江汉平原土地利用对钉螺分布的影响研究

分析了江汉平原2009年易于钉螺孳生的3种土地利用类型（滩地、河渠和水田）比例与钉螺密度的关系。首先,在ERDAS9.2和ENVI4.7软件中对江汉平原2009年的Landsat5TM遥感影像进行了预处理。在已有的多期土地利用数据的基础上,借助eCognition软件利用向量相似度指标来提取土地利用变化区域,结合目视解译经验并运用遥感指标通过建立规则集对变化区域进行分类,将变化区域的分类结果更新2000年数据,得到了该区域2009年的土地利用数据。接下来,整理了江汉平原2009年螺情资料并计算出村级钉螺平均密度,绘制了2009年钉螺分布图。将绘制的钉螺分布图与土地利用分类图叠置分析,并结合收集的螺情数据确定了钉螺易于孳生的3种土地利用类型,分别为滩地、河渠和水田。最后,将钉螺密度与这3种土地利用比例进行线性回归分析。研究结果表明,钉螺密度与这三种土地利用类型比例存在线性回归关系,模型精度为R2=0857。该结论对通过遥感影像来估算钉螺密度具有指导意义,另外也可以为湖北省提出合理用地和灭螺并重的土地利用模式提供一定的科学参考     

鄱阳湖流域水化学环境参数的变化特征

分别于2010年2月和7月,对鄱阳湖湖区和入湖河流的pH、TDS以及主要离子浓度进行了测定,分析了主要离子组成的时空变化特征及其影响机制。结果表明,鄱阳湖流域水体属于弱矿化度软水,Ca2+是湖水和河水的主要阳离子,分别占阳离子总数〖JP〗的5935%、4989%;HCO-3是湖水和河水的主要阴离子,分别占阴离子总数的5337%、5937%,水质类型为Ca-HCO-3型水;主要离子组成和TDS浓度具有明显的季节和沿程变化特征,这与降雨季节性变化以及不同水系的地质背景有关;从河流水系上游至湖区的水化学特征依次为HCO-3型、HCO-3-SO2-4和SO2-4型。从水化学控制机制上看,鄱阳湖丰水期受大气降水作用和地质条件影响显著,而枯水期降雨量大大减少,主要受岩石风化、蒸发沉淀作用和人为输入的影响。除此之外,SO2-4型水的增加与长江干流酸化以及丰水期长江顶托倒灌现象有密切关系     

基于MODIS数据的安徽区域日蒸散量估算与分析

蒸散的估算在区域能量平衡和水资源研究中具有重要意义,遥感技术发展促进了区域蒸散的研究。利用安徽省气象资料、MODIS数据产品及GIS背景信息,基于SEBAL模型,按1 km空间分辨率进行了面尺度的安徽省日蒸散量估算,并在GIS空间分析模块的支持下对不同土地覆盖类型的日蒸散量进行统计分析。结果表明：遥感估算的蒸散量与利用Penman Monteith公式计算的蒸散量比较,两者之间具有较好的相关性,遥感蒸散估算值整体偏小,不同土地利用类型的日蒸散量间差异显著。遥感蒸散估算方法在安徽省具有一定的实用性,需优化模型参数,以提高其进一步技术推广的前景     

棉花耐涝相关种质资源遗传多样性分析

为了解棉花耐涝相关种质资源的遗传多样性,选用均匀分布于棉花全基因组的145对引物,从中筛选出44对SSR引物对48份涝相关种质资源进行遗传多样性分析。结果表明,44对SSR引物在48份材料中共检测出170个等位基因变异,平均每个位点有386个。其中耐涝材料的位点多态信息含量(PIC)、每个位点的有效等位基因数(Ne)、基因型多样性(H′)分别为0632、1710 4和0393 7,涝敏感材料的PIC、Ne、H′分别为0628、1721 6和0399 4。耐涝材料和涝敏感材料的Jaccard相似性系数分别在0462~0925和0398~0845之间,遗传相似性系数总体平均值接近,但耐涝材料的变化幅度更大。用类平均法(UPGMA)聚类将48份材料分成2个类群。其中,第Ⅰ类包含39个品种,第Ⅱ类包含9个品种。大多数材料之间的遗传相似性系数较高,表明陆地棉耐涝相关种质资源遗传基础狭窄。本结果可为棉花耐涝育种亲本选配和相关机理研究提供基础资料     

基于土地利用变化的四川省生态系统服务价值研究

认识和理解土地利用变化对生态系统服务价值的影响及相互作用关系具有重要意义。在分析国内外各种生态服务价值评价方法和对各类生态系统生态服务价值系数进行修正的基础上,采用生态系统服务价值评估模型、敏感性指数和价值变率模型,对各类生态系统的各项生态服务价值、土地利用变化对四川省生态系统服务价值的影响进行了计算和分析。结果表明：（1）四川省土地利用以林地和牧草地为主,1996~2006年耕地、未利用土地、牧草地和水域面积减少,林地、建设用地和园地面积呈增加趋势;（2）1996~2006年四川省生态系统服务价值由1996年的7 214588×108元上升到2006年的7 305018×108元,增加90431×108元,园地生态系统服务价值持续增加,而农田、牧草地、水域、未利用地则继续减少;（3）土地利用的生态服务价值区域差异显著,空间上呈现西多东少的分布格局,西部高山高原区和盆周山区的生态系统服务价值总量较大,成都平原和四川盆地丘陵区所提供的较少;（4）四川省生态系统服务价值缺乏弹性,价值变率反映林地面积的变化对研究区生态系统服务价值的变化具有较大影响     

