着生藻类在苏州河黄浦江水质监测中的应用

对苏州河和黄浦江两条河流7个样点着生藻类进行了1年的动态研究,比较分析了2条河流着生藻类种类、数量、密度、多样性指数和优势种的变化情况,并且采用Palmer提出的20属耐受污染藻类的污染指数值求出水体的总污染指数。分析结果表明,苏州河和黄浦江的着生藻类主要为硅藻,各月各样点藻类的总污染指数分别为29、32,水质状况均是重度有机污染。     

苏州河上海市区段表层沉积物中多环芳烃的分布及特征

参照美国EPA8000系列方法、质量保证和质量控制,对苏州河上海市区段的表层沉积物中16种优控多环芳烃类有机物(PAHs)进行了分析.结果表明,苏州河上海市区段的表层沉积物均受到了很大程度的污染,其中处于市区中段的昌化路桥、西康路桥和长寿路桥断面的PAHs含量较高,处于黄浦江入口附近的四川路桥、河南路桥和福建路桥断面的含量较低.同时发现,近十几年来苏州河沉积物中的PAHs含量和成分发生了一定的变化,对其原因作了初步探讨.     

综合调水对苏州河周边水系水质影响的数值模拟

进行长期有效的水资源综合调度是实现2010年苏州河河水变清的综合整治目标的一项重要措施。为进一步论证该项措施对周边水系的水质影响,为综合调水提供科学的决策依据,利用MIKE11模型系统建立了上海市苏州河水系的水动力、水质模型,进行苏州河综合调水对黄浦江以及蕴藻浜水质的影响作用的数值模拟。分析表明,苏州河综合调水对松浦大桥取水口水质基本没有影响,并可以在一定程度上改善黄浦江干流中下游河段的水质;东引北排初期会增加蕴藻浜干流的污染负荷,持续调水6d后蕴藻浜干流河段的水质将得到改善。     

上海城市水环境质量改善历程与面临的挑战

上海市排污总量大,污染负荷重.历史上,黄浦江曾经黑臭,苏州河则在20世纪70～90年代终年黑臭,地表水污染一度成为困扰上海环境的一个主要问题.20世纪80年代以来,上海加大了对城市受污染河流的治理力度,开展了一系列工作,其中苏州河修复是最具代表性的一项.苏州河治理耗资157亿元,历时20年.在实施了苏州河污水合流一期、苏州河环境综合整治一、二、三期项目后,苏州河黑臭现象消失,水质持续改善,滨河风貌明显改观,受到各方面高度评价.与此同时,上海城市水环境质量总体趋好,而要进一步稳定和持续改善全市水环境质量,深化整治势在必行,水环境工作者面临新的挑战.     

北方典型干旱缺水型河流氮磷时空分布特征与富营养化评价

以北方典型干旱缺水型河流-滏阳河流域邢台段为研究对象,通过为期1年(2013年6月—2014年5月)的水质监测,阐述了流域内氮磷时空变化特征及富营养化水平。结果表明,流域内水体TN的平均质量浓度为28.27 mg·L~(-1)(其中NH_4~+-N占67.94%),TP的平均质量浓度为1.37 mg·L~(-1)(其中SRP占62.01%);流域内氮磷时空分布特征明显:在时间尺度上,水体中氮磷浓度均呈现出旱季(9月—次年5月)高于雨季(6—8月);空间尺度上,氮磷质量浓度分布差异明显且均呈现出市区流域高于市郊流域,沿河流流向逐渐减少的趋势;对数型幂函数普适指数公式对水体富营养化的评价结果显示:无论从时间尺度上还是空间尺度上,所有采样点都处于极富营养状态,其变化趋势与氮磷有明显的一致性,同时富营养化程度与地区污染水平呈现一定的相关性。水资源匮乏以及河流湖库化严重是造成该地区水体富营养化问题突出的主要原因。     

ARIMA模型在苏州河总磷预测中的应用

目前苏州河面临潜在的富营养化危机,氮、磷含量较高的污染源是富营养化形成的直接诱因.选择总磷指标为研究对象,介绍运用时间序列分析法对总磷进行ARIMA建模预测,确定ARIMA(11,0,0)即AR(11)为最终模型,用1986～2003年数据对2004和2005年进行预测,结果得出苏州河总磷在未来2年呈波动下降趋势,最终在0.4～0.6 mg/L之间上下波动,但仍高于地面水Ⅴ类标准.模型适用于苏州河总磷的短期预测,完善苏州河富营养化预测管理系统.     

