海水中挥发酚的在线蒸馏-流动注射分析

采用流动注射分析仪测定渔业养殖海水中的挥发酚.方法的检出限为0.89μg/L;线性范围为0.002～0.1 mg/L,线性相关系数r≥0.999;其相对标准偏差为1%～5%,样品测定频率为18样/h.本方法操作简便、灵敏度较高,线性范围、精密度和准确度均符合国家标准.对海水水样加标回收率的测定为90%～110%,结果令...     

Combining steam injection with hydraulic fracturing for the in situ remediation of the unsaturated zone of a fractured soil polluted by jet fuel

A steam injection pilot-scale experiment was performed on the unsaturated zone of a strongly heterogeneous fractured soil contaminated by jet fuel. Before the treatment, the soil was stimulated by creating sub-horizontal sand-filled hydraulic fractures at three depths. The steam was injected through one hydraulic fracture and gas/water/non-aqueous phase liquid (NAPL) was extracted from the remaining fractures by applying a vacuum to extraction wells. The injection strategy was designed to maximize the heat delivery over the entire cell (10 m × 10 m × 5 m). The soil temperature profile, the recovered NAPL, the extracted water, and the concentrations of volatile organic compounds (VOCs) in the gas phase were monitored during the field test. GC-MS chemical analyses of pre- and post-treatment soil samples allowed for the quantitative assessment of the remediation efficiency. The growth of the heat front followed the configuration of hydraulic fractures. The average concentration of total hydrocarbons (g/kg of soil) was reduced by ～ 43% in the upper target zone (depth = 1.5-3.9 m) and by ～ 72% over the entire zone (depth = 1.5-5.5 m). The total NAPL mass removal based on gas and liquid stream measurements and the free-NAPL product were almost 30% and 2%, respectively, of those estimated from chemical analyses of pre- and post-treatment soil samples. The dominant mechanisms of soil remediation was the vaporization of jet fuel compounds at temperatures lower than their normal boiling points (steam distillation) enhanced by the ventilation of porous matrix due to the forced convective flow of air. In addition, the significant reduction of the NAPL mass in the less-heated deeper zone may be attributed to the counter-current imbibition of condensed water from natural fractures into the porous matrix and the gravity drainage associated with seasonal fluctuations of the water table.     

连续流动分析仪测定水中总氮的特性研究

运用AA3连续流动注射分析仪测定水中总氮,测试了仪器的示值误差、重复性、稳定性等相关特性指标,由检测数据可以得出该方法线性关系好,精密度和准确度高,检出限低,加标回收率为93%-104%,与传统的碱性过硫酸钾消解—紫外分光光度法相比,该方法具有分析速率快、试剂消耗量低等优点,适用于环境监测分析工作。     

沼液施用对麦稻茬口期土壤微生物群落结构特征及功能的影响

为揭示麦稻茬口期沼液施用对土壤微生物群落及功能的影响,通过土柱试验,设置麦秆还田后3种处理［无氮肥（CM）、常规施肥（SN）和添加沼液（SZ）］,采用Illumina高通量测序技术分析了土壤淹水后1 d和21 d土壤细菌及真菌群落的组成、多样性和结构差异,并对其功能进行预测.微生物多样性分析表明,1 d时各处理的真菌α多样性指数均显著高于21 d处理且各处理间无显著差异;21 d时各处理细菌Simpson指数开始出现差异,SZ-21处理的细菌Simpson指数高于SN-21处理,而细菌Chao1指数显著低于SN-21处理;细菌群落结构分析表明,1 d时,SN处理的厚壁菌门、绿弯菌门和放线菌门与其它处理差异较大,而21d时,SZ和SN处理的各细菌菌门相对丰度相似;真菌群落结构分析表明,1 d时,SZ处理中的子囊菌门和接合菌门相对丰度高于SN和CM处理;21 d时,SN和SZ处理的子囊菌门相对丰度均低于CM处理,而接合菌门的相对丰度均高于CM处理.NMDS分析表明,21 d时,SN和SZ处理的细菌和真菌群落组成均有逐渐相似的趋势.PICRUSt功能分析表明,不同时期和不同处理的土壤细菌群落在功能层上表现相似,FUNGuild功能预测反映SZ-21和SN-21处理的真菌功能主要差异体现在腐生营养型和病理营养型上.综上说明茬口期施沼液在一定程度上可以替代化肥平衡土壤养分和维持土壤生态功能,但仍可能存在真菌致病风险.     

