巴西戈亚斯州阿拉瓜亚河中亚马孙河巨龟(Podocnemis expansa)的巢穴布局

在旱季,亚马孙河巨龟(Podocnemis expansa)将巢穴修筑在河槽边缘和内部的广阔沙洲上.这些巢穴在某些沙滩上的某些具体地点的大量聚集表明巢穴位置的选择不是随机的,而是与一些地质状况有关,如沙洲边缘的倾斜度和砂质高台的存在.通向高台顶端的通道或斜坡结构的存在是巢穴位置选择的决定性因素.被侵蚀的以及陡峭的沙滩边缘阻碍了亚马孙河龟到达最理想的筑巢位置.随着时间的推移,沙滩形态的变化会改变巢穴的分布.     

A net water production model for ultrafiltration including flow direction reversal and chemically assisted backwashing.

Flow direction reversal (FDR) was proposed as a novel method to increase net water production (NWP) during cross-flow ultrafiltration. The design of the pilot-plant study allowed measurement of specific flux recovery after each chemically assisted backwash (BW) combined with FDR and after each FDR at the midpoint of each BW/FDR cycle. The percent recovery of specific flux was higher following FDR (55%) than combined BW and FDR (53%) at lower chemical dosages; however, the percent increase in specific flux recovery by FDR was much lower (20%) when the chemical dose was doubled. A mathematical model was developed to predict the NWP achieved by any combination ofBW/ FDR and FDR frequency. For example, the advantage of introducing FDR was demonstrated at the lower chlorine dose, whereby the percent increase in NWP by alternating 15-minute intervals of BW/FDR with FDR over BW/ FDR alone was 10% for 30-minute BW/FDR intervals and 2% for 15-minute BW/FDR intervals.     

Monitoring and modeling of long-term settlements of an experimental landfill in Brazil

Settlement evaluation in sanitary landfills is a complex process, due to the waste heterogeneity, time-varying properties and influencing factors and mechanisms, such as mechanical compression due to load application and creep, and physical–chemical and biological processes caused by the wastes decomposition. Many empirical models for the analysis of long-term settlement in landfills are reported in the literature. This paper presents the results of a settlement monitoring program carried out during 6 years in Belo Horizonte experimental landfill. Different sets of field data were used to calibrate three long-term settlement prediction models (rheological, hyperbolic and composite). The parameters obtained in the calibration were used to predict the settlements and to compare with actual field data. During the monitoring period of 6 years, significant vertical strains were observed (of up to 31%) in relation to the initial height of the experimental landfill. The results for the long-term settlement prediction obtained by the hyperbolic and rheological models significantly underestimate the settlements, regardless the period of data used in the calibration. The best fits were obtained with the composite model, except when 1 year field data were used in the calibration. The results of the composite model indicate settlements stabilization at larger times and with larger final settlements when compared to the hyperbolic and rheological models.     

Distribution coefficients of potentially toxic elements in soils from the eastern Amazon

The solid-solution distribution or partition coefficient (Kd) is a measure of affinity of potentially toxic elements (PTE) for soil colloids. Kd plays a key role in several models for defining PTE guideline values in soils and for assessing environmental risks, and its value depends on edaphic and climatic conditions of the sites where the soils occur. This study quantified Kd values for Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn from representative soil samples from Brazil’s eastern Amazon region, which measures 1.2 million km². The Kd values obtained were lower than those set by both international and Brazilian environmental agencies and were correlated with the pH, Fe and Mn oxide content, and cationic exchange capacity of the soils. The following order of decreasing affinity was observed: Pb?>?Cu?>?Hg?>?Cr?>?Cd?≈?Co?>?Ni?>?Zn.     

Catalytic combustion of soot over ceria-zinc mixed oxides catalysts supported onto cordierite

Modified substrates as outer heterogeneous catalysts was employed to reduce the soot generated from incomplete combustion of diesel or diesel/biodiesel blends, a process that harms the environment and public health. The unique storage properties of ceria(CeO2) makes it one of the most efficient catalysts available to date. Here, we proposed that ceria-based catalysts can lower the temperature at which soot combustion occurs; more specifically, from 610℃ to values included in the diesel exhausts operation range(300–450℃). The sol-gel method was used to synthesize mixed oxide-based catalysts(CeO2:ZnO); the resulting catalysts were deposited onto cordierite substrates. In addition, the morphological and structural properties of the material were evaluated by XRD, BET, TPR-H2, and SEM. Thermogravimetric(TG/DTA) analysis revealed that the presence of the catalyst decreased the soot combustion temperature by 200℃ on average, indicating that the oxygen species arise at low temperatures in this situation, promoting highly reactive oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy(DRS) showed that catalyst-impregnated cordierite samples efficiently oxidized soot in a diesel/biodiesel stationary motor: soot emission decreased by more than 70%.     

