大气污染与儿童肺功能的典型相关分析

在 1 994～ 1 996年间 ,对污染点和对照点 (相对清洁点 )同时进行了大气污染 (气溶胶 ,二氧化硫等 )和儿童肺功能 (FVC,FEV1 ,FEF2 5～ 75 等 )的测定。对它们之间的关系进行了典型相关分析 ,其结果是肺功能指标和大气污染物呈负相关。统计分析提示污染点与对照点儿童肺功能的差别主要是由于大气污染 (气溶胶 )造成的 ,特别是 PM2 .5 的细粒子造成的。     

重庆大气污染与儿童肺功能横截面研究

1995年 ,在重庆市城区及远郊区进行了儿童家庭问卷调查、气溶胶 (PM1 0 、PM2 .5 )及 SO2 的测试 ,并在两个点 (城区华新小学 ,远郊北碚红岩小学 )进行二次儿童肺功能的测定。通过城区和郊区 3 53 6例 (其中男性 1 74 4例 ,女性 1 792例 )儿童肺功能数据的比较 ,说明重庆大气污染 ,特别是气溶胶的污染已影响到儿童肺功能。与美国比较 ,重庆儿童较美国的儿童肺功能 (FVC,FEV1 )要低 9%～ 1 4 %。同时得到青春前期 (7～ 1 4岁 )儿童肺功能 (FVC,FEV1 )的参考值的计算公式     

Distributions, sources, and ecological risks of DDT-related contaminants in water, suspended particulate matter, and sediments from Haihe Plain, Northern China

The residual levels of dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDXs, including p,p′-DDT, DDD, and DDE) in water, suspended particulate matter (SPM), and sediments from major rivers, lakes, and reservoirs in Haihe Plain were measured with a gas chromatograph equipped with a ⁶³Ni microelectron capture detector. In the fall of 2004, the contents of the total DDXs in the water and SPM were 0.29?±?0.69 ng L^?1 and 423.13?±?577.85 ng g^?1 dry wt., respectively. In the spring of 2005, the total DDXs were 0.36?±?0.91 ng L^?1 for water and 35.93?±?62.65 ng g^?1 dry wt. for SPM. The average concentration of DDXs for sediments was 7.10?±?7.57 ng g^?1 dry wt. during the two seasons. The Eastern-Hebei-Province Coastland River System was the most polluted, which was mainly attributable to the extensive use of DDT pesticide and dicofol in that system. Recent DDT inputs still occur in some regions, as indicated by DDT/(DDD + DDE) > 1 at 29–36 % of the sites for water and 55–61 % of the sites for SPM. The potential ecological risks of DDT in the water were assessed using a species sensitivity distribution model. Only shrimp and crabs were found to have potentially affected fraction values of 1.63?×?10^?3 to 2.27?×?10^?4, with probabilities beyond the hazardous concentration for 5 % of species (HC5) values of 1.90–2.56 %, suggesting only slight risks. DDXs in the sediments of some sites were also of potential risk to benthic organism based on consensus-based sediment quality guidelines.     

Distribution and sources of organochlorine pesticides in sediments of the Xiangjiang River, south-central China

The Xiangjiang River (XR), the second largest tributary of the Yangtze River, is mainly located in Hunan province in south-central China. Nineteen surface sediment samples (the top 3-cm layer) collected from XR were analyzed to determine the concentrations, distribution, sources, and ecological risk of organochlorine pesticides (OCPs). The concentrations of OCPs were 3.0–29.8 ng/g (dry weight) with a mean of 12.6?±?7.7 ng/g. The widely detected compounds included HCHs, DDTs, HCB, and dieldrin. Overall, the dominant OCPs in the sediments were mainly composed of residual and degradation products, e.g., β-HCH with a mean of 42.2 % in HCHs and p,p′-DDE with a mean of 43.5 % in DDTs, implying that OCPs in the sediments had suffered from long-term aging without fresh inputs in XR. However, there was a high proportion of p,p′-DDT to DDTs in three sites, suggesting that there was use of technical DDT from their surrounding areas at present. The ratios of α-HCH/γ-HCH and p,p′-DDD?+?p,p′-DDE/DDTs increase from the upper reaches to the lower reaches of XR, suggesting sediments enriched with α-HCH and metabolites DDD and DDE during sediment transport process and could be attributed to the transformation of γ-HCH to α-HCH and DDT to DDE or DDD. The assessment of the ecological risk indicates that the OCPs in the sediments of XR have a moderate adverse biological effect on organisms.     

