无机碳源对ASBR反应器中厌氧氨氧化反应的影响研究

研究了ASBR反应器中厌氧氨氧化细菌的富集以及无机碳源对ASBR反应器中厌氧氨氧化的影响。实验分别在8.0 L和4.0 L的ASBR反应器中进行。结果表明,接种污泥在驯化55 d后,第一次出现厌氧氨氧化细菌活性迹象;在85 d时候,厌氧氨氧化细菌成为优势菌种;在140 d时候,反应器运行稳定,出水浓度非常低,污泥颜色由灰色变成浅红色。随着NaHCO3溶液质量浓度从1.0 g/L增加到1.4 g/L,厌氧氨氧化细菌的活性迅速增加,当NaHCO3溶液质量浓度达到2.0 g/L时厌氧氨氧化细菌的活性受到抑制。然而,随着NaHCO3溶液质量浓度下降到1.0 g/L,厌氧氨氧化细菌活性可以恢复。     

不同水生植物富集氮磷能力的试验研究

研究了伊乐藻、菹草、微齿眼子菜、竹叶眼子菜、石菖蒲和水芹菜等水生植物在不同营养状态下体内富集N、P的能力。结果表明:植物体内氮磷浓度增加的趋势与所在水体中的氮磷去除效果相一致;挺水植物水芹菜和沉水植物微齿眼子菜吸收N、P的能力较强,可将这两种植物构成双层次群落结构用以修复太湖地区的富营养化水体。     

抚顺市大气污染颗粒物来源特征研究

在5个采样点分别采集了环境大气中的总悬浮颗粒物(TSP)和可吸入颗粒物(PM10),用富集因子分析法和化学质量平衡法解析了TSP和PM10的来源。结果表明,各主要污染源对TSP的主要分担率为煤烟尘41.6%,扬尘29.1%,冶金尘5.3%,建筑水泥1.5%,汽车尾气0.8%,燃油0.4%,有机碳21.3%;对PM10的主要分担率为煤烟尘45.8%,扬尘26.8%,冶金尘4.4%,建筑水泥0.5%,汽车尾气1.3%,燃油0.2%,有机碳20.9%。     

Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO₂ and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO₂ protected photosynthesis of both species against moderate heat stress. Elevated CO₂ increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 °C) decreased all of these parameters in birch regardless of CO₂ treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO₂ were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO₂. Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms.     

高效富集—火焰原子吸收光度法测定饮用水中的铅

用高效螯合树脂富集器富集－火焰原子吸收分光光度法可测定自来水中μｇ／Ｌ级的痕量铅,大量共存元素不干扰铅的测定,测定结果令人满意。     

上海浦东新区环境空气重金属污染特征及来源解析

于2012年3月—2013年2月在浦东新区城区点和郊区点采集TSP样品,利用双酸消解原子荧光法、ICP法分析了样品中的13种元素。结果表明,除As略超标外其他元素均达标,城区点和郊区点环境空气重金属年均值排在前3位的元素是:Fe、Sn、Zn,占样品金属总量的83%~87%;排在末4位的元素是:Ni、Cr、As、Cd,占金属总量的1%~2%。通过EPA PMF 5.0模型运算结果,在城区中6个因子贡献比最高的31.5%为Sn+Fe+Mn,贡献比最低的2.1%为Hg;在郊区中6个因子贡献比最高的36.4%为Pb+Cu,贡献比最低的9.2%为Fe+Sn+Mn。浦东新区富集因子E≤10的元素有Cr、V、Ba、Mn、Ni、Fe、Hg城、Cu郊、As;富集因子E10的元素有Hg郊、Cu城、Zn、Pb、Cd、Sn。     

乌鲁木齐市大气PM2.5中重金属元素含量和富集特征

利用PM2.5／PM10便携式采样器采集了乌鲁木齐市5个功能区PM2.5,样品,用TAS-990石墨炉原子吸收光谱仪检测了PM2.5样品中Cd、Cu、Ni、Pb、Mn的含量。结果表明,乌鲁木齐大气PM2.5质量浓度变化趋势是冬季采暖盛期〉秋季采暖初期〉春季停暖初期〉夏季停暖期。参照《环境空气质量标准》（GB3095—2012）中的二级标准,采样期间卡子湾水泥厂区样品全部超标,其余4个采样点样品在冬季采暖盛期也全部超标,部分样品在非采暖期超标。富集因子法分析表明,乌鲁木齐市5个采样区PM2.5样品中Ni、Cu、Cd、Pb污染主要来自于人类活动,Mn则来源于地壳物质。     

痕量有机氯化合物分析中的样品预处理方法

近些年来，痕量有机氯化合物分析中，各种样品预处理技术得到了迅速发展，文章介绍了一些样品预处理方法的原理和最新进展，阐述了索氏提取，超临界流体萃取，微波萃取，固相萃取等几种富集方法的原理，特点，性能及应用，论述了吸附柱层析法，凝胶渗透色谱，高效液相色谱等样品净化技术的特点和应用。     

重庆黔江区大气降水的化学特征及来源分析

通过2013年6月—2014年5月对黔江区大气降水的化学组成分析研究表明,降水样品的p H值分布范围在4.91~7.32之间;SO2-4是降水中主要的阴离子,占阴离子总量的68.9%,Ca2+是降水中含量较高的阳离子,占阳离子总量的41.4%;SO2-4/NO-3浓度比为6.78,表明降水类型为硫酸盐型。陆源性离子Ca2+、Mg2+以及海源性离子Na+和Cl-之间存在明显的相关关系。海水和土壤的富集系数表明,研究区域的SO2-4和NO-3主要归因于人为活动的影响。     

Source-specific risk assessment for cadmium in wheat and maize: Towards an enrichment model for China

Cadmium (Cd) pollution of agricultural soil is of public concern due to its high potential toxicity and mobility. This study aimed to reveal the risk of Cd accumulation in soil and wheat/maize systems, with a specific focus on the source-specific ecological risk, human health risk and Cd enrichment model. For this we investigated more than 6100 paired soil and grain samples with 216 datasets including soil Cd contents, soil pH and grain Cd contents of 85 sites from China. The results showed that mining activities, sewage irrigation, industrial activities and agricultural practices were the critical factors causing Cd accumulation in wheat and maize cultivated sites. Thereinto, mining activities contributed to a higher Cd accumulation risk in the southwest China and Middle Yellow River regions; sewage irrigation influenced the Cd accumulation in the North China Plain. In addition, the investigated sites were classified into different categories by comparing their soil and grain Cd contents with the Chinese soil screening values and food safety values, respectively. Cd enrichment models were developed to predict the Cd levels in wheat and maize grains. The results showed that the models exhibited a good performance for predicting the grain Cd contents among safe and warning sites of wheat (R² = 0.61 and 0.72, respectively); while the well-fitted model for maize was prone to the overestimated sites (R² = 0.77). This study will provide national viewpoints for the risk assessments and prediction of Cd accumulation in soil and wheat/maize systems.