环太湖丘陵地区农田氮素随地表径流输出特征

对环太湖丘陵地区农田氮素随地表径流的输出特征进行了研究,结果表明,地表径流中TN浓度随径流量而变化,浓度峰值出现时间滞后于径流量峰值;径流发生前期,NH3 N和NO-3 N浓度水平相当,后期NO-3 N浓度缓慢抬升,而NH3 N含量缓慢下降;NO-2 N浓度相对较低,随时间快速下降;对于TN和NO-3 N而言,溶解态含量高于悬浮态,而溶解态和悬浮态NH3 N的浓度相当;无机氮平均浓度高于有机氮,有机氮尤其是悬浮态有机氮浓度表现出随径流量而变化的特点。     

盐碱土壤基质人工湿地对低浓度氮磷废水的净化效果

采用实验室模拟研究了以盐碱土壤为基质的不同湿地植物人工湿地系统以及对水中低质量浓度氮和磷的去除效率。实验表明，芦苇系统、香蒲系统、车钱草系统和无植物系统均对水中低质量浓度的N具有净化效果。3种植物系统相比，香蒲系统的净化效果较其他二者较佳，芦苇系统与车钱草的净化效果相当；同时实验也表明4种湿地系统对低质量浓度的P不具有净化效果，随着水力停留时间的增加，系统中的P质量浓度反而会有所增加。     

原子吸收分光光度法测定植株中钙、镁的几种样品前处理方法的比较

本文比较了原子吸收分光光度法测定植株中钙、镁的三种样品前处理方法：干友化法、１ｍｏｌ／ＬＨＣｌ振荡提取法（振荡法）和１ｍｏｌ／ＬＨＣｌ静止浸泡提取法（浸泡法）．结果表明，振荡法和浸泡法对钙的测定结果平均分别为干灰化法的１０１％和９２．０％，对镁的测定结果平均分别为１０３％和９７．６％．振荡法和浸泡法与干灰化法之间不存在显著性差异（α＝０．０５），它们之间有极显著的正相关性（相关系数在０．９９以上）．因此，在大批量样品的常规分析中，１ｍｏｌ／ＬＨＣｌ提取法可代替干灰化法．     

微孔扩散管曝气试验

本文综术字在污水处理站使用离心鼓风机穿孔管大气泡浅 支暴气所引起的溶解氧不足。     

ANALYSIS OF NITROGEN MANAGEMENT STRATEGIES USING EPIC1

ABSTRACT: This paper illustrates a method of using a hydrologic/water quality model to analyze alternative management practices and recommend best management practices (BMPs) to reduce nitrate-nitrogen (NO₃^--N) leaching losses. The study area for this research is Tipton, an agriculturally intensive area in southwest Oklahoma. We used Erosion Productivity Impact Calculator (EPIC), a field-scale hydrologic/water quality model, to analyze alternative agricultural management practices. The model was first validated using observed data from a cotton demonstration experiment conducted in the Tipton area. Following that, EPIC was used to simulate fertilizer response curves for cotton and wheat crops under irrigated and dryland conditions. From the fertilizer response functions (N-uptake and N-leaching), we established an optimum fertilizer application rate for each crop. Individual crop performances were then simulated at optimum fertilizer application rates and crop rotations for the Tipton area, which were selected based on three criteria: (a) minimum amount of NO₃^--N leached, (b) minimum concentration of NO₃^--N leached, and (c) maximum utilization of NO₃^--M. Further we illustrate that by considering residual N from alfalfa as a credit to the following crop and crediting NO₃^--N present in the irrigation water, it is possible to reduce further NO₃^--N loss without affecting crop yield.     

MODELING OF NONPOINT SOURCE POLLUTION OF NITROGEN AT THE WATERSHED SCALE1

ABSTRACT: The Watershed Nutrient Transport and Transformation (NTT-Watershed) model is a physically based, energy-driven, multiple land use, distributed model that is capable of simulating water and nutrient transport in a watershed. The topographic features and subsurface properties of the watershed are refined into uniform, homogeneous square grids. The vertical discretization includes vegetation, overland flow, soil water redistribution and groundwater zones. The chemical submodel simulates the nitrogen dynamics in terrestrial and aquatic systems. Three chemical state variables are considered (NO₃^-_-, NH₄⁺, and Org-N). The NTT-Watershed model was used to simulate the fate and transport of nitrogen in the Muddy Brook watershed in Connecticut. The model was shown to be capable of capturing the hydrologic and portions of the nitrogen dynamics in the watershed. Watershed planners could use this model in developing strategies of best management practices that could result in maximizing the reductions of nitrogen export from a watershed.     

抚仙湖北岸入湖径流中总氮变化趋势分析

抚仙湖现有污染主要来自北岸。通过抚仙湖3条入湖河流中总氮负荷量进行调查，对抚仙湖入湖河流中总氮负荷量进行了分析评价，结果表明：3条入湖河流总氮为劣V类水质，是影响抚仙湖水质的主要因素。为湖泊总量控制与治理提供科学依据。     

复合型人工湿地对抚仙湖入湖河道污水中氮的去除

在抚仙湖北岸构建复合型人工湿地污水处理系统,对窑泥沟入湖河道污水中氮的去除效果进行了试验研究,结果表明,系统水力负荷年平均为37mm/d,氮负荷年平均为3.315g/m2·d,对污水中NOx、NH+4、TON和TN去除率年平均分别为62.7%、53.8%、62.4%和57.5%.     

废水的生物脱氮除磷新工艺的设想

结合废水生物脱氮除磷机理和影响因素，在对几种典型脱氮除磷工艺氮、磷去除率进行比较的基础上，解析了一些典型工艺除氮除磷不足之处。根据重庆城市污水水质实际情况和地形的特点，设想一种新的生物脱 氮除磷工艺，从而弥补传统工艺的不足。可望提高系统的脱氮和除磷效率，达到更好的脱氮除磷的目的，减少对水体的污染。     

关于水污染物排放总量的核定

系统分析了水污染物排放总量核定不同层次的信息关联和相关的特征信息间的相互关系，指出城市是最基本的总量核定对象；阐述了现行环境监测与环境管理制度对水污染物排放总量核定存在着不完全信息问题；指出环境管理部门不掌握的部分排污总量信息对总量控制整体的影响相当大，应对排污总量进行全面、科学的核定。