第二松花江(哈达湾-松花江村段)沉积物中有机物污染研究

本文所研究江段的有机污染物主要来自两岸工业排放的废水、生活污水、工业废弃物及生活垃圾。污染源主要位于右岸,上游右岸沉积物中有机污染物的总浓度高于左岸,下游两岸沉积物中有机污染物的总浓度趋于一致。两岸沉积物中污染物总浓度随距离的变化规律如下: 右岸:C=92.044S~(-0.3028) R=-0.962 左岸:C=9.231e~(-0.0058) R=0.946 在该江段沉积物中共检出51种有机污染物。其中致癌、可疑致癌、致突变化合物25种,占检出化合物的49％。淤泥质沉积物中有机污染物的存在量60.67吨,岸边滩及心滩土壤中存在量138.2吨。     

Polychlorinated biphenyls and organochlorine pesticides in local waterbird eggs from Hong Kong: risk assessment to local waterbirds

The contamination status of the marine environment in Hong Kong was studied by measuring concentrations of organochlorine (OC) pollutants (i.e., hexachlorobenzene, aldrin, dieldrin, endrin, mirex, total heptachlor, total chlordane, total DDTs, total PCBs, and total toxaphenes) in the eggs of selected waterbird species from different locations around the city: Little Egret (Egretta garzetta) and Chinese Pond Heron (Ardeola bacchus) from Mai Po Village, Great Egret (Ardea alba) and Black-crowned Night Heron (Nycticorax nycticorax) from A Chau, and Chinese Pond Heron (A. bacchus) from Ho Sheung Heung. The mean concentrations of total PCBs and total DDTs ranged from 191-11 100 ng g⁻¹ lipid and 453-49 000 ng g⁻¹ lipid, respectively. Recent exposure of waterbirds to technical chlordane was found in Hong Kong. The risk characterization demonstrated potential risks to birds associated with exposure to DDE, which was found to cause a reduction in survival of young in Hong Kong Ardeids based on the endpoint in the risk assessment.     

纳米金属对污水处理系统中磺胺耐药基因和耐药菌的影响及其机理

细菌耐药性和纳米材料污染为新兴环境问题。细菌耐药性遗传载体——耐药基因 (ARGs) 广泛存在于污水处理系统中,且已被证明与金属纳米材料密切相关。采用实时荧光定量PCR技术,探究了纳米零价铁 (nZVI) 和纳米氧化锌 (nZnO) 对污水处理系统中磺胺类耐药菌 (ARB) 和ARGs的分布特征的影响。结果表明,50 mg·L⁻¹ nZVI和nZnO暴露均有利于削减磺胺ARB浓度数。与对照组相比,nZVI和nZnO暴露后污泥中sul1丰度增加了0.25%~16.21%,而sul2出现明显削减 (1.51%~15.47%) 。此外,50 mg·L⁻¹ nZVI会导致游离态胞外ARGs大幅削减。nZVI和nZnO暴露通过富集污水处理系统中的intI1、改变细胞膜通透性和调节细菌转录能力促进sul1的增殖。本研究结果阐明了典型纳米金属对污水处理系统中ARB和不同形态ARGs消长的影响及其机制,可为制定有效调控和全面削减污水处理系统中耐药污染策略提供参考。     

自来水厂污泥作填埋场覆盖材料的试验研究

作者对上海市闵行自来水厂污泥渗透系数、重金属含量、浸出液性质进行了分析研究 ,研究结果表明 ,在10 0kPa压力 (一般填埋场压实设备的压实压力 )下 ,污泥的渗透系数为 1.3× 10 -7cm/s ,符合国家规定 ,污泥可以作为填埋场终场覆盖材料。同时 ,边坡稳定的分析研究结果还表明 ,该厂污泥铺设的斜坡倾角不宜超过 16 .5度     

底泥污染物释放动力学研究

采用模拟试验方式和新型微生物数量测定方法 ,研究了沼泽化湖泊底泥和受污染河流底泥在不同扰动状态下 ,底泥耗氧速率、氮和磷污染物释放动力学过程。结果表明 :( 1)底泥耗氧速率是同样条件下上覆水耗氧速率的 48倍 ,而在扰动状态下 ,底泥耗氧速率达到上覆水耗氧速率的 5 96— 93 6倍 ,扰动底泥显著增大其耗氧速率 ,底泥污染越严重 ,其耗氧速率越大 ,对水体产生的影响也越大。 ( 2 )扰动底泥可以显著增大底泥的氮磷释放速率 ,氮的释放受有机氮的氨化、氨氮的硝化、硝酸盐氮的反硝化以及氨氮被微生物吸收转化为有机氮等的影响 ;磷的释放过程受厌氧过程和底泥颗粒吸附的影响 ,耗氧速率高的底泥具有更大的氮磷释放潜力。 ( 3 )微生物数量在底泥污染物释放动力学中起着关键性作用 ,新型方法可以快速检测微生物总量。试验结果对于水环境的管理、受污染水体的修复 ,以及底泥的处理处置等都具有重要的指导意义     

Association between particulate matter air pollution and cardiovascular disease mortality in Lanzhou,China

