Advanced Materials Research Vols. 610-613

Abstract: The adsorption of trichloroethylene (TCE) and Cd²⁺ combined contamination in the groundwater by attapulgite were studied, and the effects of pH, dosage of attapulgite and adsorption time on adsorption were investigated, equilibrium of the adsorptions processes were further conducted. Results showed that the adsorption rate of TCE affected little by the pH; TCE adsorption equilibrium reached after 3d, the removal rate was 71.34%; when attapulgite dosage was 0.03g, the adsorption rate was up to more than 51.08%. Freundlich isotherm was best fitted the adsorption process of TCE. Compound contamination of TCE and Cd²⁺ decreased the removal rate of TCE; but was in line with Freundlich adsorption isotherm.

Abstract: Environmental protection has draw the attention of the world with the today's environmental pollution increasingly serious, organic agriculture as a new agricultural development model which has less impact on the environment and sustainable development had rapidly developed and promoted in the word. This article mainly analyses and evaluates the advantages and benefits of organic agriculture in environmental protection, to demonstrate their environmental characteristics, and fully affirmed the contribution of organic agriculture in terms of environmental protection so that to provide a reference for the development of organic agriculture.

Abstract: Based on the survey on deficiencies of ecological footprint model applied on regional sustainable development assessment, modification of the ecological footprint model was preliminarily discussed on three aspects: concept extension, combination with other index, and introduction of quantitative estimate indices for time series calculation. This discussion provided a scientific guidance of applying ecological footprint model on regional sustainability assessment, and a theoretical basis for further case study.

Abstract: Low-quality stands in Greater Higgnan Mountains were transformed by clear-cuttings with different area of forest gaps, then larch were planted after induced transformations. The LI-8150 multi-channel automated soil CO₂ flux system was used to measure CO₂ flux on soil surface. Changes of different soil respiration rates and influence factors were analyzed after different transformations. The results indicated that the soil respiration rates were all raised after different transformations compared with no interfered control plots. After analyzing different transformations comprehensively, it showed that the soil respiration rate performed a negative correlation with the soil density significantly, while the correlation with soil organic matter and litter weight in little decomposed was positive (p﹤0.05). The largest Q₁₀ with forest gap area of 625 m² was 3.561. Influenced by soil respiration rate, soil underground with depth of 10cm showed the strongest temperature sensitivity. The smallest Q₁₀ with forest gap area of 900 m² was 2.312, and temperature sensitivity of soil was the weakest.

Abstract: Increasing use of pyrethroid insecticides in tidal farms has resulted in the severe pollution of coastal water environment and sedimentary environment. In this work, the migration and transformation of three pyrethroid insecticides, fenpropathrin, cypermethrin and deltamethrin in Bohai coastal zone were studied. The results showed that the adsorption of pyrethroids on the coastal sediments matched pseudo-second-order kinetics and the chemical adsorption played a major role. The degradation of three pyrethroids included chemical degradation and biological degradation. The chemical degradation had predominance function at the initial 14 hours, but the biological degra- dation effect was increasing continuously in the transformation process, so that the proportion of biological degradation in total degradation reached about 68% at 110h. M-phenoxyphenyl-acetonitril was identified as the stable degradation product by GC-MS.

Abstract: The use of bacteria for red tides control is a promising method, but the microalgae sterile is the basis of the research. The effects of Amipicillin, Gentamycin sulfate, Nomycin sulfate, Chcoramphencol, Kanamycin sulfate on the growth, Chl-a and MDA content of Prorocentrum minimum were studied under laboratory conditions. The results showed that Gentamycin sulfate and Kanamycin sulfate could stimulated the growth of P. minimum under lower concentrations (0.05mg/mL), and the growth stimulation was significant (pP. minimum under higher concentrations. The growth inhibition was significant (pP. minimum showed the significant difference in sensitivity to five kinds of antibiotics. The inhibition of Chcoramphencol was the largest, while Kanamycin sulfate was the smallest in the five kinds of antibiotics. The Chl-a content was decreased (p<0.05) by five kinds of antibiotics when the concentration was 2.00mg/mL. Besides, the accumulation of MDA content was observed by Chcoramphencol treatment. Therefore, Chcoramphencol could not be used for the microalgae sterile.

Abstract: Effects of Ulva pertusa Kjellman stress and UV-B radiation on the growth, physiology and biochemistry of Alexandrium tamarense were studied under laboratory conditions. The results demonstrated that U. pertusa stress and UV-B radiation could inhibit the growth of A. tamarense. Physiology and biochemistry of A. tamarense could be affected under U. pertusa stress and UV-B radiation treatment. U. pertusa stress caused the increase in SOD activity and decrease in H₂O₂ content. As for UV-B radiation, Chl-a content and soluble content were decreased, while H₂O₂ content, MDA content and SOD activity were increased. With regard to the combined effects of U. pertusa stress and UV-B radiation, Chl-a content and soluble content were decreased, while MDA content and SOD activity were increased. Compared with UV-B radiation, the combined effects of U. pertusa stress and UV-B radiation treatment on the growth, physiological and biochemical were indiscernible.

Abstract: Reclamation is adopted by many coastal countries to develop living space. Although reclamation changes natural coast pattern in local small scope, which most happen on beach area or shallow ocean area. Therefore, it has heavy destroy to local natural system, brings negative effect to coast area ecological environment stability, biodiversity and sustainable development. The paper takes constructing Lianyun new city as example. Biomass changes before construction and during construction at four monitoring spots are analyzed, negative effects to natural environment, marine product yield and marine animals' survival environment are deeply discussed. In order to develop marine ecology , several piece of advices are advanced in the paper to reasonably exploit coast resource and protect natural ecological environment.

Abstract: The characteristics and current situation of China’s wetlands are discussed, the reasons that cause environmental degradation of China’s wetlands are analyzed in this article. The emphases of research on domestic west lands are summarized from three aspects that function and benefit development of wetlands, construction of wetland reserves, restoration and reconstruction of wetlands, in addition, the development trend of future research on wetlands is prospected.

Abstract: A new hydrothermal method was introduced to prepare TiO2 films. The films were prepared by using tetrabutyl titanate as precursor, toluene as solvent and hydrochloric acid as the inhibitor via a facile hydrothermal method. XRD, SEM, AFM, and TG-DSC were used to characterize phase structure and morphology of TiO₂ thin films. XRD analysis showed that crystal phase of as- prepared films were anatase entirely,and its average size was 9 nm. AFM and SEM analysis indicated that films had nanocrystallines,and it was homogenous,dense and crack- free. Photocatalytic properties of TiO2 film were estimated by degradation of methylene blue . The result shows that the degradation rate of 40mL methylene blue solution with initial concentration 10 mg/L reaches to 52.8 % after irradiated for 120 min under 35W ultraviolet lamp ,and as-prepared TiO2 film has better photocatalytic property.