调蓄经济植物湿地技术在农田径流污染控制中的工程应用及评价

为评价调蓄经济植物湿地技术在农田径流污染控制中的运行效果和经济效益,采用现场调研长期跟踪监测调蓄经济植物湿地进、出水水质和水量变化,深入探索其营养盐质量浓度分布特征及其去除效能.结果表明:①调蓄经济植物湿地能够有效截留营养盐,稳定出水水质,2015年7月-2017年4月出水ρ（TN）、ρ（TP）和ρ（COD_Cr）平均值分别为1.2、0.07和17.0 mg/L,TN、TP和COD_Cr去除率分别为65.8%、75.5%和41.3%.②不同调蓄量下TN和TP去除率随着进水水量的增大而减小,表现为枯水期>平水期>丰水期;COD_Cr去除率与调蓄量之间呈负相关,表现为丰水期>平水期>枯水期;在调蓄经济植物湿地中单位面积TN、TP和COD_Cr去除负荷量表现为丰水期>平水期>枯水期.③调蓄经济植物湿地中莲藕、海菜花和螺蛳产量分别为26.25、22.50和2.46 t/（hm2·a）,氮、磷去除总量分别为275和30 kg/（hm2·a）.研究显示,调蓄经济植物湿地能够有效截留氮、磷,在不同水文期均有良好的净化效果,不仅具备景观效益,且具有良好的经济价值.      

某市河道底泥污染工程总体设计方案

为截流和处理某市内河的外来污染源,河道综合整治工程是某市内河水系底泥污染系统综合开发工程的重要工程之一,主要内容包括:河道工程、截污工程、底泥疏浚、景观工程等。截污工程采取“沿河截污,超量溢流”的工程方案沿河敷设截污管道,并在河道交汇处设置合流污水调蓄池。     

城市污水管网中产甲烷菌的分布特性规律

实验通过一套1 200 m的PVC管式反应器来模拟城市污水管网,利用气相色谱法、液相色谱法和454高通量测序等手段,研究了城市污水管网中产甲烷过程中的物质变化和产甲烷菌分布特性规律.结果表明,管网中甲烷含量沿程升高,说明管网中存在产甲烷菌;产甲烷菌主要包含甲烷八叠球菌属(Methanosarcina)、广古菌门中的菌属(Euryarchaeota_unclassified)和甲烷杆菌科中的菌属(Methanobacteriaceae_unclassified)这3种优势菌属,且在管网800~1 000 m处有广古菌门中的菌属(Euryarchaeota_unclassified)取代甲烷八叠球菌属(Methanosarcina)成为第一优势菌属的演替现象;管网中产甲烷可利用基质有甲酸、甲醇、甲胺、乙酸,其中乙酸为主要基质,这些基质在管网中先增加后降低的变化趋势导致了管网中产甲烷菌演替现象的发生.     

APPLICATION OF THE CONTINUOUS STORMWATER POLLUTION SIMULATION SYSTEM (CSPSS): PHILADELLPHIA CASE STUDY1

ABSTRACT: This paper describes the Continuous Stormwater Pollution Simulation System (CSPSS) as well as a site-specific application of CSPSS to the Philadelphia urban area and its receiving water, the Delaware Estuary. Conceptually, CSPSS simulates the quantity and quality or urban stormwater runoff, combined sewer overflow, municipal and industrial waste water effuent, and upstream flow on a continuous basis for each time step in the simulation period. In addition, receiving water dissolved oxygen, suspended solids, and lead concentrations resulting from these pollutant sources may be simulated. However, only rceiving water dissolved oxygen (DO) response is considered in this paper. The continuous Do receiving water response model was calibrated to existing conditions usinv observed data at Chester, Pennsylvnia, located on the Delaware Estuary approximately 10 miles down stream from the study area. Average annual pollutant loads to the receiving water were estimated for all major sources and receiving water quality improvements resulting from removal of various portions of these pollutant loads were estimated by application of the calibrated stimultion model. It was found that the removal of oxygen-demanding pollutants from combined sewer overflow and urban stormwater runoff would result in relatively minor improvements in the overall dissoved oxygen resources of the Delaware Estuary; whereas. removal of oxygen demanding pollutants from waste water treatment plant effluent would result in greater improvemens. The results of this investigation can be used along with appropriate economic techniques to identify the most cost-effective mix of point and nonpoint source pollution control measures.     

USE OF TIME-LAPSE PHOTOGRAPHY TO ASSESS POTENTIAL INTERCEPTION IN ARIZONA PONDEROSA PINE1

ABSTRACT: The behavior of intercepted snow on a stand of uneven-aged ponderosa pine in east-central Arizona was evaluated with the use of a super 8-mm time lapse movie camera to determine the relative significance of snowfall interception in the water yield of this type forest. A snow load index was developed to estimate interception storage for two trees in the field of view for discrete time periods. The snow load index. photographs, and climatic data were combined to describe accumulation and to identify and rank according to relative magnitudes the basic processes of canopy snow removal. The rate of snow accumulation was nonlinear with initial storage being rapid. then slowing with time. Most of the intercepted snow eventually reached the snowpack on the ground by snowslide and wind erosion or by snowmelt and subsequent stemflow and drippmg of meltwater, and was therefore not considered a significant loss to the water budget on site. Some water apparently was disposed of by the evaporation of meltwater and sublimation of canopy snow, but these losses appeared to be comparatively minor.     

