Forecast of China's sewage treatment industry: the rural sewage treatment rate will reach more than 30% in 2020

Sewage treatment is a process of purifying sewage to meet the requirements of discharging into a certain water body or reusing it. Sewage treatment is widely used in construction, agriculture, transportation, energy, petrochemical, environmental protection, urban landscape, medical treatment, catering and other fields, but also more and more into the daily life of ordinary people. The components of domestic sewage are relatively fixed, mainly containing carbohydrates, proteins, amino acids, fats and other organic matters, which are more suitable for the growth of bacteria and become the places where bacteria and viruses live and reproduce; however, domestic sewage generally does not contain toxicity and has certain fertilizer effect, which can be used to irrigate farmland.

Sewage treatment method

According to the classification of sewage sources, sewage treatment is generally divided into production sewage treatment and domestic sewage treatment. Production wastewater includes industrial sewage, agricultural sewage and medical sewage. The domestic sewage is the sewage produced in daily life. It refers to the complex mixture of various forms of inorganic matter and organic matter, including: 1. The size of solid particles floating and suspended; 2. Colloidal and gel diffusers; and 3. Pure solution.

According to the quality of water pollution, there are two kinds of water pollution: one is natural pollution; the other is man-made pollution, which is harmful to water body. Water pollution can be divided into chemical pollution, physical pollution and biological pollution. The main pollutants are: (1) industrial waste water discharged without treatment; (2) domestic sewage discharged without treatment; (3) farmland sewage using large amount of chemical fertilizer, pesticide and herbicide; (4) industrial waste and domestic garbage piled up at the river bank; (5) water and soil loss; (6) mine sewage.

Sewage treatment in villages and towns

The sewage of villages and towns is mainly composed of domestic sewage and agricultural wastewater. The components of domestic sewage are relatively fixed, mainly containing carbohydrates, proteins, amino acids, fats and other organic matters, which are more suitable for the growth of bacteria and become the places where bacteria and viruses live and reproduce; however, domestic sewage generally does not contain toxicity and has certain fertilizer effect, which can be used to irrigate farmland. The components of agricultural wastewater are various. In different seasons, different places, different development goals of villages and towns, the wastewater needs different treatment methods. In the treatment of sewage, in order to reduce the amount and complexity of sewage discharge, the flushing water (black water) and other domestic water (grey water) should be separated in combination with the construction of biogas digester which is being vigorously promoted by the state. The treatment of grey water with natural purification system and black water and human and animal excrement with anaerobic biogas digester can not only reduce the discharge amount, complexity and treatment cost of sewage, but also play an important role in the development of clean new energy in rural areas, the protection of human settlements and the sustainable development of rural economy and society.

The function of the sewage treatment station is to treat the production and domestic sewage, to meet the specified discharge standards, and to protect the environment. The sewage treatment stations in developed countries are very common, but there are few sewage treatment stations in villages and towns in China, but there will be more and more in the future. To make these sewage treatment stations play a real role, we need to rely on strict discharge system, organization and management system to ensure.

Rural sewage discharge

In 2018, the country's rural sewage discharge is about 23 billion tons, which is still increasing, with a year-on-year growth of 7.5%. Rural sewage pollution has become the main manifestation of rural environmental pollution, which has a serious impact on the water, land and other natural environment in rural areas. In order to ensure the safety of rural water sources and the health of farmers, rural sewage treatment is urgent.

According to the 13th five year plan for the comprehensive improvement of rural environment, by 2020, the rural sewage treatment rate in China will reach more than 30%, and the rural sewage treatment market will usher in historic development opportunities. In 2018, the output value of rural sewage treatment industry is about 61.4 billion yuan, which is expected to reach 140 billion yuan by 2024. In 2020, the output value of rural sewage treatment will reach 84.4 billion yuan, with a treatment rate of 30%; in 2035, the output value will reach 130.5 billion yuan, with a treatment rate of 58%.

Sewage treatment target

Assuming that the 13th five year plan is completed in 2020, the annual capacity will increase by 3.3% - 2.9% in 2021-2025, respectively, and the treatment capacity will reach 220 million tons / day in 2025, that is, 31.2 million tons / day sewage treatment capacity will be increased in the 14th five year plan, which is greater than the target of 28.56 million tons / day in the 13th five year plan; However, the sewage treatment capacity in 2025 is 220 million tons / day, and the ratio with the water supply capacity in 2025 is only 69.5% (considering that the Sewage Planning and design scale is about water supply scale / daily variation coefficient * 0.9, and the daily variation coefficient is generally 1.2-1.3, the Sewage Planning proportion is about 69.2% - 75%, so the predicted value of sewage treatment capacity in 2025 is relatively reasonable), the ratio is low, and there is still some room for improvement. Based on the assumption of the length ratio between the improvement and the water supply network, the new growth rate of the 14th five year plan is 230000 km, 5.8% higher than the 217000 km in the 13th five year plan; the annual growth rate of the reverse calculation is in a reasonable range, which is consistent with the current situation of inadequate construction of the sewage network.