Pollution levels and characteristics of phthalate esters in indoor air of offices

The pollution status and characteristics of PAEs (phthalate esters) were investigated in indoor air of offices, and PAEs of both gas-phase and particulate-phase were detected in all the samples. The concentration (sum of the gas phase and the particulate phase) was 4748.24 ng/m³, ranging between 3070.09 and 6700.14 ng/m³. Diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate were the most abundant compounds, together accounting for 70% of the Σ6PAEs. Dividing the particulate-phase PAEs into four size ranges (<2.5, 2.5-5, 5-10, >10 μm), the result indicated that PAEs in PM_2.5 were the most abundant, with the proportion of 72.64%. In addition, the PAE concentration in PM_2.5 correlated significantly with the total particulate-phase PAEs (R² = 0.85). Thus, the amount of PAEs in PM_2.5 can be estimated from the total amount of particulate-phase PAEs using this proportion. In a comparison between the offices and a newly decorated study room, it was found that pollution characteristics were similar between these two places. Thus, it is implied that the PAE concentration decreased by 50% 2 yr after decorating.     

Effects of several amendments on rice growth and uptake of copper and cadmium from a contaminated soil

Heavy metals in variable charge soil are highly bioavailable and easy to transfer into plants. Since it is impossible to completely eliminate rice planting on contaminated soils, some remediation and mitigation techniques are necessary to reduce metal bioavailability and uptake by rice. This pot experiment investigated the e ects of seven amendments on the growth of rice and uptake of heavy metals from a paddy soil that was contaminated by copper and cadmium. The best results were from the application of limestone that increased grain yield by 12.5–16.5 fold, and decreased Cu and Cd concentrations in grain by 23.0%–50.4%. Application of calcium magnesium phosphate, calcium silicate, pig manure, and peat also increased the grain yield by 0.3–15.3 fold, and e ectively decreased the Cu and Cd concentrations in grain. Cd concentration in grain was slightly reduced in the treatments of Chinese milk vetch and zinc sulfate. Concentrations of Cu and Cd in grain and straw were dependent on the available Cu and Cd in the soils, and soil available Cu and Cd were significantly a ected by the soil pH.     

西安城区秋季大气中多溴联苯醚的污染特征及来源分析

为了评估西安大气中多溴联苯醚（PBDEs）的污染程度,2008年8～10月,利用大流量主动采样器采集了西安城区气态和颗粒态大气样品.分别利用GC-MS和GC/ECD对低溴PBDEs和BDE-209进行分析,12种PBDEs的总浓度（气相＋颗粒相）范围为37.43～620.30 pg/m3,平均值为216.28 pg/m...     

塔里木河流域综合治理的生态效应

结合塔里木河下游输水和中游段输水堤防建设工程,在下游、中游分别设置了9个和3个地下水位和地下水化学特征监测断面,并在中游的3个断面和下游的6个典型断面进行了植物样方调查,以分析综合治理工程的实施对地下水和植被的影响.结果表明,在生态输水影响下,塔里木河下游断流河道两岸地下水位抬升显著,植被的盖度有明显增加,胡杨的当年生枝叶都表现出积极变化;塔里木河中游地区在建有输水堤防又有生态闸的断面地下水位、水质以及植被综合优势比均明显好于无生态闸断面.     

Variation of grain Cd and Zn concentrations of 110 hybrid rice cultivars grown in a low-Cd paddy soil

Enhanced Cd uptake and Zn depletion in rice grains and high potential for food Cd exposure by the high-yielding hybrid cultivars of China had been addressed. A field experiment was conducted in 2006 to determine the di erence in grain Cd and Zn between cultivars. Total 110 cultivars including super rice and common hybrid rice cultivars were grown on a single paddy soil (Entic Haplaquept) with a neutral reaction and low total Cd content. Grain Cd and Zn concentrations were determined with graphite atomic adsorption spectrophotometer (GFAAS) and flame atomic adsorption spectrophotometer (AAS) respectively.Wide variation of Cd content in grain was found in a range of 0.004–0.057 mg/kg, while the Zn content in a range of 10.25–30.06 mg/kg among the cultivars. Higher Cd but lower Zn concentration in grains of super rice cultivars was observed compared to the common hybrid ones. A highly significant positive linear correlation of grain Cd/Zn with grain Cd was found for super rice and common hybrid cultivars, meanwhile much higher slope for these hybrid cultivars than the reported non-hybrid cultivars was also observed. Using the limit value of the Chinese chemical guidelines for foods (MOHC and SSC, 2005), calculated potential risk of food Cd exposure with “Zn hungry” through diet intake was prominent with all the studied 110 hybrid rice cultivars, possessing high potential health problems for rice production in South China using the super rice cultivars. Breeding of genotypes of rice cultivars with low grain Cd and low Cd/Zn ratio is needed for rice production in acidic red soils where Cd bioavailability is prevalently high.     

