Degradation of phenols in olive oil mill wastewater by biological,enzymatic, and photo-Fenton oxidation

Background, aim, and scope  

Olive oil mill wastewater (OOMW) environmental impacts minimization have been attempted by developing more effective processes, but no chemical or biological treatments were found to be totally effective to mitigate their impact on receiving systems. This work is the first that reports simultaneously the efficiency of three different approaches: biological treatment by two fungal species (Trametes versicolor or Pleurotus sajor caju), enzymatic treatment by laccase, and chemical treatment by photo-Fenton oxidation on phenols removal.     

Solid-phase extraction and capillary electrophoresis determination of phenols from soil after alkaline CuO oxidation

Alkaline CuO oxidation has been used on molecular-level analyses of phenols from organic matter in the last decades. This method, originally developed by Hedges and Ertel [Hedges, J.I., Ertel, J.R., 1982. Characterization of lignin by gas capillary chromatography of cupric oxide oxidation products. Anal. Chem. 54, 174-178] has several drawbacks that have limited is wider utilization. In this paper, we propose a modification of the method using a solid-phase extraction (SPE) instead of a liquid-liquid extraction. The SPE procedure using C18 cartridges was optimized to obtain high recoveries. The sequential elution with acetonitrile and methanol was found to be the most appropriate procedure. Recoveries of the 12 phenols in individual standard solutions ranged from 84% to 113% with relative standard deviation (RSD) lower than 12%. Experiments with a mixed standard solution highlighted the competition between the different phenols for the adsorbing sites. Recoveries decreased with polarity, reaching 30% for p-hydroxybenzoic acid when present at a concentration of 2.5 x 10(-3)M. A sample soil subjected to a CuO oxidation was used to test the reproducibility of the SPE method and good results were achieved, RSD ranged between 0.4% and 28.3%. The performance of the CE method was also evaluated by correlation coefficients (higher than 0.9920), linearity (higher than 99.902%) and limit of detection (ranging from 2.64 x 10(-6) to 1.25 x 10(-5)M). SPE procedure presents several advantages such as fast sample preparation, good recoveries, good accuracy, low sample handling and safety improvement due to reduced solvent/sample exposure and glassware management.     

The cost of floods in developing countries’ megacities: a hedonic price analysis of the Jakarta housing market,Indonesia

Environmental Economics and Policy Studies - Although many megacities in developing countries experience floods annually that affect a large number of people, relatively few empirical studies have...     

Phytotoxicity,cytotoxicity, and in vivo antifungal efficacy of chitosan nanobiocomposites on prokaryotic and eukaryotic cells

Environmental Science and Pollution Research - Chitosan (CS) nanosystems have potential applications for the control of microorganisms in the medical, environmental, and agrifood fields. In vivo...     

Application of Reproduction Technologies to the Conservation of Genetic Resources

Abstract: Maintaining the levels of genetic variability in captive populations of endangered species is an important objective of conservation biology. Because of the generally low sizes of captive populations, genetic drift is the main cause of loss of diversity. Several simple management rules, such as equalization of contributions from parents to the next generation, are recommended for minimizing genetic drift, but it cannot be removed completely because of the unavoidable random segregation of heterozygotes. Recent advances in reproductive technology, particularly developed for mammals, are now making a reality of the possibility of using more than one cell from a single meiosis in reproduction. With this technology it is possible to reduce or even completely cancel the genetic drift caused by segregation of heterozygotes. We evaluated the theoretical benefits of the use of such technologies to conservation biology. The effective population size can be increased enormously and, consequently, the amount of drift can be greatly reduced if manipulations in reproduction are made.     

Distribution of Heavy Metals in Surface Sediments from an Antarctic Marine Ecosystem

The concentrations of lead, cadmium, copper,chromium, iron, manganese and zinc in surfacesediments collected from Potter Cove, in the 25de Mayo Island (King George Island), Antarctica, andits drainage basin, were measured by atomic absorptionspectroscopy. The obtained results were use todetermine the areal and vertical distribution of themetals of in the Cove and potential sources of thesemetals to this environment. The geochemical datasuggest that most of the metals found in Potter Coveconstitute a redistribution of autochthonous materialswithin the ecosystem. Therefore, the metalconcentrations can be considered to be present atnatural background levels in surface sediments.     

