Cell Wall Morphology, Chemical and Thermal Analysis of Cultivated Pineapple Leaf Fibres for Industrial Applications

A study on chemical, morphology, and thermal analysis of cultivated pineapple leaf fibres (PALF) were carried out. The chemical compositions were determined by using Technical Association Pulp and Paper Industries standards. Fourier Transform-Infrared Spectroscopy analysis of PALF detect sharp band at 1,733?cm^?1, due to the absorption of carbonyl stretching of ester and carboxyl groups which is most abundant in pineapple leaf hemicelluloses. Cell wall ultra structure of PALF was studied by using Transmission electron microscopy. Transmission electron micrograph confirmed that cell wall structure of PALF consists of middle lamella, primary wall and secondary wall including S₁, S₂ and S₃ layers. X-Ray Diffraction indicated that PALF have crystalline nature. Thermal analysis of PALF shows that T_10% and T_50% weight loss occurred at temperature of 212 and 306?°C respectively. Differential Scanning Calorimetry of PALF showed the broad endothermic peak at a temperature of 80?°C. The relationships between these properties were discussed and relate it with industrial application of pineapple leaf fibers.     

The influences of industrial gross domestic product,urbanization rate,environmental investment,and coal consumption on industrial air pollutant emission in China

With the rapid economic development and urbanization, there would be severe air pollution. The path analysis method was employed to investigate the specific effects of Industrial Gross Domestic Product (IGDP), Urbanization Rate (UR), Environmental Investment (EI), and Coal Consumption (CC) on Industrial SO₂ Emissions (ISE) and Industrial Dust Emissions (IDE). The results shown that (1) IGDP is the main reason for the increase in ISE and IDE, with the direct positive influence more than 20% and a total contribution of more than 35%, and the combined effects of UR can reduce air pollutants emission considerably, especially in ISE. (2) The effects of EI and CC on ISE could be ignored, given that their contributions comprised <?10%. Meanwhile, the contribution of EI to IDE was only 8.92%. For one reason, EI is underfunded which the percentage of Gross Domestic Product was <?2%.     

布筋形式对加筋土挡墙变形性能影响研究

筋材布置是加筋土挡墙设计中的一个重要问题,通过具有不同布筋形式的加筋土挡墙砂箱模型实验,研究布筋形式对加筋土挡墙变形性能的影响。结果表明:在筋材面积相等的条件下,网格式布筋面板变形更加均匀,而条带式布筋面板易在中下部发生过大的局部变形;对于条带式布筋,减短单筋长度、加密布筋,或筋材上长下短铺设,能提高墙体稳定性;对于网格式布筋,筋材间结点越强,墙体抵抗变形能力越好;在筋带末端增加一个竖向副筋能有效控制面板变形。该研究成果可为实际工程中布筋形式的经济合理化设计提供参考。     

Environmental stress-induced extracellular isoperoxidase RC3 from rice

Effects of various environmental stresses such as heavy metals, salts and low (high) temperature on the secretion of peroxidase isozyme into the medium were examined in rice (Oryza sativa cv. Nak-Dong) suspension culture. The major extracellular peroxidases secreted into the medium by various stresses were cationic isoperoxidases. A far migrating cationic isoperoxidase RC3 was isolated from the medium after application of CaCl2, the effective stimulator for peroxidase secretion. Isolation of extracellular isoperoxidase RC3 was accomplished by ammonium sulfate fractionation, CM-cellulose cation-exchange chromatography, and Sephacryl S-100 gel filtration. The enzyme was a glycoprotein having molecular weight of approximately 34 KDa as determined by SDS-PAGE and 38 KDa by Sephacryl S-100 gel filtration. The pI value of the enzyme was 8.9. Kinetic studies revealed that the optimum pH of the enzyme was 6.0 for guaiacol and H2O2, and the Km values for guaiacol and H2O2 were 10.5 mM and 3.2 mM, respectively.     

天然气净化清洁生产工艺的应用

针对天然气净化生产过程中的主要产污环节,重庆天然气净化总厂成功推广应用了PALL高效过滤器、胺液复活装置等先进设备及超级或改良克劳斯硫磺回收、升流式厌氧污泥床层反应器(UASB)等清洁生产工艺。通过加强生产全过程管理,实施污染源头控制,显著削减污染物的产生量,取得了较好的环境效益和经济效益。     

青藏高原及邻近区域的大震危险性分析和探讨

用青藏高原及周边区域的历史地震和近代地震的分布特征来分析本区域的地震危险性。通过用1889年以来的7级以上大震的面波震级对印度块体推挤作用所积累的能量进行了分析和计算,结果表明每年在该区域将会积累的地震波能量在2.09×1016J左右。分析认为,由于应力的不均匀分布,能量得不到全面释放,所以大的地震将会在一些断层带上重复发生。     

Pb(Ⅱ) biosorption using chitosan and chitosan derivatives beads: Equilibrium,ion exchange and mechanism studies

The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initial pH, adsorbent dosage and different initial concentration of Pb(II) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non-linear Langmuir isotherm for ch...     

Sequestration of toxic Pb（II） ions by chemically treated rubber （Hevea brasiliensis ） leaf powder

Rubber leaf powder (an agricultural waste) was treated with potassium permanganate followed by sodium carbonate and its performance in the removal of Pb(II) ions from aqueous solution was evaluated. The interactions between Pb(II) ions and functional groups on the adsorbent surface were confirmed by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDX). The effects of several important parameters which can affect adsorption capacity such as pH, adsorbent dosage, initial lead concentration and contact time were studied. The optimum pH range for lead adsorption was 4–5. Even at very low adsorbent dosage of 0.02 g, almost 100% of Pb(II) ions (23 mg/L) could be removed. The adsorption capacity was also dependent on lead concentration and contact time, and relatively a short period of time (60–90 min) was required to reach equilibrium. The equilibrium data were analyzed with Langmuir, Freundlich and Dubinin-Radushkevich isotherms. Based on Langmuir model, the maximum adsorption capacity of lead was 95.3 mg/g. Three kinetic models including pseudo first-order, pseudo second-order and Boyd were used to analyze the lead adsorption process, and the results showed that the pseudo second-order fitted well with correlation coefficients greater than 0.99.     

湘江重点城市饮用水源地挥发/半挥发有机污染物调查与分析评价

采用气相色谱质谱仪（GC-MS）对湘江流域长沙、株洲、湘潭、岳阳等8个重点城市生活饮用源地水质中挥发/半挥发性有机物进行了分析,结果表明,8个重点城市饮用水源地水质中108种挥发和半挥发性有机物均未检出,含量均处在较低水平。对湘江流域有机污染物来源进行了调查分析,提出了加强有机污染物排放监测和控制管理,并定期对地表水中有机污染物进行监测的必要性。     

对国家污染物排放（控制）标准体系的探讨

在介绍中国环境保护标准体系发展概况的基础上,对国家污染物排放（控制）标准的体系结构、内容设置进行了研究,探讨了新时期国家污染物排放（控制）标准的发展趋势,结合实例分析了水污染物特别排放限值、有毒污染物的监控等在新颁布的排放（控制）标准中的适用要求。