Evaluation of heavy metal acute toxicity and bioaccumulation in soil ciliated protozoa

Laboratory toxicity tests, using ciliated protozoa, are scarce and they have been carried out usually with freshwater species. In this study, we have analysed the acute cytotoxicity of Cd, Zn and Cu in five different strains of very common soil ciliate species (Colpoda steinii, Colpoda inflata and Cyrtolophosis elongata), which were isolated from very different soil samples (polluted or not with heavy metals). Soil ciliates are quite resistant to heavy metals pollution with regard to ciliates from other habitats. The toxicity sequence was Cd>Cu>Zn. Results from Cd+Zn mixtures indicated that Cd cytotoxicity decreases in the presence of low or moderate Zn concentrations. A broad heavy metal resistance level diversity exists among isolates of colpodid ciliates and it is seen to be a genetic feature rather than a habitat dependence. Bioaccumulation is seen to be the main mechanism involved in the metal resistance, except for Cu. For the first time in ciliates, a fluorescent method has been applied to detect Zn intracellular deposits. This methodology might be an useful tool for monitoring heavy metal pollution in soils.     

Brominated flame retardants and organochlorines in the European environment using great tit eggs as a biomonitoring tool

Large-scale studies are essential to assess the emission patterns and spatial distribution of organohalogenated pollutants (OHPs) in the environment. Bird eggs have several advantages compared to other environmental media which have previously been used to map the distribution of OHPs. In this study, large-scale geographical variation in the occurrence of OHPs, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), was investigated throughout Europe using eggs of a terrestrial residential passerine species, the great tit (Parus major). Great tit eggs from 22 sampling sites, involving urban, rural and remote areas, in 14 European countries were collected and analysed (5-8 eggs per sampling site). The environmentally most important congeners/compounds of the analysed pollutants were detectable in all sampling locations. For PCBs, PBDEs and OCPs, no clear geographical contamination pattern was found. Sum PCB levels ranged from 143 ng/g lipid weight (lw) to 3660 ng/g lw. As expected, PCB concentrations were significantly higher in the sampled urban compared to the remote locations. However, the urban locations did not show significantly higher concentrations compared to the rural locations. Sum PBDEs ranged from 4.0 ng/g lw to 136 ng/g lw. PBDEs were significantly higher in the urbanized sampling locations compared to the other locations. The significant, positive correlation between PCB and PBDE concentrations suggests similar spatial exposure and/or mechanisms of accumulation. Significantly higher levels of OCPs (sum OCPs ranging from 191 ng/g lw to 7830 ng/g lw) were detected in rural sampling locations. Contamination profiles of PCBs, PBDEs and OCPs differed also among the sampling locations, which may be due to local usage and contamination sources. The higher variance among sampling locations for the PCBs and OCPs, suggests that local contamination sources are more important for the PCBs and OCPs compared to the PBDEs. To our knowledge, this is the first study in which bird eggs were used as a monitoring tool for OHPs on such a large geographical scale.     

基于AHP-FCE模型的制药废水处理技术综合评价

制药废水由于具有水质复杂、COD高、有毒有害物浓度高、可生化性差、色度高等特点,处理十分困难。目前制药废水处理技术种类较多,且各项技术均具有各自的特点。为选择合适的制药废水处理技术,构建了制药废水处理技术评价指标体系,确定了评价标准,并采用层次分析法与模糊综合评价法相结合的评价方法(AHP-FCE)对国家水体污染控制与治理科技重大专项(简称“水专项”)研发的13项制药废水处理技术进行了综合评价。结果表明:升流式厌氧污泥床-膜生物反应器(UASB-MBR)组合技术是制药废水处理较优的可行技术,其次为两级分离内循环厌氧反应器和复合氧反应器-好氧反应器(ABR-CASS)生物强化处理技术。研究结果可以为制药企业选择合适的废水处理技术提供支持。     

Nutrient and tetracycline removal from simulated biogas slurry and biogas upgrading by microalgae cultivation under different carbon nanotubes concentrations

Environmental Science and Pollution Research - The present study sought to determine the effects of multi-walled carbon nanotubes (MWCNTs) concentrations (0–10 mg L?1) on tetracycline...     

Study on dust–gas coupling pollution law and selection of optimal purification distance of air duct during tunneling process

During the excavation of high gas mine, gas and dust often exist at the same time. In order to ensure that the gas concentration remains within a safe range and minimize the risk of workers’ pneumoconiosis, we simulated the interaction mechanism of airflow, gas, and dust, explored the pollution law of gas and dust, and obtained the optimal purification distance (L_p) by the CFD method. The reliability of the numerical simulation was verified by field measurements. Firstly, the properties of the gas and dust affected the structure of the airflow field. At the same time, the change in the airflow field affected the concentration distributions of the gas and dust. During the diffusion process, some high-risk regions in which the gas or dust concentrations exceeded 0.80% or 200 mg/m³, respectively, were discovered. Moreover, we have found that the airflow velocity in the top region of the tunnel and at the intersection corner between the cutting face and tunnel wall was the main factor affecting the purification effects. When L_p = 5–8 m, the gas concentration remained below 0.50%. When L_p = 6 m, the dust concentration reached a minimum of 287.5 mg/m³. Therefore, the optimal purification distance was determined to be 6 m; in which case, the gas and dust concentrations decreased by 32.84% and 47.02%, respectively.