Airborne particulate-associated polyaromatic hydrocarbons,n-alkanes,elemental and organic carbon in three European cities

Total suspended particulate (TSP) samples were collected weekly over a period of one year at four European sites during 1995/6. Two sites were in London-a Central London site (CL, St Paul's Cathedral) and a suburban North London site (NL, Bounds Green); the other two sites were in Porto, Portugal and Vienna, Austria. TSP was collected using a low volume sampler. Organic carbon (OC) and elemental carbon (EC) concentrations were measured using a thermal-optical carbon analyser. Parallel samplers collected TSP for subsequent GC-MS analysis of thirty-nine combustion-associated organic compounds; 16 polyaromatic hydrocarbons (PAHs) and 23 n-alkanes. OC and EC correlate well at all sites (r2 = 0.39-0.65), although the London inter-site correlations were low, suggesting that local sources of OC and EC have a significant influence on local concentrations. Concentrations do not vary widely across the four urban sites, despite the significant differences in urban characteristics. Seasonal patterns of OC:EC ratios were similar at the London and Vienna sites, with highest ratios in autumn and winter, and annual mean OC:EC ratios were identical at these sites. The Carbon Preference Index (CPI) indicated vehicle emissions to have a stronger influence over particulate concentrations at the Vienna and central London sites; there was a stronger biogenic signature in north London and Porto. In addition, two PAH compounds (pyrene and fluoranthene) previously associated with diesel exhaust, were correlated with OC and EC concentrations at the London and Vienna sites.     

Measurements of carbonyls in a 13-story building

BACKGROUND, AIM AND SCOPE: Formaldehyde and acetaldehyde are emitted by many mobile and stationary sources and secondary aldehydes are intermediates in the photo-oxidation of organic compounds in the atmosphere. These aldehydes are emitted indoors by many materials such as furniture, carpets, heating and cooling systems, an by smoking. Carbonyls, mainly formaldehyde and acetaldehyde, have been studied because of their adverse health effects. In addition, formaldehyde is a suspected carcinogen. Therefore, the concentrations of formaldehyde and acetaldehyde were determined to assess the inhalation exposure doses to carbonyls for people who work in a 13-story building and in order to evaluate the cancer hazard. METHODS: Carbonyl compounds in indoor and outdoor air were measured at a 13-story building located in Mexico City. The mezzanine, fifth and tenth floors, and the third level-parking garage were selected for sampling. Samples were collected in two sampling periods, the first from April 20 to 29, 1998 and the second from December 1 to 20, 1998. Carbonyls were sampled by means of DNHP-coated cartridges at a flow rate of 1 l min(-1) from 9:00 to 19:00 hours, during 2-hour time intervals and analyzed by HPLC with hours, during 2-hour time intervals and analyzed by HPLC with UV/VIS detection. RESULTS: Mean carbonyl concentrations were highest in the 3rd level-parking garage, with the formaldehyde concentration being the highest ranging from 108 to 418 microg m(-3). In working areas, the highest carbonyl arithmetic mean concentrations (AM) were observed on the 5th floor. Acetone and formaldehyde concentrations were highest in April ranging from 161 to 348 microg m(-3) (AM = 226) and from 157 to 270 microg m(-3) (AM = 221), respectively. Propionaldehyde and butyraldehyde were present in smaller concentrations ranging from 2 to 25 and 1 to 28 microg m(-3), respectively, considering all the samples. Mean indoor/outdoor ratios of carbonyls ranged from 1.8 to 9.6. A reduction of inhalation exposure doses of 41% and 45% was observed in the fifth floor air after the air conditioning systems had been repaired. Formaldehyde and acetaldehyde concentrations were higher in smoking environments. CONCLUSION: Indoor carbonyl concentrations were significantly greater than outdoor concentrations. Tobacco smoke seems to be the main indoor source of formaldehyde. After the air conditioning system was maintained and repaired (as was recommended), an important reduction in the emission of formaldehyde and acetaldehyde was achieved on all floors, except for the 3rd level parking garage, thereby reducing the inhalation exposure doses. RECOMMENDATION: The results obtained in this research demonstrated that maintenance of air conditioning systems must be carried out regularly in order to avoid possible adverse effects on health. Additionally, it is mandatory that isolated smoking areas, with air extraction systems, be installed in every public building.