Time: December 03, 2016 Information source: the original site Click: 11 times
Sewage treatment technology is varied and diverse, but in summary, it can actually be divided into three main categories:
A-physical method of sewage treatment technology: the physical method can be subdivided into many kinds of small categories.
1-Grids, screens: like a sieve, the process of taking mechanical isolation to separate large physical solids from sewage.
2-Homogenization and water regulation: the same unit discharged sewage, at different times sewage water quality is not the same, the size of the volume of water also varies, so to homogenize this sewage, in accordance with a uniform rate of entry into the sewage treatment system.
3-Sedimentation: some tiny solid particles can not be grated. Separation is carried out by screens and sedimentation is a good way to treat them.
4-Coagulation: turbidity-causing impurities in water are large and small, fine suspended impurities settle extremely slowly, or even nearly unsinkable. Gum particles in the water to maintain the dispersion, can not be settled. Through the coagulation process, the turbidity in the water of fine suspended impurities and de-stabilized particles, as well as pharmaceutical reactants bonded to each other to become a larger size, visible to the naked eye, easy to sink and easy to filter the floc. Coagulation sewage treatment contains both physical and chemical methods.
5 - clarification: and precipitation is similar and not the same as a sewage treatment method. It uses the principle of contact coagulation, in the pool to let the flocs that have been generated suspended to form a suspended mud layer (contact cohesion area), in which the concentration of suspended solids is about 3 - 10g / L, when the coagulant is injected into the raw water through it, the newly generated micro-flocculated particles in the water are quickly adsorbed in the suspension of the mud, so that it can achieve a good removal of the effect. The efficiency of the gazelle depends on the activity and stability of the sludge suspension layer, therefore, to keep the sludge in suspension, uniform concentration, activity and stability of the working state is the same requirement of all the clarification pools ****.
6-air flotation: the use of tiny bubbles in the water density close to the water of suspended solid particles and insoluble liquids wrapped up and float to the surface of the water for separation.
7-filtration: and the principle of the grille, screen is similar, but dealing with tiny impurities in the water.
8-Extraction: the process of extracting pollutants by using solvents that do not dissolve in water, but can dissolve some of the impurities and pollutants contained in the sewage.
II-Chemical method of sewage treatment technology:
1-Redox: using the principle of redox, the chemical substances dissolved in water to form a stable chemical material,
2-Neutralization: acidic or alkaline sewage through acid and alkaline neutralization of sewage into neutral sewage, to facilitate the other parts of the treatment.
3-Chemical precipitation: the main treatment of soluble salts in water, put some kind of chemicals in the sewage, the chemical substances dissolved in water, through chemical reactions into insoluble substances, and then further separated by precipitation.
4 - adsorption method: solute from the water to the surface of solid particles, adsorption occurs, is the result of the interaction of water, solute and solid particles. The cause of adsorption is due to the hydrophobic properties of the solute to water and the hydrophobic properties of the solute to water and the solute to the solid glumes of the high affinity. The degree of solute solubility is an important factor in determining the first cause. The greater the degree of solubility of the solute, the less likely it is to move toward the surface. Conversely, the greater the hydrophobicity of the solute's solute, the greater the likelihood of movement toward the adsorption interface.
5-ion exchange method: Ion exchange method is to remove harmful ions in water by exchanging ions on ion exchanger and ions in water. In industrial wastewater treatment, it is mainly used to recover precious metal ions, but also for radioactive wastewater and organic wastewater treatment.
Three - biological wastewater treatment technology:
1 - microbial decomposition: mainly the use of microorganisms in the water decomposition of organic matter, anaerobic bacteria, aerobic bacteria and parthenogenetic bacteria and other types.
2-Biofilm method: Biofilm method mainly relies on the microbial film fixed on the surface of the carrier to purify organic matter.
3-Wetland ecological improvement method: artificial wetland environment, will be a variety of lotus root, water hyacinth and other adaptable plants planted in the sewage treatment system, after the plant absorption and filtration to improve the wastewater. It is a sewage treatment technology used more in large-scale urban sewage treatment.
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