采用压滤机回收钙镁盐泥、除硝盐泥中的盐分

介绍了连云港碱厂用压滤机回收盐水精制澄清桶排出的钙镁盐泥中的盐分和均相流除硝反应器放出的石膏盐泥中盐分的情况,装置在试生产过程中经过多次调试和改造,在设备、工艺及环境方面得到了较大改善,达到了预期的效果。     

氯碱盐泥系统的工艺改进

利用原钡法除硝闲置的道尔澄清桶改变了盐泥系统工艺流程,使盐泥系统良性循环,并且在盐泥压滤系统增加了压缩空气吹干和连锁系统,形成了良好的盐泥滤饼.     

联碱氨Ⅱ泥与母Ⅱ沉淀兑合综合处理新工艺

简介联碱生产装置母液封闭循环中的AⅡ泥、MⅡ沉淀循环、洗盐工序洗涤卤水精制的盐泥处理和排放的工艺路线,提出AⅡ泥与MⅡ桶锥底沉淀兑合进行二次澄清和稠厚,其稠厚的晶浆送入洗盐脏卤水精制除钙综合利用,其AⅡ泥与盐泥共同采用板框压滤的工艺路线,实现生产装置低消耗和环保目标。     

联碱氨Ⅱ泥与母Ⅱ沉淀系统综合处理工艺路线探讨

本文介绍了目前联碱生产装置氨Ⅱ泥排放和母Ⅱ沉淀系统处理的工艺路线。阐述母液Ⅱ杂质进入氨Ⅱ澄清桶长流程及氨Ⅱ泥压滤存在的问题，提出氨Ⅱ泥排放与母液Ⅱ沉淀排放共同入澄清桶兑合二次澄清工艺路线。澄清桶锥底泥送入精制洗盐澄清桶除钙回收母液。采用混合盐泥系统共同处理的方法。实现生产装置的优质、低消耗和环保的目标。     

盐水中硫酸根去除工艺改造

介绍一种适用于氯碱生产企业的膜法除硝处理装置。采用这种先进的膜法除硝装置替代现有的钡法除硝,可以避免人员中毒,减少硫酸钡盐泥排放,节约生产成本。吉林石化电石厂实践证明,该装置能满足烧碱装置的需要。     

无水硫酸钠生产中硝水除钙镁工艺研究

本文介绍无水硫酸钠生产中硝水除钙镁的工艺研究。采用硫脲生产中排出的石灰氮渣除镁和碳酸氢钠除钙的办法,具有清除硝水中钙镁效果好、费用低、过滤和澄清没备的生产强度大等优点,是硝水除钙镁较理想的方法。     

对硝水除钙镁生产工艺的研究

通过硝水除钙镁试验和生产运行，说明用石灰氮渣除镁、用碳酸氢钠除钙是一种较理想又实用的硝水除钙镁生产的新工艺。     

脱碳溶液中钙镁离子的带入途径及危害

合成氨装置脱碳溶液中钙镁离子的带入会在CO2富集处(再生塔除沫器顶部)产生结垢,堵塞再生塔除沫器,进而影响装置的安稳运行。分析了钙镁离子的来源、结垢机理,以及防范钙镁离子进入的措施。     

盐泥制浆装置优化改造

介绍了连云港碱业有限公司用离心机回收盐水精制澄清桶排出的钙镁盐泥,分离出的固体盐泥加水制成盐泥浆液供热电脱硫用,装置在试生产过程中经过多次调试和改造,在设备、工艺及环境方面得到了较大改善,达到了预期的效果。     

稀硝酸替代盐酸作为再生剂在除盐系统的运用

使用间硝生产中产生的镁尾水替代盐酸作为阳床再生剂对除盐再生系统进行改造。实践证明 ,改造是成功的 ,不仅解决了间硝装置含酸废水的达标排放问题 ,而且具有显著的经济效益。     

佛山市顺德新城区降水中污染物的监测和分析

为掌握佛山市顺德新城区降水中污染物的情况,2015年7月至8月,文章作者分别在雨天进行了降水取样,对降水中的pH、电导率、常见阴离子(F-、Cl~-、NO_3~(2-)、SO_4~(2-))及部分重金属(铅和镉)进行监测分析。选择有相关数据的珠江三角洲和石家庄、厦门等地的降水中污染物的情况进行对比。结果表明,顺德新城区降水中的p H和部分阴离子浓度优于珠江三角洲平均值,酸雨类型属于硫酸和硝酸混合型;其水体洁净程度略差于石家庄;铅和镉的浓度也高于厦门,甚至部分超出了人体能直接接触的安全范围。     

