Advanced Materials Research Vols. 864-867

Abstract: The combined photocatalysis and ozonation (UV/Ag-TiO₂+O₃) process has been investigated for its potential use for ballast water treatment by using Dunaliella salina (D. salina) as an indicator microorganism. Inactivation curves were obtained, and the mechanism was studied. Compared to individual unit processes, the combined UV/Ag-TiO₂+O₃ tests yield enhanced inactivation efficiency. Scanning electron microscopy (SEM) measurements showed that presence of O₃ during UV/Ag-TiO₂ exposure expedited the destruction of cell structure, which was further confirmed by the formation of malondialdehyde (MDA) and decrease in chlorophyll-a (chl-a) concentration. The results suggest that UV/Ag-TiO₂+O₃ was efficient for inactivation of D. salina in simulated ballast water, and the accelerated destruction of cell structure was an important reason for the enhanced inactivation efficiency.

Abstract: The membrane bioreactor (MBR) systems have been actively employed for municipal and industrial wastewater treatments. However, membrane fouling is one of the main obstacles that restrict MBR to wide application while soluble microbial products (SMP) are known as major foulants. The paper reviewed the effect of temperature on SMP in MBR systems. At the end, the future trends in the effect of temperature in the coming years were addressed. It will be conducive to further application of MBR in the future.

Abstract: Two aquatic macrophytes (Lythrum salicaria and Alisma plantago-aquatica) were grown in monoculture to test the relative growth rate (RGR) and abilities of removing total phosphorus (TP) by the manipulative indoor experiment. A nutrient treatment consisted of two levels of phosphorus [ low (3 mg L^-1 N) and high (12 mg L^-1 N) ] of nutrient solution. Result revealed that nutrients had significant affect on the RGR, however the RGR of the species was non-significant. The results showed that TP in wastewater were significantly higher from unvegetated microcosms compared to vegetated. L. salicaria was shown to be best removal effect with the removal rates of 81.7% and 91.1% at low and high concentrations of TP.

Abstract: To research the composition and proportion of the denitrying bacterium in denitrification tank and increase the nitrogen removals rate. With the purpose of explore the curve between the amount of different denitrying bacterium and the quality of water treating, then find out the optimum of the species of nitrogen removal bacteria and the amount of the specific type of microorganism in the denitrification tank of metal membrane bioreactor at the optimized conditions of the water treating effects. The fluorescence in situ hybridization (FISH) approach is applied in this research, to set a preliminary study on the space-time character of denitrification bacteria population structure in denitrifical tank.

Abstract: The coupling decoupling control system was presented to realize the requirement of the flue gas desulfurization (FGD), to solve the multivariable control problem in this process control system. The FGD experiment control system was designed, the spray flow was controlled by manual and automatic control mode. After the process control flow and the coupling decoupling control principle were studied, the feed-forward compensation control method was simulated. Results show that the decoupling control method could solve the multivariable control problem, with a good anti-interference capacity, meeting the requirement of FGD process control.

Abstract: Hydraulic loading rate (HLR) is an important operational parameter for constructed wetland to purify wastewater. In this paper, it is the main objective to select the optimal parameter of HLR. During the four HLRs (i.e., 6 cm/d, 12 cm/d, 24 cm/d and 48 cm/d) operation period, six days were used as one stage. The experimental results showed that the best average removal rates of COD_cr (59.7%) and NH₃-N (89.4%) were at the HLR of 6 cm/d. In the meantime, the best average removal rate of total phosphorus (TP, 50.0%) was at the HLR of 24 cm/d. According to the low influent TP concentration, it is suggested that the HLR of 6 cm/d should be used in the multi-stage constructed wetland.

Abstract: Shortcut Nitrification-Denitrification Simultaneous Phosphorus Removal applying in sequencing batch reactor were achieved successfully by Changing the run mode of SBR and controlling the operating conditions. When the MLSS:4700mg/L, PH:7.5~8.0 and DO:0.3~0.5mg/L(Aerobic phase), the removal rate of TP was more than 98%, the nitrite accumulation rate was more than 85%. After the reaction period of Shortcut Nitrification-Denitrification simultaneous Phosphorus Removal, the concentration of NH₄⁺-N was below 50mg/L and the concentration of TP was less than 0.5mg/L.

Abstract: This paper presents the adsorption behaviors of humic acid (HA) on coal ashes and powdered activated carbons (PACs). A bituminous coal, with or without calcium-loading, was used as a feedstock for coal ash preparation. The working solution of HA with a concentration of 20 mg/L was used in all adsorption tests. The results showed that calcium-enriched coal ash (CECA) gave rise to the removal rate of HA as high as 84.05%, much higher than those of raw coal ash (RCA) and PACs. The impacts of solution pH and adsorbent dosage on HA adsorption capacity were also investigated. It was found that lower pH facilitated to the removal of HA from aqueous solution by means of CECA, and the optimal CECA dosage was about 1.0g/L at pH 7.00. The data obtained in this study suggested that calcium-enriched coal ash could be useful and cost-effective in the treatment of wastewaters containing HA-like organic macro-molecules.

Abstract: In this paper, magnetic beads were separated from two different power plants fly ash by magnetic separation, and the separated magnetic beads were analyzed by XRD. In a self-built fixed-bed system, the experiments that magnetic beads from two power plants, α-Fe2O3 and γ-Fe2O3 affect formation distribution of mercury in flue gas were carried out. The results showed that the magnetic beads in fly ash have a certain capacity to oxidize the mercury in flue gas, and the γ-Fe2O3 has greater influence on the species distribution of mercury than α- Fe2O3.

Abstract: This paper mainly studied the removal of Hg by biomass activated carbon in the simulated flue gas. Biomass activated carbon of different materials were made through the control of activator concentration, activation temperature in the self-developed biomass preparation system. In the fixed bed system, the flue gas Hg removal efficiency of activated carbon samples were evaluated. The experimental results showed that the adsorption performance of biomass activated carbon was not proportional with the change of the activator concentration and activation temperature, the overall trend was firstly increased and then decreased.