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

3. Upgrade the aeration system

Secondly, taking various measures to achieve energy throttling according to local conditions is also an important part of green and low-carbon development.

Data show that the power consumption per unit volume of sewage treatment plant in China is about 0.15 ~ 0.28kW·h/m3.

Among them, the proportion of power consumption of aeration blower is 56.2%. Although the energy consumption of different treatment processes is different, it is a fact that the overall energy consumption of the aeration system is the largest. Therefore, the key point of energy saving and consumption reduction in sewage treatment plants is to upgrade the aeration system.

The core of the energy saving of aeration system is to provide dissolved oxygen required by microorganisms on demand under the premise of ensuring that the effluent reaches the standard, so as to achieve the balance between supply and demand and avoid the waste of aeration energy consumption.

This requires accurate control of the microbial activity process, while accurately controlling the operation process of the blower. It is necessary to prevent both over-aeration and under-aeration. This puts forward high requirements for the stability, reliability and accuracy of hardware equipment and control systems.

According to a domestic enterprise that has been engaged in the research of energy saving and consumption reduction technology for aeration systems for many years, in order to achieve accurate control of aeration systems, there are not only technical requirements, but also requirements for the selection and brand of equipment, and even strict requirements for the installation location of metering equipment such as flow meters and liquid level meters.

In general, upgrading the aeration system requires comprehensive consideration of various elements from a system perspective, which is a complex systematic project.

Some domestic cases show that through the energy-saving transformation of the blower, the average daily power consumption is reduced from 32,990 to 29,835, a decrease of 3155, a decrease of 11.4%. Roughly, it can reduce carbon dioxide emissions by 1,148 tons per year.

For small and medium-sized sewage treatment plants, at least hundreds of thousands or even millions of electricity costs can be saved every year. At the same time, the unit total nitrogen was reduced by 10.8%, and the unit ammonia nitrogen was reduced by 13.1%.

4. Optimize the input of raw materials

There are various wastewater treatment processes, but the essence is to remove pollutants from the water through biochemical reactions.

Therefore, carbon sources and a variety of chemical agents need to be added in the treatment process. These raw materials consume energy during production and transportation, and also consume a certain amount of energy during the dosing process.

Therefore, optimizing the feeding link helps to save energy and reduce carbon emissions.

How to optimize the input of raw materials? At present, there are two main ways in the market.

The first is to configure and upgrade the dosing system, from the commonly used frequency conversion metering pump to the digital pump, and the amount of dosing is reduced to varying degrees.

The second is to use AI technology for big data analysis of sewage water quantity, water quality and other parameters and dosing system operation data to form an optimal algorithm model, so as to achieve fine control of the dosing system and effectively reduce drug consumption and equipment operation energy consumption.

5. Optimize the performance of the drainage network

In the urban sewage treatment system, the collection and transportation of sewage involves large-scale pipe network laying and long-distance transportation, which requires a lot of energy consumption to support daily operation and maintenance. In order to minimize this energy consumption, various measures must be taken to optimize the performance of the pipe network.

Among them, the most basic is to transform and upgrade the operation and management mode of the pipe network, and the key work includes the investigation, positioning, maintenance and prevention of potential leakage risks.

Realize real-time monitoring of the operation status of the drainage network, and can quickly analyze whether leakage, blockage, and the severity, specific location, etc., to provide accurate support for managers to quickly maintain.

To improve the water transmission performance of the drainage network, the most fundamental solution is to improve the coverage rate of the drainage network, achieve 100% sewage collection, and carry out the rain and pollution diversion transformation to significantly increase the carbon nitrogen ratio of the sewage treatment plant.

In this way, it can solve the problem of insufficient carbon sources, effectively improve the organic matter - methane conversion rate of the sewage treatment plant, turn the sewage treatment plant into a power plant, fundamentally solve the problem of energy consumption, and achieve carbon neutrality.

6. Energy saving and consumption reduction of drainage pumping station