Metabolism of trideuterated iso-lignoceric acid in rats in Vivo and in human fibroblasts in culture

Saturated very long chain fatty acids (fatty acids with greater than 22 carbon atoms; VLCFA) accumulate in peroxisomal disorders, but there is little information on their turnover in patients. To determine the suitability of using stable isotope-labeled VLCFA in patients with these disorders, the metabolism of 22-methyl[23,23,23-²H₃]tricosanoic (iso-lignoceric) acid was studied in rats in vivo and in human skin fibroblasts in culture. The deuterated iso-VLCFA was degraded to the corresponding 16- and 18-carbon iso-fatty acids by rats in vivo and by normal human skin fibroblasts in culture, but there was little or no degradation in peroxisome-deficient (Zellweger’s syndrome) fibroblasts, indicating that its oxidation was peroxisomal. Neither the 14-, 20-, and 22-carbon iso-fatty acids nor the corresponding odd-chain metabolites could be detected. In the rat, the organ containing most of the iso-lignoceric acid, and its breakdown products, was the liver, whereas negligible amounts were detected in the brain, suggesting that little of the fatty acid crossed the blood-brain barrier. Our data indicate that VLCFA labeled with deuterium at the ω-position of the carbon chain are suitable derivatives for the in vivo investigation of patients with defects in peroxisomal β-oxidation because they are metabolized by the same pathways as the corresponding n-VLCFA. Moreover, as iso-VLCFA and their β-oxidation products are readily separated from the corresponding n-fatty acids by normal chromatographic procedures, the turnover of VLCFA can be more precisely measured. A preliminary report of part of this work (Reference 18) was presented at the 5th International Symposium on the Synthesis and Applications of Isotopes and Isotopically Labelled Compounds, Strasbourg, France, June 20–24, 1994.     

高效液相色谱法分析化妆品中微量成分的研究进展

综述了高效液相色谱法在化妆品中防腐剂、防晒剂中紫外线吸收剂以及性激素的检测等几个方面的应用;同时,介绍了分析所用的色谱柱、流动相、使用的检测手段以及样品的提取方法;最后针对目前存在的问题,提出了高效液相色谱用于化妆品中微量成分分析的研究方向和发展前景。     

Denitrification in shallow groundwater in a coastal agricultural area in Japan

In a coastal agricultural area in the central part of Japan (Shizuoka), we found decreasing nitrate concentration with depth in a shallow groundwater, where the depth to water table varied between 0.6 and 1.2 m below ground surface. High nitrate concentrations (5–29 mg N L^–1) were often observed in the upper layer (0–2 m) of the groundwater, but the concentration decreased to less than 1 mg N L^–1 in the deeper layer. Ammonium was scarcely detected, and the concentration of dissolved oxygen was usually low (< 1 mgO₂ L^–1) in the groundwater. Nitrate in the groundwater often had very heavy nitrogen stable isotope ratios (>20{}). There was a negative relationship between nitrogen stable isotope ratio of nitrate and its concentration. When nitrate was injected into the groundwater with acetylene and bromide (a conservative tracer), nitrate concentration decreased to 20% of the initial level within 5 days, accompanied by the increase in nitrite and nitrous oxide concentration and a little change in bromide concentration. These results indicate that microbial denitrification plays a potential role in the decrease of nitrate in shallow groundwater at the study site.     

我国硝酸工业生产技术新进展

系统叙述了我国硝酸工业2000-2007年生产现状及主要技术成果,尤其指出了国产"四合一"机组的成功投运,使我国硝酸国产化装置取得较大的进步,表现在吨酸的铂耗、氨耗和能耗等方面接近国外引进装置水平,同时介绍了国外双加压法硝酸生产技术的进展.我国已成为硝酸生产大国,仍需以先进的技术改造和发展我国硝酸工业,确保我国硝酸工业健康有序地发展,加快从硝酸生产大国向强国迈进的步伐.