Applied Mechanics and Materials Vols. 71-78

Abstract: The principle of biomass briquetting, the advantages and disadvantages of biomass briquette machine and the current research status were introduced in this paper. The influence of the four factors biomass particle size, moisture, pressure and compression speed to formation density and compressive strength was summarized, by orthogonal test method. The results show that, the influence of biomass size to the formation density is largest and to the compressive strength is least. The biomass size in the range of<40 mesh is best. The influence of compressing speed to compressive strength is largest and to formation density is least. The speed about 60mm/min is best. The influence of biomass moisture content and pressure cannot be neglected, 15% and 10MPa are best in this paper.

Abstract: The inactivation of chlorella was studied using a circular device of photocatalytic reaction with TiO₂/foam nickel as catalysts. Parameters such as reactor configuration, reaction time and pH of chlorella affecting the degradation rate of chlorella were studied. The results showed that photocatalysis with TiO₂/foam nickel was an effective process for the inactivation of chlorella. After photocatalytic reaction for 10h, the degradation rate was more than 97.75%. With reaction time increased, the removal of chlorella increased gradually.

Abstract: Based on the test results of the samples of groundwater, fishpond water, pond sediment and topsoil, analysis on migration and transformation laws of arsenic between them was executed. The SPSS statistical analysis software (V1.70) was used, in view to find out the influencing factors about migration and transformation of arsenic. It may be concluded that arsenic in groundwater was transferred to ponds through the irrigation supplies, which was adsorbed by the iron and manganese oxidation of fishpond sediment. As the changing of environment, the arsenite in the groundwater was transformed into arsenate in the fishpond water. The main factors of influencing the arsenic forms were pH、Eh、Fe and Mn in different environments. High pH and strong oxidation condition were conducive to the adsorption of arsenic in fishpond water, while low pH and strong reductive condition were conducive to the dissolution of

Abstract: The purpose of this study was to evaluate the geological and anthropogenic aspects of As pollution in groundwater of Northern Suburb Groundwater Source Field in Zhengzhou, China. Based on the groundwater samples of 78 wells in the groundwater source field of some northern city in China, distribution and influencing factors of arsenic were analyzed. The results show that: in the horizontal direction, the arsenic concentration outside beach is higher than that inside; the arsenic concentration presents the regional and continual distribution in the east area and west area, respectively. The arsenic concentration was reduced along with the increase of depth in the vertical direction. Arsenic concentration has significantly correlations with pH, Fe, Mn, SO₄2- and the water level of Yellow River, respectively (r = 0.5011, 0.7302, 0.6231, -0.5222 and -0.7671), which are the primary influencing factors on the mobilization and transform of arsenic in the groundwater.

Abstract: It has widely been demonstrated that nitrogen (N) addition enhances plant growth and net primary productivity of terrestrial ecosystems. Moreover, N enrichment could have a profound impact on ecosystem carbon fluxes, especially in the regions where N is deficient. However, there is still debate on how N affects net ecosystem CO₂ exchange (NEE). A field experiment manipulating N has been conducted in Calamagrostis anagustifolia community of Sanjiang Plain marsh of northeastern China from 2009 to 2010. N was added at a rate of 5 and 10gN m ^-2 yr ^-1 with NH₄NO₃. The results for the 2 yr showed that gross ecosystem productivity (GEP) was higher than ecosystem respiration, leading to net carbon(C)sink (measured by NEE) over the growing season in the study site. Furthermore, low nitrogen (LN) and high nitrogen (HN) addition all significantly stimulated growing-season NEE, on average, by 22 and 36%, respectively. It’s indicated that air temperature plays a major role in regulating ecosystem net C exchange and their responses to climatic change in Sanjiang Plain of northern China. we need long-term field studies to predict the long-term effects of N deposition on ecosystem processes.

Abstract: The disposal of biomass waste is of great economic and environmental importance because it can be considered as a sustainable and renewable source of energy. Biomass waste can be converted into H₂-rich fuel gas quickly by low temperature catalytic gasification technology. In the paper, fowl manure, a typical biomass waste, was pretreated by washing and the properties of the manure sample before and after pretreatment was investigated. The properties of the manure samples prepared depend strongly on washing method. Nearly all the minerals were removed from the waste by the treatment in the sequence of dilute HCl acid and HF acid washing. The difference in the pyrolysis behaviors of the samples before and after acid washing was ascribed to the changes in the organic components and the minerals present in HC during the pretreatment. A distinct catalytic effect of the minerals contained in CM on its pyrolysis behavior was observed.

Abstract: To deeply understand the performance of denitrifying phosphorus removal by aerobic granular sludge at low temperature, an aerobic granular sludge sequencing batch reactor had been operated at 10±1°C. The results showed that the PHAs components synthesized by phosphorus accumulating organisms (PAOs) in granule sludge were affected by different types of carbon source in anaerobic period, and the release and uptake of phosphate were also influenced. It was indicated that the increased ratio of PHV to PHAs led to the increase of the utilization efficiency of nitrate by denitrification PAOs. When initial COD concentration in anaerobic period was lower than 300mg/L, it can effectively keep organic substrates from flowing into the following anoxic period which influenced the efficiency of denitrifying phosphorus removal. Inhibition of nitrite to denitrifying phosphorus removal was decreased due to biology film growth manner of aerobic granular sludge. The inhibitory concentration of nitrite to denitrifying PAOs was 60 mg/L.

Abstract: Using survey information about pollution sources and water quality monitoring data, water quality condition was analyzed systematically. The result displayed that water quality in the upper reach was obviously better than that in the middle-lower reaches. Water quality was Inferior Class V and showed worse trend, with serious excess of contents of DO, COD, COD_Mn, BOD₅, NH₃-N in the middle-lower reaches. Based on the water quality change trend, influence which affected water pollution possibly on land use, urban life and industry activities were discussed. As application rate and loss of fertilizers and content of NH₃-N heightened with the increase of cultivated land area, rural activity was the major factor affecting water quality in village and town. Discharge of living pollution and industrial pollution led to water quality deterioration.

Abstract: Effect of cationic polymer on granulation and COD removal efficiency in lab scale UASB reactors was examined, treating low-strength wastewater (COD 300-500mg l^-1) at room temperature. It was shown that cationic polymer was more effective for enhancing sludge granulation and COD removal efficiency as compared to the control experiment (without additives). After day 166 of operation, the amount of granules size above 0.5mm accounted for 32.1% of total sludge, higher than that of control experiment (19.3%). At 1.03 kg COD m^-3 d^-1 of OLR and 9.8 h of HRT, the effluent VFA had a maximum value of 168mg l^-1 and 240mg l^-1 in Reactor A and B respectively. The polymer-amended reactor took 36days to receive 1.44 kg COD m^-3 d^-1 of OLR at the 7.8 h of HRT, shorter than the control reactor (54days). The two reactors obtained above 80% in COD removal efficiency. It is shown that UASB reactor can also achieve higher COD removal treating low strength wastewater at room temperature.

Abstract: Waste newspaper fiber was filled in the collagen cross-linked by glutaraldehyde. The effects of deinking fiber, glycerol dosage, glutaraldehyde dosage on the mechanical properties of composite were investigated. It is found that the deinking treatment increases the strength of the composite material. The composite has better mechanical properties under the preparing conditions as follows: waste newspaper fiber content 10%, glutaraldehyde dosage12.5%, glycerol dosage 12.5%, pH 9.7, 60°C for 2h. The tensile strength and elastic modulus are 4.98Mpa and 0.09Gpa, respectively.