Simultaneous sulfide and acetate oxidation under denitrifying conditions using an inverse fluidized bed reactor

BACKGROUND: Simultaneous removal of sulfur, nitrogen and carbon compounds from wastewaters is a commercially important biological process. The objective was to evaluate the influence of the CH₃COO^?/NO₃^? molar ratio on the sulfide oxidation process using an inverse fluidized bed reactor (IFBR). RESULTS: Three molar ratios of CH₃COO^?/NO₃^? (0.85, 0.72 and 0.62) with a constant S^2?/NO₃^? molar ratio of 0.13 were evaluated. At a CH₃COO^?/NO₃^? molar ratio of 0.85, the nitrate, acetate and sulfide removal efficiencies were approximately 100%. The N₂ yield (g N₂ g^?1 NO₃^?‐N consumed) was 0.81. Acetate was mineralized, resulting in a yield of 0.65 g inorganic‐C g^?1 CH₃COO^?‐C consumed. Sulfide was partially oxidized to S⁰, and 71% of the S^2? consumed was recovered as elemental sulfur by a settler installed in the IFBR. At a CH₃COO^?/NO₃^? molar ratio of 0.72, the efficiencies of nitrate, acetate and sulfide consumption were of 100%, with N₂ and inorganic‐C yields of 0.84 and 0.69, respectively. The sulfide was recovered as sulfate instead of S⁰, with a yield of 0.92 g SO₄^2?‐S g^?1 S^2? consumed. CONCLUSIONS: The CH₃COO^?/NO₃^? molar ratio was shown to be an important parameter that can be used to control the fate of sulfide oxidation to either S⁰ or sulfate. In this study, the potential of denitrification for the simultaneous removal of organic matter, sulfide and nitrate from wastewaters was demonstrated, obtaining CO₂, S⁰ and N₂ as the major end products. Copyright © 2008 Society of Chemical Industry     

稳定同位素井间示踪技术在深层块状稠油油藏水驱特征研究的应用

经对冷43块深层块状普通稠油水驱注水5个试验井组开展的稳定同位素示踪测试，利用中子活化技术分析样品，采用先进的示踪剂定量分析与流动模拟相互结合的方法，以示踪数值模拟为手段，评价了油井连通、油层平面及纵向上的非均质性、隔层的封隔性等因素对水驱控制程度及动用状况的影响，通过优化注水推进方向及速度，强化动态调整措施，提高了稳产基础。     

理学SMX-10/11型X荧光光谱仪的改进

对理学SMX-10／ll型X荧光光谱仪真空系统、样品定位系统及热交换器冷却水循环路径等易发生故障部位进行改进，并在11型仪器上增加了S元素分析通道。生产应用表明，改进效果良好，简化了分析工艺。降低了分析成本，提高了仪器的稳定性。     

动力配煤高温复合固硫剂研究

分析了高温复合固硫剂各成分的作用，实验研究了在不同配比的燃烧试验下，各成分对燃煤着火和燃烧以及对炉渣固硫的影响，得出了该煤种高温复合固硫剂的最佳配方。     

微波消解-ICP-AES法测定菜油中P、S

采用微波加热,在高温高压下酸消解样品,运用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定菜油中P、S。本法选用紫外区谱线P178.221nm、S180.669nm,避免了基体中存在的Fe、Zn、Al、Cu、Mn、Ca等元素的光谱干扰。实验通过用纯氮吹扫光谱仪光路的方法消减空气中氧对紫外线的吸收,获得了足够的灵敏度。该方法简便、快速,稳定可靠,P、S检出限分别为0.067、0.078μg/ml,RSD为1.35%～5.05%,回收率为89.0%～100.9%。     

激光激活化学反应分离同位素反应池参数确定及其影响

在气体分子运动论、碰撞理论、流体力学和光化学反应、热化学反应及高斯光束理论基础上建立了位于激光器腔内外的反应池的设计尺寸同各相关参量和同位素产物产率、同位素分离系数间的关系，并给出了一些计算结果。     

常减压蒸饱装置几起典型硫腐蚀事例分析

随着高（含）硫原油加工量的增加,硫腐蚀事故也时有发生。通过对常减压装置硫腐蚀事例进行分析,指出合理的混炼比,加强“一脱三注”管理,材料升级和实施腐蚀监测是防止腐蚀事故发生的有效措施。     

康山金矿地质地球化学特征及其成因

康山金矿产在豫西熊耳山古隆起区的结晶基底太华群和盖层中元古界熊耳群地层接触界面附近，矿体严格受构造破碎蚀变带控制。流体包裹体，稳定同位素等研究表明，成矿物质来自太华群变质岩，成矿流体的性质与变质热液截然不同，而与花岗岩浆热液相近似。该矿床的形成与燕山期发生的同构造－花岗岩浆期热液活动有关，金沉淀成矿阶段有大气水的混入。     

Natural isotope fractionation in the discrimination of sugar origins

More than 500 carbohydrate samples have been characterised by hydrogen, carbon and oxygen isotopic parameters measured on ethanol and water resulting from controlled fermentation. Different chemical states of the carbohydrate pool have been considered: polysaccharides from cereals, tubers and leguminosae (maize, sorghum, rice, wheat, barley, potato, bean), glucose, fructose and sucrose from fruits (pineapple, citrus, apple, soft fruits), sucrose from sugar plants (beet, cane). The overall carbon-13 content of ethanol and the deuterium and oxygen-18 contents of water before fermentation were determined by mass spectrometry of isotope ratios whereas the investigation of site-specific natural isotope fractionation by deuterium NMR has provided access to the deuterium contents in the methyl (I) and methylene (II) sites of ethanol. The results have been analysed in the multidimensional space of these isotopic variables. Hierarchical clustering, principal component and discriminant analyses have been performed. Among fruits, for example, the pineapple group exhibits a 100% discrimination with respect to the apple and citrus groups which are themselves well distinguished. A still higher discrimination is reached between the three groups, citrus, cane and beet, and the addition of 10% exogenous cane or beet sucrose to citrus juice is unambiguously detected.     

Ethynedithiol‐based polyeneoligosulfides as active cathode materials for lithium‐sulfur batteries

Ethynedithiol‐based polyeneoligosulfides have been synthesized in 96% yield by the reaction of sodium acetylides (HC?CNa, NaC?CSNa) and elemental sulfur through the Na? C_sp bond in liquid ammonia with the following spontaneous polymerization of ethynedithiols (HSC?CSH) formed by the hydrolysis. The polyeneoligosulfides synthesized are brown powders (up to 77% sulfur content, mp 128–184°C), partially soluble in organic solvents. They are high‐resistance semiconductors (10^?13 to 10^?14 S cm^?1), possess paramagnetic (10¹⁷ to 10¹⁸ spin g^?1) and redox properties. The oligosulfides obtained, being redox systems capable of reversible redox processes, provide high values of discharge capacity (345–720 mA h g^?1) of rechargeable lithium‐sulfur batteries. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008