Sewage Treatment Technology: A Brief Analysis of Treatment Methods of High Salt Wastewater

High-salt wastewater refers to wastewater containing at least 1% of the total salt content. It mainly comes from chemical plants and the collection and processing of oil and natural gas. The wastewater contains many substances (including salts, oils, organic heavy metals and radioactive substances). Saline wastewater is produced in a wide range of ways and the amount of water is also increasing year by year. The environmental impact of removing organic contaminants from salty wastewater is of paramount importance. How to deal with high-salt wastewater, first of all we do a simple analysis of their different situations. 1, salinity of less than 2g / L conditions, may be treated by domesticated salt water. However, domestication salinity concentration must be gradually increased, phasing the system domestication to require salinity levels. Suddenly the salt environment can cause delays and delays in domestication. 2, dilute the water salinity. Since high salt becomes a microbial inhibitory and toxicant, water will be diluted to a salinity below the toxic threshold and biological treatment will not be inhibited. This method is simple, easy to operate and manage; the disadvantage is to increase the scale of processing, increase capital investment, increase operating costs, wasting water resources. 3, the salinity is greater than 2g / L, the evaporation of concentrated desalination is the most economical and most effective way to work. Other methods, such as culturing salmonella bacteria, have the problem that industrial practice is difficult to run. How to deal with high-salt wastewater to achieve better results, we need to have a detailed understanding of the biological processes it deals with: (1) adjust the pool. Salinization of wastewater treatment ponds to consider the main factor is the change of wastewater salt concentration, in addition to the production cycle fluctuations, the impact of factors, should focus on changes in water salt concentration and how to adjust, such as the reduction of low salt water or too high salt The impact of water. (2) aeration tank. Depending on the type of salt in the wastewater, aeration tank selection should also be different. Biological treatment of wastewater containing CaCL2 higher should be used traditional aeration. Calcium ions can increase the floc strength of activated sludge. High CaCL2 can make the ash content in the sludge reach 40% ~ 50%, and the sludge density increases. The concentration of sludge in the aeration tank can be above 5000mg / L. Therefore, should be used to enhance the larger traditional aeration, deep well aeration, fluidized bed aeration and other aeration methods. Aeration should also use a larger bubble, enhance the stronger diffuser aeration aeration methods. Can not use the smaller bubble aeration and variable pore aeration aerator to prevent aeration holes blocked by inorganic salts, is not conducive to aeration tank agitation. In the water is less than 1000m3 conditions can also be jet aeration, jet aeration oxygen transmission efficiency, and difficult to plug the aeration equipment. Aeration intensity should also be greater than normal biological treatment, at about 10m3 / (m2? H), or use the center tube to increase the lifting and stirring capacity. In the case of high salinity, the increase of the oxygen transfer rate is beneficial to the high sludge concentration. As long as the micelles do not disintegrate, even if filamentous bacteria are produced, the sludge will not go up and down. Phosphorus nutrition salt should pay attention to dosing location, in order to avoid the precipitation of calcium phosphate not only affect the use of effect, but also easy to block the pipeline fouling. SBR process for the treatment of high-salt wastewater, because the SBR is a waterfall, sediment integration, so in the design time to give full consideration to the precipitation time, especially in the treatment of wastewater containing high concentrations of sodium salt, sodium salt wastewater sedimentation The effect is poor, so the precipitation time should be extended accordingly, then there is the decanter in order to reduce the interference of sedimentation of sludge, decanter water depth should also be reduced accordingly. In the treatment of wastewater with large fluctuations in salinity, it is still necessary to set up a regulating tank. There are units that need to dispose of high-concentration saline wastewater, and you can also consult a wastewater treatment company that has similar wastewater treatment service to the Sewage Water Project Service Platform. Biofilm process is ideal for the treatment of high salinity wastewater, such as the waterfall gas biofilter process, the contact oxidation aeration, etc., in the treatment of wastewater containing high calcium content, pay attention to the choice of filler or filter, Biofilter to design a larger backwash intensity and time. Oxidation tank should also be filled with a higher porosity of the type, packing installation to allow easy removal and flushing to prevent the formation of waste water treatment process of calcium carbonate plugging. When biological treatment of wastewater containing NaCl is higher, ash content of sludge is lower than that of CaCL2-containing waste water and density of salt-containing waste water is large. When the sludge is expanded or the aeration tank is disintegrated by the impact sludge, the bacteria micelle is easier than the wastewater containing CaCL2 Floating loss, so the higher NaCl wastewater biological treatment is best to use biofilm method. (3) Second settling tank. Secondary sedimentation tank surface load should have some margin, mainly to consider increasing the density of waste water, is not conducive to sludge sedimentation, especially with NaCl wastewater. Treatment of large amount of water, especially with CaCL2 wastewater, the best peripheral drive scraper, in order to adapt to high sludge concentration, density characteristics. In the process of using traditional activated sludge treatment of high CaCL2 wastewater, sludge return flow should be appropriately increased to reduce the impact of wastewater fluctuations and improve the stability of the system.

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