The use of δ18O as an indicator of vanadium movement in a dormant stratovolcano region

The oxygen isotope (δ¹⁸O) stable water tracer can be a promising new tool for identifying trace metals in volcanoes and their sources. In the present study, the origin of vanadium in water from a spring at the base of Mt. Fuji is examined using δ¹⁸O, a dormant stratovolcano consisting of lava and basalt rock located on the North Pacific Coast of Japan. A comparison of water from the main springs at the foot of the Mt. Fuji volcano indicates that only V, Cr, Mn and Co enrichment could be related to volcanic events, whereas Ni, Cu, Cd and Pb originate from the dissolution of particles of anthropogenic origin from the industrial areas of Fuji and Fujinomiya. The average V concentrations at the mountain sites ranged from 50 to 110 µg L^?1 and from 18 to 47 µg L^?1 in the coastal areas. The δ¹⁸O became depleted at higher elevations and increased in coastal areas as well as in some NO₃^?-contaminated water. Therefore, variations in the dissolved V/δ¹⁸O ratio in springs of the study area occur due to the elevations of their catchments and the increased concentrations of δ¹⁸O from NO₃^? as a contaminant.     

Selective separation and preconcentration studies of chromium(VI) with Alamine 336 supported liquid membrane

Chromium compounds have received considerable attention because these are used extensively in such industrial applications as electroplating, steelmaking, tanning of leather goods, and corrosion inhibition. The use of supported liquid membranes (SLMs) to remove metals from wastewaters has actively been pursued by the scientific and industrial community. In the present work, the selective separation and preconcentration of Cr(VI) ions has been studied by using a commercial amine as the membrane liquid on the porous polypropylene support. Permeation experiments were conducted on a laboratory scale batch reactor made up of perspex, with a memberane fixed amid the two chambers. The flux of Cr(VI) ions was found to be maximum (3.15?×?10^?5?mol?cm^?2?s^?1) around pH 1. Above and below this pH the flux decreases. Distribution studies show that an increase in the amine concentration leads to higher distribution coefficients at fixed pH values. At pH around unity, the distribution of Cr(VI) ions into the organic phase was found to be maximum, of the order of 56.3. The Cr(VI) transport through the membrane increases with rise in temperature. In order to check the long-term efficiency of the flat sheet SLM, an experiment was conducted with higher Cr(VI) concentration (5000?ppm) for 24?h, at optimised parameters. It was observed that in 24?h, about 1/5th of the feed Cr(VI) is left over while the rest is transported. However, minute organic droplets were also seen in the feed and strip compartments, after 1 day. This observation suggested the loss of membrane liquid. The feasibility of preconcentration of Cr(VI) by using the proposed SLM parameters, was also studied by using the hollow fibre (HF) system. Highest enrichment factor (E.F) value was obtained for 50?mg?L^?1 whereby all of the metal was transported to the stripping phase and the resulting Cr concentration was 688?mg?L^?1 (E.F?=?13.8). It was observed that while treating more diluted solutions, the enrichment factor decreases. The values of E.F equal to 8.9 and 11.3 were found for initial Cr concentration of 10 and 30?mg?L^?1.     

掺聚丙烯纤维的高强混凝土高温性能研究

高强混凝土的渗透性很低,高温下可能出现爆裂破坏现象,严重影响混凝土及其内部钢筋的结构使用性能。本文通过改变聚丙烯纤维掺量,研究其改善高强混凝土高温爆裂性能,以及高温后高强混凝土吸水率、剩余强度性能及其恢复性能。     

聚酯化纤废水中特征污染物含量与COD的相关性研究

研究了聚酯化纤废水中有机污染物乙醛、乙酸、乙二醇含量与ＣＯＤ之间的相关性，确定了ＣＯＤ与上述特征污染物含量的比值，并测定了它们的氧化率，为企业的生产工艺管理和 保管理提供了基础数据。     

翻车机通风除尘系统

介绍一种冲突网除尘器，其具有原理独特，体积小，重量轻，能耗低，除尘效率高等特点，辞别适合翻车机除尘。运用表明，岗位粉尘浓度3．8mg/m^3，外排粉尘浓度40mg/m^3，除尘效率96％。     

强度调制型光纤液体浓度检测传感器研究

根据全反射原理．菲涅尔公式及朗伯-比尔定律,证明了低浓度溶液与折射率和吸光度之间的线性关系,得到了光纤出射光强随液体包层浓度成负指数关系。根据上述结果,利用光的强度调制进行溶液浓度检测,即通过测量光强的变化,检测出待测溶液浓度。实验表明,强度调制光纤传感器可以实现溶液浓度检测。     

生态稳定塘及植物净化法处理造纸废水的应用技术

文章以某稻草原料的纸业公司废水治理工程为例,论述工程建设的造纸废水生态处理系统,包括造纸废水厌氧处理塘、混合废水兼氧-好氧处理塘及育苇塘,其中纸机白水、中段废水含有较多的流失填料,采用斜网及沉淀处理后入生态塘系统。混合后的废水经兼氧-氧化塘-芦苇湿地处理系统,大大增加了其处理效果。排水经芦苇人工湿地净化处理,用以生产造纸原料芦苇塘的种植用水。工程配备完善的给排水系统和废水循环利用系统,实现废水的零排放。     

粘胶纤维生产废气治理研究进展

介绍我国粘胶纤维生产废气治理研究的发展情况,说明普通活性炭不适合作为粘胶纤维生产废气的吸附剂、建议采用密封窗封闭操作、用TF法脱除H2S,再用改性活性炭脱除CS2,同时应重视研究开发新型溶剂代替CS2进行无害化清洁生产.关键词:粘胶纤维废气治理硫化氢二硫化炭     

The biochemical activity of soil contaminated with fungicides

Excess fungicides can pose a serious threat to the soil environment. Fungicides can lower the microbiological and biochemical activity of soil and lead to yield declines. Soils contaminated with fungicides have to be remediated to maintain the optimal function of soil ecosystems. This study evaluates the effect of neutralizing substances on soil enzymatic activity and the yield of Triticum aestivum L. in soil contaminated with fungicides. Sandy loam (Eutric Cambisols) with pH_KCl 7.0 was contaminated with an aqueous solution of Amistar 250 SC and Falcon 460 EC in the following doses: 0 (soil without fungicide – treated as a control), RD (dose recommended by the manufacturer) and 300?×?RD (dose 300-fold higher than the recommended dose). Soil was supplemented with bentonite and basalt meal at a dose of 10?g kg^?1 DM of soil (dry mass of soil). The fungicide dose recommended by the manufacturer did not induce changes in soil enzymatic activity or the yield of T. aestivum L. Our findings indicate that the tested fungicides can be safely applied to protect crops against fungal pathogens. However, when applied at the dose of 300?×?RD, the tested fungicides strongly inhibited soil enzymatic activity and disrupted the growth and development of spring wheat. Soil supplementation with bentonite and basalt meal improved the yield of T. aestivum L., and bentonite was more effective in reducing fungicide stress. The analyzed substances were not highly effective in restoring biochemical homeostasis in soil.     

活性炭纤维对气体中醋酸丁酯吸附性能的研究

通过试验选择活性炭纤维作为吸附剂,吸气气体中醋酸丁酯。对影响其吸附性能的主要因素进行了研究。