Photo-Fenton-assisted ozonation of p-Coumaric acid in aqueous solution

The degradation of p-Coumaric acid present in olive oil mill wastewater was investigated as a pretreatment stage to obtain more easily biodegradable molecules, with lower toxicity that facilitates subsequent anaerobic digestion. Thus, photo-Fenton-assisted ozonation has been studied and compared with ozonation at alkaline pH and conventional single ultraviolet (UV) and acid ozonation treatments. In the combined process, the overall kinetic rate constant was split into various components: direct oxidation by UV light, direct oxidation by ozone and oxidation by hydroxyl radicals. Molecular and/or radical ozone reaction was studied by conducting the reaction in the presence and absence of tert-butylalcohol at pHs 2, 7 and 9. Ozone oxidation rate increases with pH or by the addition of Fenton reagent and/or UV radiation due to generation of hydroxyl radicals, *OH. Hydrogen peroxide and ferrous ion play a double role during oxidation since at low concentrations they act as initiators of hydroxyl radicals but at high concentrations they act as radical scavengers. Finally, the additional levels of degradation by formation of hydroxyl radicals have been quantified in comparison to the conventional single processes and an equation is proposed for the reaction rate as a function of studied operating variables.     

Biodegradation of juvenoid diastereoisomers: radio-HPLC and MS analysis

Microbial degradation of two diastereoisomeric forms 2 and 3 of a selected juvenoid (insect juvenile hormone bioanalog), ethyl N-{2-{4-[(2-hydroxycyclohexyl)methyl]phenoxy}ethyl}carbamate was studied and the degradation products analyzed. Degradation experiments were performed using simple modeling under laboratory conditions. A Candida sp. strain T1, isolated from soil, was chosen as a biodegradation species. Radiolabeling of the studied compounds 2 and 3 was used in combination with radio-HPLC and MS analysis to increase the limits of detection, monitoring and isolation of trace quantities of the products of degradation and/or transformation. Resulting from the microbial processes using 2 or 3 as source compounds, three identical products (4-6) of their biodegradation were produced. Compound 2 also afforded two additional products (7, 8). Radio-HPLC analysis and separation, and subsequent MS analysis of the degradation mixtures resulted in identification of the degradation products. The degree and the rate of biodegradation of 2 and 3 were analyzed after 1, 3 and 7 days from the beginning of the experiment.     

Bioconversion of olive-mill dry residue by Fusarium lateritium and subsequent impact on its phytotoxicity

The present study investigated the ability of the non-pathogenic fungus Fusarium lateritium to either degrade or modify aromatic substances in olive-mill dry residue (DOR) and to reduce its phytotoxicity. The 80% reduction of ethylacetate extractable phenols in DOR colonized by the fungus for 20 weeks appeared to be due to polymerization reactions of phenol molecules as suggested by mass-balance ultrafiltration and size-exclusion chromatography experiments. Several lignin-modifying oxidases, including laccase, Mn-peroxidase and Mn-inhibited peroxidase were detected in F. lateritium solid-state cultures. Tests performed with tomato seedlings in soils containing 6% (w/w) sterilized non-inoculated DOR showed that the waste was highly phytotoxic. By contract, F. lateritium growth on DOR for 20 weeks led to a complete removal of the waste toxicity and to a higher shoot dry weight of tomato plants than that obtained in the absence of DOR.     

Healthy and happy: animal welfare as an integral part of sustainable agriculture

Good animal welfare is necessary if an agricultural system is to be sustainable. Although we have been concerned about the welfare of our animals since we first domesticated them and became dependent on their health and reproduction, this article focuses mainly on the development of the animal welfare debate since the 1960s. It presents animal welfare as a science that arose from society's concern about the way animals are kept. These moral and ethical concerns lead to it having a value framework that must also be taken into consideration. Different definitions of animal welfare, as well as examples of research, are presented and discussed in the light of developments in this area. For example, in recent years there has been an increased interest among consumers for animal-friendly products, as there has been for environment friendly products, and this has stimulated the move from experimental studies of animal welfare to its application in practice and to monitoring animal welfare on farms. Traditionally such measurements have been resource based, e.g. specifying the minimum amount of feeding space or the maximum stocking density, but now the trend is toward animal-based measures, such as the numberof lame animals, body condition, etc.     

Properties of pyrolytic chars and activated carbons derived from pilot-scale pyrolysis of used tires

Used tires were pyrolyzed in a pilot-scale quasi-inert rotary kiln. Influences of variables, such as time, temperature, and agent flow, on the activation of obtained char were subsequently investigated in a laboratory-scale fixed bed. Mesoporous pores are found to be dominant in the pore structures of raw char. Brunauer-Emmett-Teller (BET) surfaces of activated chars increased linearly with carbon burnoff. The carbon burnoff of tire char achieved by carbon dioxide (CO2) under otherwise identical conditions was on average 75% of that achieved by steam, but their BET surfaces are almost the same. The proper activation greatly improved the aqueous adsorption of raw char, especially for small molecular adsorbates, for example, phenol from 6 to 51 mg/g. With increasing burnoff, phenol adsorption exhibited a first-stage linear increase followed by a rapid drop after 30% burnoff. Similarly, iodine adsorption first increased linearly, but it held as the burnoff exceeded 40%, which implied that the reduction of iodine adsorption due to decreasing micropores was partially made up by increasing mesopores. Both raw chars and activated chars showed appreciable adsorption capacity of methylene-blue comparable with that of commercial carbons. Thus, tire-derived activated carbons can be used as an excellent mesoporous adsorbent for larger molecular species.     