Spatial, temporal, and speciation variations of heavy metals in sediments of Nan'ao Island, a representative mariculture base in Guangdong coast, China

Heavy metals in sediments from Baisha Bay, Nan'ao Island, one of Guangdong Province's largest mariculture bases in Southern China, were investigated. The results display that the concentrations of 6 heavy metals from surface sediments were 0.040-0.220 (Cd), 24.22-39.61 (Pb), 25.30-42.66 (Cr), 10.83-19.54 (Ni), 15.06-39.24 (Cu) and 55.12-141.73 mg kg(-1) (Zn), respectively. The highest concentrations and the greatest increasing rates of heavy metals were found in a sediment core in a fish cage culture area due to receiving sewage discharge, uneaten fish bait, and boat gasoline combustion. Cd was preferentially associated with the acid-soluble fraction and Pb mainly with the reducible fraction in surface sediments. Meanwhile, Cd and Pb displayed greatest labile fractions, indicating anthropogenic origin. A principal component analysis (PCA) revealed three groupings (Cd; Cr, Ni and Cu; Pb and Zn) that mainly result from different distributions of the metals in the various fractions. The ecological risk of the polluted sediments stemmed mainly from Cd, and from Pb and Cu to a lesser degree. It is suggested that the density of fish-stocking be controlled, periodic movement of rafts (cages) be introduced, and the total numbers of net-cages and human activities in the mariculture zones be restricted. in order to facilitate the recovery of the polluted sediment.     

序批式人工湿地冬季低温脱氮的效能研究

针对目前连续流人工湿地脱氮效率低、易堵塞及冬季效能下降的问题,提出了采用新型间歇流序批式人工湿地处理小城镇污水的方案,研究探讨了两级序批式人工湿地在冬季低温条件下,停留时间及排空闲置时间对脱氮效能的影响.试验结果表明,在冬季低温5～10 ℃、每级序批式湿地运行工况为瞬时进水-反应24h-瞬时排水-排空闲置12h、氮负荷为1.92g·m-2·d-1、进水COD、NH 4-N和TN浓度分别为143mg·L-1、27.0mg·L-1和32.0mg·L-1时,出水COD、NH4 -N和TN浓度分别为27mg·L-1、3.9mg·L-1和16.5mg·L-1,COD、NH4 -N和TN的去除率分别为81.12%、85.56%和48.44%.     

EDTA及其回收溶液治理重金属污染土壤的研究

试验结果表明,EDTA能够有效地萃取土壤重金属,由于其价格较贵和不易被降解等特点,限制了它的广泛运用.在运用MINTEQA2模型对萃取液中重金属离子形态分析的基础上,选用Na2S沉淀法将重金属从EDTA萃取液中有效分离.同时将回收的EDTA连续进行萃取土壤重金属,由于回收EDTA浓度下降的原因,其效果比新鲜EDTA的要稍微差一点,但从经济和效率上来说,仍旧可以用来治理重金属污染的土壤.     

上海石洞口第二电厂拟建粉煤灰分选系统的技术可行性研究

上海石洞口第二电厂拟建设粉煤灰分选系统生产国标等级灰,但其粉煤灰的游离氧化钙偏高.研究表明:游离氧化钙在细灰中没有明显富集的趋势,即源灰游离氧化钙含量指标合格,那么分选所产细灰的也合格;供分选用的源灰细度和粒度分布较利于提高分选效率,生产国标Ⅱ级灰的分选产率可达70%左右;建设分选系统在技术上是可行的,且可获得较大的综合效益.     

太湖流域水生态环境功能分区管理绩效评估研究

目前太湖流域水生态功能分区管理的绩效评估体系尚未建立,无法准确掌握分区管理体系的实施现状、把握影响太湖流域生态系统健康的关键影响因子。以太湖流域水生态环境功能分区为研究对象,基于“压力-状态-响应”模型构建不同时空尺度和管理边界下的绩效评估指标体系,实现了水生态环境功能分区不同管理目标下的差异化绩效评估。     

长三角人工智能产业空间格局及影响因素

基于从天眼查筛选的长三角人工智能企业数据,采用核密度法、空间自相关分析、地理探测器等方法,研究2015～2020年长三角41个城市的人工智能产业空间格局及影响因素。研究发现：(1)城市群层面,长三角人工智能产业呈多中心集聚发展态势,上海、杭州、苏州、南京、合肥五大集聚中心带动产业整体向沪宁合杭甬发展带集聚;从产业基础层、技术层到应用层,随着产业链环节技术门槛的降低,集聚水平提高,集聚中心数量增多,集聚规模扩大。(2)城市层面,上海和苏州呈现出“多中心”集聚特征,而杭州、南京、合肥为“单中心”的集聚模式;应用层集聚程度高于技术层和基础层,并向人口最密集和数据生产最多的中心城区集聚,基础层和技术层则相对更多布局在产业园区。(3)城市人工智能技术关联产业的基础(计算机、软件等)、科技人员数量、创新能力是影响长三角人工智能产业空间格局的核心因素,但基础层、技术层和应用层的影响因素存在一定的差异性。