Advanced Materials Research Vols. 374-377

Abstract: China is an arid country, but leakthrough phenomenon is widespread in chinese architecture, which resulting in invalid water supply and the waste of water resource. The structure of this device is simple and the effect is obvious.Its working principle is to use the pressure difference between the waterproof plugs to store a certain big amount of flow by accumulating the small flow which can not be measured,.Making the micro-flow of water be the discontinuous high flow which can be measured by water-flowmeter,so as to achieve accurate measurement of micro-flow. In addition, the device is precise and the flow losses and head losses are small, having a strong practical applicability.As an innovative product ,it has many superiorities such as no energy, low cost and so on.

Abstract: Based on the monitoring data of February~December 2009 from Xinxue River Constructed Wetland, the regression analysis theory was used to establish mathematical models to determine the correlationship among the removal rate of pollutants, pollutant concentration, water temperature and influent water inflow, and optimize the operation parameters of the wetland. The multivariate linear regression equation was established with Statistical analysis software (SPSS). According to the correlation coefficient of the equation: the NH3-N removal has a significant positive correlation with water temperature, and a significant negative correlation with influent flow, total nitrogen removal has a significant positive correlation with water temperature, COD removal has a significant positive correlation with COD influent concentration. In addition, veracity of the model was also checked by contrasting the measured and analog data of March~June 2010 from the wetland. The results show that this model has a desired effect to estimate the removal rate and effluent concentration of COD and NH3-N, but undesirable to total nitrogen.

Abstract: Polyacrylamide-urea-sulfanilamide(PUS) was prepared as a novel heavy metal ions chelator and successfully used to simultaneously remove heavy metals from wastewater effluents. The effects of reaction parameters (sodium hydroxide, material ratio, temperature and contact time) were monitored to specify the best synthesis conditions. PUS was chemically characterized by means of infrared spectroscopy (FTIR). The simultaneous chelation performance of PUS towards selected heavy metals ions, nickel, copper, lead, cadmium and zinc, was discussed, and Ni2+, Cu2+, Pb2+, Zn2+ can be chelated better especially, indicating that the synthesized PUS is a potential remediation material when used for the treatment of wastewater containing metal ions.

Abstract: In this article, Vertical A/O-MBR was used as the experimental device to study membrane fouling through dosing cylindrical rigid suspended fillers, and the best conditions for membrane fouling control and effluent quality with fillers was discussed. Results showed that the critical flux zone decreased. When the MLSS was 5g/L and the suspended fillers dose was 1%, 5%, 10%, respectively, TMP increased rapidly with the quantity, greater quantity of fillers speeded up the membrane fouling process, and in small quantity membrane fouling had some delay action. The best dosing of fillers was determined as 7% in the condition of MLSS=5g/L, and the effluent quality was good.

Abstract: Anoxic/Oxic Membrane Bioreactor (A/O-MBR) was used to treat domestic sewage, the effect of different sludge retention time (SRT) on nitrogen removal and the sludge properties were investigated. The results indicated that the change of NH3-N removal increased gradually with the SRT extension, then basically tends to be stable. The systematic elimination effect of TN rises with the SRT extension and then slightly tends to decrease. MLVSS/MLSS presents a gradually declining trend with the SRT extension. Sludge volume index (SVI) reduces along with the SRT extension according to the exponential decay tendency, but sludge sedimentation rate (SV₃₀) increases progressively by two step multinomial tendency.

Abstract: Vertical Anoxic/Oxic Membrane Bioreactor (A/O-MBR) was used to treat domestic sewage. PVDF hollow fiber membrane has been used in MBR. According to the comparison of intercommunity between three non-Newtonian fluid models (Bingham model, Ostwald model and Herschel-Bulkley model) and the test data, the Ostwald model was chose to describe the function relationship between shear intensity and aeration amount. In order to initiating a circulation velocity and to enhancing the scour to the MBR, the traditional aeration method was changed in this experiment. Two baffles were placed on both sides of the membrane modules, and aeration heads were scattered between two baffles. The influence of shear intensity and new aeration method to membrane fouling was investigated in this paper at shear intensity of 20s^-1, 40s^-1, 60s^-1 and 80s^-1. The result shows that the stronger shear intensity is, the heavier is the MBR been scoured and the smaller is the change of TMP. The best shear intensity was G=60s^-1 after considering all factors comprehensively. Finally, the membrane modules were analyzed by scanning electron microscope (SEM). By the SEM pictures we can see that there are some spots on the membrane surface which deposited by fine grains, EPS and SMP. The spots have different size and location, large scale or compact contamination layer can not been found in the pictures. So it indicates that the changing of aeration method and the controlling of shear intensity has a positive impact on slowing down the membrane fouling.

Abstract: ZnO2 nanorods were synthesized via hydrothermal treatment of 2ZnCO3•3Zn(OH)2 powder in 30 mass% H2O2 aqueous solution at 170 °C for 12 h, and characterized by means of X-ray diffraction, transmission electron microscopy and UV–vis diffuse reflectance spectra. Besides, the photocatalytic activity of the as-synthesized ZnO2 nanorods was tested for the degradation of methyl orange in distilled water under UV light irradiation.

Abstract: Removal of fluoride from drinking water using magnesia-amended activated carbon (MgO-AC) was investigated. The MgO-AC was characterized scanning electron microscope (SEM). Attempts were made to fit the isothermal data using Langmuir and Freundlich equations. The experimental results have demonstrated that the equilibrium data are fitted well by a Langmuir isotherm model and the maximum sorption capacity of fluoride evaluated is 7.22 mg/g. Thermodynamic parameters of ∆G0, ∆H0 and ∆S0 show that the adsorption is a spontaneous and endothermic process.

Abstract: Using fluorescence and optical monitoring techniques, the process of coagulation of natural humic acids (HA) was studied paying attention to the interaction of aluminium and HA. Experiments were conducted using a jar tester equipped with a PDA2000 monitoring device for online monitoring of the Al-humic coagulation process. After flash mixing, slow mixing and settling, the supernatant was collected for fluorescence analysis to measure the concentration of residual aluminium which has not reacted with HA molecules. The process of aluminium hydrolysis was also studied by online monitoring of the formation of ‘alum flocs’ in a solution free from HA. Electrophoretic analysis and TOC measurement were conducted respectively for evaluating the condition of charge neutralization and HA removal. On this basis, the mechanism of Al-humic coagulation was discussed. It can be concluded that at pH 5, charge-neutralization and co-precipitation is the main mechanisms of coagulation, while at pH 7 the main hydrolyzed species are precipitated aluminum hydroxides so that sweep flocculation becomes the main mechanism of coagulation as well as overdosing at pH 5.0.

Abstract: The application of solar energy technology is of vital significance to the development of China’s residential housing. As one kind of renewable energy source, solar energy has its advantages and distinct defects at the same time, thus, the application of such source is greatly limited. In China, an issue with realistic significance is reducing the cost of total energy consumption through solar energy to achieve the purpose of energy saving and emission reduction.