Growth and photosynthetic responses to copper in wild grapevine

The present study evaluates the tolerance and accumulation potential of Vitis vinifera ssp. sylvestris under moderate and high external Cu levels. A greenhouse experiment was conducted in order to investigate the effects of a range of external Cu concentrations (0–23 mmol L⁻¹) on growth and photosynthetic performance by measuring gas exchange, chlorophyll fluorescence parameters and photosynthetic pigments. We also measured the total copper, nitrogen, phosphorus, sulphur, calcium, magnesium, iron, potassium and sodium concentrations in the plant tissues. All the experimental plants survived even with external Cu concentrations as high as 23 mmol L⁻¹ (1500 mg Cu L⁻¹), although the excess of metal resulted in a biomass reduction of 35%. The effects of Cu on growth were linked to a reduction in net photosynthesis, which may be related to the effect of the high concentration of the metal on photosynthetic electron transport. V. vinifera ssp. sylvestris survived with leaf Cu concentrations as high as 80 mg kg⁻¹ DW and growth parameters were unaffected by leaf tissue concentrations of 35 mg Cu kg⁻¹ DW. The results of our study indicate that plants of V. vinifera ssp. sylvestris from the studied population are more tolerant to Cu than the commercial varieties of grapevine that have been studied in the literature, and could constitute a basis for the genetic improvement of Cu tolerance in grapevine.     

珠江三角洲制鞋行业挥发性有机化合物排放系数研究

采用工艺调查与现场监测相结合的方法,以物料衡算法为依据,通过现场监测结果进行验证,研究了制鞋行业挥发性有机化合物(VOCs)排放系数。结果表明,水性胶粘剂使用企业的VOCs排放系数为(5.25±2.67)g/双,油性胶粘剂使用企业的VOCs排放系数为(30.11±10.60)g/双,根据不同类型胶水在制鞋行业中所占的权重,可得到反映地方特色的制鞋行业VOCs排放系数。     

Seasonal air-water exchange fluxes of polychlorinated biphenyls in the Hudson River Estuary

Polychlorinated biphenyls (PCBs) were measured in the air and water over the Hudson River Estuary during six intensive field campaigns from December 1999 to April 2001. Over-water gas-phase SigmaPCB concentrations averaged 1100 pg/m3 and varied with temperature. Dissolved-phase SigmaPCB concentrations averaged 1100 pg/L and displayed no seasonal trend. Uncertainty analysis of the results suggests that PCBs with 5 or fewer chlorines exhibited net volatilization. The direction of net air/water exchange could not be determined for PCBs with 6 or more chlorines. Instantaneous net fluxes of SigmaPCBs ranged from +0.2 to +630 ng m(-2) d(-1). Annual fluxes of SigmaPCBs were predicted from modeled gas-phase concentrations, measured dissolved-phase concentrations, daily surface water temperatures and wind speeds. The net volatilization flux was +62 microg m(-2) yr(-1), corresponding to an annual loss of +28 kg/yr of SigmaPCBs from the Hudson River Estuary for the year of 2000.     

Mass balance and long-term fate of PCDD/Fs in a lagoon sediment and paddy soil, Niigata, Japan

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in a sediment core and in samples of surface sediment and paddy soil collected from the Toyano lagoon and Kameda basin in Niigata, Japan, were analyzed to elucidate the temporal trends of their concentrations in the lagoon sediment and the relationship between the sediment and the paddy soil. The mass balance of these pollutants was also estimated to determine their long-term fate in surface waters. An analysis by chemical mass balance identified the agrochemicals pentachlorophenol and 2,4,6-trichlorophenyl 4-nitrophenyl ether as the major sources of PCDD/Fs. On the basis of the findings regarding the mass balance in the Kameda basin over the last 40 years, we estimate that more than half the input of PCDD/Fs to the Kameda basin has disappeared. We suggest that the PCDD/Fs that flowed out from the paddy fields have been transferred to the lower basin.     

Mass balance-based regression modeling of Cd and Zn accumulation in urban soils of Beijing

Accumulation of heavy metals in urban soil can pose adverse impacts on public health and terrestrial ecosystems. We developed a mass balance-based regression model to simulate the heavy metal accumulation in urban soils as a function of time and to explore connections between metal concentration and urbanization processes. Concentrations of Cd and Zn in 68 residential soil samples in the urban area of Beijing were used. The background concentrations, the loss rates and the input fluxes of Cd and Zn in urban soils of Beijing during the last three decades were estimated using a regression of the time series of accumulations of the metals. Based on the regression estimates, we simulated the general trends of Cd and Zn accumulation in the soils from 1978 to 2078. The concentrations of Cd and Zn in urban soil generally increased with the population growth, vehicle use and coal consumption. The mean concentrations of Cd and Zn in urban soil of Beijing would increase by 3 fold over the next 70 years for the current development scenario. The mass balance-based regression approach, which is able to reconstruct the history data of urban soil pollution, provides fundamental information for urban planning and environmental management.     

