利用数字化实验研究“油封”对水中溶解氧的影响

通过光学溶解氧传感器分别测定花生油和煤油以“油封”方式对水中溶解氧的影响,证实了植物油和矿物油“油封”都不能完全隔绝氧气,但能明显减小氧的溶解速率,在一定时间内使水或溶液中溶解氧处于低浓度状态,且植物油比矿物油更有利于维持水样的贫氧状态。     

红外分光光度法测定工作场所空气中矿物油雾浓度

以玻璃纤维滤膜采集工作场所空气中矿物油雾,用四氯化碳浸提,采用红外分光光度法测定矿物油雾含量.对采样方法、玻璃纤维滤膜处理方法进行了探讨.矿物油雾浓度在0.0～252.0μg/mL范围内与吸光度呈良好的线性关系,相关系数r=0.9995,加标回收率为98.7％～102.3％,方法检出限为2.0 μg/mL,测定结果的相对标准偏差为0.80％～ 1.39％(n=6).该方法适用于工作场所空气中矿物油雾浓度的测定.     

SPME-GC联用测定环境水样中的酚类化合物

建立了固相微萃取与气相色谱联用技术测定环境水样中酚类化合物的方法. 探讨了pH、离子强度、萃取头类型、萃取时间以及解析时间等条件对酚类化合物萃取量的影响, 优化了GC仪器条件. 在优化的条件下, 酚类化合物的响应值与浓度有良好的线性关系, 线性范围为0.20～200 μg/L, 检出限在0.019～0.10 μg/L之间, 相对标准偏差(RSD, n=5)为4.4%～11%, 水样平均加标回收率为92.2%～101.9%, 所建立的方法可测定环境水样中的酚类化合物.     

氢化物发生-原子荧光光谱法对环境水样中砷(Ⅲ)与砷(Ⅴ)的直接测定

建立了氢化物发生-原子荧光光谱直接测定水样中As(Ⅲ)和As(Ⅴ)的方法,操作简便,实用性强.考察了HCl和KBH4浓度对As(Ⅲ)和As(Ⅴ)测定灵敏度的影响以及共存元素的干扰情况.通过测定经还原剂还原前后水样中砷的荧光强度,计算出As(Ⅲ)和As(Ⅴ)的含量.方法检出限为As(Ⅲ) 0.085 μg·L-1 ,As(Ⅴ) 0.108 μg·L-1.As(Ⅲ)和As(Ⅴ)的加标回收率分别为96% ～104%和97% ～104%,RSD均小于6%.该法用于实际水样的测定,结果较为满意.     

微型柱现场预富集流动注射火焰原子吸收光谱法测定环境水样中钴

以负载8-羟基喹啉(Oxine)、二乙基二硫代氨基甲酸钠(DDTC)和吡咯啶二硫代氨基甲酸铵(APDC)三种螯合剂的活性炭为微型柱的吸附材料,采用微型柱现场采样分析技术实现了连续现场富集环境水样中痕量钴,并在实验室中采用在线解吸流动注射火焰原子吸收光谱法对吸附柱中富集的钴进行了测定.该方法用于环境水样中钴的测定,10 mL富集水样的检出限(3σ)为1.13μg·L-1,分析了3件水样中的钴,测定结果的RSD(n=6)值均小于1 %.     

气相色谱法测定水样中三唑磷残留量

用气相色谱法对水样中残留的三唑磷的含量进行测定.水样经苯提取,采用HP-5毛细管色谱柱(30 m×0.32 mm,0.25 μm)分离,用氮磷检测器测定.三唑磷的质量浓度在0.0051.0 mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为3.5 μg·L-1.方法的回收率在94.0%～97.5%之间,测定结果的相对标准偏差(n=6)小于3.7%.     

污水BOD5测定中外界条件的影响

对污水BOD5(五日生化需氧量)测定中各种外界条件的影响进行了初步探讨。通过大量实验数据说明了样品保存时间、培养温度和样品pH值对BOD5测定的具体影响。当样品保存时间大于24h时,检测结果的偏差将大于10%,不能正确反映水样中有机物的含量。培养温度对不同性质的水样的影响不同。对于可生化性好的水样,培养温度对其BOD5的影响很大,25℃和20℃之间的偏差可达40%;对可生化性不好的水样,培养温度对其BOD5的影响不大,一般为5%左右,在国标GB7488-87允许的准确度范围内,可忽略。水样的pH值对其BOD5的影响很大,当水样的酸碱度为中性时,测定的BOD5才能正确反映水样中有机物的含量;当水样呈酸性或碱性时测定的BOD5均小于正常值。     

固相萃取-气相色谱法测定水中苯氯乙酮

采用固相萃取(SPE)法,从生物水样中提取目标化合物,应用毛细管气相色谱法进行测定,外标法定量.结果表明:方法的检出限为0.05 mg·L-1,加标回收率为94%～97%,测定的相对标准偏差(n＝6)小于3.0%.方法已用于生物水样中痕量苯氯乙酮的测定.     

