城市化过程中黑碳的土壤记录及其环境指示意义

以南京市为对象,通过3组共计10个土壤剖面的采样,用湿化学氧化法分析了土壤有机碳（organic carbon,OC）和黑碳（black carbon,BC）的含量.研究发现,南京城市土壤剖面中黑碳含量的变幅为0.22～32.19 g·kg^-1,平均值为4.35 g·kg^-1.第1组城市土壤剖面中黑碳含量的平均值为0.91 g·kg^-1,第2组为8.62 g·kg^-1,第3组为3.72 g·kg^-1.城市土壤剖面中BC/OC值的变幅为0.03～1.59,平均值为0.29,其中BC/OC平均值的大小顺序是：受古代工业活动影响的第2组最大,受现代工业和交通人为活动影响的第3组次之,受古代居民生活影响的第1组最低.研究认为,在城市化过程中,由于工业和交通等人类活动引起的生物物质和矿物燃料（煤、石油等）燃烧产生的BC在土壤中都有不同程度的沉积和记录.BC含量和BC/OC值的大小可能在一定程度上反映了不同人为影响过程和城市土壤的污染程度.城市区域BC的主要来源是矿物燃料燃烧,其中表层（现代层）主要来自交通车辆（尤其是柴油为动力的机车）排放的颗粒物质,而在古代（文化层）可能与燃烧用煤历史有关.     

EGSB-SBR组合工艺对城市污水脱氮除磷试验研究

采用EGSB-SBR组合工艺在常温下进行城市生活污水脱氮除磷的试验研究,试验结果表明:在6.3～14.9℃温度范围内,进水COD浓度为224.6～368.7mg/L时,COD总去除率约为94.9%,SS总去除率约为89.6%,TN总去除率约为73.2%,TP总去除率约为88.6%,其中TP出水指标<0.5mg/L。该工艺与常规脱氮除磷工艺相比较,投资和运行成本较低,处理效果较好,是一项高效、节能的新型城市污水处理技术。     

城市河流栖息地评价方法与应用

维持河流生物完整性必须要有良好的栖息地条件.城市河流栖息地评价是城市河流治理和管理的前提和基础.城市河流栖息地评价基准与城市河流栖息地特征密切关联.基于可拓学物元概念和其发散性特征,以及前人的研究,建立了包含水质、形态结构、水动力和水生生物4个类别要素的适应于城市河流健康修复实践的栖息地质量评价指标体系,同时,结合层次分析法建立了多级可拓物元评价模型,并在评价过程中引入可拓学诊断方法以确定影响栖息地质量的关键因子.将以上方法应用于镇江市古运河,结合古运河修复目标和现状条件建立了相应的指标评价标准.经过1a多时间的野外调查,在古运河上选择6个500m长特征河段,分别对其栖息地、要素质量进行比较评价.结果表明,古运河整体栖息地及水质、水动力和水生生物质量均较差;诊断分析表明,水动力和水质为影响栖息地质量的主要因素,水质污染指数、透明度、流量满足率和纵向连续性为影响古运河栖息地质量的主要因子,并根据评价结果对古运河栖息地修复提出了建议.     

浅谈城市环境问题及对策研究

城市作为人类居住生活的功能区,在很大程度上被削弱。居住条件的恶化,环境污染,人际关系冷漠等城市病正在蔓延。城市已不再是人、自然和社会健康发展的乐园。要改变现状,让城市功能朝着人居健康的目标发展是我们今天的历史责任。城市环境质量的好坏不仅关系到市民居住和生存的质量,同时也从一个侧面反映出一座城市的文明程度以及市民素质的高低。因此,抓住创建宜居城市这一有利时机,不断改善城市环境面貌,提高环境质量,这是建设适宜人居的现代化城市的重要内容和必然选择。     

OPTIMAL LONG-TERM SCHEDULING OF STORMWATER DRAINAGE REHABILITATION1

ABSTRACT: A mathematical model is developed to optimally schedule long-term stormwater infrastructure rehabilitation activities. The model is capable of considering multiple rehabilitation projects and is driven by overall cost eensiderations. Rehabilitation activities are scheduled based on perceived reliabilities and future deterioration expected within the specified planning horizon. Future growth within the stormwater drainage basin is incorporated using chance constraints that limit the likelihood that a stormwater discharge exceeds system conveyance capacity. Model structure and development are discussed, and a hypothetical example using a drainage network is presented.     

