川中丘陵县域土壤氮素空间分布特征及其影响因素

根据四川仁寿县555个表层土壤样点数据,采用地统计学和回归分析方法,对该区土壤全氮和碱解氮的空间变异特征进行分析,并探讨了不同因素对其空间变异的影响程度.结果表明,研究区土壤全氮(TN)含量在0.34~2.57 g·kg-1之间,平均值为1.12 g·kg-1,处于中等水平;碱解氮(AN)含量在25.86~184.17 mg·kg-1范围内,平均值为74.35 mg·kg-1,处于较缺乏水平.土壤TN和AN的块金效应分别为0.608和0.790,TN具有中等空间相关性,受结构因素与随机因素共同影响,而AN则主要受随机因素影响.空间上,TN和碱解氮均表现出北高南低趋势.成土母质可独立解释6.3%和1.0%的TN和AN空间变异;土壤类型对研究区TN和AN的空间变异的独立解释能力分别在26.5%~36.1%和27.7%~28.7%之间;地形条件对TN、AN空间变异的独立解释能力分别为5.5%、6.1%;土地利用方式对TN、AN空间变异的独立解释能力分别为37.7%、40.0%.土地利用方式对氮素空间变异的独立解释能力最高,是引起研究区土壤氮素空间变异最主要的因素.     

“两高一资”行业定量化判定标准研究

在国家管理制度和管理政策体系整体趋向精细化工的大背景下,结合环保科研的科学性和现行管理体制下各部门与环保相关职能和政策体系设置的可操作性二者的共同需求,以典型水环境污染物和大气污染物为例,在界定污染因子范围的基础上,基于产排污强度、产排污总量、产排污浓度、污染物治理达标成本和污染物毒性等相关定量指标,提出一整套兼顾科学性与可操作性、且便于进行横向和纵向对比的"两高一资"行业定量化判定标准体系,并以石化、纺织和轻工等行业中的典型"高污染"产品为例对此套判定标准进行了验证,证实了其科学性和可操作性,为今后科学地开展行业环保工作、有针对性地发挥相关政策在促进工业领域节能减排方面政策实效提供了共同的技术基础和连接点。     

Verification of Bacteroidales 16S rRNA markers as a complementary tool for detecting swine fecal pollution in the Yangtze Delta

To correctly assess and properly manage the public health risks associated with exposure to contaminated water, it is necessary to identify the source of fecal pollution in a watershed. In this study, we evaluated the efficacy of our two previously developed real time-quantitative PCR (qPCR) assays for the detection of swine-associated Bacteroidales genetic markers (gene 1–38, gene 3–53) in the Yangtze Delta watershed of southeastern China. The results indicated that the gene 1–38 and 3-53 markers exhibited high accuracy (92.5%, 91.7% conditional probability, respectively) in detecting Bacteroidales spp. in water samples. According to binary logistic regression (BLR), these two swine-associated markers were well correlated (P < 0.05) with fecal indicators (Escherichia coli and Enterococci spp.) and zoonotic pathogens (E. coli O157: H7, Salmonella spp. and Campylobacter spp.) in water samples. In contrast, concentrations of conventional fecal indicator bacteria (FIB) were not correlated with zoonotic pathogens, suggesting that they are noneffective at detecting fecal pollution events. Collectively, the results obtained in this study demonstrated that a swine-targeted qPCR assay based on two Bacteroidales genes markers (gene 1–38, gene 3–53) could be a useful tool in determining the swine-associated impacts of fecal contamination in a watershed.     

定量遥感支持下的红壤丘陵区土壤侵蚀敏感性评价——以长沙市为例

定量遥感技术的发展为研究区域生态环境敏感性提供了有效的手段.针对红壤丘陵区这一典型的脆弱生态系统,在遥感和地理信息系统的支持下,建立了红壤丘陵区土壤侵蚀敏感性评价信息系统.根据RUSLE方程中的4个自然条件因子对土壤侵蚀敏感性的影响,建立红壤丘陵区土壤侵蚀敏感性定量评价指标体系,并对长沙这一典型红壤丘陵区的土壤侵蚀敏感性进行评价.通过解译Lan出at TM/ETM 影像数据获得长沙市土壤侵蚀敏感性评价的K因子、C因子分布图;利用ARCGIS数字化和空间分析得到R因子以及地形起伏度分布(LS因子).通过主成分分析法确定各评价因子的权重;最后通过加权叠加法获得长沙市土壤敏感性评价结果.研究结果表明,高度敏感以上面积2618km2,占全市面积的20.3%,中度敏感面积4404km2,占全市面积的37.2%,轻度以下敏感面积5073km2,占全市面积的42.5%,这说明长沙市土壤侵蚀敏感性较高.     

Heterogeneous Fenton degradation of azo dyes catalyzed by modified polyacrylonitrile fiber Fe complexes：QSPR (quantitative structure peorperty relationship) study

The amidoximated polyacrylonitrile (PAN) fiber Fe complexes were prepared and used as the heterogeneous Fenton catalysts for the degradation of 28 anionic water soluble azo dyes in water under visible irradiation. The multiple linear regression (MLR) method was employed to develop the quantitative structure property relationship (QSPR) model equations for the decoloration and mineralization of azo dyes. Moreover, the predictive ability of the QSPR model equations was assessed using Leave-one-out (LOO) and cross-validation (CV) methods. Additionally, the effect of Fe content of catalyst and the sodium chloride in water on QSPR model equations were also investigated. The results indicated that the heterogeneous photo-Fenton degradation of the azo dyes with different structures was conducted in the presence of the amidoximated PAN fiber Fe complex. The QSPR model equations for the dye decoloration and mineralization were successfully developed using MLR technique. MW/S (molecular weight divided by the number of sulphonate groups) and NN=N (the number of azo linkage) are considered as the most important determining factor for the dye degradation and mineralization, and there is a significant negative correlation betweenMW/S or NN=N and degradation percentage or total organic carbon (TOC) removal. Moreover, LOO and CV analysis suggested that the obtained QSPR model equations have the better prediction ability. The variation in Fe content of catalyst and the addition of sodium chloride did not alter the nature of the QSPR model equations.     