城市复合生态系统碳氧平衡分析——以沿海城市厦门为例

通过综合城市复合生态系统内社会经济活动的主要排碳、耗氧行为,以及城市区域内湿地、淡水、海洋、森林和农田5种遗留自然生态系统的固碳释氧功能,构建了城市碳氧平衡分析模型（UCOB）,并估算了城市社会经济活动和城市中自然生态系统的碳氧收支,对城市生态系统平衡状况进行定量化指征.最后,以中国东南沿海城市厦门为例进行研究.结果显...     

多功能型城市人工湿地水体汞分布特征及其量变分析

以重庆某集接纳生活污水处理厂出水、水质净化、休闲娱乐为一体的城市湿地公园为研究对象,根据水流流向设点采样,分析了湿地公园内污水处理区、湖泊深度净化区中总汞(THg)和甲基汞(MeHg)的分布特征,并探讨了其源汇关系.结果表明,污水处理区出水THg质量浓度范围为1. 98～38. 03 ng·L~(-1)[平均值为(9. 10±5. 84) ng·L~(-1)],出水MeHg质量浓度范围为0. 09～0. 84 ng·L~(-1)[平均值为(0. 34±0. 08) ng·L~(-1)];湖泊深度净化区THg质量浓度范围为0. 37～85. 69 ng·L~(-1)[平均值为(6. 76±2. 29) ng·L~(-1)],MeHg质量浓度范围为0. 04～1. 47 ng·L~(-1)[平均值为(0. 35±0. 17) ng·L~(-1)],人为活动对汞浓度的干扰较为明显.水体总汞、甲基汞垂直分布规律具有一致性,均表现出表层深层.通过物料衡算,表明该湿地系统水体总汞每年降低155. 50 g,水体甲基汞每年降低1. 65 g,对下游水体具有保护作用.     

北京气象塔夏季大气O3,NOx和CO浓度变化的观测实验

以北京325m气象塔为观测平台,于2002年夏季进行了大气污染物臭氧(O₃)及其前体物氮氧化物(NO_x)和气象要素加强期的同步观测.对观测资料做了详尽的分析,结果表明:边界层内存在明显的臭氧浓度(用体积分数表示)垂直差异;中午120m高度层存在O₃浓度最大值;低层O₃浓度呈明显的日变化,且昼夜振幅较大;夜间高层(280m)O₃的湍流混合和化学消耗较弱,可维持较高的浓度;局地光化学生成是白天边界层O₃的主要来源;降水天气过程可造成O₃及其前体物浓度的显著变化.     

三峡库区1980～2005年农业用地氮平衡时空变化研究

利用三峡库区分区县农业统计资料,对OECD土壤表观氮平衡模型进行适当改进,计算分析三峡库区1980~2005年农业用地氮平衡时空变化格局及驱动机制.结果表明,1980~2005年库区氮总输入和总盈余量呈显著增长趋势,分别从23.4万t和14.4万t增长到45.6万t和30万t;氮总输出量1980~1995年呈增加趋势,从9.0万t到16.7万t,1995年后基本保持稳定趋势;单位面积氮盈余量1980~1998年总体呈持续增加趋势,从133.4 kg/hm2增长到310.3 kg/hm2,1998年后逐步趋向稳定,但空间分布区域差异性增强,主要集中在库中和库首区县,与库区移民数量空间分布具有一定的相似性;氮输入贡献主要来源于化肥、牲畜粪便、人粪尿和生物固氮,累计占总输入90%以上;1995年前库区氮平衡变化主要受国内大量使用化肥宏观环境影响,1995年后受水库淹没和移民影响较大,但其具体影响程度有待进一步分析;建议考虑适当发展副业、改变农业种植结构或进行生态移民等措施减少氮排放量.     

数据清洗对污水处理厂生物建模可靠性影响研究

为应对污水处理厂出水水质要求的不断提升,通过生物建模技术降低污水处理厂碳源、除磷药剂投加量,实现达标排放同时降低运营成本已成为必要手段.然而,数据质量是影响模型可靠性的关键因素.为提高建模数据质量,本研究在生物建模过程中提出了系统性3步清洗方法：统计分析法标定可疑数据;物料平衡计算法剔除大误差并闭合流量平衡;污泥特征分析法修正污泥组分.应用该方法成功对天津宁河芦台桥北污水处理厂2019年1—7月历史水质数据、SCADA在线流量数据及补充采集的3日水质数据实现有效的清洗,并完成基于Biowin-ASDM活性污泥模型的生物建模案例研究.通过与直接利用原始数据进行模拟拟合的对比结果表明,应用清洗后的数据进行建模可有效提升模型可靠性,不但校正参数趋于合理,更可实现生化段主要污染物TSS、TCOD、TN、TP去除率的模拟误差≤3%.