好氧颗粒污泥法处理石化废水

实验以吉林石化污水处理厂初沉池出水为原水在SBR中培养好氧颗粒污泥。实验初期,依次以比例为40%、60%的含石化废水的培养液进行培养,于第15天SBR中出现颗粒污泥,此后直接采用石化废水培养,同时逐步缩短沉降时间,第27天起反应器出水稳定,COD去除率达到89%,TN、NH3-N和TP去除率分别达到56%、86%和90%。采用此方法培养的颗粒污泥平均粒径约为1.3 mm,外表棕黄色,颗粒表面粗糙,在扫描电子显微镜(SEM)下观察到好氧颗粒污泥主要由杆状菌和丝状菌组成,颗粒内部存在若干孔隙。研究结果表明,在SBR中通过逐步增加石化废水进水比例,缩短沉降时间可以快速培养出好氧颗粒污泥,好氧颗粒污泥处理石化废水效果良好。     

Metals and PCB levels in some edible marine organisms from the Ionian Sea: dietary intake evaluation and risk for consumers

Concentrations of some metals (Cd, Cu, As, Hg, Pb) and polychlorinated biphenyls (PCBs) were investigated in edible marine organisms from different trophic levels and feeding behaviour like bivalve molluscs (Mytilus galloprovincialis and Chlamys glabra), gastropod molluscs (Hexaplex trunculus) and some commercial species of fish (Trachurus trachurus, Boops boops, Sarpa salpa and Gobius niger). These species were collected in the first inlet of the Mar Piccolo of Taranto (Ionian Sea, Southern Italy), classified as ‘Site of National Interest’ established by National Law 426 (1998) and included in the ‘National Environmental Remediation and Restoration Projects’. The aim of this work was to investigate contamination levels and public health risks, associated with consuming seafood harvested from these areas. Moreover, in this study, was also estimated the weekly intake in children and adults, both for metals and PCBs. In comparison with the permissible limits set by EC Regulations, Cd and Pb levels were over the limit in the H. trunculus (in all sampling stations) and in the fish T. trachurus respectively. PCBs were over the legal limit in all sampled species with the exception of M. galloprovincialis (station 1), C. glabra and the herbivorous fish S. salpa. In the fish T. trachurus, for example, the concentration of six target PCBs was about five times higher than the EC limit. The estimated intakes of those trace elements included in this study through seafood consumption by the population exceed the provisional tolerable weekly intake recommended by the Joint FAO/WHO Expert Committee on Food Additives for Cd and Hg in the H. trunculus and T. trachurus, especially in children. Moreover, hazard quotience (HQ) for Hg and Cd was >1 in the children for T. trachurus and H. trunculus consumption. As regard non-dioxin-like PCB (NDL-PCB), the estimated intake were always above the ‘provisional guidance value’ (70 ng/kg body weight) Arnich et al. (Regul Toxicol Pharm 54: 287–2, 2009) for all sampled organism. Thus, health risks due to the dietary Hg, Cd and PCBs intake, especially for children, cannot be excluded. Therefore, an extended remediation programme is necessary to safeguard marine ecosystem, human health and, not less important, the economic activities, in the Taranto marine area.     

The Mar Piccolo of Taranto: an interesting marine ecosystem for the environmental problems studies

The National Project RITMARE (la Ricerca ITaliana per il MARE—Italian Research for the sea) started from 1 January 2012. It is one of the national research programs funded by the Italian Ministry of University and Research. RITMARE is coordinated by the National Research Council (CNR) and involves an integrated effort of most of the scientific community working on marine and maritime issues. Within the project, different marine study areas of strategic importance for the Mediterranean have been identified: Among these, the coastal area of Taranto (Ionian Sea, Southern Italy) was chosen for its different industry settlements and the relative impact on the marine environment. In particular, the research has been concentrated on the Mar Piccolo of Taranto, a complex marine ecosystem model important in terms of ecological, social, and economic activities for the presence also of extensive mussel farms. The site has been selected also because the Mar Piccolo area is a characteristic “on field” laboratory suitable to investigate release and diffusion mechanisms of contaminants, evaluate chemical–ecological risks towards the marine ecosystem and human health, and suggest and test potential remediation strategies for contaminated sediments. In this context, within the project RITMARE, a task force of researchers has contributed to elaboration a functioning conceptual model with a multidisciplinary approach useful to identify anthropogenic forcings, its impacts, and solutions of environmental remediation. This paper describes in brief some of the environmental issues related to the Mar Piccolo basin.     

