Papers by Keyword: Immobilised

Abstract: The upflow anaerobic immobilized microbe reactor of the anaerobic ammonium oxidation process (ANAMMOX) was used in treatment of high nitrogen concentration organic wastewater, which was made to study the effect of synergistic nitrogen removal by ANAMMOX–denitrification. The experimental results showed that the mass concentrations of NH ₄⁺-N and NO － 2-N in the influent had no obvious influence on the synergistic nitrogen removal in opportune range. When the mass concentrations of NH ₄⁺-N and NO_－2-N in the influent were kept at 301-800 mg/L, the removal rates of NH ₄⁺-N, NO_－2-N and TN were 93.3 %, 98.6 % and 90.3 % respectively. When the influent COD was kept at 800-850 mg/L, COD had almost no influence on the synergistic nitrogen removal, and the removal rate kept at 95.7％. Meanwhile, the characteristic changes of NO_－3-N, N₂, pH value and organism proved that the synergism was in a good state. Introduction

Abstract: TS-1 monolithic catalysts were prepared on cordierites honeycomb ceramics supports by dip-coating method in TS-1/H₂O suspension. The cordierites honeycomb ceramics supports were treated with different methods, such as coated with a thin layer of sodium silicate, immersed in 0.5N hydrochloric acid. The monolithic catalysts were characterized by Scanning Electron Microscopy. The distribution of TS-1 Catalysts onto supported was observed. The immobilized stability of TS-1 monolithic catalysts was evaluated by ultrasonic cleaning and washing out experiment. TS-1 catalysts were uniformly deposited onto inner smoothed surface of cordierites honeycomb ceramics supports, which ware coated sodium silicate film. And experiment data proved that TS-1 catalysts may be firmly immobilized onto supports coated sodium silicate.

Abstract: Nanometer barium-stroutium titanate immobilized on aluminum oxide (ABST) was prepared by the citric acid sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometry (FTIR). Its Pb2+ and Cd2+ adsorption properties from water were studied. Adsorption and elution were investigated under different conditions. The results showed that the nanometer barium-strontium titanate was immobilized on aluminum oxide firmly, becoming a composite adsorbent. The lead and cadmium ions were quantitatively retained at pH 5-8; their adsorption capacities of ABST were 70.28 mg•g－1 and 8.12 mg•g－1, respectively. The adsorbent of adsorped lead and cadmium ions were regenerated completely by elution with 1 mol•L－1 HNO3. The adsorbent had a promising prospect in analyticl chemistry and water treatment.

Abstract: An thin reagent containing optochemical film sensor for detecting and measuring free chlorine in water is described. The film sensor has been manufactured by immobilisation indicator of 3,5-dimethyl-4-hydroxybenzaldazine in a permeable transparent polymeric membrane. A linear calibration for free available chlorine can be obtained in the range between 0.05 and 3ppm. The limit of quantitation is 0.3 ppm, and the accuracy exceeds 7%. It takes about 150s to measure the relatively low occupational exposure concentration of 0.1ppm. The interference of combined chlorine has been studied. The sensor has no response to combined chlorine. And the stability of the sensors and the effect of external parameters like relative humidity (RH), temperature on the sensor response have been investigated. The sensor response is affected by varying the temperature; however, humidity in the range between 0 and 90% RH does not affect sensor response. The 3,5-dimethyl-4-hydroxybenzaldazine remained stable inside the polymeric film and no chemical reaction, crystallization or leaching occurred during 6 months of observation. Proper choice of indicator dye and polymeric material and successful application of kinetic evaluation method for the exposure experiments determine the desired features of the sensor. Introduction