杭州市大气污染物排放清单及特征

以杭州市区为研究区域,通过调查整合多套污染源数据库及其他统计资料,研究文献报道及模型计算的各种污染源排放因子,获得杭州市区各行业PM10、PM2.5、SO2、NOx、CO、VOCs、NH3等污染物的排放量,建立了杭州市区2010年1 km×1 km大气污染物排放清单。结果表明,2010年杭州市区PM10、PM2.5、SO2、NOx、CO、VOCs和NH3的排放总量分别为7.96×104、4.02×104、7.23×104、8.98×104、73.90×104、39.56×104、3.32×104t。从排放源的行业分布来看,机动车尾气排放是杭州市区大气污染物最重要排放源之一,对PM10、PM2.5、NOx、CO和VOCs的贡献分别达到14.4%、27.1%、40.3%、21.4%、31.1%。道路扬尘、电厂锅炉、工业炉窑、植被、畜禽养殖对不同污染物分别有着重要贡献,道路扬尘对PM10和PM2.5的贡献分别为44.6%和20.0%、电厂锅炉对SO2和NOx的贡献分别为37.0%和25.7%、工业炉窑对CO的贡献为41.5%、植被排放对VOCs的贡献为27.1%、畜禽养殖对NH3的贡献为76.5%。从空间分布来看,萧山区和余杭区对SO2、NH3和植被排放BVOC的贡献要显著高于主城区;而主城区机动车对PM2.5、NOx和VOCs的贡献分别达到36.3%、56.0%和47.4%,较市区范围内显著增加,表明机动车尾气排放已成为杭州主城区大气污染最重要的来源之一。     

低碳发展研究的理论基础

理论的形成过程一般基于实践和需求的推动,而理论的发展与成熟又从更高层面促进实践的深入。随着全球气候变化引发人类对控制温室气体排放的空前重视,围绕低碳领域的理论与实践研究已成为相关学科研究的焦点,而对低碳发展理论基础的研究与讨论几乎处于空白。本文通过分析资源、环境、技术创新等领域的相关理论或者方法与低碳发展的关系,认为可持续发展理论体现了低碳发展的理念和导向,碳代谢与循环理论反映了碳循环的自然规律,脱钩理论揭示了碳排放与经济、人口的关系与规律,3E系统理论与模型提供了低碳政策分析的工具,技术创新理论可引领低碳发展的技术突破,"隧道效应"理论则指明了低碳发展的路径选择。这六大理论分别从发展理念、自然规律、发展阶段、政策工具、技术模式、实现路径等角度阐述了低碳发展的内涵,共同构成了低碳发展研究的理论基础。相关理论相互联系并融入低碳研究,必将促进绿色经济发展和低碳社会构建。     

玄武湖轮虫夏季水平分布及其与环境因子的关系

2010年7月对南京玄武湖3个区域（荷花区、湖岸区、敞水区）轮虫的水平分布进行调查,并分析其与环境因子的关系。本次调查共检出轮虫25种,全湖轮虫优势种为裂痕龟纹轮虫、多肢轮虫、端生三肢轮虫和微型三肢轮虫。荷花区种类最多,且分布有蛭态类轮虫,但3个区域中轮虫优势种组成相似。3个区域轮虫丰度差异显著（〖WTBX〗P〖WTBZ〗<005）,敞水区最高（12 700.3±3 726.4 ind./L）,湖岸区（11 648.0±4 342.4 ind./L）次之,荷花区最低（8 646.9±3 798.5 ind./L）。3个区域的pH、悬浮物烧失量、总溶解氮和总悬浮颗粒物有显著差异（〖WTBX〗P<005）,而水温、总氮、总磷和总溶解磷则无显著差异（P〖WTBZ〗>005）。冗余分析表明,与轮虫水平分布相关的重要环境因子为pH、浮游甲壳动物丰度、总悬浮物、悬浮物烧失量和总溶解氮     

