走滑断层作用下X80管道设计应变规律和神经网络预测

走滑断层是埋地管道常见的地质灾害威胁，断层作用下管道会发生较大的拉压应变而失效。为得到X80管道的设计应变，基于有限元方法建立了走滑断层作用下管道的应变响应数值计算模型，模型使用壳单元模拟管道，非线性弹簧单元模拟土壤约束，采用西二线实际工程的管道应变影响参数范围，计算了管道的设计应变；为预测管道的设计应变值，基于以上参数化分析得到的4 817组设计应变结果，采用人工神经网络建立了管道设计应变预测模型。结果表明:该神经网络模型预测结果的最大相对误差小于10%，预测准确性良好，且该方法具有较高的计算效率，可以为断层作用下埋地管道的应变设计与评估提供参考。     

便携式GC-MS仪快速测定水中硝基苯及其在应急监测中的应用

采用便携式GC-MS仪快速测定水中硝基苯,通过优化水中离子强度和顶空加热时间,使方法在0μg/L^300μg/L范围内线性良好,方法检出限为2.5μg/L。标准溶液6次测定结果的RSD为7.8%~10.9%,实际水样的加标回收率为80.7%~103%。同步测定试验表明,硝基苯与7种苯系物分离良好。与国标方法对比,该方法单个样品测定时间由2 h缩短为15 min。将该方法用于应急监测工作中,及时有效的数据可为污水处理及事故调查提供分析和研判依据。     

重金属离子与依诺沙星相互作用的荧光光谱法研究

荧光分析法是利用物质的荧光性质对物质进行分析的方法,文章应用荧光法研究了不同温度下重金属离子Cu2+、Pb2+及Mn2+与喹诺酮类药物依诺沙星(ENX)的相互作用。结果表明:Cu2+、Pb2+及Mn2+对ENX内源荧光的猝灭机制属于形成复合物所引起的静态猝灭,利用Stern-Volmer关系式计算了ENX与重金属离子Cu2+、Pb2+及Mn2+之间的猝灭常数KSV及结合位点数,根据热力学参数(自由能变ΔG、焓变ΔH、熵变ΔS)确定了ENX与重金属离子之间的主要作用力类型为静电作用力。该研究为探讨环境中重金属离子与ENX的作用机理和环境效应提供了理论依据。     

Biological sulfate removal from acrylic fiber manufacturing wastewater using a two-stage UASB reactor

A two-stage UASB reactor was employed to remove sulfate from acrylic fiber manufacturing wastewater. Mesophilic operation (35±0.5℃) was performed with hydraulic retention time (HRT) varied between 28 and 40 hr. Mixed liquor suspended solids (MLSS) in the reactor was maintained about 8000 mg/L. The results indicated that sulfate removal was enhanced with increasing the ratio of COD/SO₄^2-. At low COD/SO₄^2-, the growth of the sulfate-reducing bacteria (SRB) was carbon-limited. The optimal sulfate removal efficiencies were 75% when the HRT was no less than 38 hr. Sulfidogenesis mainly happened in the sulfate-reducing stage, while methanogenesis in the methane-producing stage. Microbes in sulfate-reducing stage performed granulation better than that in methane-producing stage. Higher extracellular polymeric substances (EPS) content in sulfate-reducing stage helped to adhere and connect the flocculent sludge particles together. SRB accounted for about 31% both in sulfate-reducing stage and methane-producing stage at COD/SO₄^2- ratio of 0.5, while it dropped dramatically from 34% in sulfate-reducing stage to 10% in methane-producing stage corresponding to the COD/SO₄^2- ratio of 4.7. SRB and MPA were predominant in sulfate-reducing stage and methane-producing stage respectively.     

Determination of ammonium on an integrated microchip with LED-induced fluorescence detection

A simply fabricated microfluidic device integrated with a fluorescence detection system has been developed for on-line determination of ammonium in aqueous samples. A 365-nm light-emitting diode (LED) as an excitation source and a minor band pass filter were mounted into a polydimethylsiloxane (PDMS)-based microchip for the purpose of miniaturization of the entire analytical system. The ammonium sample reacted with o-phthaldialdehyde (OPA) on-chip with sodium sulfite as reducing reagent to produce a fluorescent isoindole derivative, which can emit fluorescence signal at about 425 nm when excited at 365 nm. Effects of pH, flow rate of solutions, concentrations of OPA-reagent, phosphate and sulfite salt were investigated. The calibration curve of ammonium in the range of 0.018-1.8 μupg/mL showed a good linear relationship with R² = 0.9985, and the detection limit was (S/N = 3) 3.6 × 10^-4 μupg/mL. The relative standard deviation was 2.8% (n = 11) by calculating at 0.18 μupg/mL ammonium for repeated detection. The system was applied to determine the ammonium concentration in rain and river waters, even extent to other analytes fluorescence detection by the presented device.     

沸石和活性炭处理氨氮废水的实验研究

文章选用具有较强选择性和吸附性的13X沸石和活性炭作为吸附材料,以人工配置的含氨氮废水模拟实际废水,分别以溶液pH值、吸附时间、初始浓度和投加顺序等作为影响因素,通过实验来系统地考察所选材料对废水中氨氮的去除技术参数。结果表明:所选材料具有较好、较稳定的吸收效果,在其他条件一定的情况下,13X沸石在pH值为中性,吸附时间为40 min时对氨氮的去除率最大,达87.9%。且在相同实验条件下,先投放活性炭再投放沸石去除氨氮的效果较好,比先投放沸石然后投放活性炭的效果高出25%左右。     

原子荧光光谱仪测定底泥中砷含量的不确定度评定

介绍了原子荧光光谱仪测定底泥中砷含量的不确定度评定方法,分析和识别测量过程中不确定度的来源,较为全面地评定了测量不确定度。根据最小二乘法拟合计算工作曲线的标准不确定度,采用极差法评定测量次数较少时引起的标准不确定度。     

掺钴水钠锰矿对铅的吸附及对砷的氧化

为了研究过渡金属离子掺杂对锰氧化物作为环境友好材料物理化学性质的影响,在浓盐酸还原高锰酸钾制备水钠锰矿过程中添加氯化钴,在常压回流条件下一步合成了三维纳米微球状水钠锰矿,考察了其铅吸附和砷氧化能力.应用粉晶X射线衍射、化学分析、N2物理吸附、场发射扫描电镜（FE-SEM）、X射线光电子能谱（XPS）等手段表征产物晶体结...     

穗花狐尾藻化感作用对铜绿微囊藻光合效率的影响

共培养条件下,采用叶绿素含量和叶绿素荧光参数研究穗花狐尾藻分泌的化感物质对铜绿微囊藻光合效率的影响,其中叶绿素荧光参数包括qN（非化学淬灭）、YⅡ（有效量子效率）、Fv/Fm（最大量子产量）、F＇v/F＇m（光系统Ⅱ有效量子产量）和快速光响应曲线.3 d共培养处理期间,铜绿微囊藻叶绿素含量及叶绿素荧光参数都受到不同程度...     

腐蚀电池-Fenton处理渗滤液溶解性有机物光谱特征

为了研究垃圾渗滤液中溶解性有机物（DOM）在腐蚀电池-Fenton（CCF）深度处理过程中的去除特性,采用XAD-8和XAD-4树脂将DOM分成5种组分（亲水性有机物HPI、疏水性有机酸HPO-A、过渡亲水性有机酸TPI-A、疏水性中性有机物HPO-N、过渡亲水性中性有机物TPI-N）,并用紫外和荧光光谱对各组分的降解...