黄土高原人工油松林枯枝落叶截留动态研究

用定位观测的方法研究了人工油松林枯枝落叶的截流量及其截留的动态过程。结果表明,黄土高原人工油松林枯枝落叶的截流量年均为49.3mm,截留率为12.5%。枯枝落叶截留的动态过程受大气降水和环境因子的影响较大,也与其自身湿润程度有关。在次降水过程中,其截留的过程是当降水开始时,截留量增加迅速;降水持续到一定时间后,截流量的增量变小,达到最大值后,截流量在此处上下增减。枯枝落叶截留的动态过程可用直线和正弦函数的组合描述,且该函数能揭示枯枝落叶截留的生物学特性和环境因素对其过程的影响。该模型在计算森林水文及其水土保持效应评价中有广泛的应用前景。     

长江防护林——樟树林对降雨再分配的影响

林冠对降雨的再分配,是森林生态学和森林水文学研究的一个重要方面,其影响降雨从林冠到土壤的转移以及水土流失的变化,具有突出的生态水文意义。通过对樟树林下穿透雨和树干流的定位监测,旨在揭示林冠水文效应的变化规律,结果表明：林冠对降雨的再分配功能受到降雨量的影响,穿透雨、树干流和截留量与降雨量呈显著的正相关(〖WTBX〗P〖WTBZ〗<005);穿透雨率随着降雨量增加而增加,而截留率随降雨量增加而减小,并且两者在高的雨量下逐渐趋于稳定,但是树干流率随着降雨量增加先升高后降低。同时,降雨强度也影响林冠的水文效应,随着降雨强度的增加,穿透雨率升高,截留率下降。在整个测定期间,樟树林穿透雨率为685%,截留率为292%,而树干流率为23%。在不同雨量和雨强级间,樟树林冠对降雨再分配存在着差异,而且林内雨的组成比例（〖WTBX〗SF／TF〖WTBZ〗）也受到降雨量和降雨强度的影响。樟树林下水分输入存在明显的空间异质性,穿透雨率在不同位置间具有显著性的差异,而且穿透雨的空间变化率,即穿透雨率的变异系数（CV）随着降雨量或降雨强度的增加而减少。     

雨水斗截污装置对屋面初期雨水净化规律及关键参数设计

在西安市某文教区屋面排水立管设径流采样点,雨期采用人工时间间隔采样法采集径流水样,对2016年8月—2016年11月3场屋面径流SS、COD、TN、NH₃-N、TP、浊度、Pb、Zn、Cu、Cd、Ni、Cr等污染指标进行监测,界定了初期雨水的概念并根据屋面初期雨水水质、水量特征、雨水斗构造设计屋面雨水截污装置,研究了该截污装置的透水性能、工作状态、截污效果和清洗更换周期。结果表明：将暴雨次降雨前30~40 min、大雨和小雨次降雨前40~50 min雨水定义为初期雨水;土工布单位面积质量越大,透水能力越小,且其过滤通量与过滤水头呈线性关系;在不发生溢流的情况下,500 g·m⁻²的土工布制成的截污装置过滤出水可满足《生活杂用水水质标准》(GB/T 18920-2002)要求;为避免5年一遇的暴雨下屋面积水,截污装置上部溢流孔孔口面积至少应为0.015 4 m²,须至少保证有效过滤区高度为568 mm。研究为缓解西安等干旱、半干旱地区用水紧张问题提供参考。     

RELIABILITY OF THE DESIGN STORM CONCEPT IN EVALUATING RUNOFF PEAK FLOW1

A comparative study was undertaken to evaluate peak runoff flow rates using (1) a continuous series of actual rainfall events and (2) design storms. The ILLUDAS computer model was used to simulate runoff over a catchment within the city of Montreal, Canada. A ten-year period, five-minute increment rainfall data base was used to derive peak flow frequency curves. Two types of design storms were analyzed: one derived from intensity duration frequency curves (Chicago type), the other from averaging actual rainfall patterns (Huff type). Antecedent soil moisture conditions were considered in the analyses. It was found that the probability distribution of runoff peak flow was sensitive to the choice of design storm pattern and to the antecedent soil moisture condition. A symmetrical, Chicago-type design storm with antecedent dry soil moisture produced a flow frequency curve similar to the one obtained from a series of historical rainfall events.     

南太湖区域水浆管理技术与稻田磷素流失控制的研究

南太湖区域内稻田磷素的流失浓度及负荷与田间水浆管理技术密切相关.本研究在南太湖区域农业生态与植物保护监测站(余杭区)建立中长期试验基地,重点探索稻田养分管理技术.节水灌溉模式.降水资源高效利用的组合技术控制下水田磷素流失的过程及其截流机制.结果表明,不同的磷肥施用水平下田表水磷素浓度随时间的降低而降低.随之趋于背景含量水平.传统灌溉总磷负荷为0.046-3.569 kg·hm-2节水灌溉总磷负荷为0.023-2.602 kg·hm-2,传统灌溉比节水灌溉具有更高的磷素流失风险.本次试验提出了稻田水分"零排放"的技术模式.实现了传统灌溉总磷净负荷-0.102 kg·hm-2,节水灌溉总磷净负荷为-0.078 kg·hm-2,传统灌溉的截流磷素量高于节水灌溉模式.在无排水的前提下,稻田在P循环的"源-汇"交替中扮演"汇"的角色,实现了稻田圈截流磷素的生态作用.考虑多变的天气情况,节水灌溉模式在截流磷素方面将发挥更大的作用.可有效地使稻田向太湖的年磷素输出量最小化.