鳙幼鱼游泳能力和游泳行为的研究与评价

利用自制的鱼类游泳实验装置,采用递增流速法,研究了鳙幼鱼游泳能力和游泳行为。结果表明：鳙标准代谢率SMR实际测定值为18727±545 mgO2/(kg·h),方程拟合值为18281mgO2/(kg·h),实测值与拟合值接近;鳙耗氧率MO2与游泳速度U的拟合方程为MO2=18281+3983 U1.30,耗氧率幂函数方程中U的幂值为130,U的幂值越小游泳效率越高,说明鳙游泳效率较高;鳙临界游泳速度Ucrit为457±056 BL/s,与青鱼近似;鳙疲劳后的耗氧率迅速降低,在疲劳后45～60 min时耗氧率恢复到标准代谢率。鳙EPOC值为10716 mgO2/kg,说明鳙运动疲劳后的恢复能力较高;运动耗能COT与游泳速度相关关系曲线中,在4～6 BL/s时COT较低,说明此时鳙的能量利用效率较高,拟合方程为COT=664 U-1+131 U0.34;通过实验测定,鳙摆尾率TBF和游泳速度相关关系拟合方程为TBF=202+053 U。研究可为鱼道设计提供参考,对鳙保护具有指导意义     

鱼类生理和生态行为对河流生态因子响应研究进展

水利工程建设不仅阻断了河流的连续性,改变了河流生态因子,而且影响着河流水生生物,尤其是鱼类的生存、摄食、洄游、繁殖等行为。河流生态因子,如温度、流速、溶解氧浓度等,对鱼类生理和生态行为有显著性的影响。通过研究分析鱼类生理和生态行为与水力因子之间的关系,量化鱼类游泳过程中的能量消耗,结合生物学、生态工程、环境污染、管理等相关学科,建立更为精确的模型描述鱼类行为对水力因子的响应。结合河流生态因子研究鱼类生理及生态行为,对水利工程建设中鱼类资源的保护具有重要的意义。概述了水利工程建设对鱼类栖息生境的影响,归纳了目前国内外鱼类生理生态行为对河流生态因子响应研究内容及方法。同时,对以后研究重点和趋势进行了展望     

Simulation of Biomass Accumulation Pattern in Vapor-Phase Biofilters

Existence of inert biomass and its impact on biomass accumulation patterns and biofilter performance were investigated. Four biofilters were set up in parallel to treat gaseous toluene. Each biofilter operated under different inlet toluene loadings for 100 days. Two microbial growth models, one with an inert biomass assumption and the other without, were established and compared. Results from the model with the inert biomass assumption showed better agreement with the experimental data than those based on the model without the inert biomass assumption thus verifying that inert biomass accumulation cannot be ignored in the long-term operation of biofilters. According to the model with an inert biomass assumption, the ratio of active biomass to total biomass will decrease and the inert biomass will become dominant in total biomass after a period of time. Filter bed structure simulation results showed that the void fraction is more sensitive to biomass accumulation than the specific surface area. The final void fraction of the biofilters with the highest inlet toluene loading is only 67% of its initial level while the final specific surface area is 82%. Identification and quantification of inert biomass will give a better understanding of biomass accumulation in biofilters and will result in a more exact simulation of biomass change during long-term operations. Results also indicate that an ideal biomass control technique should be able to remove most inert biomass while simultaneously preserving as much active biomass as possible.     

Performance of hybrid vertical up- and downflow subsurface flow constructed wetlands in treating synthetic high-strength wastewater

The performance and temporal variation of hybrid vertical-subsurface flow constructed wetlands (VFCWs) in response to two-stage combinations of vertical upflow (VUF) and vertical downflow (VDF) were analyzed in this research. The results of high carbon (C) treatment and high nitrogen (N) treatment were similar. The Lythrum salicaria treatment showed higher removal efficiency than CWs planted with Acorus calamus. Under high C- and N-loading treatments, the optimum two-stage combination was VDF-VUF VFCWs planted with A. calamus. Furthermore, the highest nutrient removal efficiencies were achieved in late summer (July and August) and early autumn (September). The chemical oxygen demand and total nitrogen removal efficiencies were significantly affected (P?<?0.05) by season, system, and wetland plant.     

