抚仙湖、星云湖与杞麓湖营养状态演变及突变分析

为科学评价抚仙湖、星云湖和杞麓湖(简称三湖)营养状态及其变化趋势,基于三湖1991—2015年水质数据,采用综合营养状态指数法评价其富营养化水平,通过Mann-Kendall(Sneyers)方法判识三湖富营养化趋势及突变时间。结果表明:三湖都存在水质恶化现象,其综合营养状态指数及各分项指数均呈变差趋势,表征其营养物质在增加。三湖的营养化水平和演变时间存在显著差异,抚仙湖处于贫营养,星云湖由中营养转变为富营养,杞麓湖表现为中度-重度富营养化;抚仙湖和杞麓湖分别在2004、2011年出现突变点,星云湖自2000年后综合营养状态指数显著增加。基于三湖营养状态演变及趋势,结合变化特征及相关情况的讨论,提出对抚仙湖的管理应减少农业化肥和农药排放,对星云湖和杞麓湖的管理应削减高污染工矿企业排放等。     

Accumulation of Cu and Ni in successive stages of Lymantria dispar L. (Lymantriidae, Lepidoptera) near ore smelters at Sudbury, Ontario, Canada

The accumulation of Cu and Ni in successive life stages of the gypsy moth (Lymantria dispar), feces, and foliage near an ore smelter at Sudbury, Ontario and a control site was investigated. Higher concentrations of Cu and Ni were found in all larval stages collected at Sudbury than in those from the control site indicating that elevated levels of these metals in the Sudbury environment is an important factor influencing body burdens. These differences were associated with higher metal concentrations in the foliage of host trees from this site. However, differences between sites became less significant for pupae and adult stages. At the Sudbury site, concentrations of Cu (microg g(-1) dry wt) decreased in successive instars and then increased in tissues of pupae and adults. In contrast, Cu content (microg/individual) increased during larval development and then decreased in pupae and adults. The pattern of Ni concentration and content in larvae from the Sudbury site was similar to that of Cu. Patterns of Cu and Ni concentration and content throughout the life stages are explained by changes in weight resulting in a dilution effect in early stages, and a concentrating effect in later stages. Differences in Cu and Ni concentration and content between Sudbury and control populations became less significant following the pupal stage suggesting metal elimination with the exuviae and meconium. This study also illustrates the importance of sampling all stages in an insect's development when measuring accumulation of metals. Fecal and foliar concentrations of Cu and Ni from Sudbury were not significantly different suggesting that metal assimilation is low. Even though gypsy moths from Sudbury contain elevated levels of Cu and Ni, metal burdens in their tissues do not represent a significant route through the food chain. However, the conversion of foliage with high metal content to feces implies that other ecosystem consequences should be investigated.     

长三角地区气溶胶光学性质与新粒子生成观测

2019年5月27日～6月27日对江苏省常州市的气溶胶光学性质参数、颗粒物数浓度和PM_(2.5)组分进行观测,联用扫描电迁移率粒径谱仪(SMPS)、黑碳仪(AE33)、腔衰减相移式单次反照率监测仪(CAPS)、在线离子色谱分析仪(MARGA)和RT-4型有机碳/元素碳(OC/EC)分析仪分析:①新粒子生成期间化学组分与光学参数的变化;②IMPROVE、 MIE理论重建消光系数与实测值的闭合性对比.观测期间共有两次明显的新粒子生成事件,粒子粒径从4 nm持续增长到64 nm,在新粒子生成初期硫酸盐贡献较大,生成过程中实测平均消光系数为95.40 Mm~(-1),IMPROVE模型重建平均消光系数为140.20 Mm~(-1),MIE理论模型计算平均消光系数为93.54 Mm~(-1),低于我国城市气溶胶消光系数均值300 Mm~(-1).本次观测采用多仪器联用的方式从颗粒物数浓度粒径谱、化学组分谱等不同的方面更好地对气溶胶理化性质进行表征.     

Forest and Farmland Conservation Effects of Oregon’s (USA) Land-Use Planning Program

Oregons land-use planning program is often cited as an exemplary approach to forest and farmland conservation, but analyses of its effectiveness are limited. This article examines Oregons land-use planning program using detailed spatial data describing building densities in western Oregon. An empirical model describes changes in building densities on forest and agricultural lands from 1974 to 1994, as a function of a gravity index of lands commuting distance to cities of various sizes, topographic characteristics, and zoning adopted under Oregons land-use planning program. The effectiveness of Oregons land-use planning program is evaluated based on the statistical significance of zoning variables and by computing estimated areas of forest and agricultural lands falling into undeveloped, low-density developed, and developed building density categories, with and without land-use zoning in effect. Results suggest that Oregons land-use planning program has provided a measurable degree of protection to forest and agricultural lands since its implementation.     