微生物在苏州河生态系统中的地位及作用

苏州河是上海的母亲河 ,但近年来随着上海经济的发展 ,苏州河的污染越来越严重。这不仅损害了上海市民的生活质量和身体健康 ,而且与上海国际大都市的形象格格不入。 2 0世纪 80年代 ,上海市政府开始治理苏州河 ,但从未从生态学的角度治理过苏州河。微生物作为生态系统重要组成部分———分解者 ,对维持苏州河生态系统的平衡起着极其重要的作用。微生物不仅能降解苏州河水体和底泥中的有机物 ,而且可作为水体污染程度及受污后治理恢复状况的指示指标。本文主要选取有代表性的指示微生物 ,通过对苏州河上海市区段 8个采样段面处底泥 (主要是表层底泥 )中微生物指标的定量测试及代表性河段的耗氧速率测定 ,来了解目前苏州河的污染状况及微生物在整个生态系统中的地位和作用 ,从而为苏州河的综合治理提供依据。     

湖州大钱港(溇港)河流生态缓冲带的划定与构建

河流生态缓冲带(后称"缓冲带")对改善河流水环境、控制面源污染和水土流失等具有重要作用.如何确定缓冲带的宽度并对其进行合理构建,已成为学者与管理部门关注的热点之一.以浙江省湖州市平原河网型河流大钱港(溇港)为例,基于VFSMOD模型计算和地形坡度、水体流向、土地利用状况、降水条件、土壤类型等现状条件,确定了农田型河段、村落型河段、林草型河段的缓冲带宽度;针对城镇型河段,结合城市河道蓝线,确定了缓冲带的宽度.结果 表明,大钱港干流左右岸缓冲带长度共约16.1 km,面积共约0.408 km2;同时,采用GIS对数据进行处理,并实现了缓冲带的可视化表达.结合农业农村面源污染负荷空间分析,筛选出高污染入河负荷区中的唐家浒自然村汊港段,并提出了缓冲带修复方案,以期为其他缓冲带划定与构建提供参考.     

连片生态浮床对微污染河水的净化效果

选取漕桥河的支流庙尖浜作为实验河段,以睡莲(Nymphaea alba)、菖蒲(Acorus calamus Linn)和水芹(Oenan-the javanica(Blume)DC)作为微污染水体净化的浮床植物,研究连片生态浮床的净化能力随季节的变化和浮床面积对连片生态浮床净化能力的影响。结果显示,秋-冬-春季节内植物的净化能力随季节变化呈"U"型,相应的河水水质的变化呈一个倒置的"U"型;在一定营养负荷和植物正常生长状况下,沿水流方向,氮、磷含量随浮床面积的增加而降低——春季时,随浮床面积增加,菖蒲区对TN的去除率由8.6%增加到26.7%,TP的去除率由17.1%增加到58.2%,水芹区对TN和TP的去除率最高可达22.0%和28.0%。研究表明连片生态浮床是河道水质改善的有效可行的方法之一,可为太湖入湖河流的营养物质控制提供科学依据。     

新疆库尔勒对流层NO2特征分析

利用地基多轴差分吸收光谱仪(MAX-DOAS),选择新疆开孔河流域绿洲城市库尔勒为研究区,于2014—2016年对其市区及郊区的对流层NO_2垂直柱浓度(VCD)进行观测,结果表明:(1)从日变化来看,市区在不同季节的NO_2VCD日均值为冬季秋季春季夏季,郊区为冬季春季秋季夏季。(2)从季节变化来看,市区和郊区的NO_2VCD波峰均出现在冬季,波谷基本出现在夏季;NO_2VCD的年均值在2014年最高,2015年有所下降,2016年又开始回升。(3)NO_2VCD与同期NO_2地面浓度变化趋势基本一致,两者相关性良好(R=0.795)。(4)地形与风向影响使得库尔勒污染物不断向郊区扩散,造成郊区NO_2浓度的增加;冬季漫长的采暖期、风沙天气频发以及不利于污染物扩散的静稳天气条件导致污染物的聚集,难以及时扩散。     

Stemflow chemistry of urban street trees

pH and ion concentrations (Na(+), K(+), Mg(2+), Ca(2+), NO(-)(3)) in the stemflow of the evergreen broad-leaved tree, Ilex rotunda, planted in the median strip of a highway and nitrogen oxides concentration in the air in an urban site were compared with a suburban site in Fukuoka city, Japan. The annual average of the nitrogen oxides concentration in the air was higher and NO(-)(3) concentration in the stemflow at the urban site was higher or similar compared with the suburban site. However, the annual average of pH in the stemflow at the urban site was higher than at the suburban. The annual average cation concentrations in the stemflow at the urban site were higher than at the suburban except Na(+). In particular, K(+) and Ca(2+) were higher throughout the measurement period. Therefore, higher pH in the urban stemflow was probably due to neutralization by higher concentrations of K(+), Mg(2+) and Ca(2+).     