循环水养殖系统（RAS）生物载体上微生物群落结构变化分析

为研究循环水养殖系统(recirculating aquaculture systems,RAS)生物滤池挂膜及运行过程中生物载体上微生物群落结构的变化及其脱氮机制,采用传统微生物培养方法,对不同时期生物载体上的异养细菌、氨氧化细菌及硝化菌进行堵养计数.并通过变性梯度凝胶电泳技术,对细菌的16S rDNA V3可变区的...     

区域空气质量模拟中查表法的应用研究

在自行开发完善的区域空气质量模式系统RegSRRMS中应用查表法,模拟中国典型城市群对流层大气主要污染物的浓度变化,评估该方法在大气复合污染事件预测和控制中的有效性.首先,利用具有国际先进水平的空气质量模式WRF-CHEM中的化学模块建立了包含完善气相化学、气溶胶过程的箱模式WRFBOX.其次,利用WRFBOX进行化学反应敏感性分析,基于影响污染物的重要因子分别建立了臭氧(O3)及其前体物、无机盐气溶胶和二次有机气溶胶(SOA)查算表数据库,并检验其有效性.最后,将此查算表数据库引入RegSRRMS,建立简化的查表算法.利用直接耦合机制法和查表法对2000年3月珠三角地区污染个例中主要大气污染物浓度进行模拟.通过比较2种方法的模拟结果,显示查表法计算效率提高了57%,能够反映大气光化学反应的非线性特征、气溶胶及其前体物的平衡关系,具有高分辨率、高时效性,能够方便快捷地给出源和受体之间的响应关系,结果可靠.在区域空气质量模式中应用查表法有利于大气污染事件的快速预测以及大气污染控制的快速决策.     

提高前向散射型光电感烟探测器性能的算法

以国家科技部973项目中建立的火灾探测应用环境及火灾信息数据库为依据,对目前使用最为广泛的前向散射型光电感烟探测器固有特性的归纳和分析,通过数据挖掘,提出一种切实可行的算法处理技术和智能判断火灾方法,有效提高了现有前向散射型光电感烟探测器的火灾探测及其抗干扰能力。     

活性污泥高质量RNA快速提取方法研究

通过比较RNA产量、纯度、降解程度、特定基因的扩增能力、微生物多样性等评价指标,考察和探讨了5种不同RNA提取方法对活性污泥总RNA提取效果的影响并最终建立了一种快速、有效的活性污泥RNA提取方法,即在TENP和PBS洗涤沉淀污泥的基础上,分别采用溶菌酶和TRIzol裂解活性污泥细菌、氯仿去除细菌裂解液中的蛋白和大部分DNA、异丙醇沉淀核酸和DNase I水解残留DNA后,最后进一步用离心柱纯化RNA.结果表明,这种方法可以有效提取高质量的菌群RNA,不仅提取的RNA总量多(每g污泥可提取169.6μg RNA)、纯度高、降解程度低、完整性好、具有丰富的生物多样性,而且可同时进行16SrRNA和amoA基因的RT-PCR扩增反应;与其它方法相比,性价比高,具有明显的优越性,适用于活性污泥RNA的大量提取,同时,T-RFLP结果证明RNA提取方法对分析样品的微生物种类和丰度分析结果影响较大,不同的RNA提取方法所获得的微生物群落基因多样性及其种类、丰度均不同.本研究建立了一种快速、有效的高质量RNA提取方法,将在监测活性污泥菌群动态变化、菌群代谢功能学、微生物群落芯片等研究上具有重要意义.     

基于SD-CA-GIS的环境累积效应时空分析模型及应用

环境累积效应分析强调环境变化的时空放大作用,突出环境要素之间的时空交互作用,从而对环境分析方法的能力提出了挑战.因此,本文在对传统环境分析方法归纳、分析和总结的基础上,以地理信息系统(GIS)为基础平台,集成系统动力学(SD)和元胞自动机(CA)的优点,建立了能够分析时间累积、空间累积效应的SD-CA-GIS模型.以山西潞安矿区作为研究区域,在分析矿区社会、经济、工程和环境等因子之间时空交互作用的基础上,构建了SD-CA-GlS模型.考虑到矿区土地利用变化的特殊性,从影响矿区土地利用变化的驱动因子出发,预测和模拟了矿区2006-2030年土地利用变化的累积状况.结果发现,由于煤炭资源开采等人类干扰活动的影响,研究区在研究时段内,工矿用地、居民用地和交通用地呈现累积性增加,其它土地利用类型累积性减少.同时,由于不同阶段人类活动干扰的种类和强度变化,使得不同土地利用类型的空间扩展变化存在一定的差异.上述研究表明,该模型能够同时考虑时间累积效应和空间累积效应的动态变化,能为环境累积效应的分析和评价提供有效的帮助.