PE微塑料对土壤水分入渗的影响及入渗模型适宜性评价

为探究微塑料对土壤水分入渗过程的影响,通过室内土柱模拟试验,设置5组微塑料添加处理(0,1,2,4,6g/kg),研究了不同微塑料含量对湿润锋运移和累积入渗量的影响,并进一步评价了主要入渗模型在微塑料污染土壤中的适用性.结果表明,湿润锋运移速率随着微塑料含量的增加呈现出先减小后增加的特征,当含量达到T2时(微塑料含量2...     

套管损伤磁记忆检测信号定量研究

在油气生产过程中,井下套管损伤会造成井况恶化,致使正常井转变为套损井。为了防止套损井的出现和安全事故的发生,有必要对套管进行早期损伤检测。采用金属磁记忆检测技术,开展了实验研究。实验中,通过对套管内壁环切,将套管壁厚设计为等值递增和不等值递增两种形式;根据实验数据,对磁记忆检测信号梯度值、信号梯度波峰值及信号梯度峰宽值等特征参量与壁厚、壁厚变化量的定量关系进行拟合。结果表明:磁记忆检测信号梯度值、信号梯度波峰值及信号梯度峰宽值等特征参量,可以很好的表征套管壁厚的变化情况;信号梯度值与套管壁厚呈线性递增关系;信号梯度波峰值和信号梯度峰宽值均与套管壁厚变化量呈线性递增关系。该试验结果有助于完善磁记忆检测技术的定量化研究和利用磁记忆原理检测套管损伤的评价体系。     

北京一次严重雾霾过程气溶胶光学特性与气象条件

对北京地区2013年10月2~7日一次严重雾霾过程中的气溶胶光学特性开展研究,分析了气象条件对雾霾过程的影响,并结合HYSPLIT模型分析污染物的来源.结果表明,在污染天气中气溶胶光学厚度、?ngström波长指数、细模态体积尺度谱峰值浓度远高于清洁天.10月5日雾霾最为严重,440nm波长处气溶胶光学厚度高达3.89.在雾霾发生前后,单次散射反照率日均值随波长增大而增大,而在10月5日,单次散射反照率值随波长增加先增大后减小,在675nm波长处达到最大值0.965.雾霾过程中大气气溶胶以强散射型细粒子为主,人为因素贡献较大,且受气象条件影响明显.     

Removal of Eu3+, Ce3+, Sr2+, and Cs+ ions from radioactive waste solutions by modified activated carbon prepared from coconut shells

As a biomass agricultural waste material, coconut shells were used for the preparation of high-quality modified activated carbon. Chemical modification of the surface of the prepared activated carbon is done by oxidation using H₂O₂ and HNO₃, respectively. The surface area and pore volume of the coconut shells activated carbon are increased by the chemical modification, and followingly the removal of the metals is improved. The structural morphology and composition of the modified activated carbon coconut shells (MACCS) were evaluated by Fourier transform infrared (FTIR) spectra, thermogravimetric analysis–differential thermal analysis (TGA-DTA), scanning electron microscope (SEM), X-ray diffraction (XRD), surface area analysis (SAA), X-ray fluorescence (XRF), and carbon, hydrogen, nitrogen, and sulfur (CHNS) elemental analysis. The prepared MACCS has reasonably good chemical stability. The influence of solution pH, contact time, adsorbent dosage, adsorption temperature, initial metal concentrations, and interfering ions on the adsorption performance of the investigated ions onto the prepared sorbent was examined by a batch method. The selectivity sequence for sorption of Eu³⁺, Ce³⁺, Sr²⁺, and Cs⁺ ions on MACCS was found to be Eu^3+?>?Ce^3+?>?Sr^2+?>?Cs⁺. The saturation capacities of MACCS for the studied metal ions were found to be 136.84, 85.55, 69.85, and 60.00?mg?g^?1 for Eu³⁺, Ce³⁺, Sr²⁺, and Cs⁺ ions, respectively. The thermodynamic parameters, ΔH°, ΔS°, and ΔG° were also evaluated.     

