Applied Mechanics and Materials Vols. 522-524

Abstract: The global environment change is human beings are facing with the important and urgent environmental problems: in natural and human action double drive, the surface of the earth element biogeochemical process and its environmental effect is the current global change research in the area of the important content. In order to estimate and forecast geochemical cycle of change and to the global life support system influence, since the 1970s on the ecological system of the nitrogen cycle extensive and in-depth research, and in the process of this a series of ecological environment effect.Wetland biogeochemical process is refers to the carbon, hydrogen (water), oxygen, nitrogen, phosphorus and sulfur and various essential elements in the wetland soil and plant all kinds of migration between transformation and energy exchange process. Chemical process including nitrogen, phosphorus and other nutrients in the wetland system of flow and transformation, Wetland in heavy metals and other organic inorganic pollutants absorption, so close, transformation and enrichment, etc.

Abstract: A series of tailings and sediments samples were collected from Linahuashan tungsten mining area. Particle composition, arsenic concentrations and arsenic speciation distribution in the tailings and sediments were investigated. The proportion of large particle (> 170 μm) in the tailings varied from 37% to 50%. Arsenic (As) concentrations in the tailings ranged from1889 mg·kg^-1 to 3135 mg·kg^-1. The sediments upstream were similar to those in the tailings in particle composition, As concentrations and speciation distribution. The sediments in the middle or lower reaches of the stream contained finer texture and lower As concentrations than the tailings. Compared to the tailings, Acid waste water with a lot of tailings particle enter the stream. Most of larger particle in acid waste water settled upstream, and smaller particle and soluble As precipitated in the middle or lower reaches of the stream. Smaller particle fraction contained higher percentages of Fe-As, Ca-As and Al-As, while larger particle fraction contained higher percentages of FeOc-As and Res-As.

Abstract: We report the facile synthesis of triangular Pd nanoplates using aqueous extract of Syzygium Samarangense leaf. The morphology and structure of the obtained Pd nanoplates were characterized by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analysis. FTIR spectra indicated that C=C, COH, and OCOH were mainly responsible for the formation of the Pd nanoplates.

Abstract: Two pectinase-producing strains, HDYM-01 and HDYM-02, were added into retting tanks to accelerate the water-retting of flax after they were amplified in liquid medium. The results show that the yields of fiber flax retted with bacteria addition are higher than the control, and the difference is significant with F test. When reusing the retting water to the next tank to perform the water-retting with bacteria addition, the yields of fiber flax are also higher and the difference is significant with F test. The retting time would be shortened for 24 hr and the flax strength is raised for 20-30 Newton (N) with bacteria addition method and reusing retting water method.

Abstract: The effects of NaCl on the growth, the number of salt gland and salt secretion of Aeluropus littoralis were studied at different NaCl concentrations. Results showed that with the increase of NaCl concentration, the growth of Aeluropus littoralis was inhibited and MDA content increased gradually. With the increase of NaCl concentration, fresh weight, dry weight of single plant decreased, and A. littoralis salt secretion increased significantly. Salt gland density was significantly higher with the increase of NaCl concentration, and the total number of salt glands on the low surface was more than that on the upper surface. At the same time, the average secretion rates of individual salt glands increased. These showed that the salt glands could effectively secrete salt outside the body to keep normal physiological function.

Abstract: Suaeda salsa L. grown in saline inland of the Yellow River Delta were used to investigate the effect of chilling and low irradiance on antioxidant systems. Results showed that Fv/Fm and ΦPSII both decreased and the content of soluble protein increased. The H₂O₂ and O₂^-contents decreased during the first 3 h and then increased. However, the trend of antioxidant enzyme activities was opposite to that of H₂O₂ and O₂^-contents. These suggested that short time chilling and low irradiance stress may induce an increase of CAT, APX and SOD activities in order to protect plant cell from being damaged by ROS.

Abstract: According to the sap flow characteristics and photosynthetic characteristics of Haloxylon ammodendron and Tamarix, we measured the sap flow with the method of thermal diffusion. To monitor photosynthesis with application the instrument CI-340, and the result shows that: (1)The daily net photosynthetic rate change of Haloxylon ammodendron is a typical double peak type, and Tamarixs is a single peak type; (2)The daily transpiration variation of Haloxylon ammodendron is similar to net photosynthetic rate change rule, it has a phenomenon which we called noon break, Tamarixs isnt obvious, it presents volatile changes slightly; (3)The daily sap flow of Haloxylon ammodendron is a typical double peak type, Tamarixs isnt obvious, it presents volatile changes slightly, and at sometimes the sap flow of branches is greater than the breasts. The results provide some supports for ecological water demand of the plants. It has some significance for ecological environment construction of the Gurbantunggute Desert.

Abstract: The experimental study on the mechanism of CO₂ absorption and desorption was tested by two kinds of glycinate (SG and PG) with TEA. The absorption and regeneration of CO₂ by mixed absorption liquid were tested and compared with each other. The results showed that a low concentration of TEA in the SG and PG increased CO₂ absorption capacity of mixed absorption solution. Addin more TEA on PG or SG lowered CO₂ absorption capacity of mixed absorption solution. Desorption of PG didnt change with TEA. The low concentration of TEA had a role in promoting the desorption of mixed absorption solution (SG+TEA), and the high concentration of TEA inhibited the desorption of mixed absorption solution (SG+TEA).

Abstract: The steel slag was used as adsorbent for the adsorption of Phosphate. the isothermal adsorption test studies adsorption of the steel slag on phosphorus and ammonia nitrogen. The results showed that that the steel slag have very strong adsorption capacity on phosphorus. Langmuir adsorption equation can better describe adsorption of steel slag on phosphorus, the max adsorption quantity of steel slag on phosphorus is 9495.916 mg·kg^-1, adsorption intensity is 0.0132.

Abstract: Aerobic granular sludge was cultivated from activated-sludge in sequencing batch reactor. The change of physical properties and the effect of treatment of organic substance and microbial community were studied in the process of the different influent organic loading rate. The results showed that the formation process of aerobic granulation was rapid but the granular sludge was not stable and existed a disintegration-reunion dynamic balance system. The value of MLSS descended from 5.12g/L to 1.03g/L. The removal efficiency of NH₄⁺-N decreased to 74.17% and total phosphorous (TP) removal efficiency maintained beyond 90% all the while. The COD_Cr removal was over 85% which higher than that of after adding in methanol, then reduced but had trend of rise to 31.89% at last. Microbial species in granulation were speculated by detecting polyhydroxyalkan- oates between granular sludge and activated sludge in the reactor. The results showed that microbial species of activated sludge are more diverse.