Advanced Materials Research Vols. 610-613

Abstract: Activated carbon and wood chips were applied respectively as packing material of bio-trickling filter and bio-filter which composed the compound bio-filter and the effect of different operating parameters on NO_x removal efficiency were studied. The results show that the best operating conditions of the compound bio-filter are: NO inlet concentration 604.5 mg/m³, spray volume 1.2 L/h, gas flow 0.6 m³/h(empty bed residence time 103.7 s).In such cases,NO_x removal efficiency is over 96% and NO_x removal load of the packing material is 29.66 g/(m³•h) . The remove of NO_x is mainly completed by the packing layer of 0~50 cm height both in the bio-trickling filter and in the bio-filter, that is to say ,when the total packing layer height of the compound bio-filter is 100 cm, the purification effect is ideal and economical; The system can return to normal in about 7 hr when the dynamic load changes largely and suddenly, showing that it has strong anti shock load capacity.

Abstract: Two aquatic macrophytes (Monochoria korsakowii and Alisma plantago-aquatica) were grown in monoculture to test the relative growth rate(RGR) and abilities of removing total nitrogen(TN) by the manipulative indoor experiment. A nutrient treatment consisted of two levels of nitrogen[ low (14 mg L-1 N) and high (56 mg L-1 N) ]of nutrient solution. Result revealed that the RGR of the species was significantly different, however nutrients had no significant affect on the RGR. The results showed that TN in wastewater were significantly higher from unvegetated microcosms compared to vegetated. M. korsakowii was shown to be best removal effect with the removal rates of 94.9% and 77.0% at low and high concentrations of TN.

Abstract: As a new finding disinfection by-product (DBP), N-nitrosodimethylamine is becoming research focus for its high carcinogenicity. Some pretreatment technologies of drinking water such as activated carbon adsorption, enhanced coagulation, chemical oxidation, biological oxidation, advanced oxidation were summarized. As shown above, the control effect of process of NDMA and its precursors were analyzed.

Abstract: The adsorbent was prepared from peanut shell by using Zncl₂ as activating agent, copper in aqueous solution was used as the adsorbate, the influence of pH, adsorbent dosage, temperature, contact time were investigated through dynamic tests. Then the kinetics of modified peanut shell was studied. The results showed that the modified peanut shell had maximum adsorption efficiencies when the pH was 6; the dosage was 0.2g; the temperature was 25°C and the contact time was 12h.By substituting experimental data into kinetics models, quasi-second-order kinetics model could better describe the kinetics of modified peanut shell adsorbing Cu²⁺.

Abstract: C, N, S co-doped ZnO/ZnS composites were prepared by hydrothermal method using ZnSO4 and L-cysteine as raw materials, and investigated by UV-vis DRS, XRD, XPS. The results showed that C, N, S have successfully doped onto ZnO and substituted O of crystal lattice during hydrothermal process. The resulting co-doped ZnO composites exhibit significantly higher photocatalytic activity (45%) than that of pure ZnO (<5%) for degradation of reactive brilliant blue KN-R aqueous solution under simulative solar irradiation. The enhancement of photocatalytic performance of co-doped composites can be attributed to the reducing of electron-hole pair recombination and narrowed band gap.

Abstract: Streptomyces albidoflavus Z2 was immobilized in polyurethane foam and its ability to degrade nitrobenzene was investigated. Batch experiments showed that polyurethane-foam-immobilized cells (PFIC) possessed a higher degradation capacity. Compared to freely suspended cells (FSC), PFIC degraded nitrobenzene more efficiently under alkali and acid conditions, as well as higher temperature. Kinetic of nitrobenzene degradation by PFIC was well described by Andrews inhibition equation, which demonstrated that PFIC tolerated higher concentration of nitrobenzene than FSC and degraded nitrobenzene at a quicker speed. Moreover, in the presence of NaCl (≤7%, w/v), phenol (≤250 mg L-1) and aniline (100 mg L-1), respectively, PFIC exhibited better tolerance toward salinity and toxic chemicals than FSC. Therefore immobilization could be a promising method for treating nitrobenzene industrial wastewater.

Abstract: To explore the deposition mechanism of check dam and provide the basis for layout of dam system, with tracing technology of caesium-137 and local rainfall data, the siltation time of each cyclic in the profile of south ditch check dam are confirmed based on the rule of heavy rain on large sand. Then regression analysis of sediment volume with the four indexes of erosive rainfall (R, I30, P and I) are made, the results show the first three indicators are main factors causing soil erosion. Furthermore, the model predicting sediment yield of the watershed is made by multiple regression analysis of sediment deposition with the three main factors. Finally, the neural network of RBF and BP are respectively applied regarding the three main indexes as input vectors to predict siltation and fit with actual value to testify what the model built is right.

Abstract: In order to reveal the exhaust pollutant statistical characteristics of in-use passenger cars, by the technical means and methods of large sample detection, multiple parameter data analysis and mathematical modeling, the unburned hydrocarbon emission statistical characteristics of typical passenger cars have been researched, the statistical characteristics of the emission have been revealed, the high precision statistical models which can describe the statistical characteristics have been established fatherly. Checking computation showed that the calculating results got by the models have very high calculating precision. On the basis of above-mentioned researches, the specific proposals have been put forward to revise the relevant limit values of Chinese national standard about in-use passenger cars exhaust pollutant, and I/M program should be enforced in order to control the exhaust pollution of in-use passenger cars efficiently.

Abstract: The low concentration Chromium (Ⅲ) adsorption was studied by 4 biosorbents (TP, XB, MY and TQ), which were isolated from Chrome-tanned leather construction section sludge. Batch experiments were carried out to investigate the effect of contact time, solution pH, biomass dosage, initial concentration of copper and temperature on biosorption efficiency. The experiment results showed that the concentration of chromium (Ⅲ) could meet the national standard (≤1.5mg/L) after treatment. The optimal pH value, mass concentration and temperature of biosorption was 4.0, 0.5g/L and 30°C, respectively. When the biosorbent were treated by [ NaOH ]= 0.3 mol/L, absorption capacitie was increased by 34.54%、23.21%、17.86% and 38.96% respectively. And from the results of SEM (Scanning electron microscope) and FT-IR (Fourier Transform infrared spectroscopy), the structure and functional groups of biosorbents was changed after the biosorption.

Abstract: MSWI (municipal solid waste incineration) fly ash during the high-temperature treatment was a chemical reaction process system of multiphase-component systems. The thermodynamic Equilibrium of the MSWI fly ash was simulated by the part of equilibrium composition of the chemical thermodynamic calculation software HSC-Chemistry 6.0. The characteristics of heavy metals were analyzed basing on the results of simulation in a certain temperature range under different working conditions.