镉对3株不同地点生长的大麻生长及矿质元素吸收的影响

为了研究镉胁迫对不同大麻生长的影响,以来自山西的大麻M1和来自甘肃的大麻M2、M3为材料,通过土培盆栽试验,研究了镉胁迫对大麻SPAD值、光合参数、不同组织碳水化合物含量和矿质元素含量的影响及不同地点株间差异。结果表明:镉胁迫显著降低大麻SPAD值,及其光合能力,且不同植株间存在显著差异,M1受抑制严重;镉胁迫使大麻地上部蔗糖和总可溶性糖含量显著升高,根系、叶片和籽粒淀粉含量显著降低。镉含量分析结果显示,镉主要滞留在根系中,其中M1镉积累量最高;镉胁迫显著抑制了大麻M1根系对锰和铜元素的吸收,同时也影响了其在地上部各器官的分配和积累,降低了M3对锌元素的吸收。镉对大麻的影响因大麻不同植株间及组织部位而异。     

改性核桃壳对石油烃类物质的吸附试验研究

为了研究改性制备核桃壳对石油烃吸附程度,以化学改性制备核桃壳为吸附剂,考察了溶液p H值、时间和温度对改性核桃壳吸附石油烃效果的影响。结果表明:当温度为298 K,p H为7.0,0.2 g改性核桃壳吸附处理100 m L浓度为60 mg/L的柴油溶液,80 min后吸附量最大,可达到12.57 mg/g。该吸附过程符合准二级动力学方程,其相关系数达到0.9999。在3种温度(298,308,318 K)条件下的吸附等温曲线更符合Freundlich模型。通过热力学计算证实,该吸附过程是吸热的、自发的过程,一定程度上的升温有助于石油烃的吸附。     

古夫河着生藻类优势种体积与水质因子的相关性研究

通过研究长江三峡库区古夫河着生藻类优势种体积的变化,探索影响其体积的主要水质因子,为河流水质评价提供依据.于2010年12月至2012年2月,对古夫河着生藻类和地表水采样11次,共鉴定着生藻类197种,检测水质指标10项.选取Mcnaughton优势度指数(Y)>0.02的着生藻类(共30种)作为优势种并计算体积;利用主成分分析(PCA)分析优势种藻类在不同月份的体积变化.结果显示,硅藻门对冷暖季的变化较为敏感.将水质因子与优势种藻类体积进行典范对应分析(CCA),结果显示水质因子与藻类体积相关性大小为:溶解氧>氨氮>叶绿素a>酸碱度>硝态氮>总磷>水温>总氮>总有机碳>化学需氧量.Monte Carlo显著性检验结果为溶解氧和氨氮对着生藻类体积的影响最大,其次为叶绿素a、酸碱度和硝态氮.硅藻门藻类体积的变化可以判断古夫河水体中溶解氧、氨氮、叶绿素a、酸碱度、硝态氮的含量与变化.     

输氧抽气技术在垃圾填埋场治理中的关键参数试验研究

输氧抽气技术是基于好氧降解原理对垃圾填埋场中固体废弃物实施原位处理的先进环保技术。采用该技术对垃圾填埋场中固体废弃物减量化研究,总结了技术应用中的关键参数:有效影响半径,最佳真空度等。结果表明抽气流量大小与影响半径密切相关,抽气影响半径建议取20~25 m,抽气系统最优负压为20 k Pa,同时在技术应用过程中应保证垃圾场表层覆盖层的密封性能,尽量减少空气的渗入。输氧抽气技术在垃圾场的成功实施为同类型场地治理提供工程技术参考。     

基于磁化水的全尾砂胶结充填体强度研究

针对某矿山全尾砂充填体抗压强度低,水泥用量大的现状,将磁化水引入全尾砂胶结充填料浆的配浆试验,通过均匀布点理论优选出最佳磁化条件,探究了磁化水-全尾砂充填体的7天、14天、28天抗压强度的变化规律以及磁化水对水泥活性的影响。研究结果表明:在磁感应强度B=1000-2000Gs,水循环流速V=1.4-2.0m/s,磁化时间T=10-20min时,磁化水-全尾砂充填模块的7天抗压强度提高19%-28%,14天抗压强度提高17%-25%,28天抗压强度提高13-15%。     

Biochemical evaluation of hepatotoxicity in mice due to administration of artemether

Effects of artemether administration on liver and selected biochemical parameters were evaluated. Eighty albino mice were divided into four equal groups. Group 1 was given water which served as control, while groups 2, 3, and 4 were given 1.2, 2.4, or 4.8 mg kg^?1 body weight artemether intramuscularly for five consecutive days. On day 6 all mice were sacrificed by cervical dislocation and blood was collected for analysis of alanine and aspartate transaminases, alkaline phosphatase, copper, and total proteins. Liver tissues were prepared for histological studies. It was found that the serum alanine and aspartate transaminase and alkaline phosphatase activities were higher in groups treated with artemether compared to control. The serum concentrations of copper and total proteins were lower than control. The histological features of liver tissues after administration of artemether showed histopathological alterations. These findings showed that artemether administration may have reversible adverse effects on mouse hepatocytes.