升级A/O工艺污水处理系统中抗生素抗性基因的分布与去除研究

针对北方某采用升级A/O工艺的生活污水处理厂,使用实时荧光定量PCR技术,探究污水厂中ARGs的分布及各处理工艺段对ARGs的去除效果.结果表明：四环素抗性基因（tetA、tetC和tetM）、磺胺抗性基因（sul1和sul2）、大环内酯抗性基因（ermA和ermF）和喹诺酮抗性基因（parC和gyrA）在污水和污泥中均被检出.污水厂进水中ARGs的绝对丰度为2.65×10³~1.01×10⁶ copies·mL^-1,升级A/O工艺未能有效削减ARGs,出水中ARGs的绝对丰度为9.22×10³~1.15×10⁶ copies·mL^-1,污泥中ARGs的绝对丰度为8.07×10⁷~2.65×10¹¹ copies·g^-1.深度处理工艺对ARGs的去除效率对比结果显示,生物活性炭工艺对ARGs的削减效果优于紫外消毒.     

基于PMA-定量PCR选择性检测技术的病原菌消毒特性研究

建立了一种核酸染料propidium monoazide(PMA)与定量PCR技术联合选择性检测活性病原菌的技术(PMA-qPCR),以大肠杆菌作为模式菌,研究了氯和一氯胺消毒对病原菌的灭活特性.结果表明,PMA染料能够分别去除99.94%和99.99%的来自非活性大肠杆菌和沙门氏菌的DNA,PMA-qPCR技术能够有效区分活性菌与非活性菌;PMA-qPCR技术得到的氯和一氯胺消毒对大肠杆菌的灭活曲线符合一级动力学方程,灭活速率常数分别为 2.24 L·(mg·min)^-1和0.0175 L·(mg·min)^-1,低于平板培养法得到的灭活速率常数;当大肠杆菌的去除率达到99%时,采用PMA-qPCR技术检测需要的ct值相比于平板培养法从0.6 mg·L^-1·min上升到0.9 mg·L^-1·min(氯消毒)和从20 mg·L^-1·min上升到超过100 mg·L^-1·min(一氯胺消毒);随着ct值的升高,常规qPCR的检测结果基本不变,因此常规qPCR不能够反映氯和一氯胺消毒对病原菌的灭活效果.作为一种新的表征消毒特性的检测技术,PMA-qPCR技术有助于更为准确地评价氯和一氯胺消毒对病原菌的灭活效果.     

激光诱导击穿光谱技术在环境领域中的应用动态

激光诱导击穿光谱技术是一种通过分析物质等离子体发射光谱而获取物质成分和含量的分析技术。近些年,该技术已经成为光谱学领域的研究热点且发展迅速,涌现出多种新的检测手段和仪器。从它的基本原理、发展历史及其在土壤、水和大气等生态环境保护领域的应用情况为基础,分析总结其优点以及所面临的问题和挑战。     

湖南省农业旱灾脆弱性综合分析与定量评价

旱灾是湖南省农业特别是粮食生产可持续发展的严重制约因素。在同一致灾强度下，灾情随灾害脆弱性的增强而加重，降低灾害脆弱性可减轻灾害造成的直接经济损失，因此农业旱灾脆弱性的研究对湖南省减灾和农业可持续发展具有特别重要的意义，湖南省自然生态环境和社会经济状况各异，农业旱灾脆弱性各地不同，选择降水量，蒸发量，水利化程度等9个指标综合评价了各个县市的旱灾脆弱性，并利用GIS技术进行旱灾脆弱性区划，结果表明，湘中衡邵盆地和湘西北山地是农业旱灾严重脆弱带，湖南山地区为强度旱灾脆弱带，沅麻盆地山地区为中度旱灾脆弱带，洞庭湖平原和湘东北山地旱灾脆弱性较小。     

FTIR对大气颗粒物PM2.5中硝酸盐的定量分析

大气细颗粒物PM2.5作为复合型大气污染的核心污染物之一备受人们关注,NO3-作为其中水溶性离子的主要成分之一,对大气降水和人体健康有着重要影响,因此实现对其快速可靠的检测是一项重要的研究工作.基于傅里叶变换红外光谱技术的优点,采用液态制膜的方法测量比较了颗粒物中NO3-和NH4NO3中NO3-的红外光谱图,结果保持一致.在此基础上测量了一系列不同质量NO3-的红外光谱,拟合其吸光度与质量,相关性达到0.994 8,线性范围为7.82～73.78μg,实现了对其定标.然后利用样品溶液与采样膜样品质量的对应关系,直接测量采样膜上样品的红外谱图,分析了合肥地区2012-03-20～2012-04-20为期1个月的硝酸根质量浓度,平均质量浓度为4.171 3μg.m-3.