Photocatalytic degradation of C. I. Reactive Red 24 solution with K6SiW11O39SnII

Environmental friendly materials, K₆SiW₁₁O₃₉Sn (SiWSn), was synthesized. SiWSn photocatalytic decomposition of C. I. Reactive Red 24 (RR24) with the UV-lamp (253.7 nm, 20 W), Xenon lamp filtered less than 390 nm light (500 W) and sun light was investigated. The results showed that RR24 solution could be effectively decolorized with the SiWSn photocatalyst. The photocatalytic degradation efficiency of RR24 with SiWSn was affected by the initial concentration of RR2 solution, the amount of SiWSn and the photolysis time. It is demonstrated that the process of photodegradation of RR24 with SiWSn is a pesudo first-order reaction, which can be described by Langmuir-Hinshelwood equation. Hydroxyl radicals and holes are both the main oxidants in the photocatalytic reaction of RR24 with SiWSn.     

改性GAC联合H2O2去除氨苄青霉素钠的研究

文章研究了用Fe（NO3）3NaOH改性的活性炭联合过氧化氢对水溶液中氨苄青霉素钠的处理效果．确定了它们的优化处理条件,并对两者的处理效果作了相应比较。在T=30℃,pH：3．0,青霉素初始浓度为200mg／L条件下,投加5．0g／LFe（N03）3改性活性炭和80mg/LH202,反应120min后,COD、TOC去除率分别可以达到88．5％和77．9％;在T=30℃,pH=70,青霉素200mg／L条件下,投加8．0g／LNaOH改性活性炭和80mg／LH202,反应120rain后,COD、TOC去除率分别可以达到85．2％和76．4％。     

电子鼻预处理装置的开发及适用性研究

针对气敏传感器的信号响应受气体湿度影响较大的问题,开发了一套用于快速检测和实时监测土壤中挥发性氯代烃污染的电子鼻的预处理装置.优选了干燥剂的材质,评价了最适干燥剂的除湿性能和对氯代烃化合物的吸附情况;把预处理装置与电子鼻联用,通过与气相色谱（GC）检测结果的比较,评价了其用于土壤通风净化过程监测的适用情况.结果表明：①以无水氯化钙和卤代烃分离管搭配组合的干燥装置效果最佳,湿度去除率达99%以上,电子鼻各传感器的基线值与对照组接近;②上述干燥剂连续通入湿度为75%的空气,90 min内湿度几乎可完全去除,120 min内湿度去除率保持在95%以上,对传感器的基线影响较小.③预处理装置未造成检测气体的吸附损耗,通入干燥预处理装置前后的挥发性氯代烃气体浓度差异只有3%～5%;④在土壤通风脱附过程的检测中,通气湿度98%以上的情况下,预处理装置在120 min内对湿度去除率达99%以上;电子鼻与GC对四氯乙烯污染物的检测结果线性拟合判定系数R2〉0.99（n=18）,表明配以干燥预处理装置的电子鼻能够较好地适用于土壤修复过程监测.     

中国环境管理参与的研究现状、问题与对策研究

基于中国学术期刊网络版数据库,采用文献计量法,对中国440篇环境管理参与文献进行分析.结果表明,当前中国环境管理参与研究具有研究阶段性显著、期刊文献信息分布离散性与集中性并存、高校为研究主力军且高校间合作为主要合作形式、制度建构与创新是主要研究问题、多元协作成为研究新趋势、基金支持以单项基金为主、北京是文献产量和受基金资助最多的地区等特点.同时,中国环境管理参与研究存在研究成果少、期刊质量低、跨机构合作不足、研究深度浅、基金分布不均、研究"东强西弱"等问题.最后,与问题相对应提出相关建议.     

发动机缸体开裂失效分析

目的研究发动机缸体出现开裂失效原因。方法通过化学成分分析、力学性能分析、断口扫描分析、显微组织分析、能谱分析及低倍缺陷分析测试手段,对发动机缸体的开裂模式及失效原因进行分析。结果发动机缸体原材料中Si元素超标,导致晶界析出较多的Al Si Cu及Al2Cu脆性相,在开裂区域组织存在过热过烧现象,两个原因导致组织晶间结合力大大降低。同时,在开裂区域存在热节效应,低倍疏松和缩孔较集中的现象,为热裂纹形成及继续扩展提供了有利条件。结论通过不断改进设计工艺,控制原材料成分及调节浇注参数,大大减小了热裂纹出现概率,在后序批量生产中,未发现类似失效样件。     

Assessing the life cycle study of alternative earth-retaining walls from an environmental and economic viewpoint

Environmental Science and Pollution Research - This research aims to assess the sustainability of the most common earth-retaining walls (Gravity Walls and Cantilever Walls) in terms of...     

Toward ecological function zoning and comparison to the Ecological Redline Policy: a case study in the Poyang Lake Region,China

Environmental Science and Pollution Research - Faced with huge environmental problems of ecosystem degradation, “Ecological Redline Policy (ERP)” in China is a new key national-level...     

Green synthesis of metal nanoparticles using Garcinia extracts: a review

Environmental Chemistry Letters - The demand for nanoparticles has been increasing rapidly in recent years due to their unique properties of interest for a wide range of applications. Several...     

High removal of nitrogen and phosphorus from black-odorous water using a novel aeration-adsorption system

Black-odorous waters are an increasingly common phenomenon characterized by excessive levels of nutrients, the formation of metal sufide precipitates, volatile sulfurous compounds, low dissolved oxygen and high chemical oxygen demand. Black-odorous waters frequently occur in lake and river systems where inputs have restricted circulation. The key remediation issue is the removal of nitrogen and phosphorus. Here, we present a novel aeration-adsorption system using fiber balls and we study treatment parameters and removal mechanism. Kinetics and changes of the solid phase were followed using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Results show complete removal of ammonia N, initially at 31 mg/L, and 92.8% removal of total nitrogen, initially at 29 mg/L, after a 24 h reaction time at pH 9.67. At pH 5.67 and 9.67, total phosphorus and phosphate could be significantly reduced by 90–92% at 3.2–5.2 mg/L after 24 h. Treatment met China’s integrated wastewater discharge standards, demonstrating an effective and robust treatment capability. First-order and second-order kinetic models provided a good fit to the treatment data, indicating physical and chemical adsorption were involved in the treatment reactions. The reaction mechanism involved hydrogen substitution and binding to oxygen. These results present a cost effective and robust approach for the removal of N and P from black, odorous water, providing opportunity to abate environmental contamination.

     

Energy-water-climate governance from interdisciplinary perspectives

Environmental Science and Pollution Research -