Ambient particulate matter (PM) pollution has been linked to elevated mortality, especially from cardiovascular diseases. However, evidence on the effects of particulate matter pollution on cardiovascular mortality is still limited in Lanzhou, China. This research aimed to examine the associations of daily mean concentrations of ambient air pollutants (PM_2.5, PM_C, and PM₁₀) and cardiovascular mortality due to overall and cause-specific diseases in Lanzhou. Data representing daily cardiovascular mortality rates, meteorological factors (daily average temperature, daily average humidity, and atmospheric pressure), and air pollutants (PM_2.5, PM₁₀, SO₂, NO₂) were collected from January 1, 2014, to December 31, 2017, in Lanzhou. A quasi-Poisson regression model combined with a distributed lag non-linear model (DLNM) was used to estimate the associations. Stratified analyses were also performed by different cause-specific diseases, including cerebrovascular disease (CD), ischemic heart disease (IHD), heart rhythm disturbances (HRD), and heart failure (HF). The results showed that elevated concentration of PM_2.5, PM_C, and PM₁₀ had different effects on mortality of different cardiovascular diseases. Only cerebrovascular disease showed a significant positive association with elevated PM_2.5. Positive associations were identified between PM_C and daily mortality rates from total cardiovascular diseases, cerebrovascular diseases, and ischemic heart diseases. Besides, increased concentration of PM₁₀ was correlated with increased death of cerebrovascular diseases and ischemic heart diseases. For cerebrovascular disease, each 10 μg/m³ increase in PM_2.5 at lag4 was associated with increments of 1.22% (95% CI 0.11–2.35%). The largest significant effects for PM_C on cardiovascular diseases and ischemic heart diseases were both observed at lag0, and a 10 μg/m³ increment in concentration of PM_C was associated with 0.47% (95% CI 0.06–0.88%) and 0.85% (95% CI 0.18–1.52%) increases in cardiovascular mortality and ischemic heart diseases. In addition, it exhibited a lag effect on cerebrovascular mortality as well, which was most significant at lag6d, and an increase of 10 μg/m³ in PM_C was associated with a 0.76% (95% CI 0.16–1.37%) increase in cerebrovascular mortality. The estimates of percentage change in daily mortality rates per 10 μg/m³ increase in PM₁₀ were 0.52% (95% CI 0.05–1.02%) for cerebrovascular disease at lag6 and 0.53% (95% CI 0.01–1.05%) for ischemic heart disease at lag0, respectively. Our study suggests that elevated concentration of atmospheric PM (PM_2.5, PM_C, and PM₁₀) in Lanzhou is associated with increased mortality of cardiovascular diseases and that the health effect of elevated concentration of PM_2.5 is more significant than that of PM_C and PM₁₀.

     

底泥对河流的二次污染浅析

根据底冲中污染物质累积和释放过程和底泥对河流二次污染的机理,运用适用的模式和苏州河的实测资料,可得到二次污染ＢＯＤ和ＣＯＤ的年释放量,以及增加上覆河上的ＢＯＤ和ＣＯＤ浓度。由此认为,对于底泥污染严重的河流,疏浚是必不可少的,其目的在于清除或隔绝黑富集层上覆河上的二次污染。     

低声能密度超声波破解污泥的效果研究

以生活污水处理厂污泥为研究对象,采用超声波技术进行污泥破解,研究不同声能密度和超声作用时间对污泥预处理效果的影响。结果表明,低声能密度超声波在120min内可破碎污泥絮体,分解细胞壁,使胞内有机物溶出;延长超声作用时间、增加声能密度均有助于污泥中有机物、氮、磷等物质的释放,当声能密度为0.10 W/mL、超声作用时间为120 min时,溶解性COD(SCOD)、可溶性蛋白质、可溶性多糖、TN、氨氮、TP、正磷酸盐的浓度较破解前分别提高了29.99、44.49、17.31、14.06、3.19、1.35、1.00倍;破解污泥释放出的氮以有机氮为主,磷的释放作用不明显。利用Pearson相关性分析得知,在声能密度变化条件下,除TP外,SCOD、可溶性蛋白质、可溶性多糖、TN、氨氮、正磷酸盐之间均呈极显著相关(p0.01);在超声作用时间变化条件下,各指标间均呈极显著相关(p0.01)。     

A trust-enhanced and preference-aware collaborative method for recommending new energy vehicle

Environmental Science and Pollution Research - New energy vehicle (NEV), an Eco-friendly innovation to alleviate the problems of energy scarcity and environmental pollution, is increasingly popular...     

典型农业活动区土壤重金属污染特征及生态风险评价

联合野外采样和室内分析,以典型农田土壤为研究对象,分析土壤中重金属Cr、Ni、Cu、Zn、Cd、Pb、As和Hg的含量及污染特征,并采用单因子污染指数法、内梅罗污染指数法及潜在生态危害指数法,对农田土壤进行生态风险评价,同时利用主成分因子分析法,提取出3主因子,分析土壤重金属可能来源。结果表明,研究区农田土壤各重金属含量均高于背景值,表层污染程度高于底层;各重金属单因子污染指数对应污染等级均为清洁,内梅罗污染指数为0.46,污染等级为安全。潜在生态风险评估结果显示,研究区土壤重金属污染的潜在生态风险危害程度为中等,各重金属的潜在生态危害程度依次为Cd> Hg> As> Cu> Pb> Ni> Cr> Zn。主成分因子分析显示,研究区土壤中Hg、As和Cr主要由工业污染源贡献,土壤中Cd、Pb的污染主要来源于不合理的农业生产活动和居民生活,Ni、Zn和Cu与自然成土过程密切相关。综合评价表明,尽管研究区农田土壤目前重金属污染情况较轻,未达到警戒水平,但由于城市化的发展及长期现代化农业耕作活动造成农田土壤重金属的富集,因此,增强农田土壤安全性生产管理、严控土壤污染源与推行标准农业生产是十分必要的。