上海大气氮湿沉降的污染特征

为探讨上海大气氮湿沉降的污染特征,采集了2007年11月至2008年10月上海雨水样品,分析了大气氮湿沉降浓度,探讨了上海大气湿沉降氮通量及上海市区,市郊和远郊大气氮湿沉降的时空污染特征.结果表明:(1)上海市区、市郊和远郊大气氮湿沉降质量浓度平均值分别为2.96、2.31、2.21 mg/L.从上海大气湿沉降总体来看,大气氮湿沉降劣V类、V类的超标率分别达到51.09%和13.87%.推断大气氮湿沉降的主要来源是机动车辆所排放的大量氮氧化物.(2)除冬季外,其余季节上海市区大气氮湿沉降浓度均大于市郊和远郊;市区和远郊大气氮湿沉降浓度均在秋季最大,市郊大气氮湿沉降浓度在春季最大.(3)上海大气年氮湿沉降通量为78.42 kg/hm~2,同其他区域相比较,属于世界上高氮沉降区域.(4)上海大气月氮沉降通量与月平均降雨量呈显著的线性正相关(p<0.05),说明上海大气氮湿沉降通量主要受降雨量的影响.     

Temporal variations of surface water quality in urban, suburban and rural areas during rapid urbanization in Shanghai, China

As the economic and financial center of China, Shanghai has experienced an extensive urban expansion since the early 1980s, with an attendant cost in environmental degradation. We use an integrated pollution index to study the temporal variations of surface water quality in urban, suburban and rural areas between 1982 and 2005. Data on monitored cross-sections were collected from the Shanghai Environmental Monitoring Center. The results indicated that the spatial pattern of surface water quality was determined by the level of urbanization. Surface water qualities in urban and suburban areas were improved by strengthening the environmental policies and management, but were worsening in rural areas. The relationship between economic growth and surface water quality in Shanghai showed an inversed-U-shaped curve, which reflected a similar pattern in most developed countries. This research suggests that decision makers and city officials should be more aware of the recent pollution increases in Shanghai.     

Elevated atmospheric CO2 concentration and temperature across an urban–rural transect

The heat island effect and the high use of fossil fuels in large city centers are well documented, but by how much fossil fuel consumption is elevating atmospheric CO₂ concentrations and whether elevations in both atmospheric CO₂ and air temperature from rural to urban areas are consistently different from year to year are less well known. Our aim was to record atmospheric CO₂ concentrations, air temperature and other environmental variables in an urban area and compare it to suburban and rural sites to see if urban sites are experiencing climates expected globally in the future with climate change. A transect was established from Baltimore city center (Urban site), to the outer suburbs of Baltimore (suburban site) and out to an organic farm (rural site). At each site a weather station was set-up to monitor environmental variables for 5 years. Atmospheric CO₂ was consistently and significantly increased on average by 66 ppm from the rural to the urban site over the 5 years of the study. Air temperature was also consistently and significantly higher at the urban site (14.8 °C) compared to the suburban (13.6 °C) and rural (12.7 °C) sites. Relative humidity was not different between sites whereas the vapor pressure deficit (VPD) was significantly higher at the urban site compared to the suburban and rural sites. An increase in nitrogen deposition at the rural site of 0.6% and 1.0% compared to the suburban and urban sites was small enough not to affect soil nitrogen content. Dense urban areas with large populations and high vehicular traffic have significantly different microclimates compared to outlying suburban and rural areas. The increases in atmospheric CO₂ and air temperature are similar to changes predicted in the short term with global climate change, therefore providing an environment suitable for studying future effects of climate change on terrestrial ecosystems.     

Toxic heavy metal contamination and risk assessment of street dust in small towns of Shanghai suburban area, China

The aims of this paper were to quantify the heavy metal concentrations in street dust of small towns in Shanghai suburban area compared with those in urban area, and examine their seasonal and spatial variations, and to assess their risks to water environment and local populations. Street dust samples were collected from three small towns and urban area in Shanghai in different seasons. Levels of heavy metals were determined by atomic adsorption spectrophotometer analyzer. The method of potential ecological risk index and the health risk assessment model were used to evaluate the potential risks to water bodies and local residents, respectively. The mean metal concentrations in street dust of small towns were far above soil background values but still lower than those in the urban area. No significant seasonal change was observed except for Cr, Ni, and Zn concentrations. Higher metal concentrations tended to be located in central area of towns and township roads. The integrated metal contamination was high and posed a strong potential ecological risk. Children had greater health risk than adults. The carcinogenic risk probabilities were under the acceptable level. The hazard index values to children were close to the safe level. Street dust from the studied area has been contaminated by heavy metals. The contamination of these elements is related more to the pollution source than seasonal change. The combination of the six metals may threaten the water environment and has non-cancer health risk to children, but not to adults.     

