While many municipal sewage treatment plants are still worrying about the stability of Class A emissions, many provinces such as Zhejiang, Hunan, and Jiangsu have proposed quasi-four-category of water discharge standards. The introduction of high standard emission requirements is very different for the technical process routes introduced by various design institutes in China. This involves biochemical, physicochemical, membrane technology and advanced oxidation technology to deal with total phosphorus TP, total nitrogen TN, COD and other indicators. At the same time, it is necessary to consider the factors of land shortage, investment cost and operating cost of the existing sewage treatment plant, and it is necessary to conduct in-depth research and process comparison.

As China's economy is moving towards high-quality development and more provinces and cities have proposed that sewage treatment plant discharges meet quasi-four or ultra-clean emission standards, the high-quality voice of environmental protection equipment has begun to increase. As the saying goes, opportunities are always reserved for companies that are prepared. When SafBon acquired the KWI company in Austria a few years ago, many people expressed doubt and thought that traditional technology had no value. As the original company of DAF technology, KWI's intellectual property, patents and R&D personnel are a huge asset. Today, with a high degree of internationalization, it seems that SafBon is very visionary. We can no longer follow the old path of "introduction, digestion, and absorption" in the early days of Reform and Opening-up. Infringement and violation of patent laws have become unworkable. Nowadays, some companies are still enjoying it, and they are not relying on their own innovation to develop their business. This way, the road will be narrower and narrower. SafBon KWI’s DAF has the following advantages in the deep dephosphorization of municipal sewage plants:

1. Hydraulic load can be as high as 30 m3/(m2h)

2. Small footprint

3. The phosphorus removal effect is good, we can deep phosphorus removal to reach TP<0.05mg/L

To this end, we introduce the KWI’s DAF phosphorus removal process technology as follows:

1. U-shaped board patent technology, hydraulic load can be up to 30 m3/(m2h)

▲ Schematic Diagram of U-Shaped Board

2. ADR air dissolving reactor patent technology - to achieve the ultimate solid-liquid separation in the DAF tank.

▲ ADR Air Dissolving System (The Third Generation ADR Technology)

The process position of the DAF phosphorus removal process in the municipal sewage treatment plant is as follows:

In order to reflect the excellent performance of KWI DAF phosphorus removal, SafBon’s technology team obtained the following results through an on-site pilot test of about 8 months of a large municipal sewage treatment plant in a city in southern China.

When the hydraulic load is 25m3/(m2·h) and the reflux ratio is 20%, the effect of DAF phosphorus removal is shown in Table 1:

From the above data, it can be concluded that KWI’s DAF technology can achieve ultra-high hydraulic load and ultimate solid-liquid separation, breaking through the constraints on the “technology” and “land use” of the total phosphorus upgrading of sewage treatment plants, showing high efficiency DAF’s advantages of phosphorus removal. This lays a solid foundation for the promotion and application of KWI’s DAF in the municipal industry.