Evaluation of Pb (II) biosorption utilizing sugarcane bagasse colonized by <Emphasis Type="Italic">Basidiomycetes</Emphasis>

The contamination of water resources by metallic ions is a serious risk to public health and the environment. Therefore, a great emphasis has been given to alternative biosorption methods that are based on the retention of aqueous-solution pollutants; in the last decades, several agricultural residues have been explored as low-cost adsorbent. In this study, the ability of Pb (II) biosorption using sugarcane bagasse modified by different fungal species was evaluated. The presence of carbonyl, hydroxyl, and carboxyl groups in the biosorbent was observed by spectroscopy in the infrared region. By scanning electron microscopy, changes in the morphology of modified material surfaces were observed. The highest adsorption capacity occurred at pH 5.0, while the shorter adsorbate-adsorbent equilibrium was at 20 min, and the system followed the pseudo-second-order model. The maximum biosorption in isotherms was found at 58.34 mg g^?1 for modified residue by Pleurotus ostreatus U2-11, and the system followed the Langmuir isotherm. The biosorption process was energetically spontaneous with low desorption values. This modification showed great potential for filters to remove Pb (II) and provide the preservation of water resources and animal health.     

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.     

Altered physiology, cell structure, and gene expression of Theobroma cacao seedlings subjected to Cu toxicity

Seedlings of Theobroma cacao CCN 51 genotype were grown under greenhouse conditions and exposed to increasing concentrations of Cu (0.005, 1, 2, 4, 8, 16, and 32 mg Cu L^?1) in nutrient solution. When doses were equal or higher than 8 mg Cu L^?1, after 24 h of treatment application, leaf gas exchange was highly affected and changes in chloroplasts thylakoids of leaf mesophyll cells and plasmolysis of cells from the root cortical region were observed. In addition, cell membranes of roots and leaves were damaged. In leaves, 96 h after treatments started, increases in the percentage of electrolyte leakage through membranes were observed with increases of Cu in the nutrient solution. Moreover, there was an increase in the concentration of thiobarbituric acid-reactive substances in roots due to lipid peroxidation of membranes. Chemical analysis showed that increases in Cu concentrations in vegetative organs of T. cacao increased with the increase of the metal in the nutrient solution, but there was a greater accumulation of Cu in roots than in shoots. The excess of Cu interfered in the levels of Mn, Zn, Fe, Mg, K, and Ca in different organs of T. cacao. Analysis of gene expression via RTq-PCR showed increased levels of MT2b, SODCyt, and PER-1 expression in roots and of MT2b, PSBA, PSBO, SODCyt, and SODChI in leaves. Hence, it was concluded that Cu in nutrient solution at doses equal or above 8 mg L^?1 significantly affected leaf gas exchange, cell ultrastructure, and transport of mineral nutrients in seedlings of this T. cacao genotype.     

The electro-oxidation of tetracycline hydrochloride in commercial DSA® modified by electrodeposited platinum

Environmental Science and Pollution Research - Tetracycline hydrochloride (TCH) electro-oxidation by commercial DSA® and commercial DSA® modified by platinum electrodeposition was...     

Human and crab exposure to mercury in the Caribbean coastal shoreline of Colombia: impact from an abandoned chlor-alkali plant

Human hair samples from male and female people aged 6-85 years, as well as muscle of crabs (Callinectes sapidus and Callinectes bocourti) were collected from different fishing places along the Caribbean coastal shoreline of Colombia and analyzed for total mercury (T-Hg) in order to establish the impact of mercury-polluted sediments in Cartagena bay on the ecosystem. Hair T-Hg in inhabitants varied between 0.1 and 21.8 microg/g, with average and median of 1.52 microg/g and 1.1 microg/g, respectively. Differences between sampling locations were significant (P<0.01) and median values decreased in the order: Ca?o del Oro (1.5 microg/g)相似文献   

Perfluorooctanesulfonate and related fluorochemicals in biological samples from the north coast of Colombia

Perfluorinated compounds are widespread pollutants of toxicological importance that have been detected in environmental matrices. However, little is known on their distribution in South America. In this study, distribution of perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexanesulfonate (PFHxS), and perfluorooctanesulfonamide (PFOSA) was determined in the bile of mullet, Mugil incilis, and in tissues of pelicans (Pelecanus occidentalis) collected from North Colombia. Analysis was performed by HPLC mass spectrometry after ion-pair extraction. PFOS was found in all bile samples and PFOA and PFHxS were detected at lower frequency. Average concentrations of PFOS, PFOA, and PFHxS in bile of fish from Cartagena Bay, an industrialized site, and Totumo marsh, a reference site, were 3673, 370, 489 and 713, 47.4, 1.27 ng/mL, respectively. PFOS concentrations in pelican organs decreased in the order of spleen>liver>lung>kidney>brain>heart>muscle. These results suggest, for the first time, that perfluorinated compounds are also found in wildlife from Latin American countries.     

Effect of salinity on hemolymph calcium concentration during the molt cycle of the prawn Penaeus monodon

Prawns (Penaeus monodon) were obtained from ponds in Iloilo, Philippines, in 1984 and 1985 and maintained in salinities from 8 to 44. Total hemolymph calcium was largely affected by molt stage and less so by salinity. A sharp, transient increase in hemolymph calcium occurred 3 to 6 h postmolt, followed by an equally rapid decrease from 6 h postmolt to intermolt. This biphasis response was limited to prawns in 8, 20 and 32S; in 44S, hemolymph calcium remained the same throughout the sampling period. Peak concentrations of total calcium were greater in low (8 and 20S) than in high salinities. Salinity had no effect on the duration of molt cycle nor on time of occurrence of molt. Almost half of molting incidents occurred between 18.01 and 0.00 hrs, and one-third between 0.01 and 06.00 hrs.     

