The start-up and operation performances of EGSB were investigated for municipal sewage treatment,and the key operational parameters were also analyzed.After 45 days,EGSB could be started-up effectively with the removal of CODCr and NH3-N being 58.8% and 32.9%,respectively.In the mean time,the removal efficiency of ammonia and nitrite were from negative to positive,and the anammox strengthened gradually.It was also found that the reactor operated well at ambient temperature with the average CODCr removal efficiencies of 66.6%.The average removal efficiencies of NH3-N,NO-2-N and NO-3-N were up to 90% and the anammox appeared markedly in this system.The quality of the effluent in the system could meet grade I of Integrated Wastewater Discharge Standard(GB 8978—1996).It was suggested that the HRT of EGSB in operation is less than 2 h and the reflux ratio less than 400%.

Two groups of different mixed sludges,with one group including anaerobic granular sludges,malodorous river sediments and aerobic activate sludge(R1),and the other including anaerobic digested sludge,malodorous river bottom sludge and aerobic activate sludge(R2),were used as inocula in two parallel ASBR systems treating actual municipal wastewater for 180~210 d.At the end of the experiment,the inner cultured sludge were observed by scanning electron microscope for analysis of their surface morphology.It was found that anaerobic ammonia oxidation(ANAMMOX) could be successfully achieved in the two systems.The ANAMMOX occurred after operation of 135 days.Additionally,removal efficiencies of NH+4-N(97.35%) and NO-2-N(99%) were observed at the stable stage in the R1 reactor.Comparatively,the R2 reactor took on notable ANAMMOX after 102 days' operation,the averaged removal efficiencies of ammonia and nitrite were 93.17% and 99% respecfively during stable operation.Taken together,the mixed sludge of R2 can be deemed as a relatively ideal inoculum for the ANAMMOX reactor due to its quicker start-up.The electron microscopy results showed that the anammox bacteria may exist in ASBR reactor.

Based on the microbial synergism,the current status of hybrid nitrogen-removal technology was reviewed mainly including simultaneous nitrification and denitrification,synergism of anaerobic ammonium oxidation and denitrification,simultaneous denitrification and methanogenesis,coupling of anaerobic ammonium oxidation,methanation and denitrification.The main principles,process and characteristics are also discussed.This paper may provide a useful reference for effective N-removal of wastewater.

Three different mixed sludges,including anaerobic granular sludge and aerobic activate sludge,river sediments and aerobic activate sludge,anaerobic digested sludge and aerobic activate sludge,were used as inocula in three parallel SBR systems treating typical municipal wastewater,respectively.It was found that the anaerobic ammonia oxidation(ANAMMOX)reactors could be successfully started-up after 150～180 days' operation with the NH_4~+-N removal efficiencies of 88%,80%and 85%,respectively.Moreover,all the NO_2~--N removal efficiencies of these reactors were more than 96%.Comparatively,the start-up period of the seeding sludges, namely the mixed anaerobic digested sludge and aerobic activate sludge,was relatively the shortest.Therefore,the above mixed sludge can be considered a promising inoculum for the start-up of AMAMMOX reactor.

<正>城市地表径流污染是指地表沉积物与大气沉降物等在降雨的淋溶和冲刷作用下,扩散性进入水体造成城市水环境质量下降的过程。地表径流是城市水体的主要面源污染之一,是造成城市内河环

In A2/O system,the effect of temperature on the PHB is limited. The increase of temperature can promote the PAO metabolism rate,thus contributing to the PHB synthesis. Both PHB content and system F/M are notably and positively related. The synthesis quantity of PHB increases with the quantity of anaerobic phosphorus releasing. The organism removal efficiency of A2/O system can be characterized by OUR,and the nitrification function changes of OUR can be characterized by nitrification OUR. The conventional OUR value is between 7.1 mg/(g.h) and 13.3 mg/(g.h),nitrification OUR values is between 0.88 mg/(g.h) and 2.95 mg/(g.h). Temperature has obvious effect on the raise of OUR of active sludge. The efficient temperature range of nitrification OUR is between 25-33 ℃,and NO3--N concentration is between 9.2-11.0 mg/L. Improving the F/M acts on the promotion of OUR.

The influences of variations of temperature and F/M on the TTC-ETS activity have been experimentally studied. The correlation between TTC-ETS activity and COD degradation was also analyzed. Comparing TTC-ETS activities with physical and chemical indexes when high C/N ratio impacted A2/O process, the advantages and disadvantages of using TTC-ETS activity to characterize the status of A2/O process were illustrated. The results showed that both temperature and F/M were positively correlated with TTC-ETS activity. TC-ETS activity was in the range of 13.2-48.3 mg/(g x h) and the maximum value was 60 mg/(g x h) which had a significant relationship with COD removal rate. In this system, abnormal state was pre-warned by TTC-ETS activity. The highest removal rate of COD appeared when TTC-ETS activity was 41.0 mg/(g x h).

By adding ammonium into the raw wastewater to simulate the low C/N shock,two sets of lab-scale A2/O (anaerobic-anoxic-oxic) system were constructed to investigate the physiological biochemical activities of the shock and further restoration.Results showed that oxygen uptake rate (OUR), dehydrogenases activity (DHA), adenosine triphosphate (ATP) and poly-β-hydroxybutyric acid (PHB) responsed well to the shock with a drop over 81.8%、87.0%、90.5% and 72.9%,respectively.Both increasing the sludge reflux ratio (R) and reducing the sludge retention time (SRT) were effective restoration measures.After the restoration the value of R,OUR barely resumed, however, DHA、ATP and PHB still had a 10% to 20% gap left,compared to those before the shock.The reduction of SRT could gradually eliminate impacts of the shock by discharging the damaged sludge.Although the A2/O system didn’t well perform during the restoration period,all of the four physiological and biochemical activities of micro-organisms recovered fully in the end.

