How to achieve green and low-carbon development of sewage treatment?

Carbon neutrality means the total amount of carbon dioxide emissions directly or indirectly generated by an enterprise, group or individual over a certain period of time, offset by afforestation, energy conservation and emissions reduction to achieve "zero emissions".

01 What changes will carbon neutrality make?

From China's current situation, the power generation and industrial end and the transportation sector are the main sources of carbon emissions, and the carbon emissions of agriculture, residential, commercial and public services are relatively low.

At the industrial end, energy processing industry, steel industry and chemical raw material manufacturing and other related high-energy industries are not only the key industries of coal consumption, but also the main industries of carbon dioxide emissions.

As a result, China's energy system will be revolutionized over the next 40 years as its carbon-neutral strategy is in full swing.

At the same time, due to the industrial chain effect, the transformation of the energy system will certainly promote the all-round change of the national economy.

Li Junfeng, executive director of the China Energy Research Society and researcher of the National Center for Strategic Research and International Cooperation on Climate Change, pointed out that "carbon neutrality is not only about energy, it is related to all aspects of the industrial chain." The goal of carbon neutrality will profoundly influence the restructuring and reorganization of the industrial chain and the new international standards."

Achieving carbon peak by 2030 will require some regions and some industries to peak first.

According to China's carbon peak, carbon neutral target node, the Ministry of Industry and Information Technology this year will implement industrial low-carbon action and green manufacturing engineering, and formulate steel, cement and other key industries carbon peak action plan and road map.

The 14th Five-Year Plan, which is being formulated, also regards carbon peaking and carbon neutrality as the main targets of the battle against pollution. It is expected that special plans for departments, localities and industries will be introduced this autumn and winter.

From January 1, 2021, the first compliance cycle of the national carbon market (until December 31, 2021) was officially launched, involving 2,225 key emission units in the power generation industry.

This is the first time that China has consolidated the responsibility for carbon dioxide control and emission to enterprises at the national level, and promoted industrial technology upgrading through the market forcing mechanism. The prelude to change has quietly begun!

02 Sewage treatment industry is a big energy consumer

In contrast, although the energy consumption of the sewage treatment industry is not as high as that of the power generation, steel, chemical and other industries, the total energy consumption is not small, and it is also a large energy consumer.

According to statistics, in 2014, China's sewage treatment plant power consumption accounted for 0.26% of the country's total power consumption, including industrial wastewater treatment and sludge treatment, the proportion will exceed 2%.

There are more than 16,000 wastewater treatment plants in the United States, which account for 1% of society's total electricity consumption. In Denmark, water and wastewater treatment processes consume 25 to 40 percent of municipal electricity.

In addition, sewage treatment needs to consume a lot of fuel and chemicals, indirectly emit a lot of greenhouse gases, the treatment process itself will also directly emit greenhouse gases.

According to United Nations data, the global water treatment industry, such as sewage treatment, accounts for about 2% of global carbon emissions. About 2 percent of U.S. energy consumption in 2017 was used in drinking water and wastewater treatment systems, generating about 41 million tons of greenhouse gases.

In addition, the pump is also one of the main sources of energy consumption for sewage treatment. According to Grundfos, pumps account for 10% of all water-related energy consumption.

From the perspective of energy conversion, the traditional sewage treatment model is essentially energy consumption in exchange for water quality. In order to reduce water pollution, we use a lot of electricity, which indirectly produces a lot of carbon dioxide emissions, causing a negative impact on the global ecological environment.

Therefore, in order to reduce carbon emissions, reducing energy consumption and material consumption of sewage treatment is the inevitable goal of industry upgrading.

At present, many countries in the world have issued a carbon neutral technology roadmap for sewage plants, and the United States has proposed that all sewage treatment plants should achieve carbon neutrality by 2030.

However, as an important public utility, China's sewage treatment rate has not reached 100%, and reducing water pollution is still the top priority of ecological and environmental protection work.