Adsorption of cadmium on carbonaceous adsorbents developed from used tire rubber

Carbonaceous adsorbents (CAs) are developed from used tire rubber (UTR) and tested as adsorbents of Cd(2+) in aqueous solution. In the preparation of the CAs, UTR was treated thermally at 400-900 °C for 2 h in N(2) and at 850 °C for 2 h in steam. Concentrated NaOH, HCl, H(2)SO(4), HNO(3) and H(2)O(2) solutions were also used. UTR and H900 (i.e. UTR pyrolyzed at 900 °C) were treated with O(3) at 25 °C for 1 h and with air at 250 °C for 1 and 24 h. CAs were characterized texturally by N(2) adsorption at -196 °C, mercury porosimetry, and density measurements. The surface groups were analyzed by FT-IR spectroscopy. Using the batch method, the adsorption process of Cd(2+) was studied mainly from the kinetic standpoint at various pH values of the adsorptive solution. Significant porosity developments are achieved only when UTR is heat-treated, in particular in steam. However, the variety and concentration of surface groups are low in CAs. This is so even for CAs prepared using oxidizing agents as strong as O(3) and H(2)O(2), which has been associated with a lack of available or accessible surface active sites for oxidation in UTR and H900, respectively. Thermal and thermal-chemical treatments are usually more effective than chemical treatments to increase the adsorption of Cd(2+) in aqueous solution. The adsorption process of Cd(2+) is first fast and then much slower. Adsorption-time data fit better to a pseudo-second order kinetic equation than to a pseudo-first order kinetic equation. The extent to which the adsorption process occurs is strongly dependent on the pH of the Cd(2+) solution, being larger at pH 4.6 or 7.0 according to the adsorbent.     

Bioaccumulation Dynamic by Crassostrea gigas Oysters of Viruses That Are Proposed as Surrogates for Enteric Virus Contamination in Environmental Samples

Food and Environmental Virology - Oysters are filter-feeders and retain sewage-derived pathogens in their organs or tissues. Since most enteric viruses involved in outbreaks cannot grow in cell...     

Heavy metals and metalloid levels in the tissues of yellow-legged gulls (Larus michahellis) from Spain: sex,age, and geographical location differences

Environmental Science and Pollution Research - In the present study, mercury (Hg), cadmium (Cd), lead (Pb), selenium (Se), and arsenic (As) were measured in liver, kidney, and feathers of adult,...     

Determination of inorganic and organic priority pollutants in biosolids from meat processing industry

The biosolids (BS) generated in the wastewater treatment process of a meat processing plant were monitored and the priority pollutant content was characterized. The trace metal and organic pollutant content – polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) – were determined quantitatively and compared to guideline limits established by the US EPA and EU. PCBs were not detected in the solid samples, while trace metals, PAHs and PCDD/PCDF were detected in concentrations below the limits established by international standards. Toxic equivalent factors were evaluated for the biosolids, and the results proved that these wastes can be safely deposited on land or used in combustion/incineration plants. Since no previous data were found for meat processing waste, comparisons were made using municipal sewage sludge data reported in the literature. Since, this report monitored part of the priority pollutants established by the US EPA for meat and poultry processing wastewater and sludge, the results verified that low pollution loads are generated by the meat processing plant located in the southern part of Brazil. However, the BS generated in the treatment processes are in accordance with the limits established for waste disposal and even for soil fertilizer.     

EU-28’s progress toward the 2020 renewable energy share: a club convergence analysis

Environmental Science and Pollution Research - This paper assesses the convergence of the EU-28 countries toward their common goal of 20% in the renewable energy share indicator by year 2020. The...     

Territorial Recognition and Control of Changes in Dynamic Rural Areas: Analysis of the Naturbanization Process in Andalusia,Spain

This paper analyses new dynamics in rural areas of Andalusia belonging to protected environments. These dynamics relate to demographic developments that have taken place over the past 20 years, and their repercussions on changes in the use of land and regional planning in a wider context. The author calls this process 'naturbanization', building on the work of Berry and Champion on the concept of counterurbanization. Whilst most of the work on demographic movements and restructuring in rural areas is based on the trends set by city dwellers, this work aims to show the importance of environmental conditions on human behaviour and how this can have medium and long-term repercussions on the population dynamics of rural areas in Andalusia. The main results of this study show clear evidence of a nature urbanization process, as measured by a relative population development, in rural areas where protected natural areas are present. However, there are also clear differences in the population growth rates that support the presence of a naturbanization process between natural parks. In the protected natural areas situated in inland locations, population growth rates have generally been lagging behind while the protected areas situated nearer to the coast have proved to be more attractive to migration and have experienced a positive population development in the 1981‐2001 period. Apparently, the presence of protected nature is not the only factor determining the attractiveness of a rural area as a place to live. The naturbanization in rural areas can have negative implications for the ecological, landscape and social values of rural areas and therefore needs careful policy attention.     

Multiple exposure pathways and health risk assessment of selenium for children in a coal mining area

Environmental Science and Pollution Research - Selenium (Se) presents a dual role to human body, harmful or beneficial, depending on its concentration. The exposure to this element has been...     

Quantification and composition analysis of plastic pollution in riverine beaches of the lower Paraná River,Argentina

Environmental Science and Pollution Research - Plastic pollution and the numerous consequences it has on aquatic life have become a huge concern in recent years. While many studies have been...