Impact assessment of human diet changes with rapid urbanization on regional nitrogen and phosphorus flows—a case study of the megacity Shanghai

Regional material flows are strongly influenced by human diets. To diagnose and prevent environmental problems that threaten urban sustainability, the impact of human diet changes with rapid urbanization on the regional nitrogen (N) and phosphorus (P) flows were quantitatively evaluated. A survey of day-to-day activities was conducted of 450 individuals surveyed (adults over 18 years old) in three representative areas (the central district, the new district, and the suburban/rural areas) of Shanghai, a megacity which has attracted worldwide attention. The lifestyle (eating habits, domestic sanitation, drainage facilities, etc.) pattern was determined and the potential N and P loads from human diets on the environment were calculated. The daily potential nitrogen and phosphorus loads from human diets was 19.36 g-N, 1.80 g-P in the central district, 16.48 g-N, 1.52 g-P in the new district, and 13.04 g-N, 1.20 g-P in the suburban/rural areas of Shanghai. Respondents in all three areas, especially those in the suburban/rural areas reported a preference for increasing the intake of animal-derived as well as processed foods, which means that the potential N and P load from human diets to the environment will increase further. In addition, most respondents consider industrial wastewater discharge as the main cause of eutrophication of waterbodies, though in recent years water pollution caused by domestic wastewater has increased rapidly, but this has received much less attention. Environment-friendly eating habits and improvements in the environmental awareness will be required.     

Concentrations of two organic contaminants in precipitation, soils and plants in the Essex region of Southern Ontario

Recent research has indicated that the atmosphere is an important pathway by which pollutants enter terrestrial and aquatic ecosystems. We report here concentrations of PCBs and octachlorostyrene (OCS) in precipitation, soils and plants in Essex County, Ontario. The average PCB concentration in urban precipitation (23 ng litre(-1)) was lower than that previously reported for urban areas in the Great Lakes basin. Differences between sites and with varying wind directions were not significant. OCS concentrations in precipitation averaged 1.6 ng litre(-1). Concentrations of PCBs in soils were 2-3 orders of magnitude greater than in precipitation. Concentrations of these pollutants in city soils and plant roots were consistently higher than those from suburban and rural sites. Ratios of urban to suburban concentrations in soils and precipitation were approximately 5:1 for PCBs. However, concentrations of OCS were similar in urban and suburban samples of precipitation, soils and plant tissues. These comparisons suggest an urban source for PCBs, but not OCS. Concentrations of all contaminants in plant leaves, unlike those in precipitation, roots and soils, were relatively similar in urban and suburban areas. That similarity suggests that direct foliar uptake is not an important pathway for pollutant uptake in plants.     

Airborne ammonia and ammonium within the Northern Adriatic area, Croatia

Determination of airborne ammonia started in the early 1980s, as a part of air pollution monitoring of industrial plants. Due to high emissions, the city of Rijeka was one of the most polluted in Croatia in the mid-1980s. Considerable reductions in SO2 and NO(x) emissions led to lower airborne levels of these pollutants in the mid 1990s. In spite of the coke plant closure in 1994, there was only a weak decline in airborne ammonia over the period 1980--2005, with annual means in the range of 12-20 microg m(-3) at urban Site 1 and 6-28 microg m(-3) at suburban Site 2. Similar behaviour has been observed with ammonium in bulk rainwater samples since 1996. Higher and approximately equal deposition of nitrogen as ammonium (N-NH4+) were obtained for the urban Site 1 and the mountainous Site 4, but with different causative facts. Ammonium's contribution to total nitrogen (NO3(-)+NH4+) deposition is approximately two thirds, even for a remote Site 3.     

运河(杭州段)沉积物耗氧物质释放的模拟实验研究

通过室内模拟试验研究了运河 (杭州段 )沉积物污染引起的上覆水 CO DCr的变化 ,并研究了连续曝气、换水清洗的方法对其耗氧物质释放的影响。结果发现由于沉积物的释放使得上覆水 CODCr浓度维持在劣四类水以上。连续曝气可以降低水体的恶臭 ,但由于曝气对沉积物的扰动引起沉积物更多地再悬浮 ,上覆水 CODC r也没有明显降低。在不考虑外源影响的情况下 ,换水清洗可以将上覆水 CODCr浓度降到 30 m g· L-1以下。本研究说明运河 (杭州段 )沉积物内源释放对上覆水 CODCr有较大的影响。