**3. MBBR case study**

This chapter provides a case study where the novel CFIC biofilm process has been studied for municipal wastewater treatment, including for organic, ammonia, and total nitrogen removal. The CFIC process operates in two modes, a normal operation where high carrier filling is applied and a washing mode for extra sludge removal (**Figure 6**). Detailed process concept description can be referred to [34], and more information is given in the following presentation of a three-stage CFIC pilot for municipal organic and nitrogen removal. The first full-scale three-stage CFIC process has also been accomplished for a 30,000 m3 /d municipal wastewater treatment in Guiyang, China, in 2017.

**11**

**Table 2.**

*Feed wastewater characteristics in the two test periods.*

**Figure 7.**

*Pilot system PID layout.*

*Biofilm in Moving Bed Biofilm Process for Wastewater Treatment*

A pilot CFIC plant with a maximum feeding capacity of 6 m3

(**Figure 7**). The three biological stages are 8.7, 8.3, and 8.3 m3

cycle was performed in the other two aerobic stages.

structed for municipal wastewater treatment study at NRA, Norway. The pilot plant constitutes of a pre-denitrification (R1), two aerobic CFIC stages (R2 and R3), and a sludge settler for sludge removal and supernatant return to biological stages

volume. Biocarriers of BWT15® and BWTX® (**Figure 3**) were filled in the first and the other two stages separately. During normal CFIC operation, a filling ratio of 62, 86, and 83%, respectively, is applied. The filling degree of the pre-denitrification was kept constant at 62% while reduced to 71 and 69% when intermittent washing

The pilot was fed with municipal wastewater directly pumped from the full-scale primary clarifier onsite (**Figure 7**), and the wastewater characteristics are given in **Table 2**. The wastewater temperature was around 15°C in the whole year. The waste-

To facilitate biofilm growth on carriers, washing mode was applied at the beginning of the test until stable biofilm growth was observed. The pre-denitrification stage was washed daily, and the two aerobic stages were washed together in every 1 or 2 days after the first reactor washing cycle finished. The washing cycle for each stage

**Average feed condition Period 1 (15.05–29.06) Period 2 (24.10–01.12)**

TCOD (mg/L) 392 214 TSS (mg/L) 264 123 NH4-N (mg/L) 20.4 14.5 TN (mg/L) 45 29 pH 7.2 7.0

/h to the system with a recycle ratio of 1–1.5 during the study.

/h has been con-

, respectively, in

*DOI: http://dx.doi.org/10.5772/intechopen.88520*

**3.1 Pilot layout**

water was fed at 3–6 m3

**Figure 6.** *The CFIC® during (a) normal operation and during (b) the cleaning cycle.*