Estimating catchment nutrient flow with the HBV-NP model: sensitivity to input data

The dynamic catchment model HBV-N has been further developed by adding routines for phosphorus transport and is now called the HBV-NP model. The model was shown to satisfactorily simulate nutrient dynamics in the R?nne? catchment (1,900 km2). Its sensitivity to input data was tested, and results demonstrated the increased sensitivity to the selection of input data on a subcatchment scale when compared with the catchment scale. Selection of soil and land use databases was found to be critical in some subcatchments but did not have a significant impact on a catchment scale. Although acceptable on a catchment scale, using templates and generalization, with regards to emissions from point sources and rural households, significantly decreased model performance in certain subcatchments when compared with using more detailed local information. A division into 64 subcatchments resulted in similar model performance at the catchment outlet when compared with a lumped approach. Adjusting the imported matrixes of the regional leaching of nitrogen, from agricultural land, against mean subcatchment water percolation did not have a significant impact on the model performance.     

Monitoring of the booster biocide dichlofluanid in water and marine sediment of Greek marinas

Dichlofluanid (N-dichlorofluoromethylthio-N'-dimethyl-N-phenylsulphamide) is used as booster biocide in antifouling paints. The occurrence of dichlofluanid and its metabolite DMSA (N'-dimethyl-N-phenyl-sulphamide) was monitored in seawater and marine sediment from three Greek marinas. Seawater and sediment samples were collected at three representative positions and one suspected hotspot in each marina and shipped to the laboratory for chemical analysis. As part of the project, an analytical method had been developed and validated. Furthermore, some additional experiments were carried out to investigate the potential contribution of paint particle bound dichlofluanid on the total concentration in the sediment. As expected, given its known high hydrolytic degradation rate, no detectable concentrations of dichlofluanid were measured in any of the seawater samples. DMSA was detected in seawater samples at very low concentrations varying from <3 ng l(-1) (LOD) to 36 ng l(-1). During method validation, it had already been demonstrated that dichlofluanid is unstable in sediment and can therefore only be determined as its metabolite DMSA. In a separate experiment, in which marine sediment was spiked with artificial paint particles containing dichlofluanid and then analysed according to the validated method, it was demonstrated that if there is any dichlofluanid originating from paint particles, this would be determined as DMSA. No DMSA was detected in any of the sediment samples. It could therefore be concluded that there were no significant concentrations of dichlofluanid in the sediment samples.     

Applicability of Fenton and H2O2/UV reactions in the treatment of tannery wastewaters

In this paper we evaluated the H2O2/UV and the Fenton's oxidation processes for the treatment of tannery wastewater under different experimental conditions. Efficiencies were judged by the amounts of organic substances degraded or eliminated under these treatment techniques. Daphnia magna and Vibrio fischeri were used to monitor toxicity. Organic compounds contained in the untreated and treated tannery wastewater were determined and identified using substance specific techniques. Gas chromatography-mass spectrometry (GC-MS) in positive electron impact (EI(+)) mode was applied to determine volatile organics. Atmospheric pressure ionization (API) mass (MS) and tandem mass spectrometry (MS-MS) coupled with flow injection analysis (FIA) or liquid chromatography (LC) were used to detect or identify polar organic pollutants. The experimental results indicated that both oxidation processes--H2O2/UV at pH 3 and Fenton at pH 3.5--are able to reduce TOC content by mineralisation of the organic compounds.     

Trace element concentrations in soils along urbanization gradients in the city of Wien, Austria

Urban soil is an important component of urban ecosystems. This study focuses on heavy metal contamination in soils of Wien (Austria) and results are compared to those for a few large European cities. We analysed the elemental contents of 96 samples of topsoil from urban, suburban and rural areas in Wien along a dynamic (floodplain forest) and a stable (oak–hornbeam forest) urbanization gradient. The following elements were quantified using ICP-OES technique: Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Pb, P, S and Zn. For heavy metals PI (pollution index) values were used to assess the level of pollution. The PI values indicated high level of pollution by Pb in the suburban and rural area of stable gradient and in the urban area of dynamic gradient; moderate level of pollution was indicated for Cd in the urban area of stable gradient. The level of pollution was moderate for Co in the suburban and rural area of the stable gradient, and for Cu in suburban area of stable gradient, and urban area of dynamic gradient. The pollution level of Zn was moderate in all areas. Urban soils, especially in urban parks and green areas may have a direct influence on human health. Thus, the elemental analysis of soil samples is one of the best ways to study the effects of urbanization. Our results indicated that the heavy metal contamination was higher in Wien than in a few large European cities.