硅藻土吸附在线柱富集-火焰原子吸收光谱法测定环境水样中痕量铜

提出了硅藻土吸附在线柱富集-火焰原子吸收光谱法测定环境水样中痕量铜的方法。利用硅藻土对环境水样中痕量铜在线预富集,浓集因子达到27.6,使火焰原子吸收光谱法的检测能力达到测定环境水样中痕量铜的要求。方法检出限为0.32μg.L-1,RSD(20μg.L-1)为3.52%,加标回收率为97.0%~105.0%。     

电极法测定废水中氨氮

介绍了采用电极法测定废水中氨氮时,以吹气法代替蒸馏法对废水水样进行预处理,简化了水样预处理的程序,样品中氨氮的释出率可达90%,加标回收率在60%-98.8%之间。对两种废水样各分析8次,得出其RSD值均小于5%。按3倍标准偏差计算方法的检出限为0.008 mg.L-1。定量测定的最高值为350 mg.L-1。     

Simultaneous Determination of Oil and Water in Soybean by LF-NMR Relaxometry and Chemometrics

A fast, non-destructive and eco-friendly method was developed to simultaneously determine the oil and water contents of soybean based on low field nuclear magnetic resonance(LF-NMR) relaxometry combined with chemometrics, such as partial least squares regression(PLSR). The Carr-Purcell-Meiboom-Gill(CPMG) magnetization decay data of ten soybean samples were acquired by LF-NMR and directly applied to the PLSR analysis. Calibration models were established via PLSR with full cross-validation based on the reference values obtained by the Soxhlet extraction method for measuring oil and oven-drying method for measuring water. The results indicate that the calibration models are satisfactory for both oil and water determinations; the root mean squared errors of cross-validation(RMSECV) for oil and water are 0.2285% and 0.0178%, respectively. Furthermore, the oil and water contents in unknown soybean samples were predicted by the PLSR models and the results were compared with the reference values. The relative errors of the predicted oil and water contents were in ranges of 1.25%-4.96% and 0.44%-2.49%, respectively. These results demonstrate that the combination of LF-NMR relaxometry with chemometrics shows great potential for the simultaneous determination of contents of oil and water in soybean with high accuracy.     

毛细管气相色谱法分析水及食油样品中倍硫磷的残留量

本文提出了分别以ＣＨ２Ｃｌ，及ＣＨ３ＣＮ为水样及食油样中残留倍硫磷的萃取剂，由弗罗里硅土柱预净化，采用高分离效能的宽口径毛细管柱和高灵敏的氮磷检测器分析倍硫磷残留量的方法。该方法的灵敏度、准克度及精密度均令人满意，经实际样品测定，表明方法是可行的。     

油田水中烷基酚的胶束电动色谱分离

采用硼酸盐-十二烷基硫酸钠胶束电动色谱对油田水中存在的烷基酚进行了分离分析。考察了影响分离的各种不同因素：缓冲液浓度、体系的pH值、胶束溶液浓度、分离电流、管住温度及有机添加剂β-环糊精等。在恒流100μA下,38min内可分离20种烷基酚。采用Cl－TBP萃淋树脂对油田水样进行了浓缩富集预处理。     

Demulsification of Gas Oil/Water Emulsion via High-Intensity Ultrasonic Standing Wave

High-intensity ultrasonic standing wave field was established in a horizontal direction and its effect on “gas oil” in “water” emulsion separation rate was studied. Also, effects of four parameters on emulsion instability behavior were investigated: ultrasound irradiation time (5–30 min), emulsion position in ultrasound field (17–37 cm), ultrasound input intensity (20, 45, and 75%) and dispersed phase concentration (0.5, 2, and 10%). Emulsion light absorbance, droplet diameter and distribution were measured to analyze separation efficiency. The optimum states were 10% oil in water emulsion treated at 17 cm distance from ultrasound source under 30 minutes irradiation time and 20% sound intensity.     

