Spatial distribution and source identification of persistent pollutants in marine sediments of Hong Kong

A data matrix, obtained during a 3-year monitoring period (2007–2009) from 45 sampling sites in Hong Kong marine, was subjected to determine the spatial characterization and identify the sources of main pollutants. Indicator analyses indicated that polycyclic aromatic hydrocarbons (PAHs), nickel, manganese, and arsenic (As) were at safe levels. Five heavy metals (zinc, lead, cupper, cadmium, chromium (Cr)) were moderate to severe enrichment at some sites. Inner Deep Bay and Victoria Harbor were considered as hot spots for PAHs and the heavy metals, while Tolo Harbor was highly polluted by the heavy metals. Cluster analysis classified the 45 sampling sites into three groups, representing different pollution levels. Principal component analysis/factor analysis identified four principal components (PCs) and explained 84.9 % of the total variances, standing for persistent pollution, N factor, P and Cr factor, and As factor, respectively. Group A was highly polluted by persistent pollution, group B was the less polluted group, and subgroup B1 was less affected by PC3 and PC4 than subgroup B2. Group C, considered as the moderately polluted group, was greatly affected by N factor or persistent pollution, while subgroup C2 received more N pollution than subgroup C1.     

17β-雌二醇在水体中的分布水平及去除方法研究现状

17β-雌二醇(E2)是一种常见的天然雌激素,普遍存在于各类水体环境,在水环境分布水平已经达到干扰鱼类内分泌系统的水平,被认为是作用最强烈、最具潜在影响的环境内分泌干扰物之一。文章重点介绍了17β-雌二醇在水体环境中的分布水平及去除方法,指出由于传统的污水处理工艺和净水工艺无法将其完全去除,增加深度处理工序已经迫在眉睫。针对E2的特点,现有水处理工艺宜增加能够生成强氧化剂.OH的工序。     

厌氧序批式反应器预处理垃圾渗滤液的碳平衡研究

为初步了解垃圾渗滤液中有机物降解过程的物质和能量转化,对渗滤液实际处理工程提供借鉴,在最优工艺参数条件下,分别用处于中温(35±1)℃和常温状态的厌氧序批式反应器(ASBR)对垃圾渗滤液进行预处理。通过对反应器内的液相、气相和固相碳素进行全面的分析测定,结果表明:中温(常温)条件下,整个反应周期内约有86.4%(77.6%)的碳进入气相,约有1.7%(1.4%)的碳进入固相,其余约11.7%(22.3%)的碳仍存于液相中;其中,进入气相部分的碳有77.6%(71.3%)以甲烷形式存在,8.8%(4.7%)以二氧化碳形式存在,这说明ASBR预处理垃圾渗滤液过程中产生的甲烷资源化利用潜力较大。另外,反应器在中温状态下较常温状态处理效果更佳。     

新民城市居民头发重金属含量测定及相关分析

文章采用电感耦合等离子体原子发射光谱法(ICP-AES)及原子荧光光谱法(AFS)对辽宁省新民市城市居民不同年龄、性别群体头发中镉(Cd),铅(Pb),汞(Hg),砷(As)等重金属含量进行了测定,比较并分析了人发中各种重金属含量水平及与年龄、性别的关系。结果表明,新民市城市居民整体群体头发中镉,铅,砷,汞等4种重金属平均含量分别为(0.14±0.10),(3.80±2.43),(0.29±0.17),(0.39±0.21)mg/kg,均在中国居民头发中重金属含量正常值上限以下。回归分析表明,头发中所测定的重金属中只有金属Hg含量变化与年龄之间存在线性关系(R2=0.71);单因素方差(One-way ANOVA)分析表明,不同年龄群体间Cd,Pb,Hg,As等重金属含量无显著性差异(p>0.05);皮尔逊相关分析表明各重金属含量与年龄、性别之间无显著相关性(p>0.05)。     