The role of urban green infrastructure in mitigating land surface temperature in Bobo-Dioulasso,Burkina Faso

Green infrastructure in developed countries has been used as a climate change adaptation strategy to lower increased temperatures in cities. But, the use of green infrastructure to provide ecosystem services and increase resilience is largely overlooked in climate change and urban policies in the developing world. This study analyzed the role of urbanization and green infrastructure on urban surface temperatures in Bobo-Dioulasso, Burkina Faso, in sub-Saharan Africa. We use available geospatial data and techniques to spatially and temporally explore urbanization and land surface temperatures (LSTs) over 20 years. The effect of specific green infrastructure areas in the city on LSTs was also analyzed. Results show increased urbanization rates and increased temperature trends across time and space. But, LST in green infrastructure areas was indeed lower than adjacent impervious, urbanized areas. Seasonal phenological differences due to rainfall patterns, available planting space, and site limitations should be accounted for to maximize temperature reduction benefits. We discuss an approach on how study findings and urban and peri-urban agriculture and forestry are being used for policy uptake and formulation in the field of climate change, food security, and urbanization by the municipal government in this city in Burkina Faso.     

Use of a reactive transport model to describe reductive dechlorination (RD) as a remediation design tool: application at a CAH-contaminated site

In this paper, a numerical model is presented that is capable of describing the complex set of biochemical processes that occur in chlorinated aliphatic hydrocarbon (CAH)-contaminated groundwater when an exogenous electron donor is added. The reactive pattern is based on the degradation pathways of both chlorinated ethanes and ethenes, and it includes electron donor production (H₂ and acetate) from the fermentation of an organic substrate as well as rate-limiting processes related to electron acceptor competition. Coupling of the kinetic model to a convection–dispersion module is described. The calibration phase was carried out using data obtained at a real CAH-contaminated site in the north of Italy. Model simulations of different application scenarios are presented to draw general conclusions on the effectiveness of reductive dechlorination (RD) as a possible cleanup strategy. Early outcomes indicate that cleanup targets can only be achieved if source longevity is reduced. Therefore, metabolic RD is expected to produce beneficial effects because it is known to induce bioenhanced degradation and transformation of CAHs.     

基于流动人口特征的环洞庭湖区县域城镇化的水平和性质分析

改革开放以来,中国的人口迁流带有明显异地城镇化的性质,这种跨大区域的异地城镇化对人口流入区和人口流出区的影响是不同的。以环洞庭湖区为例,在第六次人口普查县域资料的基础上,利用SPSS170软件定量分析了湖区县域人口净流出率与城镇化率之间的关系,得出人口净流出区县域城镇化水平与县域人口净流出率呈高度负相关的结论;进而,按县域城乡人口内外流比(城镇人口净流入与农村人口净流出之间的比例),将本区城镇化划分为主动型城镇化、内流为主的被动型城镇化、外流为主的被动型城镇化和衰退型城镇等类型,并探讨了各类城镇化的人口流动的特征、动力机制和综合效益;在此基础上,提出了环洞庭湖区合理推进城镇化的对策     

不干胶废弃物热解焦燃烧特性

采用非等温热重分析和固定床热解实验研究了不干胶废弃物热解焦生成特性及热解焦燃烧特性,并计算了不同升温速率下热解焦的燃烧动力学参数。结果表明,不干胶废弃物热解焦产率随温度升高而逐渐降低,当热解终温在400~700℃时,热解焦产率在34.64%~22.03%之间;空气气氛下热解焦燃烧过程包括3个阶段:挥发分燃烧阶段(390~600℃)、混合燃烧阶段(390~600℃)和残炭燃烧与矿物分解阶段(650℃);升温速率对热解焦燃烧效果作用明显,升温速率越大,燃烧特性指数越高,燃烧稳定性越好;热解焦燃烧过程可以通过3个一级反应描述,当升温速率为40℃/min时热解焦燃烧各阶段表观活化能明显降低,表明升温速率提高有助于热解焦的燃烧反应活性,更有利于燃烧反应的进行。     

