土壤硝酸盐中15N同位素测定前处理自动化辅助装置设计和验证

随着稳定同位素质谱技术在土壤氮循环研究中的广泛应用,氮稳定同位素分析对样品前处理方法提出了更高要求,而合适的样品处理方法是确保分析结果准确可靠的关键。设计开发1种适用于土壤微量硝酸盐中氮稳定同位素分析前处理辅助装置,将基于光电感应装置的自动进样系统与注液、抽真空-气体置换系统相融合,将原前处理方法中液体试剂注入,反应体系抽真空及氦气置换等人为操作过程改为自动化处理环节。系统测试结果表明:该套辅助装置具有良好的自动抽真空、注气和加液重复性。装置抽真空系统的真空度绝对误差可控制在0.5 Pa以内,气体注入体积绝对误差可控制在0.2 mL以内,而注液系统的注液体积绝对误差也可控制在0.1 mL以内,变异系数(CV)均小于1%。使用标准参比样品测试整套系统的准确度和精密度,所有测试样品均获得了较好的准确度和精密度,CV<1%。研制的装置结合痕量气体预浓缩装置—稳定同位素质谱(PreCon-IRMS)联用仪,可以建立方便快捷的低样品量下硝酸盐中15 N同位素质谱检测方法,可为土壤氮循环过程研究提供关键技术支撑。     

典型油泥物化性质分析及其处理工艺研究

以典型老化油泥为研究对象,通过分析油泥的基本物化性质、油泥中原油的基本组成及性质、油泥中固相的基本组成及性质等信息,针对性地开发了一种分层次联合处理工艺,并通过详细的工艺试验,确定了联合处理方案的最佳工艺参数,在最佳工艺条件下,三层油泥的尾矿干基含油率分别可降低到0.89%、0.62%和0.45%,满足油田对油泥的环保处理要求,为国内外油泥处理方案设计提供了良好的思路。     

贵州省望谟县耕地土壤重金属含量特征及影响因素

伴随社会经济快速发展，土壤重金属污染越来越成为人们关注的环境问题。为有效预防土壤重金属污染，以贵州省望谟县耕地表层土壤为研究对象，应用经典统计分析、相关性分析等方法，研究重金属元素含量特征及其影响因素。研究结果表明，该地区耕地土壤重金属元素Cd、Cr、Hg、Ni含量较高，均高于全国背景值，其含量主要受成土母质影响，在泥盆系、石炭系、二叠系的碳酸盐岩分布区平均含量较高，在陆源碎屑岩分布区含量普遍较低。该研究结果为该县耕地种植规划和农产品结构调整等提供了依据。     

含油污泥资源化处理方法进展

为更好地回收含油污泥（即油泥）中可用资源，国内外油泥资源化处理方法不断更新和突破，并在室内实验研究阶段取得较好的处理效果。本文从油泥的高温热处理法、常温法、低温冻融法三个方面综述了热解、微波、萃取等油泥资源化处理方法的研究进展、优缺点以及适用条件等。热解法油品回收率达95.8%，具有油泥处置彻底、油品回收质量高的特点。电动力学法处理油泥，油泥减量化达44.3%，采用浮选法，油泥减量化达95%，两种方法均具有操作简单、易实施、适合大批量处理的特点，工程化应用潜力较大。油泥来源不同，性质各异，采用单一技术难以实现大量油泥的资源化和无害化目标。多项技术联合，如热解法联合浮选法或电动力学法处理大规模油泥能提高油品回收率和质量，降低残油率和处理成本，将成为油泥资源化处理技术的发展方向。     

Predicting the settlement of geosynthetic-reinforced soil foundations using evolutionary artificial intelligence technique

In order to ensure safe and sustainable design of geosynthetic-reinforced soil foundation (GRSF), settlement prediction is a challenging task for practising civil/geotechnical engineers. In this paper, a new hybrid technique for predicting the settlement of GRSF has been proposed based on the combination of evolutionary algorithm, that is, grey-wolf optimisation (GWO) and artificial neural network (ANN), abbreviated as ANN-GWO model. For this purpose, the reliable pertinent data were generated through numerical simulations conducted on validated large-scale 3-D finite element model. The predictive power of the model was assessed using various well-established statistical indices, and also validated against several independent scientific studies as reported in literature. Furthermore, the sensitivity analysis was conducted to examine the robustness and reliability of the model. The results as obtained have indicated that the developed hybrid ANN-GWO model can estimate the maximum settlement of GRSF under service loads in a reliable and intelligent way, and thus, can be deployed as a predictive tool for the preliminary design of GRSF. Finally, the model was translated into functional relationship which can be executed without the need of any expensive computer-based program.     

Isolation and identification of soil bacteria resistant to surfactants in washing detergents

Linear alkylbenzene sulfonate (LAS) and polyoxyethylene lauryl ether (POLE) are the major surfactants in washing detergents. In the present study, we isolated surfactant-resistant bacteria from soil samples collected from a sports ground and a farm field. The samples were treated with 2.0% LAS or POLE at 25°C for 30 min and cultivated on agar plates at 25°C for several days, after which manifold bacterial colonies were isolated. Thereafter, we tested the ability of each bacterial isolate to resist the antibacterial activity of the surfactant. Ten LAS-resistant strains were isolated, and all were found to be Gram-negative bacteria such as Enterobacter and Pseudomonas. On the other hand, 18 POLE-resistant strains were isolated, of which 14 were Gram-positive bacteria including Bacillus and Microbacterium. Notably, one POLE-resistant strain was identified as Bacillus cereus, a potential causative agent for foodborne illness. The genera of LAS- and POLE-resistant bacteria did not overlap. Therefore, the combination of LAS and POLE could be more effective to eliminate soil bacteria from clothes and/or daily necessities.     

非线性状态下饱和紧密砂土的孔隙压力估算

介绍了无限土体中球孔扩张理论,以及在高应力状态下,考虑材料非线性时紧密砂性土的八面体应力及极限承载力解答,推演出了在非线性饱和紧密砂土内,球孔扩张压力下的孔隙压力公式,并分析了其分布特性。     

贵州污染土壤治理方法的探讨

根据贵州在矿产资源开采过程中污染物对土壤的影响，结合目前土壤治理方法的部分研究成果，对土壤中的铅、锌、氟、砷等元素的土壤污染问题提出了一些治理方法和建议。