生物填料塔处理餐厅污水传质反应研究

从传质和生化反应基本过程出发,经合理简化,将复杂的生物填料塔中三相传质生化反应过程综合为一个有效生化反应过程并得到其数学模型。模型中综合参数——总传质有效因数η可通过容易测定的本征反应和实际反应速率来确定;实验研究了不同入塔污水CODCr和入塔水量对η的影响。结果表明：入塔污水CODCr较高时,有较大的孕;当入塔水量增大,传质效果增加η增大。     

面向生态城市的水资源供需平衡分析

提出了面向生态城市的水资源供需平衡分析原则,强调了水质水量的统一性,人与自然的和谐性,生态环境需水的优先性.在此基础上,建立了面向生态城市的水资源供需平衡分析概念框架,并对供需平衡的基本内涵进行了界定.以广州为例,进行了实证研究.结果表明,生态环境需水对供需平衡状态影响显著,2000年花都区与中心区非汛期分别缺水0.91,4.86亿m3/月;基本控制方案下,各目标年(2005,2010,2020年)全市非汛期缺水量将分别高达19.74,41.78,77.62亿m3/月;实施以污染负荷控制和节水为主导的综合强化方案才能保证供需平衡.     

二龙山水库流域生态环境与小气候的关系研究

根据不同的植被覆盖率,对二龙山水库流域进行分区,并在春季组织小气候观测,研究不同小区的小气候综合特征.分析结果表明,二龙山水库流域生态环境与小气候综合特征之间存在密切关系.      

Estimating Forest Ecosystem Evapotranspiration at Multiple Temporal Scales With a Dimension Analysis Approach1

Abstract:  It is critical that evapotranspiration (ET) be quantified accurately so that scientists can evaluate the effects of land management and global change on water availability, streamflow, nutrient and sediment loading, and ecosystem productivity in watersheds. The objective of this study was to derive a new semi‐empirical ET modeled using a dimension analysis method that could be used to estimate forest ET effectively at multiple temporal scales. The model developed describes ET as a function of water availability for evaporation and transpiration, potential ET demand, air humidity, and land surface characteristics. The model was tested with long‐term hydrometeorological data from five research sites with distinct forest hydrology in the United States and China. Averaged simulation error for daily ET was within 0.5 mm/day. The annual ET at each of the five study sites were within 7% of measured values. Results suggest that the model can accurately capture the temporal dynamics of ET in forest ecosystems at daily, monthly, and annual scales. The model is climate‐driven and is sensitive to topography and vegetation characteristics and thus has potential to be used to examine the compounding hydrologic responses to land cover and climate changes at multiple temporal scales.     

Risk assessment and prioritisation of contaminated sites on the catchment scale

Contaminated sites pose a significant threat to groundwater resources worldwide. Due to limited available resources a risk-based prioritisation of the remediation efforts is essential. Existing risk assessment tools are unsuitable for this purpose, because they consider each contaminated site separately and on a local scale, which makes it difficult to compare the impact from different sites. Hence a modelling tool for risk assessment of contaminated sites on the catchment scale has been developed. The CatchRisk screening tool evaluates the risk associated with each site in terms of its ability to contaminate abstracted groundwater in the catchment. The tool considers both the local scale and the catchment scale. At the local scale, a flexible, site specific leaching model that can be adjusted to the actual data availability is used to estimate the mass flux over time from identified sites. At the catchment scale, a transport model that utilises the source flux and a groundwater model covering the catchment is used to estimate the transient impact on the supply well. The CatchRisk model was tested on a groundwater catchment for a waterworks north of Copenhagen, Denmark. Even though data scarcity limited the application of the model, the sites that most likely caused the observed contamination at the waterworks were identified. The method was found to be valuable as a basis for prioritising point sources according to their impact on groundwater quality. The tool can also be used as a framework for testing hypotheses on the origin of contamination in the catchment and for identification of unknown contaminant sources.     

施肥对华北高产区土壤NO-3-N淋失与作物NO-3-N含量及产量的影响

利用4a的平衡施肥定位试验，研究太行山山前平原高产区冬小麦、夏玉米轮作制度下施肥对潮褐土中硝态氮的分布、移动、积累、植株吸收以及作物产量的影响。结果表明，土壤剖面中硝态氮含量与施肥量直接相关，过量施用氮肥使硝态氮在土壤中大量积累并向下层快速移动；氮磷对作物的养分供应存在着既相互促进又相互竞争的关系，施用适量磷肥可以促进小麦、玉米对氮素的吸收，提高作物产量，减少氮素在土壤中积累和淋失，但施磷量太高，由于氮磷之间的竞争作用，作物吸氮量反而下降，从而导致土壤中硝态氮的积累和淋失加剧，施用钾肥抑制了土壤硝态氮积累，促进了两季作物植株对氮素的吸收，从减少土壤硝态氮积累和淋失的角度，提出该区合理的施肥配比为组合N2P2K2，即ρA(N)=200kg hm^-2，ρA(P)=32．5kg hm^-2，ρA(K)=150kg hm^-2。图6参13。     