The mode of lowering DO in the aerobic tank was used to accumulate NO-2-N for enhancing ANAMMOX reaction in the anoxic tank,thus improving the nitrogen removal efficiency of A2/O process.The results show that the concentration of NO-2-N is increased by 500% when DO concentration is 0.5 to 1.0 mg/L in the aerobic tank.The effective accumulation of NO-2-N is formed,and ANAMMOX reaction is enhanced.The removal rates of NH+4-N and TN in the anoxic tank are improved by 15% and 9% respectively.The removal rate of TN in the whole system is improved by 7%.It is known through the software analysis of SPSS13.0 that the nitrogen removal efficiency of A2/O process with ANAMMOX enhancement reaction is remarkable.However,lowering DO has negative influence on the removal of COD and TP,and the removal rates of COD and TP are decreased by 5% and 1.4% respectively.

The original water of Bailonggang wastewater treatment plant was used to construct A2/O process,The influence of F/M on nitrogen removal was studied by regulating the BOD5 loading (F/M) of A2/O process. The results showed that the best range of F/M for COD remove was 0.15～0.28 gBOD5·gMLSS-1·d-1; the best range of F/M for BOD5 remove was 0.14～0.22 gBOD5·gMLSS-1·d-1;the best range of F/M for denitrification was 0.13～ 0.23 gBOD5·gMLSS-1·d-1. the best range of F/M for nitrification was 0.14～0.28 gBOD5·gMLSS-1·d-1. According the analyse,the best range of F/M for the A2/O system was 0.14～0.22 gBOD5·gMLSS-1·d-1.

Poly-β-hydroxybutyrate(PHB) plays an energy transformation role in activated sludge wastewater treatment processes,particularly in biological phosphorus-removal system.OUR is an important factor to monitor microbial metabolism activity.PHB and OUR monitoring are very important in A2/O system management and regulation.

A systematic review of molecular biology research methods applied in environmental microbiology is given,including clone library profiling,molecular hybridization and genetic fingerprinting.Progress in the application of these methods to the analysis of community composition and distribution,diversity and dynamic analysis of nitrifying bacteria is also presented.The results show that molecular biology techniques play an important role in the study of the community characteristics of nitrifying bacteria.

In a pilot-scale anaerobic-anoxic-oxic experimental system for municipal wastewater treatment, PHB consumption in an oxic tank and PHB production in an anaerobic tank had been monitored overtime, and relations among PHB consumption/production, phosphorus removal/release and BOD5 loading had been analyzed. The results indicated that the consumption of PHB was positively related with phosphorus removal, and about 140 mg PHB consumption could result in 1 mg P removal. In the anaerobic tank, about 1.17 mg P release could result in 100 mg PHB production. The PHB production at the loading of 0.176 g/(g x d) was 4 mg/g MLSS less than that at 0.413 g/(g x d). No significant relevance was observed between PHB and BOD5 removal. The PHB of microorganism synthesizes was increased with the increase of temperature. Compared with the lowest temperature (17.1 degrees C), 20% of the total PHB content was increased at the maximum temperature (33.2 degrees C) in active sludge.

The effect of dissolved oxygen (DO) on the methanogenic activity of anaerobic granular sludges introduced into the expanded granular sludge bed (EGSB) reactor was measured in serum flasks. Results show that the specific methanogenic activity (SMA) decreases with DO increases. At 22 degrees C, the SMA drops from 75.9 mL x (g x d)(-1), 91.1 mL x (g x d)(-1) to 47.6 mL x (g x d)(-1), 71.4 mL x (g x d)(-1), respectively as DO increases from 0.00 mg/L to 7.00 mg/L. Higher temperature can weaken this trend and significantly promote SMA. As the control levels of temperature is 28 degrees C, 35 degrees C, the SMA average increases by 54.0%, 114.4% compared with that of the first gas production experiment. The study confirms that the presence of dissolved oxygen in the influent of an EGSB reactor does not constitute any evidently detrimental effect on the performance of anaerobic treatment process. Anaerobic granular sludges are demonstrated high tolerance for dissolved oxygen so that in practice this factor can be neglected.

Separate and integrated membrane bioreactors using white rot fungi were used to investigate the decolorizing effect of reactive brilliant red X-3B under non-sterile condition,and the micro-structure and variation of the biofilm during the treatment were observed and analyzed by scanning electron microscope(SEM).The results show that the fungal MBR is effective in decolorization of the dyes under non-sterile condition.The decolorization rate is high in the initial stages.For X-3B of 50 mg/L,the two fungal MBRs can decolorize about 65% of dye in 1 day,and more than 80% in 4 days.The decolorization rate decreases with increases in dye concentration and retention time.Meanwhile,the white rot fungi biofilm experiences a decrease in biomass.To ensure a stable source of white rot fungi in the initial stage for better dye decolorization,the Phanerochaete chrysosporium should be incubated in the sterilized culture medium for several days and the bioreactors also need to be washed and disinfected.The high dye loading and microbial contamination are the two major factors that affect the biofilm structure and the decolorizing capability of Phanerochaete chrysosporium.In practice,lowering the dye concentration,stopping the influent and adding culture medium at the appropriate time are necessary to recover the biofilm structure and biodegradation activity.