溶气浮选技术在某油田污水处理中的应用研究

对气浮技术用于处理江苏某油田采出水进行现场调试和运行,分析了影响浮选除油效果的因素。该工艺适用于油水密度差小、乳化程度高的采出水处理,大量污油在气浮选工段被去除,除油效率达90％以上,提高了回收污油质量,减少大量的污油排出,延长了过滤罐滤料的使用周期,减轻过滤罐的生产负荷,为高乳化含油污水处理提供了可借鉴的经验。     

离子色谱法测定高氯、高钠油田回注水中的阴、阳离子及有机酸

建立了高氯、高钠油田回注水中痕量无机阴、阳离子和有机酸的离子色谱分析方法。对高钠基质中痕量阳离子的测定,选用IonPac CS12A分析柱、H2SO4溶液梯度淋洗、电导检测器检测;对高氯基质中阴离子及有机酸的测定,选用对OH-具有高选择性的高容量的IonPac AS11-HC柱、KOH梯度淋洗、电导检测器检测。在优化的梯度淋洗条件下,高氯或高钠的存在不影响痕量阴离子或阳离子的测定。该方法具有良好的线性(r=0.9926~0.9990)和精密度(测定组分峰面积的相对标准偏差(n=7)在8.0%以下),回收率     

气相色谱-质谱联用技术测定水中油

本文综述了近年来用气相色谱法测定水中油的技术进展。引用文献13篇。     

Separation and Determination of Diol Pollutants Come from Demulsifier in the Produced Water of Oil Fields

This paper introduced a novel test method for determination of the main demulsifier‐based pollutants in the produced water of oil wells, before draining to seawater. The type, concentration and distribution of diols depend on the demulsifier of interest; however, the main chemical species are the same. The novelty of this work is selective extraction and preconcentration of low chain diols in the produced water of oil fields. In this extraction method, dispersive solvent (1.2 mL, acetonitrile) containing extraction solvent (10.0 μL, carbon tetrachloride) was rapidly injected into the water sample containing analytes, and a cloudy solution was formed. After centrifugation (2 min at 3,000 rpm), these droplets were sedimented in the bottom of the conical test tube. Then 2.0 mL of sedimented phase containing preconcentrated analytes was injected into the gas chromatograph with flame ionization detector. The parameters affecting the extraction efficiency were evaluated and optimized. Factors such as the kind and volume of both extraction and disperser solvents, extraction and centrifugation times, pH and temperature, and salt effect were studied and optimized. The method exhibited enrichment factors and recoveries ranging from 39.0 to 44.4 and 78.9 to 92.2%, respectively, within very short extraction time. The linearity (and limit of detection) of the method ranged 4.0‐100.0 (2.0) ng/mL for 1,2‐ethandiol, 6.0‐80.0 (4.0) ng/mL for 1,3‐propandiol, 2.0‐90.0 (1.0) ng/mL ng/mL for 1,4‐butanediol, 5.0‐120.0 (2.0) ng/mL for 1,5‐pentandiol. The relative standard deviations (RSD) for the concentration of diols, 5.0 ng/mL in water by using the internal standard were in the range of 1.5–4.5% (n = 5) and without the internal standard was in the range of 2.6–9.0% (n = 5). It is concluded that this method is successful for determination of diols in produced water samples.     

Continuous In Situ Oil Recovery From Oil/Water Mixture with Natural Kapok Fiber and External Pumping

An oil recovery system composed of an oil capture module packed kapok fibers and a vacuum pump was developed for continuous oil recovery from artificial oil/water (O/W) mixture. The mechanism of porous hydrophobic–oleophilic kapok fiber layer (KFL) for O/W separation was analyzed, and a physical model for continuous oil recovery process was established. The oil recovery performance, which was evaluated by oil recovery rate (ORR, %) and oil enrichment rate (OER, %), depended on turbulence intensity of O/W mixture, driving pressure, KFL porosity and thickness, initial oil content of O/W mixture, and oil viscosity. Owing to the well oil selectivity of kapok, the oil content of the permeate was above 95.0% when the initial oil content of the O/W mixture was between 6.0% and 8.0%. The system was capable of collecting low viscosity oil efficiently.     

油/水界面张力的影响因素及无机盐对油水铺展的影响

讨论不同有机相与水形成的油/水界面处水/气、油/气及油/水3个界面张力的影响因素及相对大小。重点讨论了加入无机盐对作用于透镜状油滴上的3个界面张力的影响,总结出基本的规律并进行了实验验证。