Experimental evidence for a significant contribution of cellulose to indoor aerosol mass concentration

An apartment bedroom located in a residential area of Aveiro (Portugal) was selected with the aim of characterizing the cellulose content of indoor aerosol particles. Two sets of samples were taken: (1) PM₁₀ collected simultaneously in indoor and outdoor air; (2) PM₁₀ and PM_2.5 collected simultaneously in indoor air. The aerosol particles were concentrated on quartz fibre filters with low-volume samplers equipped with size selective inlets. The filters were weighed and then extracted for cellulose analysis by an enzymatic method. The average indoor cellulose concentration was 1.01 ± 0.24 μg m^?3, whereas the average outdoor cellulose concentration was 0.078 ± 0.047 μg m^?3, accounting for 4.0% and 0.4%, respectively, of the PM₁₀ mass. The corresponding average ratio between indoor and outdoor cellulose concentrations was 11.1 ± 4.9, indicating that cellulose particles were generated indoors, most likely due to the handling of cotton-made textiles as a result of routine daily activities in the bedroom. Indoor cellulose concentrations averaged 1.22 ± 0.53 μg m^?3 in the aerosol coarse fraction (determined from the difference between PM₁₀ and PM_2.5 concentrations) and averaged 0.38 ± 0.13 μg m^?3 in the aerosol fine fraction. The average ratio between the coarse and fine fractions of cellulose concentrations in the indoor air was 3.6 ± 2.1. This ratio is in line with the primary origin of this biopolymer. Results from this study provide the first experimental evidence in support of a significant contribution of cellulose to the mass of suspended particles in indoor air.     

Bioreactor treatment of municipal solid waste landfill leachates: characterization of organic fractions

Quantitative and qualitative changes in organic matter were studied at different stages of treatment in a bioreactor designed to process leachates from a municipal solid waste landfill. The particulate matter (PM) and macromolecular fractions of the dissolved organic matter with solubility properties comparable to humic (acid-insoluble) and fulvic (acid-soluble) acid fractions (AI, AS, respectively) from the incoming black liquid, the bioreactor content, and the final processed effluent were isolated, quantified, and characterized by visible and infrared (IR) spectroscopies. The macromolecular signature either aliphatic (glycopeptides, carbohydrates) or aromatic (coinciding with infrared patterns of lignin, tannins etc.) enabled us to characterize the different organic fractions during the course of microbial transformation. The results reveal significant changes in the nitrogen speciation patterns within the different organic fractions isolated from the wastewater. The final increase in the relative proportions of nitrogen in the least aromatic AS fraction during microbial transformation could be related to protein formation inside the bioreactor. After biological treatment and ultrafiltration, the amount of organic matter was reduced by approximately 70%, whereas aromaticity increased in all fractions, indicating preferential elimination of aliphatic wastewater compounds. Most of the remaining fractions at the end of the process consisted of a yellow residue rich in low molecular weight AS fractions.     

Copper, zinc and lead speciation in salt marsh sediments colonised by Halimione portulacoides and Spartina maritima

Total concentrations and fractionation of Cu, Zn and Pb in seven operationally defined phases (exchangeable, carbonates, manganese oxides, organic complexes, amorphous iron oxides, crystalline iron oxides and residual) were determined in sediments colonised by the halophyte species Halimione portulacoides and Spartina maritima in a Tagus estuary salt marsh (Portugal). We aimed to determine whether the speciation of these metals was different in areas colonised by each halophyte. Higher concentrations of Cu, Zn and, in particular Pb, were found in the rhizosphere of S. maritima than in the root sediments of H. portulacoides. Geochemical fractionation of Cu, Zn and Pb in sediments of the salt marsh depended upon the metal, and for Zn and Pb clearly varied with depth and with the colonising species. The higher redox potential observed in sediments colonised by H. portulacoides may in part explain the observed differences in the speciation of Cu, Zn and Pb.     

Spatial relationships between nitrogen status and pitch canker disease in slash pine planted adjacent to a poultry operation

Pitch canker disease (Fusarium circinatum Nirenberg & O'Donnell) causes serious shoot dieback, reduced growth and mortality in pines found in the southern and western USA, and has been linked to nutrient imbalances. Poultry houses with forced-air ventilation systems produce nitrogen (N) emissions. This study analyzed spatial correlations between pitch canker disease and foliar, forest floor, soil, and throughfall N in a slash pine (Pinus elliottii var. elliottii Engelm.) plantation adjacent to a poultry operation in north Florida, USA. Tissue and throughfall N concentrations were highest near the poultry houses and remained elevated for 400 m. Disease incidence ranged from 57-71% near the poultry houses and was spatially correlated with N levels. Similarly, stem mortality ranged from 41-53% in the most heavily impacted area, and declined to 0-9% at distances greater than 400 m. These results suggest that nutritional processes exacerbate changes in disease susceptibility and expression in slash pine.     

Evaluation of optimal conditions for determination of low selenium content in shellfish samples collected at Todos os Santos Bay,Bahia, Brazil using HG-AFS

This work proposes a procedure for the determination of total selenium content in shellfish after digestion of samples in block using cold finger system and detection using atomic fluorescent spectrometry coupled hydride generation (HG AFS). The optimal conditions for HG such as effect and volume of prereduction KBr 10 % (m/v) (1.0 and 2.0 ml) and concentration of hydrochloric acid (3.0 and 6.0 mol L^?1) were evaluated. The best results were obtained using 3 mL of HCl (6 mol L^?1) and 1 mL of KBr 10 % (m/v), followed by 30 min of prereduction for the volume of 1 mL of the digested sample. The precision and accuracy were assessed by the analysis of the Certified Reference Material NIST 1566b. Under the optimized conditions, the detection and quantification limits were 6.06 and 21.21 μg kg^?1, respectively. The developed method was applied to samples of shellfish (oysters, clams, and mussels) collected at Todos os Santos Bay, Bahia, Brazil. Selenium concentrations ranged from 0.23?±?0.02 to 3.70?±?0.27 mg kg^?1 for Mytella guyanensis and Anomalocardia brasiliana, respectively. The developed method proved to be accurate, precise, cheap, fast, and could be used for monitoring Se in shellfish samples.     

Biological activities of the essential oil from the leaves of Lantana montevidensis (Spreng) Briq. in mice

Environment, Development and Sustainability - This work aimed to analyze the chemical composition and evaluate the anti-inflammatory and antinociceptive properties of the essential oil obtained...     

Does energy efficiency and trade openness matter for energy transition? Empirical evidence for countries in the Organization for Economic Co-operation and Development

Environment, Development and Sustainability - An energy transition is currently underway around the world, in response to the objectives laid out by international agreements. Since the Kyoto...