高速公路路面雨水径流下渗系统性能研究

为了分析径流下渗系统在径流削减和污染控制方面的性能,本文对一个高速公路路面雨水径流下渗系统性进行了监测.结果表明,降雨量、径流量、径流削减量和径流排放量之间存在明显的正相关性(r=0.82～0.97,p0.05).该系统表现出高效的径流削减能力,当降雨量小于20 mm时,可以削减70%以上的径流量.与径流削减相比,该系统在污染物负荷控制方面更为有效.当降雨量在0～10 mm之间时,污染负荷的削减率几乎为100%;而当降雨在10～20 mm之间时,污染负荷的削减率仍然可以超过60%.相对总氮(TN)和总磷(TP)而言,下渗系统对悬浮物(SS)和化学需氧量(COD_(Cr))的去除能力要更高、更稳定.研究表明,径流下渗系统作为雨水管理的工具,在径流削减和改善水质方面具有良好的性能.     

The simultaneous removal of ammonium and manganese from surface water by MeOx: Side effect of ammonium presence on manganese removal

Manganese and ammonium pollution in surface water sources has become a serious issue.In this study, a pilot-scale filtration system was used to investigate the effect of ammonium on manganese removal during the simultaneous removal of ammonium and manganese from surface water using a manganese co-oxide filter film(MeO_x ). The results showed that the manganese removal efficiency of MeO_x in the absence of ammonium was high and stable, and the removal efficiency could reach 70% even at 5.5 °C. When the influent ammonium concentration was lower than 0.7 mg/L, ammonium and manganese could be removed simultaneously. However, at an ammonium concentration of 1.5 mg/L, the manganese removal efficiency of the filter gradually decreased with time(from 96% to 46.20%). Nevertheless, there was no impact of manganese on ammonium removal. The mechanism by which ammonium negatively affected manganese removal was investigated, demonstrating that ammonium affected manganese removal mainly through two possible mechanisms. On one hand, the decreased p H caused by ammonium oxidation was unfavorable for the oxidation of manganese by MeO_x ; on the other hand, the presence of ammonium slowed the growth of new MeO_x and retarded the increase in the specific surface area of the Me Ox-coated sand, and induced changes in the morphology and crystal structure of Me Ox. Consequently, the manganese removal efficiency of the filter decreased when ammonium was present in the inlet water.     

施用餐厨垃圾调理剂对果园土壤有机碳组分的影响

为研究施用餐厨垃圾调理剂对土壤有机碳组分的影响,以果园土壤为研究对象,从时间、空间维度解析长期施用餐厨垃圾调理剂对土壤有机碳积累、组成及其分布规律的影响,结合CPMI（碳库管理指数）和相关性分析,揭示施用餐厨垃圾调理剂对土壤碳汇的影响机制.结果表明,施用餐厨垃圾调理剂可显著提高土壤中w（TOC）（TOC为总有机碳）,并随施用时间的增加逐渐向深层土壤迁移,改善TOC分布状况.随着施用餐厨垃圾调理剂时间的增加,0~20 cm土壤层中w（NOC）（NOC为非活性有机碳）和30~40 cm土壤层中w（AOC）（AOC为活性有机碳）呈增加趋势,AOC分配比例低于NOC分配比例.随着施用时间的增长,0~30 cm土壤层中w（POC）（POC为颗粒有机碳）显著提高,最大值为42.94 mg/g,MOC（矿质结合态有机碳）分配比例与POC分配比例呈相反变化趋势,有利于提高土壤碳稳定性.各土壤层中CPMI均大于空白对照组,最大值为154.437,表明施用餐厨垃圾调理剂有利于提升土壤肥力.相关性分析表明,w（POC）与pH呈负相关,与含水率、EC（电导率）、w（OM）（OM为有机质）呈正相关,其中与含水率相关性最高（R=0.91）.可见,长期施用餐厨垃圾调理剂对提高果园土壤碳汇、改善土壤肥力具有重要意义,研究结果有助于进一步提升土壤碳汇的新型土壤调理剂的研发与应用.      

