混合氢管道的腐蚀失效分析

针对原油劣质化导致蜡油加氢处理装置原料中硫、氮、氯等腐蚀性杂质含量增加,装置腐蚀风险增大等情况,通过分析加氢处理装置混合氢管道的腐蚀状况,试验测定了管道所处的环境中介质的腐蚀性杂质的类型和含量,分析了管道材料的化学成分,进行了管道材料的金相组织分析,以及腐蚀穿孔部位材料的电子显微分析和微区EDX分析,对管道内部的流体流动状态进行了模拟计算,确定了混合氢管道三通的腐蚀失效原因,提出了防止管道腐蚀失效的技术措施。     

用高效染料脱色菌和PVA降解菌混合培养液处理印染废水

在厌气－好气－活性碳三级串联工艺系统中，用７株高效染料脱色降解菌在厌气池中接种，在好气池中用聚乙烯醇降解菌富集培养液接种挂膜处理含ＰＶＡ和ＢＯＤ５／ＣＯＤｃｒ＜０．２的印染废水，经日处理１７ｔ废水的中试表明，当进水ＣＯＤｃｒ，ＢＯＤ５，ＰＶＡ，洗涤剂和色度含量分别为６８０ｐｐｍ，１１０ｐｐｍ，１３４ｐｐｍ，２．９４ｐｐｍ和６５倍时，在厌气池，好气池和活性碳池中的水力负荷分别为３．１７，３．０，１４     

污泥混配土中氮磷转化研究

污泥通过好氧堆肥反应腐熟,除去其中有害物质及降低重金属含量后达到农用标准,然后在温室大棚内进行种植实验,将堆肥按不同混配方式施入土壤中。研究污泥混配土中氮磷的变化表明:混配土中的总氮在种植过程中被作物吸收和自身流失,有一定程度降低;氨态氮经过转化和作物吸收,降低很快。混配土中总磷的含量在种植过程中基本不变,作物生长只需少部分磷,在温室中种植避免了磷的流失;速效磷的变化较为复杂,种植一段时间后,速效磷呈现上升趋势。     

Effect of lanthanum loading on nanosized CeO2-ZnO solid catalysts supported on cordierite for diesel soot oxidation

We report the application of a solid lanthanum–ceria–zinc catalyst in the catalytic regeneration of diesel particulate filters(DPF) in diesel engines.We synthesized a CeO_2–ZnO–La_2O_3(Ce–Zn–La) mixed oxide by a lactic acid-mediated sol–gel method,which efficiently coated cordierite substrates for soot capture and combustion.We studied the effects of La loading on the physicochemical and catalytic properties of Ce–Zn mixed oxide during lowtemperature soot combustion processes.We characterized the synthesized catalysts by X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),N2 adsorption,Raman spectroscopy,oxygen storage capacity(OSC),and scanning and transmission electron microscopy(SEM and TEM).Thermogravimetric and differential thermal analysis(TGA/DTA)confirmed that the catalysts effectively reduced the soot oxidation temperature.The ternary Ce–Zn–La mixed oxide catalyst with Ce/Zn/La atomic ratio of 2:1:0.5 had the highest catalytic activity and promoted soot oxidation at temperatures below 390°C.This indicated that the large number of oxygen vacancies in the catalyst structure generated oxygen species at low temperatures.Raman spectroscopy measurements revealed the presence of oxygen vacancies and lattice defects in Ce–Zn–La samples,which were key parameters concerning the stability and redox properties of the prepared catalysts.     

海洋菌株y3的分离鉴定及其异养硝化-好氧反硝化特性

从胶州湾海底沉积物中筛选出1株高效的海洋异养硝化-好氧反硝化细菌y3,经形态学观察、生理生化实验和16S rRNA基因序列分析,确定该菌株为假单胞菌属(Pseudomonas sp.).对其在实际含氮海水中的脱氮实验结果表明,菌株y3的最佳碳源为柠檬酸三钠,最适p H为7.0,最适C/N为13;菌株均能以NH4Cl、Na NO_2和KNO_3为唯一氮源进行反应,20 h后其去除率分别为98.69%、78.38%和72.95%,在硝化过程中几乎没有亚硝酸盐和硝酸盐的积累.以不同比例混合两种氮源反应20 h,当NO~-_3-N∶NO~-_2-N分别为2∶1、1∶1和1∶2时,脱氮率分别为99.56%、99.75%和99.41%;当NH~+_4-N∶NO~-_3-N分别为2∶1、1∶1、1∶2时,脱氮率均为100%;当NH~+_4-N∶NO~-_2-N分别为2∶1、1∶1、1∶2时,脱氮率分别为90.43%、92.79%和99.96%,多高于单一氮源的情况.该菌株具有较好的高盐废水脱氮处理效能.     

有机胺对CO2吸收解吸的研究

利用常压搅拌吸收-解吸装置,在不同温度和浓度条件下,对MEA(乙醇胺)、DEA(二乙醇胺)、MDEA(N-甲基二乙醇胺)、TETA(三乙烯四胺)、DETA(二乙烯三胺)5种有机胺吸收解吸CO2进行研究.探讨了反应温度、吸收液浓度、有机胺种类对CO2吸收和解吸过程的影响规律,并利用正交试验法筛选出性能较好的混合胺复配剂.结果表明,当TETA/DEA=5:1,吸收温度为318K,解吸温度为388K时,混合胺具有较优的吸收解吸综合性能.     

