黄土丘陵沟壑区生态环境建设中的水问题--以延河流域为例

水在生态环境建设中具有重要的地位,同时生态环境建设也对水文情势产生重要影响,两者密切相关.黄土丘陵沟壑区属于资源性缺水地区,水土流失非常严重,同时这一地区也是生态环境建设特别是植被恢复与重建的重点区域,研究这一地区的水与生态环境建设间的相互关系具有更加重要的意义.根据黄土丘陵沟壑区的典型流域--延河流域的社会经济统计数据、水文站监测数据及土壤水分和植被生长的有关研究,综合分析后认为:①人口快速增长和社会经济高速发展需要更多的水资源支持,生态环境建设用水受到直接威胁;②生态环境建设特别是建成植被减少了河川径流,由于植被蒸腾过度消耗土壤水库中的水分,一些地方出现土壤干层;③水资源的不足不仅限制了进一步的植树种草,而且也对建成植被产生了不利影响,一些地方甚至出现了"小老树",从而使植被的生态环境效益受到影响.在此基础上,通过分析生态环境建设与水的关系,提出了黄土丘陵沟壑区水资源可持续利用、生态环境可持续建设和社会经济可持续发展的建议.     

Improved product selectivity of electrochemical reduction of carbon dioxide by tuning local carbon dioxide concentration with multiphysics models

Environmental Chemistry Letters - Electrochemical reduction of carbon dioxide (CO2) is promising to alleviate carbon emissions and produce fuels and materials in a circular way, yet effective...     

Evaluation of activated sludge properties’ changes in industrial-wastewater pre-treatment: role of residual aluminum hydrolyzed species with different polymerization degree

● Medium poly Al salts dominated the PAC residual salts with a rational dosage. ● Settlement flocculation effect under medium poly Al salts showed a better trend. ● Complex of medium poly Al salts and enzymes promoted cell activity. ● Medium poly Al salts were beneficial to the effluent indexes. With the widespread introduction of pre-coagulation prior to the biological unit in various industrial wastewater treatments, it is noteworthy that long-term accumulation of residual coagulants has certains effect on both micro and macro characteristics of activated sludge (AS). In this study, the morphology distributions of residual aluminum salts (RAS) and their effects on the removal efficiency of AS were investigated under different PAC concentrations. The results showed that the dominance of medium polymeric RAS, formed under an appropriate PAC dose of 20 mg/L enhanced the hydrophobicity, flocculation, and sedimentation performances of AS, as well as the enzymatic activity in cells in the sludge system, improving the main pollutants removal efficiency of the treatment system. Comparatively the species composition with monomer and dimer / high polymer RAS as the overwhelming parts under an over-dosed PAC concentration of 55 mg/L resulted in excessive secretion of EPS with loose flocs structure and conspicuous inhibition of cellular activity, leading to the deterioration of physico-chemical and biological properties of AS. Based on these findings, this study can shed light on the role of the RAS hydrolyzed species distributions, closely relevant to Al dosage, in affecting the comprehensive properties of AS and provide a theoretical reference for coagulants dosage precise control in the pretreatment of industrial wastewater.     

城镇社区地震应急工作模式的建立

社区地震应急工作是我国地震应急管理工作的重要内容之一,是减轻地震灾害的有效途径。如何依托社区开展地震应急工作是近年来,特别是汶川地震后全社会关注的问题。从地震应急组织管理、应急预案、志愿者队伍建设、宣传培训、应急演练、物资储备、避难场地和疏散通道设置以及地震应急处置等几个方面讨论了社区地震应急工作模式。     

Clomazone dissipation, adsorption and translocation in four paddy topsoils

IntroductionClomazone,(2 [(2 chlorophenyl)methyl ] 4 ,4 dimethyl 3 isoxazolidinone) ,isasoil appliedisoxazolidinoneherbicideproducedbyFMCCorp .Itisintroducedforannualgrassandbroad spectrumweedsinsoybeans(Rani,1998;Vyas,2 0 0 0 ) .Itisalsocurrentlyregis…     

Physicochemical interaction and its influence on deep bed filtration process

The capillary model was used to analyze the hydraulic conditions in the deep bed filtration process. The physicochemical interaction forces between the filter media and suspended particles and their influence on deep bed filtration process were also studied theoretically. Through the comparison of the hydraulic and physicochemical forces, the key influencing factors on the filtration process were proposed and investigated. Pilot study of the microflocculation deep bed filtration was carried out in the No. 9 Potable Water Treatment Plant of Beijing, and the experimental results of hydraulic head loss, particle distribution and entrapment were presented. The theoretical prediction was reasonably consistent with the experimental results under different conditions, which indicated that the regulation and control of micro-flocculation and deep bed filtration could be realized by the evaluation of the physicochemical interactions. Further theoretical and experimental research should be carried out to investigate the interaction mechanism and its application in the deep bed filtration and other cases.     

热湿舒适性运动面料研究概况

影响运动服装综合舒适性的因素很多,其中,热湿舒适性是评价运动服装舒适性的一项重要指标,它直接影响到人们的健康情况以及运动员在运动项目中的能力发挥情况,成为运动服装面料开发过程中不可忽视的重要环节。本文介绍了运动面料的热湿传递机理,通过分析影响运动服装热湿舒适性的重要因素来探讨运动服装面料的研究现状,并详细介绍了目前已经开发或即将开发的具备热湿舒适性的运动服装面料的种类。     

上海城市污水厂污泥处理与利用系统分析

上海市城市污水处理规划的实施，将在2020年前使该市的城市污水厂污泥产生量从现状的85tDS/d增长至1300－1500tDS/d，将形成可观的污泥消纳压力。预期了该市的污水污泥产生状况，以现有污水污泥处置与利用技术为基础，测算了可行的污泥处置与利用方向及相应的容量，以及满足容量利用的前处理要求。以此为基础，推荐了适宜的容量利用方案，并建议以生物稳定化干化处理为污泥处置与利用前的改性处理步骤，且可在适当的条件下增加厌氧消化环节，提高处理体系的水平与容量宽余度。此污泥处理与利用体系可达到污泥消纳运行的柔性化和可靠性，兼具环境安全性与经济合理性。     

高温分解及烟气净化处理电子垃圾的技术和设备

提出高温分解及烟气净化处理废弃电子垃圾的技术。通过喷水系统调节分解炉内气氛,控制有机物分解速度,使有机物裂解成二氧化碳和水蒸气,有害成份经净化系统再次处理后达到环保排放标准。金属部分可进一步进行提炼回收,实现有机物和金属的绿色分离。     

Adsorption and reduction of trichloroethylene by sulfidated nanoscale zerovalent iron (S-nZVI) supported by Mg(OH)2

Environmental Science and Pollution Research - Sulfidated nanoscale zerovalent iron (S-nZVI) supported on a flower spherical Mg(OH)2 with different Mg/Fe ration were successfully synthesized. The...