[Effect of Ca on the Nitrification Activity and the Flocculation and Sedimentation Performances of the Activated Sludge].

Ca is an important microbial growth factor that can affect the activity, flocculation, and sedimentation of activated sludge. In order to study the roles of Ca in the activated sludge system, the activity changes of ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) were analyzed using the specific oxygen uptake rates (SOUR and SOUR). The changes in composition and structure of extracellular polymeric substances (EPS) were analyzed using Fourier transform infrared spectroscopy (FTIR) and three-dimensional excitation emission fluorescence spectroscopy (3D-EEM).

[Effect of NaCl Salinity on Extracellular Polymeric Substances and Bioflocculation of Anoxic Sludge in A/O Process].

In order to improve the biological removal efficiency of nitrogen and phosphorus and bioflocculation performance of salt-containing wastewater, the effect of NaCl salinity on the efficiency of denitrification and phosphorus removal in the anoxic zone of an A/O process was investigated. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to analyze the composition and structure of extracellular polymeric substances (EPS) in activated sludge of the anoxic zone, to discern the effect of salinity on bioflocculation. Results showed that when NaCl salinity was 0-5 g·L, flocculation ability (FA) in A/O anoxic zone was about 44% and the sludge particle size was 45.

[Preparation of Mn-Co/Ceramic Honeycomb Catalyst and Its Performance on Catalytic Ozonation of Hydroquinone].

In order to improve the activity and working life of metal catalysts in the heterogeneous catalytic ozonation of organic wastewater, four kinds of Mn-Co/ceramic honeycomb (CH) catalysts with different mass ratios of Mn and Co were prepared by coating method using cobalt nitrate hexahydrate [Co(NO)·6HO] and manganese nitrate [Mn(NO)] as precursors, respectively, and CH as the carrier. The structure of the catalysts was analyzed via X-ray diffraction (XRD), N adsorption/desorption, field emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS). The mechanical properties of the catalysts were studied.

[Pollution Characteristics of Antibiotic Resistant Bacteria from Atmospheric Environment of Animal Feeding Operations].

Animal feeding operations is considered as a source of airborne human pathogens and antibiotics genes. In this study, we investigated the concentration, size distribution and aerodynamic diameter of airborne bacteria, tetracycline resistant bacteria and erythromycin resistant bacteria from 22 animal feeding operations in three districts of Beijing. The results indicated that the highest and lowest concentrations of these three types of bioaerosol were detected in pig and cow house, respectively.

[Distribution Characteristics of Antibiotic Resistance Genes in Vegetable Soils in Beijing].

In order to study the distribution characteristics and pollution status of antibiotic resistance genes (ARGs) in the vegetable soils, greenhouse and field soil samples in 11 organic vegetable bases with long-term manure amended in Beijing were collected. All samples were subjected to the determination of 13-type antibiotics and related ARGs. The experimental results showed that tetracycline residues were the highest among all antibiotics tested, followed by sulfanilamides.

Performance of biotrickling filters for hydrogen sulfide removal under starvation and shock loads conditions.

In the industrial operation of biotrickling filters for hydrogen sulfide (H(2)S) removal, shock loads or starvation was common due to process variations or equipment malfunctions. In this study, effects of starvation and shock loads on the performance of biotrickling filters for H(2)S removal were investigated. Four experiments were conducted to evaluate the changes of biomass and viable bacteria numbers in the biotrickling filters during a 24-d starvation.

[Treatment of mix gas containing butyl acetate, n-butyl alcohol and phenylacetic acid from pharmaceutical factory by bio-trickling filter].

The bio-trickling filter packed with ZX02 stuffing is used to treat the mix gases containing butyl acetate, n-butyl alcohol and phenylacetic acid(BBP), which are discharged from Penicillin workshop of Pharmaceutical Factory. The reactor was operated for 110 days to investigate the effect of influent load, retention time and spray water on the removal of BBP and the biodegradation characteristics. The reactor displayed preferential utilization of BBP, when the maximum influent load of BBP were 229.