Do national levels of individualism and internal locus of control relate to well‐being: an ecological level international study

Data were collected from managers in 24 nations/territories on work locus of control (LOC), individualism–collectivism (I–C), and well‐being (job satisfaction, absence of psychological strain, and absence of physical strain). There were significant mean differences across samples on all five of these measures, and consistent with our hypothesis, at the ecological or sample mean level well‐being was associated with an internal locus of control. However, contrary to our hypothesis, well‐being was not associated with I–C, despite a strong correlation between I–C and LOC. Findings at the ecological level were consistent with the literature concerning the salutary effects of control on well‐being. Copyright © 2001 John Wiley & Sons, Ltd.     

The Orange-Brown Patina of Salisbury Cathedral (West Porch) Surfaces: Evidence of its Man-Made Origin (5 pp)

Goal, Scope and Background In this paper, we attempt to elucidate the composition and origin of the orange patina on the surfaces of the West-Porch of Salisbury Cathedral by comparison to other known patinas: (i) the orange-brown patina on the marble surfaces of the Acropolis in Athens and the Arch of Titus in Rome whose analyses have shown very high amounts of phosphates, and generally amino acids from animal-skin glue or other protein binders; (ii) the phosphated patinas which also contain oxalates, found in 1996 on Catalonian calcareous sandstones and in the calcareous dolomites of the Monastery of Silos, Spain, whose origin is either the application of calcium caseinate, or egg yolk and animal glue; and (iii) the patinas with only oxalates found in some of Verona's monuments (St Zeno) and Spanish sites as in the Monastery of Guadalupe and Cuenca cathedral, formed either by the mineralization of algal filaments or by biological reactions yielding oxalate from yolk egg (added to stone as part of preservative empirical treatments). Methods In the winter of 2003, the West-Porch of Salisbury Cathedral received conservation works, but the old patina was not entirely removed. This fact has allowed us to collect the samples for its study. The IR spectra were registered with a Golden Gate ATR Mk II system using attenuated total reflectance Fourier transform infrared (ATR/FTIR) spectrometry. Mineral composition was determined by XRD (Philips PW 1710 spectrometer with Cu tube), whereas major and trace elements analyses were performed by XRF (Philips PW1480 PW). Microscopy examination was performed on a Leica M655 microscope. Phosphate, oxalate, calcium and sulphate contents were analysed by usual chemical methods. Results ATD-FTIR spectra of the Salisbury's patina exhibit peaks at 2361, 2341 and 671 cm–1 (assigned to phosphates); 3410, 1680, 1620, 1122 and 602 cm–1 (assigned to sulphates); and 1447/1437 and 876 cm–1 (attributed to carbonates). The little peaks at 1620 and 798 cm–1 could be assigned to oxalates. XRD and XRF have led to identify the carbonates, phosphates and sulphates as pertaining to the species dolomite, hydroxyapatite and gypsum, respectively. Oxalates are detected only in small amounts by chemical analyses but wewellite and weddellite have not been well identified. The interface between the patina and the calcareous dolomite is very uneven and full of cavities in certain cases, but well-defined and rather smooth in other cases. In accord with the very small amounts of the oxalates found, remnants of micro-organisms are not detected in the patinas. Discussion The Salisbury's patina is a composite material formed by particulates and matrix constituents. Regarding the patina particulate, e.g. animal bones, it is necessary to refer to the apatite phase composition. The bone mineral contains 4–8 wt % of carbonate in animal body and its presence in the apatite phase is advantageous as it increases the mechanical strength. We think that FTIR bands at around 1440 and 876 cm–1 arise from vibration of CO32– ions, but not necessarily from the limestone. They could be attributed to carbonated hydroxyapatite through the substitution of groups PO43– for CO32– in the lattice of hydroxyapatite. Concerning the matrix and also from the FTIR spectra, the absence of specific bands of the following species: proteins (3350–3225, 1660, 1550–1535, 1270–1230 and 620 cm–1), oils (1778, 1738 and 1051 cm–1), bee waxes (3000, 1470, 720–730 and 1700 cm–1) and aged egg-yolk (2954, 2920, 2850, 1650, 1549, 1465 and 1240 cm–1) had led us to exclude these usual binders. On the other hand, the amount of sulphates in the paste that covers the walls of the Salisbury's Cathedral is excessively high (above 20% in weight) to consider it as a biotransformation product of calcium oxalate from fungal biofilms. Consequently, we must think that the gypsum found in the samples has a man-made origin (it was deliberately added as part of a protective paste) and that it is the matrix searched for. Thus, we deduce that the patina of Salisbury's Cathedral is a special stucco made mixing plaster with powdered bone (the colour of the bones is the same that it exhibits in the patina), low quantities of an uncharacterized binder (collagen, possibly) and water. Conclusion We believe that the patina of the Salisbury's Cathedral is a variant of the Greco-Latin empirical protective treatment that included bone as a hardening material. Nevertheless, we also think that the presence of the bones in the paste could be related to an aesthetical intention: gaining a warm tone for the original stone through the ochre colour of the bones. Recommendation and Perspective Our results have been an excuse to contribute to the controversy started at the 80's on the origin of orange-brown patinas observed on stone surfaces of Greco-Latin and medieval monuments. There are two major theories on provenance: biological vs. man-made. In Salisbury Cathedral, neither of them has been proven through scientific evidence as yet. Our opinion is that Salisbury patina can be classified into the man-made group.