HBF waste water treatment plant technology

(Hybrid Biological & Fixed Film Technology)

Combined with the advantages of activated sludge watsewater treament and biofilm watsewater treament, HBF process can degrade COD and ammonium at the same time. HBF is a hybrid continuous/batch treating system developed based on the theories of continuous plug reaction, batch reaction and precipitation separation. It includes series processes of pre-denitrification, aerobic nitrification, post-denitrification and two alternatively operated sequence batch reactors. HBF integrates the biological nitrogen removal ability of two stages A/O (a process and the sequencing reaction or settling characteristics of SBR). The aerobic and SBR reactors are packed with our own products, fixed plate biofilm carriers, which can create a favorable ecological environment and proper hydraulic condition for the growth of dominant microorganisms. These structures improve the mass transfer conditions and separation effects in reactor, so the biodegradation efficiency increased significantly. In all, HBF can keep high removal rate of COD and ammonium through nitrification and denitrification.

Technological Route

Wastewater firstly flows into anoxic reactor for pre-denitrification. Meanwhile, the returning sludge from SBR and part of effluent from aerobic reactor are also pump into anoxic tank and mixed with influent. The organic carbon required for denitrification is provided by raw water while the nitrate is provided by reflux from aerobic reactor. The SBR sludge returning ratio is 1 while the aerobic reactor reflux returning ratio is adjusted according to the ammonium concentration in raw water to ensure the ammonium concentration is less than 80mg/L after mixed in anoxic reactor.

Next, the effluent from anoxic reactor flows into aerobic reactor to degrade COD and transform ammonium to nitrate through aerobic nitrification. Aerobic reactor is filled with fixed plate biofilm carrier with 40-60% filling rate. The biofilm carriers provide different niche for nitrification and denitrification bacteria respectively so that it can help achieve simultaneous nitrification-denitrification and improve biodegradation efficiency. In order to further remove total nitrogen from aerobic reactor effluent, post-denitrification reactor can be added after aerobic tank. The carbon source required for post-denitrification is supplied by external or a portion of the raw water.

In the end, the effluent from aerobic tank alternatively flows into SBR1 or SBR2 to further carbon removal and deep nitrification so that the COD or ammonium in effluent can be thoroughly removed. When SBR1 is in effluent stage as a sedimentation tank, SBR2 will be in aeration stage or settling stage. Part of sludge from SBR is recycled into the first anoxic tank by sludge pump to balance the sludge concentration. 

HBF Advantages

■ High nitrogen removal efficiency---achieve simultaneous nitrification-denitrification which can decrease the pH change degree and reduce the demand for carbon source and alkalinity in nitrification and denitrification processes. The system has efficient and stable nitrogen removal ability.

■ Good solid-liquid separation property ---the biofilm peeled off from filling carrier has good sludge settling ability which is easy to separate from water.

■ Low residual sludge production---the biofilm in fixed plate biofilm carrier is thicker than ordinary with an anaerobic area inside for anaerobic bacteria degrading the residual sludge synthesized by outer aerobic bacteria. As a result, the residual sludge amount can be reduced significantly.

■ Low cost of civil engineering investment---the system can run in higher volumetric loading rate or with smaller reactor volume because of more than 6000mg/L sludge concentration. The civil engineering cost is much lower because the system has high automation level and no secondary sedimentation tank.

■ High oxygen transfer and utilization efficiency---the fixed plate biofilm carrier can prevent aeration bubble aggregation to extend the contact time between oxygen, wastewater and microorganism. Turbulent formed by filling material interception produces strong hydraulic shear force which can break the aeration oxygen into fine bubbles and dispersed evenly. All above improve transfer and utilization efficiency of oxygen.

■ High resistance to impact load---HBF has capacity to dilute the pollution and resist or impact load toxic.

Typical Case:
Wastewater treatment plant up grading and reconstruction program
Jiaxiang County, Jining, Shandong

Program capacity: 20000m³/d

Influent quality: CODcr<400mg/L, B〇D5<200mg/L, SS<250mg/L, NH3-N<35mg/L, TN<40mg/L,TP<3mg/L

Effluent quality: CODcr<50mg/L, BOD5<10mg/L, SS<10mg/L, NH3-N<5mg/L, TN<15mg/L, TP<0.5mg/L

Core technology: HBF aerobic technology

Technology features: The biological process was upgraded from oxidation ditch to HBF without increasing construction costs. The aerobic tank was filled with fixed plate biofilm carrier in order to increase the sludge concentration, achieve simultaneous nitrification-denitrification and ultimately improve the total nitrogen removal ability. The alternatively operated SBRs ensured good precipi-tation separation efficiency so that the concentration of SS and TP in effluent can meet the discharged standard. After reconstruc tion, the effluent quality can conform first grade A permitted criteria of GB18918-2002.