铁屑协同玉米芯/花生壳处理玛瑙染色废水

针对农村玛瑙染色工业废水中存在高浓度Cr(Ⅵ)、SO42-和H+等污染严重、难处理的问题,基于玉米芯、花生壳和铁屑,分别构造了1#(玉米芯)、2#(花生壳)、3 #(铁屑+玉米芯)、4#(铁屑+花生壳)动态柱实验模型,研究了生物质材料及其与铁屑协同处理玛瑙染色废水中Cr(Ⅵ)、SO42-、H+的效果和机理.结果表明,铁屑+玉米芯、铁屑+花生壳动态柱对Cr(Ⅵ)、SO42-的平均去除率分别为95.97％、96.42％和72.17％和59.55％,高于玉米芯、花生壳动态柱的89.67％、90.74％和39.00％、28.73％的平均去除率,且具有较强的抗污染负荷变化和一定的pH值提升的能力.对比分析可见,经过铁屑强化的生物质动态柱对Cr(Ⅵ)、SO42-、H+有更好、更稳定的去除效果.     

The sea–air exchange of mercury (Hg) in the marine boundary layer of the Augusta basin (southern Italy): Concentrations and evasion flux

The first attempt to systematically investigate the atmospheric mercury (Hg) in the MBL of the Augusta basin (SE Sicily, Italy) has been undertaken. In the past the basin was the receptor for Hg from an intense industrial activity which contaminated the bottom sediments of the Bay, making this area a potential source of pollution for the surrounding Mediterranean. Three oceanographic cruises have been thus performed in the basin during the winter and summer 2011/2012, where we estimated averaged Hg_atm concentrations of about 1.5 ± 0.4 (range 0.9–3.1) and 2.1 ± 0.98 (range 1.1–3.1) ng m⁻³ for the two seasons, respectively. These data are somewhat higher than the background Hg_atm value measured over the land (range 1.1 ± 0.3 ng m⁻³) at downtown Augusta, while are similar to those detected in other polluted regions elsewhere. Hg evasion fluxes estimated at the sea/air interface over the Bay range from 3.6 ± 0.3 (unpolluted site) to 72 ± 0.1 (polluted site of the basin) ng m⁻² h⁻¹. By extending these measurements to the entire area of the Augusta basin (∼23.5 km²), we calculated a total sea–air Hg evasion flux of about 9.7 ± 0.1 g d⁻¹ (∼0.004 t yr⁻¹), accounting for ∼0.0002% of the global Hg oceanic evasion (2000 t yr⁻¹). The new proposed data set offers a unique and original study on the potential outflow of Hg from the sea–air interface at the basin, and it represents an important step for a better comprehension of the processes occurring in the marine biogeochemical cycle of this element.     

Chironomid mouthpart deformities as indicator of environmental quality: a case study in Lake Trasimeno (Italy)

The aim of the present study was to monitor mouthpart deformities of Chironomus plumosus (Insecta-Diptera) in Lake Trasimeno (2000-2010) in relation with sediment contamination by heavy metals, which is one of the main causes of deformity induction. In Lake Trasimeno, concentrations of heavy metals in the investigated littoral zone were low, in comparison with those of the central area. By contrast, the incidence of deformities was much higher in the littoral station (2006-2009) than in the central area. In the littoral zone, the deformities progressively decreased and by 2010 reached values similar to those observed in the central area (2000-2002, 2010). This decrease was mainly due to the reduction of severe deformities, thus indicating an environmental quality recovery of this littoral sector. Chemical analysis revealed that the higher incidence of deformities in the littoral zone was not caused by heavy metal contamination, unless they may have contributed to a joint action with other toxicants. The present study on Lake Trasimeno provided additional evidence that chironomid mouthpart deformities can be used in biomonitoring programs to evaluate sediment contamination by toxicants. Since mouthpart deformities may also be induced by compounds not included in routine chemical analyses, they may better reflect sediment quality than chemical analysis alone.