上海梦清园生态净化工艺设计与研究

梦清园工程采用人工湿地、水生植物塘组合技术,构建了一套复杂的生态系统净化苏州河水,效果明显,同时还取得了良好的经济、社会效益。     

原位生态净化集成系统对二级生化尾水的处理效果

为研究原位生态净化技术对微污染河水的净化效果,选择某硬质纳污河道作为研究对象,以二级生化尾水作为水源,考察生态河床-生态滤坝集成系统对水质的净化情况。结果表明:在水力负荷为5 m/d条件下,集成系统对二级生化尾水中COD、NH~+_4-N、TP和TN的平均去除率分别为26.26%、16.09%、11.48%和10.15%;与常规人工湿地相比,虽然集成系统在去除率方面较差,但在去除污染物总量方面具有一定优势。集成系统中生态河床和生态滤坝对COD、NH~+_4-N、TP、TN污染物去除总量的贡献率分别为14%、34%、60%、44%和86%、66%、40%、56%。通过在生态河床中合理搭配种植植物类型,以及在生态滤坝中添加具有缓释碳源功能的净水基质,能够增强净水效果,进一步提高生态河床和生态滤坝在集成系统中去除污染物的贡献率。     

积极创新生态环境价格机制 加速甘肃绿色发展转型

生态环境价格机制的本质是在市场经济体系中充分体现生态环境作为资源属性的价值,是实现绿色发展的核心政策之一,更是深入推动生态文明建设的重要组成部分。近年来,甘肃省制定和实施了一系列生态环境价格政策,并初步取得了一定成效,但是仍然存在环境价格税费政策不完善、生态环境价格形成机制不健全等问题,难以有效支撑甘肃省作为国家西部生态安全屏障的战略定位以及环境质量达标的需要。本文在系统评估甘肃省生态环境价格政策实施现状的基础上,结合甘肃省生态文明建设需要,提出了甘肃省生态环境价格机制建立的基本思路、重点任务和实施对策。     

典型医药活性物质在污水处理厂中的归趋及其风险评估

采用固相萃取、高效液相色谱/串联质谱法 (污泥样品先采用超声波萃取预处理方法提取) 检测分析了包括磺胺类、喹诺酮类、大环类酯类抗生素、心血管类、止痛剂类等8类医药活性物质在重庆某污水厂中的含量水平及其行为归趋.采用 EC/PNEC 综合评价体系评估环境中目标医药活性物质的生态风险,利用质量平衡分析的方法分析了其在水相及污泥相中的分布.结果表明,目标物质在水相中均可检出,其检出浓度在ng/L~μg/L,在污泥样品中可检测出18种目标物质,其浓度在ng/g (干重,下同).仅仅1.1%的目标物质被污泥吸附去除.污水处理厂初级处理及氯化消毒阶段对目标物质无明显去除效果,目标物质的去除主要发生在生物处理阶段,生物的降解或转化作用是目标物质的主要去除机制.EC/PNEC分析表明,磺胺嘧啶、磺胺甲恶唑、氧氟沙星与脱水红霉素在污水处理厂出水及其污泥中综合评价因子均大于1,它们的存在可能对环境产生不同程度的危害.本研究结果表明,污水处理厂并不能完全去除水相中微量的医药物质,为防止排放导致的潜在生态风险,出水及污泥中活性医药物质需采取措施进行进一步的处理.     

负载金属改性活性炭降解VOCs的研究

本文对活性炭表面的负载金属改性进行了综述,并对经金属改性后的活性炭在VOCs处理中的作用原理进行了讨论。认为根据VOCs的具体组成成分,选择某一种特定的金属物质对活性炭进行改性可提高其去除空气中VOCs的效果。     

Restoring native fish assemblages to a regulated California stream using the natural flow regime concept

We examined the response of fishes to establishment of a new flow regime in lower Putah Creek, a regulated stream in California, U.S.A. The new flow regime was designed to mimic the seasonal timing of natural increases and decreases in stream flow. We monitored fish assemblages annually at six sample sites distributed over approximately 30 km of stream for eight years before and nine years after the new flow regime was implemented. Our purpose was to determine whether more natural stream flow patterns would reestablish native fishes and reduce the abundances of alien (nonnative) fishes. At the onset of our study, native fishes were constrained to habitat immediately (<1 km) below the diversion dam, and alien species were numerically dominant at all downstream sample sites. Following implementation of the new flow regime, native fishes regained dominance across more than 20 km of lower Putah Creek. We propose that the expansion of native fishes was facilitated by creation of favorable spawning and rearing conditions (e.g., elevated springtime flows), cooler water temperatures, maintenance of lotic (flowing) conditions over the length of the creek, and displacement of alien species by naturally occurring high-discharge events. Importantly, restoration of native fishes was achieved by manipulating stream flows at biologically important times of the year and only required a small increase in the total volume of water delivered downstream (i.e., water that was not diverted for other uses) during most water years. Our results validate that natural flow regimes can be used to effectively manipulate and manage fish assemblages in regulated rivers.