铈离子光催化降解茜素绿的性能和机理简

主要研究了简单铈离子（Ce³⁺）在紫外光（UV）的作用下对蒽醌染料茜素绿（AG）的光催化降解效果和反应机理。结果表明，UV/Ce³⁺体系能够有效降解AG，初始反应速率随AG浓度的倒数值和Ce³⁺浓度的增加而线性增加，随初始溶液pH的增加先降低后增加，在酸性条件下有很高的TOC去除率。荧光探针实验表明，反应过程中可以产生·OH自由基。UV/Ce³⁺体系对其他类型染料和对硝基苯酚都有较好的降解效果。     

鄱阳湖乐安江流域非点源氮污染时空变化特征分析

乐安江是影响鄱阳湖水质的一条重要河流，近年来非点源污染迅速增加，水质呈下降趋势。运用GIS手段建立了研究区非点源污染的基本空间信息库，在野外水样监测和土地利用调查的基础上，分析了乐安江流域非点源氮的时空变化特征。氮的流失主要以可溶态形式，TN和DTN全年变化剧烈，在12月份普遍较高，4月份次之，9月份最低。在监测各月份乐安江流域TN浓度的范围为0.09~1.359 mg/L，水质属中营养水平。NO3-N浓度平均值为DTN的65%，是DTN流失的主要形态，其时空分布与TN具有明显的相似性；在丰水期4月份，NH3-N的平均浓度为全年最低水平，平水期9月份NH3-N平均浓度为三氮之首；NO2-N全年含量最低。各种形态的氮浓度在空间上从上游向下游基本呈增加趋势；西南部地区各种形态的氮浓度普遍高于东北部地区，说明上游水质普遍好于下游水质。     

双波长紫外吸收法有机废水COD测量技术与仪器设计

紫外吸收法直接测定有机废水COD是一种无需化学试剂、无样品前处理、无二次污染的绿色无损检测技术,但在实际应用中发现,有机废水中的悬浮物对测量结果产生较大影响.以实际废水水样为例,详细阐述了双波长紫外吸收法测量有机废水COD的操作方法及其消除悬浮物干扰的原理,并介绍了运用该技术设计开发的COD在线测量仪器.该仪器采用嵌入式计算机系统实时采集和处理数据,根据实际废水在双波长测量条件下的有效紫外吸光度快速推算出其COD值,具有快速、准确、无污染的特点.     

Measurement and spatial convergence analysis of China’s agricultural green development index

Environmental Science and Pollution Research - Based on the comprehensive evaluation system of agricultural green development index (AGDI), this paper uses entropy weight method and linear weighted...     

活性炭辅助微波活化煤矸石的“枣糕”模型

采用活性炭辅助微波活化煤矸石,将煤矸石的活化时间由传统高温焙烧方法的2 h缩短到了24 min以内。将70目活性炭与200目煤矸粉以2.0∶1的质量配比充分混合后在800 W微波功率下活化24 min,铝铁浸出率可达750℃焙烧2 h的1.71倍。将微波看做实体物质,将活化过程看做是由活性炭向煤矸粉的单向微波能量传递,引入化学反应工程学方法,"枣糕"模型计算表明,在680 W功率下,活性炭的微波附着速率常数ka=0.334 min-1,微波脱附速率常数k’a=0.050 min-1,煤矸粉的微波附着速率常数kb=0.262 min-1,相关系数R=0.99997。在528、680、800 W 3个功率水平下,"枣糕"模型的计算值均与实验值拟合良好,相关系数均高于0.999,在以上3功率下,发现极限铝铁相对浸出率a与极限温升ΔTmax近似成正比。     

垃圾焚烧炉炉拱改造与燃烧优化的数值模拟

炉排式垃圾焚烧炉在处理比设计水分高、热值低的垃圾时,容易出现着火位置滞后、垃圾＂烧不透＂、残炭含量高等问题。采用FLIC软件的床层模型和商业软件FLUENT,对焚烧炉炉排和炉膛燃烧过程进行了模拟计算。结合某城市生活垃圾焚烧炉存在的燃烧不完全问题,通过一系列的数值实验,探索后拱高度和挡板的有无对燃烧过程的影响。比较了炉拱辐射强度、挥发分质量分数、温度沿炉排长度方向的分布以及炉膛内的速度矢量图。结果表明,降低后拱高度或增加挡板均可使着火位置有不同程度的前移;同时降低炉拱高度和增加挡板可使着火位置前移约1.1 m,提前进入稳定燃烧阶段。     

