Mieczysław Metzger

The classical continuous activated sludge process must contain at least two (aerobic and anoxic) reactors for both carbon and nitrogen removal. Although such classical processes are widely used, sequentially operated continuous processes (SOCP) and sequencing batch reactors (SBR) are an attractive alternative. In these processes, carbon and nitrogen removal can be accomplished in only one bioreactor in which the aerobic and anoxic phases are periodically sequenced. The application of these processes is very attractive from the energy saving point of view.

In comparison to classical continuous biological processes when the process can be carried out without any control system, the sequences of the periodically operated process must be controlled and thus the development of the SBR (or SOCP) as a real-world pilot plant can be very interesting for the real-world experiments.

During the year 2000 a great effort has been done (with financial support of the KBN) to design and develop the pilot plant. Designed by D. Choiński a special 30-liter SBR with appropriate fitting system as well as the pH, Redox and dissolved oxygen continuous measurements were manufactured by the Hydro-Eco-Invest. The first control experiments dealing with the hydraulic operations (fill, mixing, aeration and draw) will start at the 2001.

In the 2002, a new idea has been developed. It can be noticed that with very little financial costs the SBR reactor can be augmented with secondary clarifier and in that way we can obtain the SOCP process in witch the same reactor used as SBR can be applied as continuous aerator for sequentially operated continuous process.

The simplified scheme of the process is presented in Figure 1 while the view of the pilot plant is presented in Figure 2. The control and monitoring with visualisation of the process are based on the new equipment from the National Instruments and from the Rockwell-Allen-Bradley. The wastewater storage tank and the pumping system are manufactured by the Milton-Roy. The equipment from the Hach (spectrophotometer and COD reactor) allows us to analyse chemical oxygen demand (COD), nitrates and nitrites as well as ammonia nutrients according to the international standards for wastewater measurements.

An idea of switcheable SBR and SOCP processes for biological wastewater treatment

Figure 1. An idea of switcheable SBR and SOCP processes for biological wastewater treatment.

 

View of the pilot installation

Figure 2. View of the pilot installation.