一、 Basic methods for water pollution control
The purpose of wastewater treatment is to separate the pollutants in the wastewater in a certain way, or decompose them into harmless and stable substances, so that the sewage can be purified. Generally, it is necessary to prevent the infection of poisons and germs, and avoid visible objects with peculiar smell and bad sensation, so as to meet the requirements of different uses.
Wastewater treatment is quite complex, and the choice of treatment method must be considered according to the quality and quantity of the wastewater, the receiving water body to which it is discharged, or the use of the water. At the same time, it is also necessary to consider the treatment and utilization of sludge and residue generated in the wastewater treatment process, as well as the possible secondary pollution, as well as the recycling of flocculants.
The choice of wastewater treatment method depends on the nature, composition, state and water quality requirements of the pollutants in the wastewater. General wastewater treatment methods can be roughly divided into three categories: physical, chemical and biological.
Physical method: The object of physical treatment is mainly the pollutants in the suspended state and part of the colloidal recovery wastewater. For example, the sedimentation method is used to remove the suspended particles with a relative density greater than 1 in the water and recover these particles, the flotation method (or air flotation method) can remove the emulsion oil droplets or the suspended solids with a relative density of nearly 1, the filtration method can remove the suspended particles in the water, and the evaporation method is used to concentrate the non-volatile soluble substances in the wastewater.
Chemical method: The chemical method is to use chemical reactions to remove pollutants in water, and the treatment objects are mainly inorganic substances and a few organic substances that are difficult to degrade. There are mainly chemical adsorption, chemical precipitation, redox, hydrolysis and other processes to reduce the concentration of pollutants.
Biological method: The biological method is to use the biochemical action of microorganisms to treat organic matter in wastewater. For example, biological filtration and activated sludge are used to treat domestic sewage or organic production wastewater, so that organic matter can be converted and degraded into inorganic salts and purified.
The above methods should be used in combination with the degree, quantity and quality of water pollution, and also consider what the recycled water is used for, and comprehensively consider the cost and economic value of wastewater recycling to select the treatment method. The three methods of the city complement each other's strengths and complement each other, and work together to achieve better governance results.
二、 Water pollution countermeasures
First, it is necessary to strictly manage water in accordance with the law, and formulate and implement effective laws, rules, and regulations. For example, at the legal level, the prevention and control of water pollution should be truly incorporated into the development of the national economy, water conservation and cleaner production should be included in the law, and criminal punishment should be imposed on those responsible for illegally discharging pollutants and causing great pollution harm. To achieve the utilization of wastewater resources, the discharge of industrial wastewater should be increased, if only pay attention to the end treatment, it is difficult to achieve the purpose of improving the current water pollution situation, so we must realize the utilization of wastewater resources.
Second, to strengthen the protection of drinking water source water intakes, the relevant departments should demarcate water source areas, set up notices in the areas and strengthen the greening of water intakes. Organize personnel to conduct inspections on a regular basis. Eliminate pollution fundamentally and achieve the goal of treating both the symptoms and the root causes.
Third, increase investment in sewage treatment. Intensify the treatment of urban sewage and industrial wastewater, and vigorously build sewage treatment plants. Speeding up the construction of urban sewage treatment plants plays a great role in improving the water pollution situation in our country. At present, with the increase of urban population and the improvement of residents' living standards, the speed of urbanization is also accelerating, while the urban sewage treatment plants and industrial sewage plants have not increased significantly, and the increase rate is far less than the rate of sewage discharge. This will inevitably lead to a decline in the quality of the water environment. Therefore, the construction of more sewage treatment plants is urgent. At present, the total discharge of urban domestic sewage in China has exceeded that of industrial wastewater, and the treatment of water pollution must put the treatment of urban domestic sewage in the first place in water pollution control.
Fourth, we should adopt economic policies that are conducive to the prevention and control of water pollution. Water should be considered one of the city's most valuable natural resources, treated on an equal footing with other resources, and the external costs of water pollution should be borne by those who discharge sewage. The price of water resources is correctly determined according to local conditions. The full implementation of the levy of sewage treatment facilities operating fees, sewage charges should be determined according to the principle of maintaining the operation of urban wastewater treatment plants, and at the same time formulate and implement relevant financial and tax preferential policies to support and promote cleaner production.
标签：Control,water,method,Water,treatment,pollution,wastewater,sewage,Pollution From： https://www.cnblogs.com/SA6D2AS6/p/17825184.html