【 Weak current College 】 indoor drainage-the first section indoor drainage system of classification and composition

This section describes the shunt system and combined two different drainage system, through the study of this section to understand how different circumstances choose appropriate drainage system, and to understand the composition of the indoor drainage system, drainage system layout principles.　　Indoor drainage system's mission is to eliminate various types of buildings. A, indoor water drainage system of classification used later changed the original chemical composition or physical properties, are subject to different levels of pollution, and therefore usually after use of water called sewage or waste, including rainfall generally wastewater and water-snow melt. Traditionally, the daily life of used water is known as the domestic sewage, sewage in general contain more protein, animal and vegetable fats and organic matter such as urea; used to clean the water after washing with SOAP and synthetic detergent and bacteria and pathogenic microorganisms, etc. Similarly, the industrial production of used water known as industrial waste, which are mildly contaminated wastewater from production; be called more serious pollution as production waste water with different levels of harmful, toxic substances.　　Rain, snow melts, the water are collectively referred to as precipitation, air pollution and precipitation for entrainment flow CDA-specific material contamination, the precipitation is subject to varying levels of pollution. Indoor drainage system is divided into the sewage and drainage systems, wastewater drainage system and roof rainwater drainage system 3 class.
II. indoor drainage system and select exclude City (town) and the industrial enterprises of domestic sewage, industrial effluents and rain snow, is to use a pipe drainage system to exclude, or with two or more separate tube drainage system to exclude, such exclusion patterns formed by the drainage system, known as the drainage system (hereinafter referred to as drainage system).　　Building internal drainage system is divided into shunt system and combined two called building internal shunt drainage and construction Interior combined drainage.　　Building internal shunt drainage, refers to the residential and public buildings in the droppings of sewage and wastewater, industrial buildings production wastewater and wastewater free separate sewer system.　　Building internal combined drainage, is building two or more combined sewage and waste water from a drainage pipe system.　　Building roof rainwater drainage system should be set up independently, with a view to the speedy, timely rain. Interior of the drainage system determines, according to the nature and extent of contamination of sewage, combining building external drainage system, conducive to comprehensive utilization, wastewater treatment and water development, factors to consider.　　In General, the city has a wastewater treatment plant, wastewater reuse is not desired, or production wastewater and sewage properties similar to timely adopt combined drainage system. General conditions should be diverted drainage system. ① After two sewage combined will produce toxic gases or other harmful substances.
② polluting substances similar, but the concentration difference is large.
③ Hospital wastewater contains a large number of pathogens or containing radioactive elements exceeds the standards.
④ without treatment or with some processing reusable water volume is large.
⑤ building water systems require the collection of raw water.
⑥ catering kitchen contains a lot of washing water and fats.
⑦ industrial wastewater with precious industrial raw material recycling and clips you need a large number of minerals or toxic and harmful substances need to be processed separately.
⑧ boilers, water heaters and other heating equipment more than 40 ℃ temperature drainage, etc.
The confluence of the drainage system should be adopted. ① city sewage treatment plant, wastewater reuse is not required.
② production wastewater and sewage is similar in nature.
Third, the Interior of the drainage system is composed of drainage systems to systematically exclude the construction of a sewage works.　　Civil construction of drainage system from health apparatus and production equipment affected by water, sewerage, ventilation pipes, clearing equipment, pumping up the local sewage treatment equipment and structures.　　Fourth, the drainage system of drainage system layout and topography, plane and vertical planning, drainage system and wastewater treatment plant, sewage water accept and the type of pollution levels, treatment and other pipeline projects and other factors. In the layout of the drainage pipe, generally should follow the following principles: wastewater should as far as possible to the shortest distance and gravity flow of excretion into the sewage treatment plant; pipeline should as far as possible along the parallel laying of the natural slope of the ground to reduce pipeline buried deep, terrain a flat low discharge piping to the shortest route touches with dry pipe; when pipe depth reached the maximum allowed value, and then continue to dig deep to increase the difficulty of construction rather than economic, consideration should be given to setting in the middle of upgrading sewage pumping station, but should seek to reduce the number of pumping stations; pipeline should try to avoid or reduce crossing rivers, railways and other underground structure; when the city as stage construction, the first phase of the project should be dry tube larger flow through from initial velocity is too small to affect the normal drainage pipes. For checking and clearing sewage network, in the pipe slope change Office, turning, pipe diameter change Department, the branch pipe access service and the straight pipe length exceeds a certain distance should be set to check mine drainage. Buried pipeline general layout of the road on both sides, maintenance less sewerage and rainwater pipes can also be arranged in the following; the depth of the laying of the pipeline, no insulation measures of domestic sewage pipes or water temperature and its closest industrial waste water pipe, tube base can be placed above freezing, and should ensure 0.15m jacking minimal thickness of the soil.
5. sewage treatment methods and flow of sewage treatment is the use of various techniques, wastewater removal of pollutants from, or convert it into harmless substances, or recycle useful substances, the waste water is purified.　　Modern wastewater treatment technology, according to the principle can be divided into physical treatment, chemical treatment and bio-chemical treatment methods. Physical treatment method, is the use of physical effects of separation of sewage pollution substances in suspension.　　Its methods are: screening, sedimentation, uplift, flotation, filtration and reverse osmosis method and so on. Chemical treatment method is the use of chemical separation and recycling of sewage in various States of polluting substances. The main methods are: and, coagulation, electrolysis, redox, extraction,Adsorption, ion exchange and electrodialysis.　　Chemical process used for the treatment of industrial production waste. Bio-chemical treatment method is the use of microbial metabolism, allowing sewage is solubility, colloidal State of organic substances into stable harmless substances.　　 　　The main method can be divided into aerobic biological treatment and anaerobic treatment, which is widely used in the treatment of municipal (town) sewage and organic production sewage and its method has activated sludge and biofilm and biological contact oxidation; the latter is usually used for wastewater treatment in sewage sludge and high concentration of organic. Sewage and wastewater production contained in a wide variety of pollutants is to use a way to put all the pollutants all removal, so a sewage often used by several methods of treatment system to remove different types of pollutants, reach the purpose of decontamination and emission standards. On some sort of sewage, whether using the method of processing system, according to the waste water, recycling, water quality and quantity of useful substances which possibilities and efficiency, the receiving waters of self-purification capacity, etc., through research and comparative economic technology. Research and scientific experiment was to determine the sewage treatment system or process in important ways. The typical urban sewage treatment process as shown in the figure below.