With the rapid development of society and economy and the acceleration of urbanization, the problem of water pollution has become increasingly serious, which has become one of the key factors restricting the sustainable development of economy and society. In order to solve this problem, human beings have invented various sewage treatment technologies, trying to purify the polluted water before discharging it into the natural environment. However, in practice, we found that there are still many shortcomings in the existing sewage treatment methods, which not only affect the treatment effect, but also pose a potential threat to the ecological environment.

First, the resource consumption is high

Traditional biochemical treatment processes such as activated sludge process need a lot of power support to maintain operation, such as the energy consumption in aeration process is very considerable. In addition, in order to ensure that the effluent quality meets the standard requirements, it is often necessary to add chemical agents for auxiliary treatment, such as coagulants and disinfectants, which undoubtedly increases the cost, and some chemical residues may cause secondary pollution.

Second, the processing efficiency is limited

Although modern science and technology have significantly improved the technical level of sewage treatment, the existing facilities and technical means sometimes seem inadequate in the face of increasingly complex types of pollutants and changes in their concentrations. For example, the effective removal of emerging pollutants such as microplastics, drugs and personal care products (PPCPs) is still a huge challenge; At the same time, due to the great differences in water quality characteristics in different regions, it is difficult for a fixed model to meet the needs of all scenarios.

Third, ecological risks have not been completely eliminated

Even after strict treatment of wastewater, its safety is not absolutely safe. Studies have shown that some trace harmful substances may have long-term adverse effects on human health even if their concentrations are extremely low. In addition, if the by-products (such as sludge) produced in the treatment process are not properly disposed, new environmental pollution pressure will be transferred to the soil or groundwater system.

Fourth, the public participation is not high.

Although the government and all walks of life are actively promoting sewage treatment, there is a lack of extensive public participation and support in actual operation. On the one hand, because the transparency of relevant information is not high enough, ordinary citizens have insufficient understanding of the importance of sewage treatment; On the other hand, there is a lack of effective incentive mechanism to encourage people to change their living habits to reduce source pollution.

To sum up, in order to realize the real "green" sewage treatment, in addition to constantly optimizing and upgrading the existing technologies and equipment, we need to work together from the perspectives of policy guidance, scientific research and civic education to build an all-round and multi-level comprehensive treatment system, so as to maximize the role of sewage treatment in protecting the earth's homeland.