Advanced Materials Research Vols. 356-360

Abstract: _{Subscript text}The degradation of Reactive Brilliant Blue KN-R by NaNO₂/Fe³⁺/O₂ system was evaluated. The optimal conditions of dye degradation by the NaNO₂/Fe³⁺/O₂ system were: reaction temperature 150°C, oxygen partial pressure 0.5Mpa, pH 3.0, Reactive Brilliant Blue KN-R /NaNO_{Subscript textSubscript text}2/FeCl₃ (mole ratio) equal to 1:2:0.2.Under the optimal conditions, the removal rates of color 、COD and TOC were 100% 、64% and 52%, respectively.

Abstract: Br-impregnated activated carbon for gas-phase elemental mercury adsorption experiments were carried out at a fixed-bed system to get the suitable mass fraction of KBr impregnation solution. Hg removal efficiency of 1% wt KBr-ACs was 69.0%, while that of 10% wt KBr-ACs was 57.9%. Both of them were higher than that of the raw activated carbon, 42.2%. The removal efficiency of Hg⁰ was not proportional to bromine concentration. Under 80-180°C, Hg removal efficiency of 1% wt KBr-ACs were 68.3%-71.8%, and at 140°C it reached the highest due to the increasing chemical adsorption ability of the functional groups which was on the surfaces of activated carbons by impregnating. At 160°C, Hg removal efficiency was lower than that at 140°C due to desorption making physical adsorption decrease, so that the total adsorption decreased.

Abstract: In this paper, fly ash samples were collected from a coal-fired power in Shanghai. A series of experiments, including unburned carbon testing, mercury content measurement, SEM analysis, specific surface area, average pore size and pore volume test, were conducted, and the adsorption ability of the fly ash on the flue gas mercury was also experimentally studied. It has shown that fly ash with particle size bigger than 100µm is with the highest adsorption efficiency, 67.83%, and that fly ash with particle size smaller than 25µm is with the smallest adsorption efficiency, 13.67%. The relative mechanism was analyzed.

Abstract: Ferric chloride (FeCl₃) and polyacrylamide (PAM) are used as flocculant and coagulant aid for treating the dredging wastewater from Chongqing Liangtan river. The effects of dosages of flocculant and coagulant aid on removal rate of turbidity, suspended solid (SS) and COD were investigated. The effects of Zeta potential and particle size distribution on treating performance were also discussed. It was found that the optimal flocculation performance was achieved when the absolute Zeta potential approached zero. Lower dosages of flocculant and coagulant aid were needed when the average particle size of SS in dredging water was smaller.

Abstract: Removal of phenol from aqueous solution by a new emulsion liquid membrane (ELM) system and its heat-induced demulsification have been investigated. The ELM consists of commercial kerosene as organic solvent, OP-4 as surfactant agent, hydrochloric acid as the stripping phase. Effect of different operating parameters such as internal phase concentration, surfactant concentration, stirring speed, PH value in external phase, volume ratio of membrane phase to internal phase and volume ratio of membrane phase to external phase were investigated for the removal of phenol from aqueous solution. At the optimum condition about 95.7% phenol is removed in less than 20min of contact time. The demulsification efficiency was investigated under different temperature and time and proved to be high at 80°C.

Abstract: The influencing factors on radon emanation rate of uranium tailings storehouse, migration mechanism, theoretical research of the radon emanation and research status of radonmetry were introduced. Reasonable measurement, network, sampling time and measuring times are very necessary to the measurement of radon emanation rate of uranium tailings. Combining numerical simulation, physical experiment simulation and field test, put forward reasonable management standards for decommissioning uranium tailings.

Abstract: Sequencing batch biofim reactor (SBBR) can remove nitrogen by simultaneous nitrification and denitrification in the biofilm. Based on the relationship between the degradation of COD, NH3-N and ΣN in wastewater and the variation of DO, ORP and pH, the results showed that when DO and ORP rapidly increased and reached a platform (DO and ORP turning point) and pH value rapidly decreased and approached the lowest value (pH turning point), the NH₃-N and ΣN reduced to minimum. Utilizing DO, ORP and pH turning points as on-line controlling points to stop aeration ensured NH₃-N completely removed and the lowest ΣN. The effect control of aeration time could save energy.

Abstract: The effect of TCE cometabolism degradation with glucose as electron donor on reduction progress was investigated with enriched nitrate, sulfate, trivalent iron and their mixtures under anoxic or anaerobic conditions. The removal effect of TCE was found to be better in anoxic environment; TCE degradation was inhibited by the addition of trivalent iron salts and the mixed salts under anoxic condition or strongly inhibited by nitrate under anaerobic condition; promoted by the addition of trivalent iron salts under anaerobic condition; little inhibited by the addition of nitrate and sulfate under anoxic condition or sulfate and the mixed salts under anaerobic condition.

Abstract: Polyethylene film destruction by mixed culture of microorganisms was studied. The initial culture was adapted for growth on the media with ion exchange resin. During cultivation of the microorganisms on the mineral media with a polyethylene as the only source of carbon and energy the increase of film roughness and decrease of amorphous fraction and crystal size was detected. Using atomic-force microscopy and scanning electron microscopy it was found the film reduce to the crystals of micron size and unilamellar crystal fragments. The film relief change and crystal size decrease was detected after contact with oil-oxidizing bacteria and after composting with plant residuals with redworm Eisenia foetida.

Abstract: The Visual MODFLOW has been used in this paper for modeling an opencast mine groundwater. Its sub model MODPATH and MT3D have been used for particle tracking and plume simulation .The simulation results are very useful to identify the contaminated sources of the opencast mine and contaminated solutes transport paths .These results provide the decision support not only for predicting the underground water level and quality variation ,but also for selecting monitoring system and protecting measures.