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MnOx/wasted rock dust catalyst (WZ01) and modified wasted rock dust catalyst (WZ02) were prepared by impregnation method and hydrothermal method as the wasted rock dust (WRD) generated in stone processing plants was used as carriers. The structure of the two catalysts were characterized by energy dispersive spectrometer (EDS), X-ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). Their removal efficiencies and reaction mechanisms of oxalic acid were compared and analyzed, which could provide an innovative perspective for catalytic efficiency improvement and cost reduction. The results showed that the WRD contained O, Si, Al, K, Mg, Fe, Ca and Na elements. Mn was amorphous in WZ01 and loaded on the surface of WRD, and Mn was in the form of orthorhombic Mn2O3 in WZ02. WZ02's surface morphology showed obvious changes and was wrinkled with many microchannels. The specific surface area, total pore volume and average pore size of WZ02 had been improved. After 30 minutes of reaction at room temperature, the removal efficiencies of oxalic acid with an initial concentration of 500 mg·L-1 were 40.6% and 54.6% by using WZ01 and WZ02 as catalysts with catalyst dosages of 2 g·L-1 and O3 concentration of 4.92 mg·L-1, respectively. The removal efficiency of oxalic acid decreased greatly after WZ01 recycling and Mn, which acted as active components, was massively washed out. The removal efficiency of oxalic acid was stable after WZ02 was triply recycled as only a small amount of Mn was washed out. The removal efficiency of oxalic acid reduced after tert butanol was introduced into the two reaction systems, and a large amount of •OH was detected by using coumarin fluorescence technology. The removal of oxalic acid by WZ01 and WZ02 catalyzed ozonation were achieved by the combination of adsorption and hydroxyl radical reaction.

Mesoporous CeO2 was synthesized by a sol-gel method using the biological renewable microcrystalline cellulose (MCC) as the template and Ce(NO3)3•6H2O as the precursor of CeO2. XRD, TEM, N2 adsorpti...

Ca

C27H33CoMo4N21O19, triclinic, P1̄ (no. 2), a = 12.1200(6) Å, b = 13.0412(6) Å, c = 15.7235(7) Å, α = 103.800(1) o , β = 98.427(1) o , γ = 110.278(1) o , V = 2191.08(18) Å3, Z = 2, R gt(F)=0.030, wR ref(F 2)=0.073, T = 296 K.

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

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. The concentration of airborne bacteria was higher in layer house, whereas concentration of antibiotic resistant bacteria was higher in broiler house. Tetracycline and erythromycin resistant bacteria were detected from the atmospheric environment from out door of layer and broiler house with the percentages of 8.81%, 15.89% and 23.19%, 36.53%, respectively. The size distribution and aerodynamic diameter varied from inside and outside of pig, cow, and layer and broiler house. Most of tetracycline resistant bacteria and erythromycin resistant bacteria from current four types of animal feeding operations mainly deposited in pharynx, larynx and bronchus of respiratory system. This study would offer the base data for evaluating the detriment of bioaerosol from animal feeding operations to the worker and environment.

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. Antibiotic residues were higher in greenhouse soils than in field soils. For all soil samples, sulfanilamide resistance genes

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

In order to achieve the simultaneous denitrification and dephosphorization from wastewater, the effect of SRT on denitrifying dephosphorylation process was investigated for a long time by using an anaerobic/anoxic sequencing batch reactor (A2SBR). The results showed that when SRT was controlled at 20 days, removal efficiency of PO43--P was kept at high value and it was higher than 90%, and removal efficiency of NO3--N and COD was 90.3% and 80.4%, respectively. A2SBR process can be operated steadily by using a periodical operation mode of 10min feeding, 2.5 h anaerobic and 3.5 h anoxic followed by 10 min aerobic, 90 min setting and 10 min withdraw. The whole system shows a good performance of denitrification and dephosphorization under a steady operation.

