Are non‐poor households always less vulnerable? The case of households exposed to protracted civil war in Southern Sudan

Civil wars in Africa are now the leading contributory cause of vulnerability of rural communities. Understanding vulnerability during civil war is critical for humanitarian response and post-conflict rehabilitation planning. The lack of understanding of vulnerability has led existing studies to make sweeping generalizations, either by equating the dynamics of vulnerability during civil wars with vulnerability in other risk events, or by projecting people in the 'war zones' as unable to cope and subsequently becoming vulnerable. This paper is an attempt to gain a more nuanced understanding of the dynamics of vulnerability during protracted civil war. It shows that during civil war the non-poor are not necessarily less vulnerable than poor households. The idea that people caught up in civil war are all vulnerable is not supported by the findings of this paper. It shows that the 'standard' pattern of vulnerability to drought is similar to that during exogenous counter-insurgency warfare, while a different pattern of vulnerability to endogenous shocks is identified.     

BAF处理生活污水过程中同步去除H2S的试验研究

采用曝气生物滤池处理生活污水的过程中,以混和臭气的空气为气源,以掺入了陶粒和铁炭颗粒的复合填料为载体,研究了反应器的运行条件和参数,结果表明,以混合臭气的空气作为气源对污水处理过程的需氧量基本无影响.当反应器的进气量为40 L/h,进水容积负荷和进气H2S的浓度分别在0.3～1.6 kg COD/(m3·d)和0.8～2.3 mg/m3之间变化时,可以实现出气和出水中H2S和COD分别小于0.04 mg/m3和90 mg/L,满足同时达标排放的要求.H2S的同步去除可能是通过微生物的氧化分解和形成FeS沉淀来实现的.     

水环境质量模糊综合评价中的一些问题探讨

水环境质量评价,对于正确了解水环境现状,合理利用与开发水环境资源,科学预测未来水环境变化趋势具有重要意义.建立在模糊集合论基础上的模糊综合评价法是评价水环境质量的一种新方法.与常规评价方法相比,模糊综合评价方法有其突出的优点,因此,日益受到环境评价工作者的重视.国内已有工作发表.我们就水环境质量评价的特点与模糊综合评价方法中的一些问题进行探讨.     

我国山岭公路汽车CO、HCs和NOx排放系数

在１５６０ｍ 长的甘肃七道梁山岭公路隧道内设监测点,对进入隧道内汽车排出的污染物浓度、交通量、车种以及气象条件进行采样分析、计数、分类和观测．根据在隧道内实测数据,用建立的隧道空气质量方程计算出我国高海拔山岭公路汽车单车ＣＯ、ＨＣｓ和ＮＯ_x 排放系数分别为４１．８６１±２６．１０１、５．３６７±３．１５８和３．８８３±１．９４３ｇ／（ｋｍ ·ｖｅｈ）．与国外成果相比,我国山岭公路汽车ＣＯ和ＨＣｓ排放系数明显高于国外发达国家汽车的排放水平,而ＮＯ_x 排放量低于一些发达国家     

HSY算法在水质模型参数识别中的应用探讨

参数识别是水质模拟中的技术核心，数据稀缺是水质模型经常面临的问题。采用HSY算法可求得模型参数的分布，而不再是一个单一的最优参数，从而在一定程度上避免了由于“最优”参数失真带来的决策风险，本文以南水北调一期工为例，讨论了在稀疏数据条件下如何应用HSY算法识别CSTR水质模型的参数，并对识别的模型参数进行了检验。模型检验采取了2种方法：分别用动态和稳态计算方法得出的参数进行比较；用模拟结果分布于实测值进行比较。结果表明，HSY算法为稀疏数据条件下进行识别、建立数学模型提供了一条有效的途径。     

垃圾渗滤液对潮滩沉积物营养盐污染影响研究

以上海市老港垃扭填埋场附近潮滩为例,研究了垃圾渗滤液的排放对潮滩沉积物营养盐污染负荷的影响,结果表明：由于垃圾渗滤液的排放,潮滩表层沉积物中营养盐N、P的含量显著增加;在向海向上,随距排污口距离的增加表层沉积物中N、P的含量有所降低;受垃圾填埋时间长短的影响。南北线潮滩沉积物中N、P的含量有明显差异,北线沉积物中总无机氮和总无机磷的含量均明显高于南线。柱样沉积物中N、P的含量随深度也呈现一定的变化规律：氨氮含量随深度的增加而增加,总磷含量随深度的增加而减少。     

综合生物塘处理城镇污水研究

报道了一种新的高效低能耗的污水处理塘系统的中试研究结果．本生物塘系统分为三个功能区域，分别为污水净化区，水质修饰区和综合利用区．水生维管束植物呈带状分布于塘系统中，在时间上和空间上进行不同搭配组合．较之传统氧化塘和一般的水生植物塘、综合生物塘的处理效果较好，ＣＯＤ、ＢＯＤ、ＴＳＳ、氮、磷等污染组分去除效率较高，细菌，病毒及诱变活性明显下降。在污水净化的同时，收获大量的水生植物及鱼，蚌等水产品．水质明显改善，出水可用于水产养殖和农业灌溉．     

火焰原子吸收法测定废水中的钴

研究采用硝酸-高氯酸消解样品,用火焰原子吸收分光光度法测定废水中钴的方法.通过标准样品和实验样品的分析,验证了方法的准确度和精密度.方法的加标回收率为94.0％ ～ 108.0％,检出限为0.010mg/L.该方法简单可靠,干扰少,适合废水分析.     

Perchlorate removal using granular activated carbon supported iron compounds: Synthesis, characterization and reactivity

Synthesis and use of the iron compounds supported on granular activated carbon (ICs/GAC) have shown significant environmental implications for perchlorate (ClO 4 ) removal. ICs/GAC was synthesized via hydrolyzing FeSO 4 ·7H 2 O on GAC, reduced by NaBH 4 solution in polyethylene glycol 6000 and ethanol solution, dried in vacuum condition and exposed to air. Synthesized ICs/GAC was characterized using transmission electron micrograph (TEM), Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy (XPS). ICs/GAC was determined to be containing a large amount of FeOHSO 4 , Fe 2 O 3 and a small amount of zero-valent iron (ZVI) nanoparticles according to TEM and XPS measurements. Batch static kinetic tests showed that 97% of ClO 4 was removed within 10 hr at 90°C and 86% of ClO 4 was removed within 12 hr at 25°C, at ICs/GAC dosage of 20 g/L. The experimental results also showed that FeOHSO 4 and Fe 2 O 3 nanoparticles have the function of perchlorate adsorption and play important roles in ClO 4 removal. The activation energy (E a ) was determined to be 9.56 kJ/mol.     

烟气脱硝低温选择性催化还原金属氧化物催化剂的研究进展

低温选择性催化还原(SCR)技术具有很高的脱硝效率。概述了低温SCR金属氧化物催化剂的制备方法和性能,分析了催化剂的失活原因和再生方法,探讨了催化反应的机理,并介绍了低温SCR技术在工业烟气脱硝中的应用案例。SCR催化剂未来的发展不仅要以低温下的高活性和高选择性为主要目的,还要考虑到催化剂的抗失活性能(如抗硫性和抗水稳定性)和操作温度范围,使其可广泛应用于不同的工况中,以满足我国日益提高的环保要求。