Degradation and decolorization of a biodegradable-resistant polymeric dye by chelator-mediated Fenton reactions

Chelator-mediated Fenton reactions (CMFRs) were used to decolorize a biodegradable-resistant polymeric dye (Poly R-478). Screening of different iron chelators was performed on Fe(3+)-reduction activity. All chelators showed Fe(3+)-reduction activity over a wide range of pH (2-7) and each mol of catecholate chelators (3,4-dihydroxiphenilacetic acid--DOPAC and 2,3-dihydroxibenzoic acid--DHBA) reduced about 5-6 moles of Fe(3+) whereas hydroxamate chelators (acetohydroxamic acid-AHA and desferrioxamine B-DFB) reduced Fe(3+) stoichiometrically. The most effective decolorization of Poly R-478 was achieved by CMFR using catecholate chelators. In addition, a 2(4) factorial design was performed with the aim of evaluating the effects of the variables considered in this study (pH, [DOPAC], [Fe(3+)] and [H(2)O(2)]) and optimizing the dye decolorization, using response surface methodology. Statistical analysis of results showed that, in the range studied, except for Fe(3+), all variables have a significant effect on dye decolorization. A second-order model is proposed to represent the Poly R-478 decolorization. At optimum conditions, complete decolorization of the dye (degradation of the chromophoric group) and also complete chemical degradation of the dye was observed.     

Comparison of European national legislation efficiency on the reduction of air pollutant emissions

Since 1995, the Institute for Environment and Development in Portugal has obtained >300 stack samples from various point sources of Portuguese industries. A coherent database was made with the collected results. The limit values fixed by several European legal documents consulted, Portuguese, Spanish, French, Italian, and Dutch emission legislation, were applied to the Institute for Environment and Development stack sampling inventory (from 1995 to 2000) to evaluate the efficiency of these standards in promoting the control and reduction of atmospheric pollutants emissions, especially regarding nitrogen oxides, sulfur dioxide, and particulate matter. The conclusion was that the original Portuguese legislation was not restrictive enough and not very efficient regarding emissions reduction. In contrast, the Dutch and Italian legislations are quite restrictive but very efficient concerning emission control for the three pollutants analyzed. One of the outcomes of this study was the publication of a new law in Portugal regulating the emissions of atmospheric pollutants. The strategy of this emissions control law follows the conclusions found in this study including the concept of a mass flow threshold and different approaches depending on source dimension.     

The issue of sustainability and disclosure. A case study of selective garbage collection by the Urban Cleaning Service of the city of Rio de Janeiro, Brazil - COMLURB

The Urban Cleaning Company of the City of Rio de Janeiro - COMLURB launched the Recycling Separation Center Project (Projeto Central de Separação de Recicláveis or CSR) in 2003. The objectives of the project were the adequate disposal of solid urban waste as well as the generation of employment and income. The COMLURB Project had economic, environmental and social facets, and the researchers sought to establish whether COMLURB had prepared reports that would enable evaluation of the investment made and the results obtained. In particular, the researchers sought to establish whether COMLURB financial statements set out the results of actions inherent to the CSR. We concluded from our analysis of the Project that the three elements of sustainability (social, environmental and economic), despite being fully present, were not adequately demonstrated. This study therefore proposes a model report with a view to enabling various information users to evaluate the results of the CSR Project.     

Promoting the use of environmental data collected by concerned citizens through information and communication technologies

Public participation within environmental monitoring may contribute to increasing the knowledge on the state of the environment at the same time it promotes citizens' involvement in environmental protection. However, the use of voluntary collected data is limited due to a lack of confidence in data collection procedures. Additionally, data quality is often unknown and the data are usually dispersed and non-structured. Information and communication technologies (ICT) may promote the use of voluntary collected data through the development of a collaborative system that incorporates tools and methodologies to facilitate data collection, access and validation. Furthermore, the use of ICT may promote public involvement within environmental monitoring, since it facilitates communication among all the stakeholders. This paper analyses the role of ICT in developing a system for environmental collaborative monitoring intending to promote the use of volunteer collected data. It starts by analysing the role of volunteers within environmental monitoring and continues analysing the potential of ICT to take advantage of the benefits of using data collected by citizens. A collaborative system that allows the public to express its knowledge on the state of the environment is described. Special emphasis is given to tools that explore non-traditional types of environmental data such as images, sounds and videos in association with spatial information. To illustrate the above mentioned concepts, a case study for beach quality monitoring developed within the Senses@Watch project, is described.     

137Cs in marine samples from the Brazilian southeastern coastal region

The present work presents the results of ¹³⁷Cs concentration in seawater, fish and sediments samples collect in 11 sampling points, crossing the Brazilian Southeastern coastal region, from Vitória (ES) to Santos (SP), on a routine basis from 1997 to 2002. This monitoring program was carried out by the Instituto de Radioproteção e Dosimetria (IRD/CNEN/MCT), in cooperation with the Instituto de Estudos do Mar Almirante Paulo Moreira (IEAPM/Brazilian Navy), aiming at determining artificial radionuclides in marine samples. Additionally to the ¹³⁷Cs results, ⁹⁰Sr concentrations in fish samples from 1998 to 2002 are also reported.The ¹³⁷Cs in seawater follows a lognormal distribution, with a geometric mean of 1.8 Bq m^-3 and a geometric standard deviation of 1.4 (n=54), decay corrected to June/2002. For ¹³⁷Cs levels in fish samples a geometric mean of 0.19 Bq kg⁻¹ and a geometric standard deviation of 2.9 (n=39), decay corrected to June/2002, with a range of 0.03 to 1.7 Bq kg⁻¹, were obtained. Based on the ¹³⁷Cs mean concentration in fish as well as in seawater, a transfer factor of 1 × 10² was calculated, which is quite in agreement with the recommended value found in the Safety Report Serie 19.