风筒位置对掘进巷道流场影响的PIV实验*

为探究风筒位置对掘进巷道风流分布规律的影响,利用Fluent软件确定出实验模型内流体进入“第二自模区”的临界风速,保证实验模型与实际巷道的流动相似,采用粒子图像测速仪（PIV）对压、抽风筒距迎头不同距离下的前压后抽式通风流场进行测量。实验结果表明:抽风筒距巷道迎头距离的改变对迎头处流场影响较小,涡流中心位置也不会发生改变,当抽风筒距迎头距离大于4.5S,回流区的风流充分发展,流动较为平缓。压风筒距巷道迎头距离的改变对迎头处流场和涡流影响较大,当压风筒距迎头距离大于3S,涡流中心位置向远离迎头的方向移动,涡流区域逐渐扩大。基于相似理论的PIV实验结果可为矿井掘进巷道通风工作提供一定参考。     

油田化工污水中总氰化物的检测

采用在线蒸馏-流动注射分析法检测大庆油田化工污水中总氰化物。分析流速和温度对流动注射仪检测结果的影响,得出结论:载流流速为1.8mL/min,显色剂流速在1.3mL/min,缓冲溶液流速稳定在1.6mL/min时,分析精度最好;显色反应在60℃以下进行时,可以消除温度差异对检测结果的干扰。该方法适用于油田化工废水中总氰化物的检测。     

浅谈防止海上油田地质性溢油的几个因素

油田在注水开发过程中由于注水工艺不完善、注水水质不达标、注采比不合理、井控措施无效等因素会导致地质性溢油事故的发生。文章主要针对注水性油田在开发过程中可能会导致地质性溢油的几个关键因素进行探讨,为注水性油田开发风险防范和环境保护提供参考。     

Combustion,performance and emissions of a DI-CI engine running on Karanj methyl ester: influence of injection timing

This study aims at evaluation of the effect of injection timing on the combustion, performance and emissions of a small power diesel engine, commonly used for agriculture purpose, running on pure bio-diesel, prepared from Karanj (Pongamia pinnata) vegetable oil. The effect of varying injection timing was evaluated in terms of thermal efficiency, specific fuel consumption, power and mean effective pressure, exhaust temperature, cylinder pressure, rate of pressure rise and the heat release rate. Furthermore, the effects on emissions of unburnt hydrocarbons, oxides of nitrogen, carbon monoxide and carbon dioxide and smoke were also studied. It was found that retarding the injection timing by 3° enhances the thermal efficiency by about 8.2% with reduction in emission of oxides of nitrogen.     

长距离输煤管道储浆罐与石油储罐对比研究

对比研究长距离输煤管道储浆罐与石油储罐搅拌设计特点、罐顶设计特点、消防安全设施特点。经分析可知,长距离输煤管道储浆罐宜选用推进式搅拌器,罐壁上设置导流结构,宜采用固定顶、锥顶,设置简单消防安全设施,宜选用难燃保温材料;石油储罐优先选用旋转喷射式搅拌器,罐内油品进行定期搅拌,采用浮顶,大型的一般选用外浮顶,需设置完善消防安全设施。     

Use of micellar liquid chromatography for rapid monitoring of fungicides post harvest applied to citrus wastewater

A method based on micellar liquid chromatography has been developed to simultaneously monitor four pesticides largely post-harvest applied to citrus:thiabendazole,pyrimethanil,o-phenylphenol and imazalil.Water samples were filtered and directly injected without other treatment,thus avoiding extraction steps.The composition of the mobile phase was optimized using a chemometrical approach to achieve and excellent resolution to 0.07 mol/L SDS/5%,V/V 1-pentanol buffered at p H 3.Mobile phase run through a C18 column at 1 m L/min at room temperature.The detection was performing by UV–Visible absorbance using a wavelength program:0–10 min,305 nm(for thiabendazole);10–12;265 nm(for pyrimethanil)and 12–18,220 nm(o-phenylphenol and imazalil).The developed method was validated following the guidelines of the US Environmental Protection Agency in terms of:quantitation range,(0.5–4 to 15μg/m L),linearity(r20.9995),sensitivity(LOD,0.18–1.4μg/m L),precision(9.2%),trueness(93.9%–103.7%),and ruggedness(9.9%).It was found that the fungicides remain up to eight days in surface water at outdoor conditions.The method was used to screen the presence of the analytes in several waste water samples,and was proved to be useful in routine analysis.