基于Matlab/Simulink的导弹运输振动载荷分析

目的分析导弹在车辆运输中的振动载荷情况,为开展导弹结构可靠性分析和寿命预估提供输入条件。方法根据导弹运输车的动力学模型,利用Matlab/Simulink对不同路况条件下导弹运输车振动响应情况进行仿真计算,获得不同路况和运输车速时的振动响应情况。结果随着路面等级下降和车辆速度的增加,导弹运输车振动的幅值也相应增加。结论滤波白噪声方法模拟得到的时域路面功率谱与标准等级功率谱一致性较好,可以作为振动响应分析的输入激励。     

霾与非霾期间汞在不同粒径颗粒物上的分布特征

在我国高速经济增长过程中,霾污染日趋突出,同时大气汞污染也十分严重,而颗粒汞对于汞在大气中的循环演化意义重大.为了探讨霾污染期间汞在不同粒径颗粒物中的分布特征,采用Nano-moudi 12级(6.2~9.9μm、3.1~6.2μm,1.8~3.1μm、1.0~1.8μm、0.56~1.0μm、0.32~0.56μm、0.18~0.32μm、0.10~0.18μm,0.056~0.10μm、0.032~0.056μm、0.018~0.032μm、0.010~0.018μm)大气颗粒物采样器,对上海霾与非霾期间不同粒径大气颗粒物中的汞进行分析.结果表明,颗粒态汞含量与颗粒物含量正相关;采样期间霾天颗粒态汞平均浓度0.31 ng·m-3是非霾天颗粒态汞平均浓度0.11 ng·m-3的2~3倍;霾和非霾天颗粒态汞浓度以及颗粒物质量浓度随粒径分布呈双峰型,霾期间峰值分别出现在0.56~1.0μm粒径段和3.1~6.2μm粒径段,而非霾期峰值分别出现在0.32~0.56μm和3.1~6.2μm粒径段;霾天较非霾天颗粒态汞和颗粒物的粒径分布均出现了向大粒径方向偏移;颗粒态汞主要分布在粒径≤1μm粒子上,能够长时间停留和长距离输送;非霾期间颗粒态汞在颗粒物中的平均含量为0.029 ng·μg-1,而霾期间为0.015 ng·μg-1;霾污染过程中其他污染物迅速成长,而汞成长较慢;霾天积聚核模态粒子中颗粒态汞质量浓度为2.06 ng·m-3,而非霾天为0.55 ng·m-3,积聚态颗粒物的大幅增加,是灰霾形成的主要原因.本地源燃煤等的排放以及风沙扬尘的增加和外地源的输送是导致霾天污染严重的重要原因.     

聚糖菌颗粒污泥基于胞内储存物质的同步硝化反硝化

采用特殊运行方式的厌氧-好氧SBR系统(厌氧后排水),以乙酸钠为有机基质成功富集了聚糖菌颗粒污泥.聚糖菌颗粒污泥厌氧-好氧批式实验表明,聚糖菌颗粒污泥具有较强的SND能力,TOC/N分别为5.0,4.0,2.8时,SND效率分别96.4%、95.3%及96.2%,而周期总氮去除效率随着碳氮比降低而降低,分别为66.0%、61.2%及56.3%.通过对周期氨氮、亚硝酸盐氮、硝酸盐氮、TOC以及胞内糖原、PHB变化的测定分析,证明聚糖菌颗粒污泥SND过程中,污泥以厌氧阶段储存于胞内的多聚物PHB作为反硝化碳源,并且反硝化聚糖菌是系统中反硝化能力的来源.与溶解性基质相比,PHB的降解速率相对较低,因此在SND过程中,反硝化可以与硝化保持相近的速率,从而有助于获得良好的SND效果.