混合菌种在发酵法生物产氢中的协同作用

为探讨产氢发酵细菌混合培养时菌种间的协同作用,本研究在间歇试验条件下,分别考察以葡萄糖和复杂有机物(淀粉、牛肉膏、聚乙二醇乙二酸酯和胰蛋白胨)为底物时,5株HPB(B49、H1、LM12、LM11和B51)混合培养,高效HPB(B49)与3株非产氢发酵细菌(L10、拟3-2和芽孢1)分别混合培养,以及B49与活性污泥混合培养对产氢能力的影响.试验结果表明,混合菌种间协同作用发挥是有条件的.当利用葡萄糖发酵产氢时,菌种间对共同底物的竞争使其协同作用无法发挥,从而制约了高效产氢细菌(HPB)的产氢能力;而利用复杂有机物发酵产氯时,菌种间的协同作用得以发挥,并促进了高效HPB产氢能力的提高.同时提出,针对不同底物可以采用不同的培养方式.     

系列混合碳源条件下颗粒化EBPR系统菌群结构变化规律研究

在SBR反应器中接种富含聚磷菌的活性污泥,采用一系列不同丙酸/乙酸比例混合的碳源进行EBPR系统污泥的颗粒化培养,并考察了颗粒化进程中的系统菌群结构变化,以及不同混合碳源条件对系统功能菌种竞争的影响.结果表明,污泥颗粒化过程对EBPR系统菌群结构产生了较大的筛选作用.原本在系统中占优势的一类Uncultured bacterium被迅速淘汰;Uncultured Rhodocyclaceae bacterium、部分Candidatus Competibacter phosphatis、部分Denitrifying bacterium、Acinetobacter及部分Uncultured alpha proteobacterium分别逐渐被淘汰.在各个成熟的颗粒化EBPR系统中,除磷微生物主要为Uncultured Chlorobi bacterium与Uncultured alpha proteobacterium.不同混合碳源条件培养的颗粒化EBPR系统菌群结构差异主要表现为Candidatus Competibacter phosphatis(聚糖菌)与Uncultured Chlorobi bacterium(聚磷菌)菌群数量的不同.混合碳源中乙酸比例的提高可造成颗粒化EBPR系统中Candidatus Competibacter phosphatis的增长,使系统的除磷效率下降.而碳源中丙酸比例相对较高的条件有利于Uncultured Chlorobi bacterium增长,从而有助于颗粒化EBPR系统维持较好的除磷效率.     

污泥与煤在CO2/O2及N2/O2气氛条件下的混燃特性分析

采集了广州具有代表性的市政污泥,利用热重法对单一污泥、煤及其混合样品在CO_2/O_2及N_2/O_2气氛条件下进行了TG(热重)实验,同时计算了污泥和煤的4个燃烧特性指数,获得了燃烧的动力学参数.实验结果表明,污泥燃烧有4个燃烧阶段,包括水分析出、挥发分析出与燃烧、固定碳的燃烧和无机盐类挥发分解,其中,挥发分析出与燃烧是污泥燃烧的主要阶段;煤掺烧污泥可以提高煤的着火性能.在CO_2/O_2及N_2/O_2燃烧气氛下,增加O_2浓度,污泥与煤混合样的热重曲线整体向低温区移动,微商热重曲线峰值增大,峰宽变小,燃烧性能增强.在CO_2/O_2气氛下,O_2浓度从30%增加到60%时,污泥的挥发分释放特性指数D、可燃性指数C、燃尽指数Cb、综合燃烧特性指数S分别增加了45%、12%、18%、6%.相同O_2浓度条件下,污泥与煤在CO_2/O_2气氛下的着火性能较N_2/O_2气氛滞后,最大峰值变小,高浓度的CO_2抑制其混合样的燃烧.采用Coats-Redfern方程计算得到3个燃烧阶段反应的动力学参数,其中,增加O_2浓度,污泥与煤混合样品的质量平均表观反应活化能Em减小,并且O_2浓度越高越有利于燃烧反应的进行.污泥与煤混合燃烧取n=2可以对挥发分燃烧与固定碳燃尽峰峰前与峰后的反应模型进行描述.     

Total mercury in wild fish in Guizhou reservoirs, China

The health hazard of mercury (Hg) compounds is internationally recognized, and the main pathways for methylmercury (MeHg) intake in humans are through consumption of food, especially fish. Given the large releases of Hg to the environment in China, combined with the fast development of hydropower, this issue deserves attention. Provided similar mobilization pathways of Hg in China as seen in reservoirs in North America and Europe one should expect increased Hg contamination in relation to future hydropower reservoir construction in this country. This study presents total Hg (THg) concentrations in wild fish from six Guizhou reservoirs, China. The THg concentrations in fish were generally low despite high background levels in the bedrock and depositions from local point sources. The over all mean ± SD concentration of THg was (0.066 ± 0.078) μg/g (n = 235). After adjusting for among-reservoir variation in THg, there were significant differences in THg among functional groups of the fish, assumed to re?ect trophic levels. Predicted THg- concentration ratios, retrieved from a mixed linear model, between the functional groups were 9:4:4:1 for carnivorous, omnivorous, planktivorous and herbivorous fish. This result indicated that MeHg accumulation may prevail even under circumstances with short food chains as in this Chinese water system. No fish exceeded recommended maximum THg limit for human consumption set by World Health Organization and the Standardization Administration of China (0.5 μg/g fish wet weight (ww)). Only six fish (2.5%) exceeded the maximum THg limit set by US Environmental Protection Agency (0.3 μg/g fish ww).