and practical work has been done on water reuse in buildings. It has been used in many cities across the country...gt;gt;