Enhanced biological nitrogen and phosphorus removal from sewage driven by fermented glycerol: comparative assessment between sequencing batch- and continuously fed-structured fixed bed reactor

Environmental Science and Pollution Research - The nutrient biological removal from sewage, especially from anaerobic reactor effluents, still represents a major challenge in conventional sewage...     

Trust via disasters: the case of Chile's 2010 earthquake

Chile has a long‐standing history of natural disasters and, in particular, earthquakes. The latest big earthquake hit Chile on 27 February 2010 with a magnitude of 8.8 on the Richter scale. As an event that had a profound impact on significant portions of the population, the earthquake could theoretically have served to build trust by promoting new trust networks through the enhancement of distant family ties and the interaction between affected neighbours. This study offers an empirical analysis of this theory in the Chilean case. It finds that if initial social capital is very low (thus allowing for post‐disaster looting and violence), then the impact of the trust‐increasing effect is smaller. It also shows that the effect of the disaster was not transitory, but that it persisted and actually increased over time.     

High NOx levels and lack of ozone in downtown Caracas

An evaluation of the NO, NO₂ and O₃ concentrations in downtown Caracas atmosphere at two different heights (1.5 and 56 m ) during the dry and wet season was performed.The qualitative variation of NO and NO₂ concentrations throughout the day was the same for all conditions. The profiles are explained considering the automobile emissions and the fates by photochemical reactions and dispersion. The daily mean averages for NO_x exceed all available air quality standards, making the downtown Caracas air polluted with these compounds at harmful levels.The O₃ concentrations are lower than the natural background levels practically all day long for all conditions. This lack of O₃ is explained mainly by the very high continuous NO emissions occuring in Caracas. NO reacts very fast with O₃ consuming all the O₃ produced by photochemical reactions. Possible health implications of the low O₃ levels are pointed out.     

Chemometric data analysis application to Sparus aurata samples from two offshore farming plants along the Apulian (Italy) coastline

The levels of polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), dioxin-like polychlorobiphenyls (DL-PCBs), non-dioxin-like polychlorobiphenyls (NDL-PCBs), and polybromodiphenyl ethers (PBDEs) in fish collected from two marine offshore farming plants were determined. Each sample was constituted by specimens of the same size collected at the same time in four different seasons along the farming year. The feeds given were of industrial origin and the plants were positioned in two different sites respectively exposed to different environmental characteristics. A chemometric approach was applied to interpret the subtle differences observed in fish body burdens across the three chemical groups taken into consideration. The approach consisted in a stepwise multivariate process including a hierarchical cluster analysis (CA) and a linear discriminant analysis (DA). The two main clusters determined by CA were subjected to the canonical DA, backward and forward selection procedures to select the best discriminative functions. A clear temporal and spatial discrimination was found among the samples. Across the three chemical groups, the monthly separation seemed to depend on the growth process and the main exposure was due to the feed. In addition, the two plants differed significantly from the environmental point of view and the most important discriminating group of chemicals were the NDL-PCBs. The approach resulted really effective in discriminating the subtle differences and in individuating suggestions to improve the quality of culturing conditions.     

Assessment of a process to degrade metal working fluids using Pseudomonas stutzeri CECT 930 and indigenous microbial consortia

The development of a novel biological process to treat metal working fluids (MWFs)-containing effluents at bioreactor scale was pursued in this work. The bacteria Pseudomonas stutzeri CECT 930 was investigated for the first time as an alternative agent for MWF degradation. An adequate medium design and mixing and aeration system, as well as an appropriate microorganism proved to be crucial for reaching high levels of degradation by P. stutzeri and by an indigenous consortium (about 70% and 50% of reduction in total petroleum hydrocarbon content in less than 2 wk, respectively). Additionally, as there is no information in literature trying to kinetically characterize an MWF-polluted effluent degradation process, all the experimental data were fitted to logistic and Luedeking and Piret models, that allowed to elucidate the growth-associated character of the biodegradation process.     

Temporal evolution of polycyclic aromatic hydrocarbons (PAHs) in sludge from wastewater treatment plants: comparison between PAHs and heavy metals

This paper presents results on the presence and temporal variability of the 16 PAHs recommended by the EPA in primary, secondary and digested sewage sludge over a year. The sewage sludges originated from the Guadalete wastewater treatment plant (WWTP) site in Jerez de la Frontera (Cádiz, Spain). These organic pollutants have been extracted from the sewage sludge by microwave energy. High performance liquid chromatography coupled with diode array (HPLC-DAD) or fluorescence (HPLC-FL) detectors have been used. The results showed that total PAHs concentration varied between 1,945 ng g(-1) dry matter (DM) for primary sludges collected in March and 10,100 ng g(-1) DM for primary sludge collected in June. Generally, concentrations of PAHs were higher in compost and digested sludge than in fresh one. On the other hand, the highest concentration of PAHs were found on summer. This thing is associated to the traffic increase from inland zones to the coast (Jerez de la Frontera is very near to beaches). Finally, this paper present a comparative study of the American an European legislation concluding that the limits of concentrations established are not exceeded. In addition heavy metals were analysed. The origin of PAHs and heavy metals seems to be different.     

Growth and green income: evidence from mining in Chile

This paper estimates the true economic income for the Chilean mining sector, using the welfare foundations for the usual net domestic product (NDP) income measure of the traditional National Accounts System (NAS) provided by [Weitzman, M., 1976. On the welfare significance of national product in a dynamic economy. Quarterly Journal of Economics. 90, 156–162; Weitzman, M., 2000. The linearised Hamiltonian as comprehensible NDP. Environment and Development Economics. 5, 55–68]. The total depletion of natural capital caused by mining is calculated by estimating, on the one hand, the depreciation of resources (using the net price approach) and, on the other, the environmental costs provoked by mining activity. The results show that, correcting the usual GDP measure for man-made capital depreciation plus the total loss of natural capital, the standard mining GDP measure of the NAS overestimates by 31–36% the economic income generated by Chile's mining sector during the period 1985–1996.     

A review on molecular topology: applying graph theory to drug discovery and design

Molecular topology is an application of graph theory and statistics in fields like chemistry, biology, and pharmacology, in which the molecular structure matters. Its scope is the topological characterization of molecules by means of numerical invariants, called topological indices, which are the main ingredients of the molecular topological models. These are statistical models that are instrumental in the discovery of new applications of naturally occurring molecules, as well as in the design of synthetic molecules with specific chemical, biological, or pharmacological properties. In this review, we focus on pharmacology, which is a novel field of application of molecular topology. Besides summarizing some recent developments, we also seek to bring closer this interesting biomedical application of mathematics to an interdisciplinary readership.

在全球化的世界经济中中小企业所面临的挑战

中小企业越来越期望对他们自己环境和社会影响负起责任来(正如跨国公司所做的那样),理解不同利益相关者的兴趣和要求,并且通过更大的透明度证明自己的行为是负责任的.许多要素既可以阻碍也可以驱动较小企业推动法人环境与社会责任战略的实施.为了克服实施这类战略的障碍,适合小型或中等企业需要的方法才可用.在某些领域.会同跨国公司这个关键的利益相关者团体一起,这方面的促进努力已经行动起来了.