Advanced Materials Research Vols. 113-116

Abstract: This study discusses the hydrogen-producing properties of continuous stirred tank reactor (CSTR) after inoculating the Biohydrogenbacterium R3. Biohydrogenbacterium R3 grow well and produce H2 stably at temperature of (35±1)°C and HRT of 6 hours. In this study, the optimum range of pH is 4.5~4.6. The amount of biogas production and H2 content maintained at 3.4 L and 47%, respectively. The main liquid end products are ethanol and acetic acid. Dry cell weight changes showed wavy. COD removal is about 16%～18%.

Abstract: Removal of nitrate from groundwater was investigated using biodegradable snack ware (BSW) as carbon source and biofilm carrier. The experimental results show that low temperatures affect significantly denitrification efficiency using BSW as carbon source. Denitrification rates at 5 0C and 10 0C were 5 % and 13 % of rates observed at 30 0C, respectively. Denitrification supported by BSW could tolerate a relatively wide range of variation of pH and DO in the influent. Nitrite concentration in the effluent had little difference when pH value ranged from 4.5 to 8.5 in the influent. When DO concentration was between 0.9 and 5.0 mg/L, NO2-N concentration in the treated water never exceeded 0.15mg/L.

Abstract: In this experiment, the effects on improve of flux and prevention of membrane from fouling was studied. The results demonstrated that after backwashing, the flux was completely recovered by addition of 4mg/L and 10mg/L（as Al）, while the flux was only 40% of initial flux without coagulation pretreatment. It was also found that whether or not prevention of fouling by coagulation was depended on the characteristics of cake layer formed on membrane surface during membrane filtration. In the presence of filtration of coagulation floc suspension, coagulation could form cake layer on membrane surface, thus prevent membrane from fouling effectively, while in the presence of filtration of supernatant, fouling was occurred due to cake layer comprising small, neutral, hydrophilic compounds, which can not removed by backwash.

Abstract: The aim of this study is to investigate the denitrification efficiency enhancement and to evaluate the denitrification potential at the condition of lower temperature. Three identical biofilter were operated in parallel at batch tests. Results showed that the denitrification potential can be substantially increased by addition of ethanol and hydrolysate of sludge as external carbon sources compared with raw sewage. The mean denitrification rates of ethanol and hydrolysate reached up to 0.058 and 0.08 mgN/(g MLVSS•h), respectively, while that of raw sewage was only 0.041 mgN/(g MLVSS•h). The denitrification potential increased respectively from 0.76 to 1.54 and 5.3 mg NO3-N/L owing to ethanol and hydrolysate addition. By comparison, hydrolysate of sludge was found to be the better carbon source for denitrification considering strengthening denitrification performance and price. This study provides evidence for external carbon sources choice of sewage plant and surplus sludge reutilization.

Abstract: According to the companies' purified water testing data, this paper established a product Boolean test model and used principal component analysis for analyzing security risk of purified water, and then based on probability theory, this paper set the distribution of testing batches to help the inspection department attaining the optimal sampling plan in the limited funding inspection.

Abstract: There are many ways to predict drinking water quality such as neural network, gray model, ARIMA. But the prediction precise is need to improve. This paper proposes a new forecast method according the characteristic of drinking water quality and the evidence showed that the prediction is effectively. So it is able to being used in actual prediction.

Abstract: Aimed at determining the durability of concrete in very salty regions, this paper describes a study carried out to examine the performance of various high performance fine aggregate concrete in a sulfate environment, such as high performance concrete inside a composite additive, and Portland cement concrete, and sulfate resistant cement concrete. They experienced dry-wet cycles in sodium sulfate solutions. By examining the changes of elastic moduli and analyzing the SEM of the concrete, the test results show that the salt resistances of sulfate resistant cement concrete is no better than Portland cement concrete in the extremely aggressive dry-wet cycle environment, and high performance concrete containing a composite additive has better resistance to a sulfate environment. Besides, the composite additive can create the environment for a second hydration to reduce the amount of Ca(OH)2 inside the concrete, and build additional C-S-H gel to reform the microstructure of concrete effectively. Finally, the paper offers some advice for mixing concrete in salt regions.

Abstract: The removal efficiency of ametryn in water and the influencing factors by the combined process of solar irradiation and S-doped TiO2 were studied in detail, in which S-doped TiO2 photo-catalyst with high sunlight activity was prepared by acid catalyzed hydrolysis method with thiourea as sulfur source; As a comparison, solar/TiO2 process was studied in the meantime; The experiment results showed that ametryn could be more effectively oxidized by the solar/S-doped TiO2 process than the solar/ TiO2 one, while the removal efficiency of 60% and 40% respectively after 30 min’s irradiation; Pseudo-first-order model could be used to simulate the oxidation process in which the degradation rate coefficients were independent of the initial concentration of ametryn; Degradation rate could be greatly affected by the concentration of H2O2, the optimum concentration for the system of solar/S-doped TiO2 was found to be 20mg/L, which was 5mg/L higher than that of solar/TiO2 system; Lower water pH favored the degradation of ametryn for the change of charge density of both the ametryn molecular and photo-catalyst surface.

Abstract: In this paper, the pith of sunflowers was used to be the main raw material. Therefore, the properties of the biodegradable packaging materials were studied. The quantity of starch and density of PVA were changed under the condition of 20% content of PVA, the hot-pressing time for 15min and the pressure of 1.19Mpa. The orthogonal experiment was made under the above conditions. It got the conclusion that the thickness of the plank is 1.65 mm. Its density is 0.80 g/cm3. According to GB/T12941-2008 and GB/T 2679.7-2006, the mechanical properties of the material meet the relevant standards.

Abstract: In order to conduct the integrated management in the whole process of plastics waste management, plastics waste generation should firstly be studied, especially the generation of each kind. The results of factors acting during the generation process should also be studied. Using Beijng as an example city, this paper established a predicting model for the generation and proportion of each shape and component of plastics waste, and analyzed the generation characteristics and trend of plastics waste in Beijing according to the predicting results. In terms of shape, the plastic film has the largest proportion. While in terms of component, PP and PE have the largest proportion among all the components.