Prolonged environmental exposure of arsenic through drinking water on the risk of hypertension and type 2 diabetes

Prolonged exposure to inorganic arsenic has been a severe environmental public health issue worldwide in the recent decades. Increasing evidence has suggested a possible role of prolonged arsenic exposure through drinking water in the development of arsenic-induced chronic noncancer diseases, among which hypertension and type 2 diabetes (T2D) are the focus of concern. Although exposure to high levels of arsenic has been reported to be associated with excess risk of hypertension or T2D in a dose-dependent manner, the association has yet to be established, especially low-level exposure. This cross-sectional study was designed to evaluate the potential association between prolonged environmental arsenic exposure through drinking water and the prevalence of hypertension and T2D in Inner Mongolia, China, with emphasis on the assessment of low-level exposure. In this study (a total of 669 men and women), we found that the blood pressure levels were significantly correlated with cumulative arsenic exposure and that the systolic blood pressure of the subjects with arsenic exposure >50 μg/L was significantly higher than those of the subjects with <10 and 10–50 μg/L exposure. Significant prevalence of hypertension was found in the subjects of the >50 μg/L group both before and after adjustment for confounders. In addition, a significant negative relationship was found between urinary arsenic percentage of dimethylated arsenic (DMA%) and the prevalence of hypertension in the >50 μg/L group. However, low-level arsenic exposure (10–50 μg/L) was not statistically associated with hypertension. No significant difference of blood glucose was found among the groups with different arsenic exposure levels. No statistical association was found between arsenic exposure and T2D. Our findings suggested that prolonged arsenic exposure might play a role in the development of hypertension; however, only high-level arsenic was associated with the risk of hypertension. Our findings also indicated that lower DMA% might be related with the increased susceptibility of arsenic-induced hypertension.     

The effects of Herba Andrographitis hedgerows on soil erodibility and fractal features on sloping cropland in the Three Gorges Reservoir Area

To evaluate if hedgerows could improve the soil physicochemical properties and enhance the soil anti-scouring and anti-shearing capabilities, the effects of Herba Andrographitis hedgerows on soil erodibility and fractal features on sloping cropland in the Three Gorges Reservoir Area were investigated. Results showed that: (1) the clay particle accumulation around the hedgerows was significantly affected by the hedgerows; (2) the fractal dimension of soil particles was positively correlated with both silt and clay contents and had a negative linear correlation with sand content; (3) fine-grained content significantly influenced fractal dimension of the soil particles; (4) soil erodibility K was significantly and positively correlated with the sand content (correlation coefficient r?=?0.870), but significantly and negatively correlated with the silt content (r?=??0.538), clay content (r?=??0.739), organic carbon content (r?=??0.603), the aggregation degree (r?=??0.486), and soil fractal dimension (r?=??0.538); and (5) the contents of organic matter and clay particles in the soil were found to be the effective indicators for soil erodibility at the Three Gorges Reservoir Area. The hedgerows may improve soil fractal features and decrease soil erodibility. The effective distance between hedgerows on a slope of 10° was less than 6 m.     

湿热水解处理餐厨垃圾氮素转化规律

为了研究餐厨垃圾湿热水解过程中氮素的变化规律,设计了10、30、60、90和120℃5个温度水平以及30、60、90、120、150和180min6个加热时间水平,进行了30组完全实验,对不同湿热条件下餐厨垃圾粗蛋白、TN、NH4＋-N、NO3-N、有机氮及氨基酸等氮的不同存在形式的变化规律进行实验研究。结果表明,10、30及60℃条件下蛋白质的高级结构不会改变,利于粗蛋白的积累,且在温度120℃,加热时间90min条件下粗蛋白百分含量最高,占干物质的31．34％;随温度的升高和加热时间的延长TN、NHf-N和有机氮含量均上升;当温度达到120℃,由于水解反应,各温度处理下NHf．N浓度超过有机氮浓度,而NO3-N始终维持较低水平。氨基酸总量随温度的升高和水解时间的延长呈上升趋势,当温度达90％,加热时间达180min时,处理后餐厨垃圾总氨基酸百分含量最高,达164％,但温度达到120℃时,随着处理时间的延长,餐厨垃圾总氨基酸含量明显降低。