Distribution and Health Risk Assessment of HCHs in Urban Soils of Beijing,China

The concentrations of hexachlorocyclohexanes (HCHs) were investigated in urban soil samples collected from business area, classical garden (CL), culture and educational area, large public green space (LA), residential area, and roadside area in Beijing. HCH concentrations ranged from 0.32 to 136.43 ng/g, with a geometric mean of 3.46 ng/g. The HCH concentrations in CL and LA were much higher than that in the other types of land use, which was due to the usage of HCHs to protect vegetation in CL and LA. Source identification showed that contamination source of HCHs was derived from historical HCHs (including technical HCHs and Lindane) as well as the long-range atmospheric transportation of HCHs. HCH concentrations showed a decreasing trend from the city centre to the suburb, and it increased with the age of the urban area. HCHs were negatively correlated with pH and positively correlated with total organic carbon and black carbon in soils. Health risk assessment with CalTOX and Monte Carlo analysis showed that health risks mainly came from dermal uptake and inhalation exposure pathways, and the total risk values were lower than the acceptable health risk value (10^− 6). The sensitivity analysis indicated that the reaction half-life of HCHs in soil, fraction dermal uptake from soil, exposure duration, and organic carbon fraction in soil significantly contributed to the variance of the health risk.     

初探污染场地的土壤修复工作过程与修复技术

"土壤修复"产业,我国目前处于起步阶段,其工作过程和技术路线是迫切需要解决的问题。本文在调研市场需求的基础上,探讨了土壤修复的工作流程、工作内容和修复技术。土壤修复的前期工作是场地土壤环境调查评估,首先从场地土壤环境质量(污染)调查开始,通过土壤样品采集、分析测试、结果分析和环境现状评价,进行场地土壤污染风险识别,包括污染因子、污染程度、修复因子的识别;通过污染风险评价,确定修复目标值、场地修复范围和修复量;通过试验筛选修复技术和修复工艺,确定修复方案和修复工程设计;对修复工程设计进行环境影响评价和环保行政审查;环保审查通过,实施修复工程。样品采集和分析测试、结果分析和评价、修复技术和修复工程成为"土壤修复"产业的工作核心。市场上应用的修复技术路线主要是隔离/封闭技术、稳定/固化技术、淋洗技术。     

氮掺杂二氧化钛可见光催化降解曙红Y溶液

采用溶胶凝胶法制备了氮掺杂二氧化钛光催化剂,用XRD、SEM、FTIR和粒度分析仪对催化剂进行了表征,并且在可见光作用下对曙红Y溶液进行了光催化降解实验。研究了催化剂的投加量、曙红Y的初始浓度、光照时间和pH对曙红Y溶液的光降解效果。结果表明,以可见光作光源,催化剂的投入量为0.4 g,曙红Y溶液的初始浓度为20 mg/L,光照时间为50 min,pH=4条件下,曙红Y溶液的降解率达98.87%。     

Evaluation of methane oxidation activity in waste biocover soil during landfill stabilization

The results of a nationwide survey of uranium in Swiss drinking water are reported. Elevated concentrations of uranium in groundwater are found mainly in the alpine regions and can be traced back to the geology of the bedrock. Water sources were systematically surveyed and analysed for the presence of Li, B, Si, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Cd, Sn, Sb, Ba, Tl, Pb and U and the results were analysed to determine if any correlation with uranium concentration was apparent. No correlation was found. The results are interpreted in relation to the current WHO guideline and those of other countries with a view to determining which areas would be affected if a maximum value were to be adopted and which areas require further investigation. Uranium content varied considerably, from below the limit of detection to almost 100 μg L⁻¹. Of the 5548 data samples, 98% are below the 2004 WHO provisional guideline value of 15 μg L⁻¹ and 99.7% below the revised (2011) value of 30 μg L⁻¹.