夏季潮滩对上海老港垃圾填埋场渗滤液氮、磷净化效果研究

垃圾填埋产生的渗滤液造成的环境污染问题El益严重。采用自然湿地对垃圾渗滤液净化有诸多优点,而相关的研究较少。根据渗滤液的不同浓度和不同滞留时间的净化效果不同,采用实验室模拟和培养的方法来研究老港垃圾填埋场附近潮滩对垃圾渗滤液营养盐N、P的净化效果。研究发现：夏季老港中、低潮滩在较短滞留时间（6h）内对各浓度渗滤液中N、P的净化效果不明显,而在较长滞留时间内（96h）中、低潮滩对各浓度渗滤液净化效果明显,净化后污水中N、P含量可达到排放标准;垃圾渗滤液质量分数为5％时,潮滩对N、P的净化效果最为明显。     

二氧化钛光催化降解甲醛反应动力学研究

以钛酸丁酯为前驱体，应用溶胶一凝胶法制备TiO2粉体和负载TiO2薄膜，考察了不同活化温度和活化时间对TiO2光催化降解甲醛性能的影响，并对TiO2薄膜光催化降解甲醛的反应动力学进行了研究。试验结果表明，在活化温度450℃、活化时间5h条件下，所得TiO2粉体及薄膜的光催化活性较好。不同初始浓度下甲醛光催化降解率与时间关系的动力学研究表明，一级反应动力学模型与试验数据拟合较好，方差R^2大于或等于0．99。     

序批式反应器工艺的研究进展

回顾了序批式反应器(SBR)技术的发展历史，介绍了近20年来国内外SBR技术研究与应用的新发展，着重分析了其基本原理、技术优势和不足之处，指出SBR技术是一项极具竞争力的废水生物处理技术。     

铁炭内电解预处理阿维菌素废水

采用铁炭内电解预处理阿维菌素废水，当原水pH为3.7、COD为31600mg/L、AVM含量为204μg/L时，最佳工艺条件为铁炭比1：1、停留时间30min、混凝pH8－9时，废水COD和AVM的去除率分别达到19.5%和68.5%，为后续生化处理创造了有利条件。     

警惕日趋加剧的地质灾害

我国是个多山的国家,山地、丘陵和高原占全国总面积的1／3,一般都存在着不同程度的地质灾害。2002年全国共发生滑坡、崩塌、泥石流、地面沉陷等突发性的地质灾害4．8万余起(重大地质灾害333起),其中滑坡数量最多约占84．3％,其次是崩塌和泥石流,分别占6．6％和6．0％。造成962人死亡,1797人受伤,直接经济损失近51亿元。     

桩土刚度比及布桩位置对桩身内力分布的影响研究

桩土刚度比及布桩位置直接影响抗滑桩的桩身内力分布及边坡加固效果。采用数值模拟的方法,考虑不同桩土刚度比和布桩位置,分别进行了计算分析。结果表明:(1)桩身剪力近似呈反"S"型分布,弯矩呈现向桩后的凸型分布,且桩身剪力和弯矩均随桩土刚度比的增加而增大,呈现先陡后缓的变化趋势;(2)桩位一定时,桩身正负最大剪力分别出现在桩身1/2和1/4高度位置,对应位置应加强抗剪箍筋的配置;桩身弯矩最大的位置出现在桩身1/3高度位置,即边坡滑带所在的位置,对应位置应加强抗弯钢筋的配置;(3)布桩于边坡中部及两侧时,加固后边坡的安全系数提高明显,桩身剪力和弯矩较大,而且对塑性区有明显的隔断作用。考虑到一般边坡中部的滑体厚度较深,在坡体中部位置布桩无论在技术上还是经济上都不太合适,因此,建议布桩于边坡中部两侧的位置,可取得较好的加固效果。     

湖北气象灾害的特点及防御对策

通过分析大量的气象灾害资料,并与其它自然灾害相联系,将发生在湖北的气象灾害进行了归纳,将其划分为6大类18种,并对其影响作了简要的描述．同时,根据历史上湖北气象灾害发生发展的时空分布规律以及气象灾害之间的相互联系,找出了湖北气象灾害发生的特点．最后,从减轻自然灾害的角度出发,针对湖北减灾工作的实际,提出了相应的防御对策．     

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.     

Tetracycline resistance in semi-arid agricultural soils under long-term swine effluent application

Annually, millions pounds of antibiotics are released unmetabolized into environment along with animal wastes. Accumulation of antibiotics in soils could potentially induce the persistence of antibiotic resistant bacteria. Antibiotics such as tetracyclines and tetracycline-resistant bacteria have been previously detected in fields fertilized with animal manure. However, little is known about the accumulation of tetracyclines and the development of tetracycline resistance in semi-arid soils. Here we demonstrate that continuous land application with swine effluent, containing trace amounts of chlortetracycline, does not necessarily induce tetracycline resistance in soil bacteria. Based on the testing of more than 3,000 bacteria isolated from the amended soils, we found no significant increase in the occurrence and level of chlortetracycline resistant bacteria in soils after 15 years of continuous swine effluent fertilization. To account for a possible transfer of tetracycline-resistant bacteria originated from the swine effluent to soils, we analyzed two commonly found tetracycline resistant genes, tet(O) and tet(M), in the swine effluent and fertilized soils. Both genes were present in the swine effluent, however, they were not detectable in soils applied with swine effluent. Our data demonstrate that agronomic application of manure from antibiotic treated swine effluent does not necessarily result in the development of antibiotic bacterial resistance in soils. Apparently, concentrations of chlortetracycline present in manure are not significant enough to induce the development of antibiotic bacterial resistance.