Advanced Materials Research Vols. 347-353

Abstract: In the cold area, there always exists the problem to treat low-temperature sewage in winter by bio-treatment technology, but it is difficult to reach the criterion since the low efficiency and the high difficulty. Domestic wastewater is a high concentration of oil wastewater and if it is discharged directly without treatment, it will affect the water body reoxygenation and its self-purification process, which endangers the water ecosystem. The study tried to tackle the problem from the morphology and physiology perspective of microorganisms. The sewage water samples were taken from a residential area and eight cold-adapted strains with high oil degradation capacity were isolated and at the temperature of 5°C. The bacteria were identified and determined the genus through physiological and biochemical tests and fatty acid identification system. The effect of pH value on the oil degradation rate was investigated. The results showed that the optimal culture conditions were 5°C, 7.0 of initial pH, peanut oil as carbon source. Under the conditions, the bacteria had the higher degradation capacity.

Abstract: Rongcheng Swan Lake is a small lagoon in eastern Shandong Peninsula, China, whose water quality and ecological environment has deteriorated in recent years. The surface and core sediments were collected from Swan Lake to investigate the concentrations and spatial-vertical distribution of total phosphorus (TP) and various P forms. TP concentrations of the surface sediments (0-10 cm) were low, ranging from 79.15 mg kg-1 to 565.12 mg kg-1. TP concentrations in sediments were relatively high in the northwestern and central lake, and low near the sand spit, which was largely influenced by the anthropogenic inputs and sediment grain size. Inorganic P (IP) was the dominant form of TP, and apatite phosphorus (AP) was the major component of IP in surface sediments. At four of the six sediment profiles, the concentrations of TP, organic P (OP) and non-apatite inorganic phosphorus (NAIP) decreased rapidly with depth in the surface 0-10 cm layers, which was related to the increase of anthropogenic inputs in recent 20-30 years. In conclusion, the sediments in northwestern area had great potential for P release in the alkaline water of Swan Lake.

Abstract: After desulfurated by electric furnace process, yellow phosphorus tail gas could be used to generate electricity or produce C1 chemical products. Through comparing the restraining factors and feasibility of the above two comprehensive utilization methods, the generation of using yellow phosphorus tail gas is considered as a more advantageous and developing comprehensive utilization way. Moreover this paper recommends a cascade recycling technology which focuses on the generation and recycling heat energy. Based on the above, the downstream products structures of yellow phosphorus can be divided into three kinds, Class A, B and C. Through comparative analysis, Class A is thought to be the best structure that could make the complete recycling of tail gas come true and recycle the waste heat to gain vapor which replaces coal-fired boiler.

Abstract: In our study, a new kind of material for Cr⁶⁺ absorbency was prepared by melt blending with EPDM as the matrix and modified zeolite as the filler. Contrast between natural zeolite, acid modified zeolite and modified zeolite / EPDM composite on equilibrium adsorption amount (Q), the results showed that the Q of composite were far greater than that of natural zeolite and acid modified zeolite.

Abstract: Greenhouse trials with brassica camprestris (BC) and raphanns sativns (RS) grown in three types of Chinese soils (Henan fluvo-aquic soil; Jilin black soil; and Hunan red soil) were conducted to evaluate the growth effect and accumulation of As on/in vegetables resulting from different arsenic contents in soils. The arsenic uptake rate of the vegetables response to type of soils and investigated plant species as well. Experimental results show that low arsenic content in soil has no effect on vegetable growth, but promote the biomass of vegetables. However, higher arsenic concentrations in soils lead to decrease in growth of both leaf- and root systems of the vegetables, especially when arsenic concentration is above 90 mg kg-1 in the soil. Arsenic levels in soils and vegetables correlated positively according to the experimental results. The tests also reveal that vegetables grown in alkali soils may accumulate more arsenic than that in acid soils, which suggests that arsenic in different types of soil may have different impacts on vegetables even with the same concentration. Arsenic concentration in RS is always higher than that in BC during the experiments, which indicates root vegetables may, have greater ability for arsenic uptake from soil than leafy vegetables potentially.

Abstract: Based on the daily average concentration of sulfur dioxide (SO2), nitrogen dioxide (NO2) and respirable particulate matter (PM10) from 2001 to 2010, the atmospheric environment quality over the past 10 years in Xi'an was comprehensively evaluated. The process of the evaluation method involves the follow key procedures. First, the pollution factors are put in order by using the evaluation factors dynamic sorting method for determining the importance of each factor. Second, the Analytic Hierarchy Process (AHP) method is used to determine the weight value of every factor. Finally, the composite index, which represents the environment comprehensive quality, is calculated by weighted average method. The results can provide scientific basis for the related departments to understand the atmospheric environment comprehensive quality in Xi'an.

Abstract: In our study, a new kind of material for oil adsorption was prepared by melt blending with EPDM as the matrix and roasting Fe₂O₃ as the filler. The effects of dicumylperoxide (DCP) and roasting Fe₂O₃ contents on the oil absorbency were studied. The results show that the oil absorbency reaches the highest value for the roasting Fe₂O₃/EPDM composite with 2 wt % DCP and 30 wt % roasting Fe₂O₃. Comparing the oil absorbency for three samples, the experimental result indicates that the oil absorbency of roasting Fe₂O₃/EPDM composite is higher than that of EPDM (crosslinked) and EPDM.

Abstract: The mathematical model of the grid-side converter is analyzed. A control system of the grid-side converter used in 7.5kW doubly-fed wind power generation simulation test platform is designed. The TI TMS320F28335 DSP is choosing to be the main controller. The decoupled control and the double closed loops control are adapted in the system. The control strategies of stabilizing DC-link voltage and unity power factor control operating at sub-synchronous and super-synchronous state are realized. The experimental results show that the mathematical model and control strategies are correct and effective.

Abstract: Until now, there are different opinions upon basic principles of environmental science. Few scholars believe that there are no unique basic principles in environment science, but many scientists disagree with this opinion. Based on the foundations of previous work, four basic principles of environmental science are put forward in this paper: systematic principle of environment, principle of environmental capacity, symbiosis principle of human between environment, and entropy principle.

Abstract: Baihua Lake, a man-made reservoir located in a typical plateau karstic area, is one of the five drinking water sources for Guiyang city. In the present research, the organochlorine pesticides and polychlorinated biphenyls in the muscle tissues of six fish species collected from Baihua Lake were estimated by gas chromatography/mass spectrometry (GC/MS) . The total concentration of OCPs ranged from 2.83 to 94.25 ng g-1 (dry weight), and that of PCBs ranged from ND to 4.78 ng g-1. p,p’-DDD, p,p’-DDE, γ-HCH and PCB28 were detected in the majority of the samples. However the biomagnifications of OCPs and PCBs were not significant in the selected fish from the lake.