A SBR was used to treat power plant sewage based on SND when pH, DO(dissolved oxygen),MLSS, were 7.0-8.0, 0.5-1mg/L, 3000±200mg/L, respectively. Results indicated average removal efficiency of COD and NH4+-N were 89% ,96.34%.Because of low COD/ NH4+-N, average removal efficiency of TN(total nitrogen)was only 71.15%, effect of SND was not apparent. After improving COD/ NH4+-N by adding carbon source intermittently, removal effects of COD and NH4+-N were not reduced, and effluent NO3--N and NO2--N was not accumulated, average removal efficiency of TN was 95%, and efficiency of SND was enhanced obviously. The effluent of system was recycled effectively. It indicates that SBR based on SND is feasible in theory and technology which is applied to treat power plant sewage.

The second-order nonlinear optical (NLO) properties of a series of the polyoxometalate (POM)-spiropyran derivatives have been studied by using quantum chemical calculations. The photochemical reaction of spiropyran compounds will produce two different species, spiropyran and merocyanine. The merocyanine species has a large second-order NLO responses because of its good π-conjugated character. And thus a large contrast of the first hyperpolarizability has been obtained. According to quantum chemical calculation, this photo-triggered switchable effect derived from the spiropyran-merocyanine conversion has been enhanced because of introduction of the POM unit. Meanwhile, the substituted effect of the POM species also has been considered in this work. It can be found that introduction of the electron donor/acceptor group into the POM derivative does not significantly affect the magnitude of the first hyperpolarizability.

The potassium permanganate chemicals (PPC) was used to enhance the chroma removal of the typical raw water in northeast China. Two dosing points were investigated for PPC application and the optimized dosing point and an optimized dose of 0.5-1.5 mg/L were determined. The results showed that the PPC could solve the problem of chroma residual. The turbidity and CODMn removal were also increased. The PPC was a good alternative of polyacrylamide as coagulation aid and could save some cost.

The nanocomposite membranes were prepared by mixing 2.5 wt% of TiO2 nanoparticles in casting solution. In order to determine the nanocomposite membrane property, a long-term operation of membrane bioreactor (MBR) was carried out and membrane flux were measured though the filtration tests. Results showed that TiO2 addition significantly improved the permeability of membrane and decreased the cake resistance compared with the sulfonated polyethersulfone (SPES) membrane in MBR.

In this study, a sequencing batch reactor (SBR) was used to treat synthetic wastewater when dissolved oxygen (DO) concentration and temperature were 0.5-1.0mg/L and 30±1°C, respectively. Effect of sludge loading(Ns) on simultaneous nitrification and denitrification (SND) was investigated. The results indicated that removal efficiencies of ammonia nitrogen (NH4+-N), COD and total nitrogen (TN) were all higher than 90%, respectively, when influent NH4+-N and Ns were 35-45mg/L, 0.15kgCOD/(kgMLSS•d) under 7 hours of aeration time and 1 hour of idle time, respectively. Therefore, the SBR has obviously achieved simultaneous nitrification and denitrification.

In order to investigate the effect of MLSS on the denitrifying dephosphorization process, a lab experiment was carried out by using an anaerobic/anoxic sequencing batch reactor (A2SBR) for a long time. The results showed that when MLSS was maintained at 2500-3500mg/L, removal efficiency of PO43--P was kept high value and it was higher than 90%.

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. Compared to biomass, viable bacteria numbers decreased significantly during the starvation, especially when airflow was maintained in the absence of spray liquid. During the subsequent re-acclimation, all the bioreactors could resume high removal efficiencies within 4 d regardless of the previous starvation conditions. The results show that the re-acclimation time, in the case of biotrickling filters for H(2)S removal, is mainly controlled by viable H(2)S oxidizing bacteria numbers. On the other hand, the biotrickling filters can protect against shock loads in inlet fluctuating H(2)S concentration after resuming normal operation. When the biotrickling filters were supplied with H(2)S at an input of lower than 1700 mg/m(3), their removal efficiencies were nearly 98% regardless of previous H(2)S input.

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 229.5g/(m3 x h), 275.4 g/(m3 x h) and 42.5g/(m3 x h), the removal efficiencies were 96%, 95% and 100% respectively. The results show that the bio-trickling filter can effectively treat the mix gases and the optimum parameters were as followed: retention time was 31.2 s, the volume of spray water was 4 L/(L x d). The bio- trickling reactor has strong ability to resist shock of high influent load and resistance is maintained at low value, what's more, it doesn't need to carry out back washing frequently. With all these advantages it can be operated steadily for long time.