Hydrograph Separation by Incorporating Climatological Factors: Application to Small Experimental Watersheds 1

Abstract: Evaluating the relative amounts of water moving through the different components of the hydrological cycle is required for precise management and planning of water resources. An important aspect of this evaluation is the partitioning of streamflow into surface (quick flow) and base‐flow components. A prior study evaluated 40 different approaches for hydrograph‐partitioning on a field scale watershed in the Coastal Plain of the Southeastern United States and concluded that the Boughton’s method produced the most consistent and accurate results. However, its accuracy depends upon the proper estimation of: (1) the end of surface runoff, and (2) the fraction factor (α) that is function of many physical and hydrologic characteristics of a watershed. Proper identification of the end of surface runoff was accomplished by using a second derivative approach. Applying this approach to 12 years of separately measured surface and subsurface flow data from a field scale watershed (study area) proved to be accurate for 87% of the time. Estimation of the α value was accomplished in this study using two steps: (1) alpha was fitted to individual hydrographs: and, (2) a regression equation that determines these alpha values based on climatological factors (e.g., rainfall, evapotranspiration) was developed. Using these strategies improved the streamflow partitioning method’s performance significantly.     

基于灰色理论的废弃电路板金属回收模型研究

电子废弃物的资源化既能实现资源的二次利用,又能防止环境污染,具有重要的理论意义和应用价值.运用灰色理论对离心复合力场回收废弃电路板金属过程中反冲水、转速和浓度等操作参数对分选效果(精矿品位和精矿的回收率)的影响进行了研究,建立了基于GM(0,N)灰色模型的离心复合力场回收废弃电路板分选模型.经验证模型精度较高.     

低水平放射性废水中钚的分析方法研究进展

钚是重要的核燃料,也是一种极毒的放射性核素,在核燃料循环和放射性废物处置过程中占有重要地位.近些年来,钚在自然水体中的含量、分布引起人们的关注.科研工作者针对低水平放射性废水,核设施周围自然水体,核试验、核事故情况下可能污染的自然水体等,建立了一些钚的分析方法.作者在对这些方法进行了比较的基础上,提出了一种在盐酸体系中用TEVA树脂负压微色谱柱液闪法将水溶液中钚与其他锕系元素及金属离子分离并测量的新方法.该方法有望在日常和应急监测中的得到应用.     

Enhancing anoxic denitrification of low C/N ratio wastewater with novel ZVI composite carriers

External organic carbon sources are needed to provide electron donors for the denitrification of wastewater with a low COD/NO₃^--N（C/N） ratio, increasing the treatment cost. The economic strategy is to enhance the bioactivity and/or biodiversity of denitrifiers to efficiently utilize organic substances in wastewater. In this study, novel zero-valent iron（ZVI） composite carriers were prepared and implemented in a suspended carrier biofilm reactor to enhance the bioactivity an...     

城中村雨水污水完善改造方案浅析

结合深圳盐田区城中村污水完善改造设计及施工服务中所遇到的问题,提出为彻底解除雨水污水混流现象而采取的措施和方法,以作为今后城中村雨水污水分流制改造过程中的借鉴或参考。     

磁絮凝法处理DZA有机废水的研究

本文介绍了磁絮新颖产分离技术，应用该技术能有效处理水中ＤＺＡ有机物，实现数秒内的快速分离污泥，污泥含水率低。     

Strategies for improving the photocatalytic performance of metal-organic frameworks for CO2 reduction: A review

Photocatalytic CO₂ reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels. Numerous attempts have been made to produce effective and efficient photocatalysts for CO₂ reduction. In contrast, the selection of competitive catalysts continues to be a substantial hindrance and a considerable difficulty in the development of photocatalytic CO₂ reduction. It is vital to emphasize different techniques for building effective photocatalysts to improve CO₂ reduction performance in order to achieve a long-term sustainability. Metal-organic frameworks (MOFs) are recently emerging as a new type of photocatalysts for CO₂ reduction due to their excellent CO₂ adsorption capability and unique structural characteristics. This review examines the most recent breakthroughs in various techniques for modifying MOFs in order to improve their efficiency of photocatalytic CO₂ reduction. The advantages of MOFs using as photocatalysts are summarized, followed by different methods for enhancing their effectiveness for photocatalytic CO₂ reduction via partial ion exchange of metal clusters, design of bimetal clusters, the modification of organic linkers, and the embedding of metal complexes. For integrating MOFs with semiconductors, metallic nanoparticles (NPs), and other materials, a number of different approaches have been also reviewed. The final section of this review discusses the existing challenges and future prospects of MOFs as photocatalysts for CO₂ reduction. Hopefully, this review can stimulate intensive research on the rational design and development of more effective MOF-based photocatalysts for visible-light driven CO₂ conversion.     

New eco-friendly proposal for the crystallization of beet raw juice

In the past years we evaluated different strategies with the aim of eliminating completely from the beet sugar factory, the traditional calco-carbonic purification process taking into account the well-known problems related to the utilization of lime and the production of carbonation sludge.To complete the picture of the possible solutions to be adopted for the elimination of the traditional purification process, we tested and evaluated in laboratory and in pilot plants a new eco-friendly proposal.The results obtained, as well as the proposed flow-sheet and some economic evaluations, are presented and discussed.     

An Experimental Study on the Treating River Sewage with New Bioreactor

A new bioreactor on the basis of a dynamic fluidized bed was designed, which combines advantages of the fluidized bed and a biological contactor. The experiments of start up, normal operation and parameter adjustment are carried out. The results show that the bioreactor can be quickly started up in the condition that the fill is 50%, the hydraulic retention time is 72 min, aerate speed is 2.5 m3/h, rotation-cage rotated speed is 1.5 r/min, and the removal rates of chemical oxygen demand （CODcr） and Ammonia nitrogen （NH3-N） are 75.34% and 80.98% respectively. The influence of the operation parameter on removal rates of the bioreactor is analyzed, and an appropriate operation parameter is provided.