Design requirements
1, the accident pool volume should be determined by the implementation of the standards or norms are: GB50483-2009, Q/SY 1190-2009 and Sinopec Anhuan [2006] No. 10, etc. GB50483 provides for the determination of the emergency accident pool volume, all projects involving hazardous chemicals environmental risks accidental drainage should be applied to the implementation of the project. Apply the implementation.
The determination of water consumption for fire-fighting and the determination of the effective volume of cofferdam or fire breakwater should be carried out in accordance with relevant regulations such as Code for Fire Protection in Building Design (GB50016-2014), Code for Fire Protection in the Design of Petrochemical Enterprises (GB50160-2008), Code for the Design of Petroleum Reservoirs (GB50074-2014), and Code for the Design of Fire Breakwaters in Tank Areas (GB50351-2014).
Maximum rainfall is determined in accordance with the Design Code for Outdoor Drainage (GB50014-2006), Design Code for Water Supply and Drainage Systems in Petrochemical Enterprises (SH3015-2003) and other implementation. Must be based on the characteristics of the project, industry standards or norms, accident pool volume determination of specific requirements, etc., pay attention to distinguish between the scope of application of the standards and norms and the implementation of specific provisions of the article, especially petrochemical enterprises and oil depots.
2, the emergency pool capacity should be based on the occurrence of accidents in the equipment capacity, the amount of fire fighting water in the event of an accident and may enter the emergency pool precipitation and other factors to determine. Tank area fire embankment volume, drainage to the accident pool of the drainage pipe in the self-flowing water intake below the highest level of the accident pool volume, the volume of the existing storage of accidental drainage facilities can be used as an effective volume of accidental drainage storage.
Calculation of emergency accident wastewater volume, the device area or storage tank area accident is not for simultaneous consideration, take the maximum value. Should be the maximum flow of accidental drainage water collection system for accidental drainage capacity calibration, clear guide drainage system of fire, explosion-proof, seepage, corrosion, frost, flood, anti-floating, seismic and other measures.
3, must pay attention to the accident into the accident pool of rainwater, and normal production of the initial amount of rainwater (i.e., pre-rainwater) of the essential difference, not to be confused.
One is the rainfall calendar is different, normal production and operation process of the initial rainfall is just under the rain, a rainfall process in the first 10 ~ 20min maximum precipitation, its design parameters must be calculated according to GB50014 short calendar rainstorm intensity formula to determine; and the accident should be based on the amount of precipitation in the event of a fire time (with reference to the provisions of the GB50016, GB50160 General) For 2 ~ 6h, Q / SY 1190 provisions for 6 ~ 10h) to determine.
The second is a different catchment area, the catchment area of the initial rainfall must be considered in the production area and the total catchment area of the storage area; accident only consider the device area or tank area alone can enter the maximum amount of accidental rainfall drainage system, do not consider the catchment area at the same time, and measures should be taken to minimize access to the accidental drainage collection system rainfall catchment area.
4, in the non-accident state need to occupy the accident pool (for example, pre-rain pool *** with), the occupied volume shall not exceed 1/3 of the volume of the accident pool, and should be equipped with emergency emptying in the event of an accident can be technical measures. Sewage treatment accident ponds must not be used as accident storage facilities and must not further transfer risks to the sewage treatment system.
Expanded Information
Treatment Methods
By Role
Sewage treatment can be divided into three kinds of physical, biological and chemical methods according to its role.
①Physical method: the main use of physical separation of non-soluble substances in the sewage, in the treatment process does not change the chemical nature. Commonly used gravity separation, centrifugal separation, reverse osmosis, air flotation. Physical method of treatment structures are simpler, more economical, used for village and town water capacity, self-purification ability, the degree of sewage treatment requirements are not high.
② biological method: the use of microbial metabolism, the sewage is dissolved or colloidal state of organic matter decomposition and oxidation into stable inorganic substances, so that sewage is purified. Commonly used activated sludge and biofilm method. Biological method of treatment is higher than the physical method.
3 chemical method: is the use of chemical reactions to treat or recover sewage dissolved substances or colloidal substances, mostly used for industrial wastewater. Commonly used are coagulation, neutralization, oxidation reduction, ion exchange method. Chemical treatment method is good, high cost, mostly used as a biochemical treatment of the effluent, for further treatment to improve the quality of the effluent.
By the degree of treatment
Sewage treatment can be divided into primary treatment, secondary treatment and tertiary treatment according to the degree of treatment.
The primary treatment is mainly to remove the suspended solids in the sewage, commonly used physical method. Primary treatment of wastewater BOD removal rate of only 20%, is still not suitable for discharge, but also need to carry out secondary treatment. The main task of secondary treatment is to substantially remove the colloidal and dissolved organic matter in the state of sewage, BOD removal rate of 80% to 90%.
Generally after secondary treatment of sewage can meet the discharge standards, commonly used activated sludge and biofilm treatment. The purpose of tertiary treatment is to further remove some special pollutants, such as fluoride, phosphorus removal, etc., belongs to the depth of treatment, commonly used chemical method.
Baidu Encyclopedia - Accident Tank
Baidu Encyclopedia - Sewage Treatment