To improve water quality of Buji Stream and Shenzhen River, the Bujihe Wastewater Treatment Plant has been reconstructed from the original coagulkation-flocculation sedimentation system into the enhanced hybrid submerged biofilm-activated sludge (EHYBFAS)system developed by the authors. The main design parameters of the EHYBFAS system, process characteristics, operational performance, techno-economic index, and experience in design, construction and operation are described，which set up an example of the municipal wastewater treatment plants using the novel process of EHYBFAS, which has lots of advantages, such as stable and high operational performance with the final effluent quality well meeting 1A-1B standard of GB 18918-2002( Chinese national standard for pollutants of effluent from the MWWTPs), much less footprint of 1ha/(100×103m3/d)) vs 4-5ha/(100×103m3/d), much lower capital and operation costs of 700-800 Yuan(RMB)/(m3/d) and 0.5 Yuan(RMB)/m3 vs 1200-1500 Yuan/(m3/d)and 1.0-1.2 Yuan/m3 and much less sludge production of 0.3g dry solid/g removed BOD5 vs 0.7 g dry solid/removed BOD5 respectively for the MWWTP with AS process.

Anaerobic Digestion of thickened septage was investigated in this study. Thickening could reduce the volume of septage to be treated to about 40% with 12hr HRT. The VS and BOD removal efficiencies were respectively 28 to 45%, and 75% when digested the thickened septage with 30 day HRT Or $1.4kgVS/m^3/d$. The BOD removal efficiency could be increased to about 90% with subsequent settling tank with about 6 hours HRT. The gas production rate was 0.22 to $0.35m^3gas/kgVSadd$($0.75m^3gas/kgVSrm$), or $1.32m^3gas/kgBOD_{rm}$. In addition, the supernatant of thickener could be returned to the aeration tank treating domestic sewage. In this case, a BOD loading rate of 0.5 to $0.7kgBOD/m^3/d$ or 0.5kgBOD/kgMLVSS/d was proposed for 80% BOD reduction.

The purpose of this study was to confirm the applicability of aerobic granular sludge (AGS) in the advanced sewage treatment process. Simulated influent was used in the operation of a laboratory scale reactor. The operation time of one cycle was 4 h and the reactor was operated for six cycles per day. The volume exchange ratio was 50%. The influent was injected in divisions of 25% to increase the removal efficiency of nitrogen in every cycle. As a result, the removal efficiencies of CODCr and TN in this reactor were 98.2% and 76.7% respectively. During the operation period, the AGS/MLVSS concentration ratio increased from 70.0% to 86.7%, and the average SVI30 was 67 mL/g. The SNR and SDNR were 0.073 0.161 kg NH4 +-N/kg MLVSS/day and 0.071 0.196 kg NO3 --N/kg MLVSS/day respectively. These values were higher or similar to those reported in other studies. The operation time of the process using AGS is shorter than that of the conventional activated sludge process. Hence, this process can replace the activated sludge process.

A new biological nutrient removal system combining A2/O process with fixed film was developed in this work and the characteristics of denitrifcation were especially investigated in the combined fixed film reactor(CFFR). Media was added in the anaerobic, anoxic and aerobic reactors, respectively. Tests were made to establish the effluent level of NOx-N, COD, DO and nitrite effects on NOx-N removal in the CFFR by decreasing hydraulic retention time (HRT) from 10.0 to 3.5 hours and by increasing internal recycle ratio form 0% to 200%. The influent was synthesized to levels similar to the average influent of municipal wastewater treatment plants in Korea. SARAN media with a porosity of 96.3% was packed 40%/30%/25% based on its reactor volume, respectively. It was found that COD rarely limited denitrification in the anoxic reactor because of high C/NOx-N ratio in the anoxic reactor, while DO concentration in the anoxic reactor and NO2-N/NOx-N from the aerobic effluent inhibited denitrifcation in the anoxic reactor. It was proved that the critical points of DO concentration in the anoxic reactor and NO2-N/NOx-N from the aerobic effluent were 0.15㎎/L and 10%, respectively. As the internal recycle ratio increased, DO concentration in the anoxic reactor and NO2-N/NOx-N from the aerobic effluent increased. Especially, at the condition of internal recycle ratio, 200%, DO concentration in the anoxic reactor and NO2-N/NOx-N from the aerobic effluent exceeded the critical points of 0.15㎎/L and 10%, respectively. Then, denitrification efficiency considerably decreased. Consequently, it was represented that the control of DO concentration in the anoxic reactor and NO2-N/NOx-N from the aerobic effluent can assure effective denitrifcation.