Comparison of Stormwater Lag Times for Low Impact and Traditional Residential Development1

Abstract: This study compared lag time characteristics of low impact residential development with traditional residential development. Also compared were runoff volume, peak discharge, hydrograph kurtosis, runoff coefficient, and runoff threshold. Low impact development (LID) had a significantly greater centroid lag‐to‐peak, centroid lag, lag‐to‐peak, and peak lag‐to‐peak times than traditional development. Traditional development had a significantly greater depth of discharge and runoff coefficient than LID. The peak discharge in runoff from the traditional development was 1,100% greater than from the LID. The runoff threshold of the LID (6.0 mm) was 100% greater than the traditional development (3.0 mm). The hydrograph shape for the LID watershed had a negative value of kurtosis indicating a leptokurtic distribution, while traditional development had a positive value of kurtosis indicating a platykurtic distribution. The lag times of the LID were significantly greater than the traditional watershed for small (<25.4 mm) but not large (≥25.4 mm) storms; short duration (<4 h) but not long duration (≥4 h) storms; and low antecedent moisture condition (AMC; <25.4 mm) storms but not high AMC (≥25.4 mm) storms. This study indicates that LID resulted in lowered peak discharge depth, runoff coefficient, and discharge volume and increased lag times and runoff threshold compared with traditional residential development.     

新装修商场室内空气质量(甲醛)监测分析研究

文章对新建商业区室内空气甲醛的含量进行了监测,采用单因子指数、模糊综合和功能分区分析与评价方法,研究其空气污染的程度,分析了产生的原因;提出了改进措施,以利于改善空气污染状况,为促进资源节约型和环境友好型社会建设提供了科学的依据。     

Dry Weather Water Quality Loadings in Arid,Urban Watersheds of the Los Angeles Basin,California, USA1

Abstract: Dry weather runoff in arid, urban watersheds may consist entirely of treated wastewater effluent and/or urban nonpoint source runoff, which can be a source of bacteria, nutrients, and metals to receiving waters. Most studies of urban runoff focus on stormwater, and few have evaluated the relative contribution and sources of dry weather pollutant loading for a range of constituents across multiple watersheds. This study assessed dry weather loading of nutrients, metals, and bacteria in six urban watersheds in the Los Angeles region of southern California to estimate relative sources of each constituent class and the proportion of total annual load that can be attributed to dry weather discharge. In each watershed, flow and water quality were sampled from storm drain and treated wastewater inputs, as well as from in‐stream locations during at least two time periods. Data were used to calculate mean concentrations and loads for various sources. Dry weather loads were compared with modeled wet weather loads under a range of annual rainfall volumes to estimate the relative contribution of dry weather load. Mean storm drain flows were comparable between all watersheds, and in all cases, approximately 20% of the flowing storm drains accounted for 80% of the daily volume. Wastewater reclamation plants (WRP) were the main source of nutrients, storm drains accounted for almost all the bacteria, and metals sources varied by constituent. In‐stream concentrations reflected major sources, for example nutrient concentrations were highest downstream of WRP discharges, while in‐stream metals concentrations were highest downstream of the storm drains with high metals loads. Comparison of wet vs. dry weather loading indicates that dry weather loading can be a significant source of metals, ranging from less than 20% during wet years to greater than 50% during dry years.     

Relative Influence of Streamflows in Assessing Temporal Variability in Stream Habitat1

Abstract: The effects of streamflows on temporal variation in stream habitat were analyzed from the data collected 6‐11 years apart at 38 sites across the United States. Multiple linear regression was used to assess the variation in habitat caused by streamflow at the time of sampling and high flows between sampling. In addition to flow variables, the model also contained geomorphic and land use factors. The regression model was statistically significant (p < 0.05; R² = 0.31‐0.46) for 5 of 14 habitat variables: mean wetted stream depth, mean bankfull depth, mean wetted stream width, coefficient of variation of wetted stream width, and the percent frequency of bank erosion. High flows between samples accounted for about 16% of the total variation in the frequency of bank erosion. Streamflow at the time of sampling was the main source of variation in mean stream depth and contributed to the variation in mean stream width and the frequency of bank erosion. Urban land use (population change) accounted for over 20% of the total variation in mean bankfull depth, 15% of the total variation in the coefficient of variation of stream width, and about 10% of the variation in mean stream width.     

城市生活垃圾堆肥处理工程技术发展探讨

文章分析了我国城市生活垃圾堆肥陷入滞销困境多年的原因，指出摆脱这一困境的技术途径是要大幅度提高堆肥品质。而要实现这一目标，首先必须引进先进的堆肥翻堆技术，缩短腐熟时间，提高腐熟度；其次是应用气流密度分选系统对粗堆肥进行精分选。