山谷型垃圾填埋场渗沥液水量计算方法比较研究

山谷型垃圾填埋场渗沥液水量是工程设计中的一个重要基础参数，主要由场内降雨转化为场外地下径流组成。对于场外地下径流，目前国内外尚无成熟的计算方法。作者针对几种常用的水量平衡法，通过实验，验证了每种方法的精度。结果表明，考虑了树冠戴流、表层土调蓄作用等因素的模型具有相当的精度，可以作为场外地下径流的计算模型。     

Experimental study and modeling of the transfer of zinc in a low reactive sand column in the presence of acetate

Nowadays, it is necessary to understand and identify the reactions governing the fate of heavy metals introduced into the environment with low complexing organic compounds, particularly when they are transferred through soils in urban areas. In this work the concomitant influence of pH and acetate on the fate of zinc on siliceous sand was studied in batch and non-saturated column experiments. Total zinc concentrations varied between 2 and 20 mg/l, and total acetate concentrations were fixed at 22, 72, 132, and 223 mM to obtain solution pHs of 4, 5, 6 and 7, respectively. Natural sand (diameter, 0.3-2 mm), mainly constituted of silica, was used. In batch adsorption experiments, zinc adsorption is insignificant at pH 4, low and linear at pH 5, and increasingly nonlinear, of the Langmuir type, at pH 6 and 7 indicating near-saturation conditions of surface sites at these high pH values. In column experiments, Zn retardation increases and the maximum outlet concentration of Zn decreases with rising pH and acetate concentrations. Previous column tracer experiments revealed the occurrence of regionalized water transport in the column. Modeling these data was based on a non-electrostatic approach. Batch and column data modeling was based on the PHREEQC code that allows concomitant resolution of chemical speciation and regionalized water transport. The speciation calculation indicates that the ZnAcetate+ species is the dominant Zn species in the solutions used. Batch experimental curves are correctly modeled assuming the formation of the three surface species triple bond SiOZn+, triple bond SiOH-Zn Acetate+ and triple bond SiO-Zn(Acetate)2-. The column data could be adequately modeled assuming a two-region water transport and the formation of the same three species with the same thermodynamic constants determined in the batch experiments. The hypothesis of the modeling leads to a slight overestimation of the quantities of zinc eluted (10%) at pH 6 and 7, mostly in the desorption phase. These results show that the methodology used facilitates the correct modeling of both batch and transport experiments and formulation of the hypothesis on the interactions between the low reactive sand and a complex solution.     

气候变化及人类活动影响下的潮白河月水量平衡模拟

尽管分布式水文模型已有30多年的发展历史,但是迄今的应用还只是其潜力的很少一部分。Freeze-Harlan蓝图中由于理论上的深化带来了应用上的困难,同时也指出模型并不是越复杂越好。按照科学的建模原则,建立了一个简单的分布式月水量平衡模型(DTVGM);其中通过引入土壤湿度因子,改进后的Bagrov模型同时考虑了前期土壤湿度与降水对蒸散(发)的贡献;通过设置人类活动影响背景参数集,表述人类活动对水文过程的影响。将DTVGM月模型应用于华北地区密云水库以上潮白河流域,识别出白河流域气候变化对径流减少的贡献为44%,人类活动导致下垫面变化对径流减少的影响达54%;潮河流域气候变化的贡献率为24%,而人类活动的贡献率高达74%,是导致径流减少的主要原因。     

异养与硫自养反硝化协同处理高硝氮废水特性研究

在异养反硝化反应器中添加单质硫,实现硫自养与异养反硝化联合处理NO_3~-废水,探讨异养和硫自养反硝化协同过程中的p H恒定及污泥减量化的特性.结果表明,硫自养反硝化菌在异养反硝化反应器内能够实现快速生长.经过65d的运行,控制进水TOC/N为0.65~0.75时,协同反硝化在无额外碱添加的情况下,厌氧反硝化产生的碱度满足自养反硝化的需求;运行至116d时,协同反硝化的总氮去除率为85%以上,脱氮效能稳定在2.5 kg·(m~3·d)~(-1).通过与完全异养反硝化相比,协同反硝化的污泥产量仅为完全异养反硝化的60%,极大地降低了污泥产量.但是利用协同自养反硝化处理高浓度NO_3~--N废水时,存在NO_2~--N累积的现象,即使是最终稳定期也有20 mg·L~(-1),需进行深度处理.