What Are the Different Treatment Methods for Domestic Sewage Equipment?

Domestic sewage treatment affects the quality of life for thousands of households and the safety of our ecological environment. With the deepening of China’s ecological civilization construction, especially the ongoing advancement of “Beautiful Village” initiatives and urban environmental management, domestic sewage treatment equipment has become a standard part of urban and rural environmental infrastructure. So, what are the different treatment methods for domestic sewage equipment? Which one is best for your situation? Today, we’ll break it down clearly and simply.

I. Classification by Treatment Mode: Three Models with Their Own Strengths

The choice of treatment mode largely depends on the volume of sewage, discharge characteristics, and local terrain. Currently, there are three main treatment modes:

Centralized treatment mode. For densely populated villages, towns, and areas with large sewage discharge, centralized treatment is the most efficient option. This mode requires proper planning and laying of sewage pipe networks to collect domestic sewage uniformly, then treating it in stages through physical filtration, microbial purification, and advanced treatment.

Decentralized treatment mode. For areas with scattered populations and small sewage volumes, decentralized treatment is more practical. Common methods include three-chamber septic tanks, courtyard-type constructed wetlands, or ecological filters. These require no large-scale pipe networks and are relatively simple to maintain.

Integrated treatment equipment. For small to medium-scale scenarios such as farm stays, bed & breakfasts, or sites discharging 30 to 50 tons per day, integrated equipment is becoming the first choice for many users due to its high level of integration, strong impact resistance, and ease of operation and maintenance.

For example, in the Rizhao Economic and Technological Development Zone, Shandong Province, authorities adopted tailored strategies for different villages: eight villages used underground natural treatment equipment, ten villages used BBR integrated biological treatment equipment, and five villages were connected to the municipal sewage network, achieving effective sewage control.

II. Classification by Treatment Process: Five Mainstream Processes Explained

The core of domestic sewage treatment equipment lies in the treatment process. Different process principles determine treatment efficiency, effluent quality, and operating costs. Currently, the five mainstream processes on the market are:

AO process (Anaerobic-Oxic). This is a relatively basic biochemical treatment process. In the anaerobic stage, anaerobic bacteria break down large organic molecules into smaller ones, which are then further decomposed in the oxic stage. The AO process is simple, requires lower investment, and achieves a total nitrogen removal rate of over 70%. It is suitable for scenarios where effluent quality requirements are not extremely high.

A²O process (Anaerobic-Anoxic-Oxic). As an upgrade of the AO process, the A²O process removes both nitrogen and phosphorus. It achieves higher removal rates of nitrogen, COD, and organic matter, making it one of the mainstream biochemical treatment methods today.

MBR process (Membrane Bioreactor). MBR combines the activated sludge process with membrane separation technology, greatly improving treatment efficiency and producing high-quality effluent. It is considered a “top performer” among sewage treatment processes. The MBR process is suitable for domestic sewage with high treatment requirements and for hard-to-degrade organic sewage. However, the investment and operating costs of MBR equipment are relatively high.

SBR process (Sequencing Batch Reactor). SBR operates with intermittent aeration. The process is flexible and has strong impact resistance, making it particularly suitable for situations with intermittent discharge and large flow variations, such as school sewage treatment plants or small to medium-sized sewage stations.

Biological Aerated Filter.This is a new type of biofilm treatment process that combines multiple functions, including removal of SS, COD, BOD, as well as nitrification, denitrification, and phosphorus removal. It has a wide range of applications and performs well in advanced water treatment, slightly polluted raw water treatment, and low-temperature sewage treatment.

III. New Trends: Smart and Green

In recent years, driven by the “dual carbon” goals and increasingly stringent environmental policies, domestic sewage treatment equipment has been evolving toward smarter, more energy-efficient, and more compact solutions. From traditional underground integrated equipment to efficient MBR membrane bioreactors and flexible containerized modular units, technological iteration is accelerating.

Moreover, the installation and maintenance of equipment are becoming more standardized. For example, choosing a flat, solid, and well-drained site for installation, and regularly inspecting key components such as blowers and pumps, are critical to ensuring long-term stable operation.

Conclusion

There are many different treatment methods for domestic sewage equipment, and there is no absolute “best” — only the “most suitable.” When choosing, users should comprehensively consider factors such as treatment volume, discharge standards, site conditions, investment budget, and operating costs, and select the type that best fits their actual situation.

With continued policy support and technological progress, domestic sewage treatment equipment is poised for even broader development. If you are considering purchasing or upgrading sewage treatment equipment, start by understanding the treatment methods outlined above to find the solution that works best for you. Protecting our clear waters and green mountains begins with choosing the right sewage treatment equipment!