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101.
Effect of ortho- and pyrophosphates on dissolution of Fe,Al, Si,Ca, and organic C in three soils 总被引:1,自引:0,他引:1
Phosphate application changes chemical properties of surface soils, consequently influencing crop nutrient availability and pedological process. Sodium ortho- (OP) or pyrophosphate (PP) was equilibrated with three Quebec soils: an Uplands sand (Orthic-Podzol), a St. Bernard loam (Eutric-Cambisol), and a Dalhousie clay (Humic Gleysol) in 0.03 M KClO4 solution at an initial pH 6.0. Both autoclaved and nonautoclaved soils were used, and dissolution of Fe, Al, Si, Ca and organic C was studied.Concentrations of Fe and Al in OP equilibrated solutions were not detectable. Ca solubility was reduced while dissolution of Si and organic C was increased in the presence of OP. These changes were possibly due to P—Ca precipitates or increased Ca sorption by P, and competition between OP and Si or organic materials for sorption sites. PP enhanced dissolution of Fe, Al, Si and organic C but reduced solubility of Ca. Comparisons showed that PP added to autoclaved soils had greater effects on increasing dissolutions of Fe, Al, Si and organic C and on reducing Ca solubility than OP in both autoclaved and nonautoclaved soils. Autoclaving resulted in greater dissolution of organic C. Dissolved Si with added OP was greater with nonautoclaved soils probably due to more P sorption in the nonautoclaved system, compared with autoclaved soil. Added PP dissolved Fe and Al ions which may ultimately enhance P precipitation by forming less soluble compounds upon hydrolysis of PP to OP. 相似文献
102.
用Alltech DS-Plus~(TM)离子色谱抑制器测定有机弱酸 总被引:1,自引:0,他引:1
葡萄糖酸、乙酸、甲酸、丙酮酸、山梨酸等有机弱酸在流速为 1 m L/ min,淋洗液的浓度为 1mmol/ L Na HCO3 ,用 Alltech DS- Plus TM抑制器时能很好地检测。弱电离物质检测限分别为 0 .5 0 0μg/ m L、0 .1 45 μg/ m L、0 .0 97μg/ m L、0 .1 95 μg/ m L、1 .0 78μg/ m L(S/ N=3 ) ,具有良好的线性关系和重现性。对饮料样品进行测定 ,结果令人满意。 相似文献
103.
New organodilithium initiators were prepared in a hydrocarbon solvent in the absence of any polar additive. Although these initiators are insoluble when they are synthesized, they may be easily purified and reacted with dienes to give perfectly telechelic polydienes having unimodal distributions and low dispersity. A good agreement between experimental and theoretical molecular weights was observed. The polymer microstructures were similar to those of polymers initiated by butyllithium in the same solvent. Triblock thermoplastic elastomers were also prepared, the characteristics of which are given. The mechanical properties of a S.B.S. sample support also the claim of a good initiating ability and difunctionality of these initiators. 相似文献
104.
介绍氨纶干法纺丝技术中纺丝介质 (SM )循环系统的主要设备 ,对循环风压力、风温度和风量控制进行了探讨。严格控制SM循环工艺参数 ,可减少并丝现象。 相似文献
105.
该文通过水质调查和大量实验数据,对循环水改为黄河水质运行的配方进行了筛选,并提出了自然pH全有机配方的概念,通过监测数据,对黄河水配方运行情况进行了总结,该配方投用后,不但能节约地下水资源,而且经济效益显著。 相似文献
106.
107.
Desislava Bögner Frederike Schmachtl Björn Mayr Christopher P. Franz Sabine Strieben Gregor Jaehne 《臭氧:科学与工程》2019,41(2):105-117
Recirculating Aquaculture Systems (RAS) reduce water consumption by efficient filtration to maintain appropriate levels of accumulating compounds and sludge. Sludge is mechanically separated by drum filters and disposed of to the detriment of overall system water budgets. Dissolved nitrogen compounds are reduced via nitrification–denitrification filters, requiring commercial external carbon sources. The reuse of sludge after ozone pre-treatment may represent the next step in RAS optimization. The present study analyzes the content of sludge from RAS and tests ozonation as a pre-treatment for recycling as carbon source. The dissociative effect of ozone and the physicochemical changes due to ozonation lead to a significant increase in soluble carbon availability. Predominantly long-chain fatty acid (FA) (saturated and unsaturated) with 16 and 18 carbon atoms independently of the treatment were found in the profiles. Saturated FA concentrations in solution increased after 20, 40, and 60 min ozonation. The solid content of the sludge was practically unaffected by ozonation in terms of FA profile: only saturated FA slightly increases after 40 min treatment. The implications of these findings for denitrifying bacteria are discussed.
Abbreviations: Recirculating Aquaculture Systems (RAS); Advanced Oxidation Processes (AOPs) 相似文献
108.
以厌氧折流形式的发酵生物制氢反应器进行了连续流有机废水发酵产氢试验研究。反应器由有机玻璃制成,三格室,单格有效容积9.16L。以好氧生物处理系统剩余污泥为种泥,在容积负荷为8.89kg COD·(m~3·d)~(-1),水力停留时间为13.5 h,温度(35±1)℃等条件下,系统启动运行25 d后达到稳定运行状态。系统稳定运行时,总产气量和产氢量分别稳定在59.0 L·d~(-1)和32.0 L·d~(-1)左右。其中,第一格室、第二格室和第三格室的平均产气量及其氢含量分别为14 L·d~(-1)、25 L·d~(-1)、20 L·d~(-1)和50%、60%、50%。系统污泥的比产氢速率为76.64 L·(kg VSS·d)~(-1)。与同类生物制氢反应器相比,厌氧折流发酵生物制氢反应器具有结构简单、运行稳定、操作灵活、容积利用率高、生物持有量高以及运行费用较低等优点,在发酵生物制氢技术领域有很好的开发前景。 相似文献
109.
The behavior of sulfur transformation during rapid hydropyrolysis of coal was investigated using a pressurized, continuous free fall pyrolyzer under the conditions of temperature ranging from 923 to 1123 K and hydrogen pressure up to 5 MPa. The yields of sulfur converted to gas, tar and char were determined, together with the analyses of sulfur form distributions in coals and chars. The results showed that the decomposition of inorganic sulfur species was affected only by the temperature, while the increases in temperature and hydrogen pressure obviously enhanced the removal of organic sulfur from coal. The extent of organic sulfur removal was proportional to the coal conversion, depending on coal type. A significant retention of gaseous sulfur products by the organic matrix of the char was observed during hydropyrolysis of a Chinese coal above 1023 K, even under the pressurized hydrogen atmosphere. The kinetic analysis indicates that the rate of organic sulfur removal from coal was 0.2th-order with respect to the hydrogen pressure, and the activation energy for total sulfur removal and organic sulfur removal is 17-26 and 13-55 kJ/mol, respectively. The low activation energies suggest that the transformation and removal of sulfur from coal might be controlled by the diffusion and/or thermodynamic equilibrium during hydropyrolysis under the pressurized conditions. 相似文献
110.
建立了计算机辅助红外光谱法鉴定有机化合物及聚合物的新方法,介绍了计算有机化合物和聚合物的一些经验公式。程序设计首先收集、整理常用聚合物、有机添加剂和有机小分子的红外光谱数据,然后提取反映该物质特征的吸收峰数据,制作ACCESS数据库,利用VisualBasicDAO数据链接方式,根据查询要求动态链接数据库,利用要求查询的聚合物特性,经过经验公式的算法翻译,生成SQL查询语句进行查询。 相似文献