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Polyvinyl alcohol (PVA), being a dominant contributor of total organic carbon (TOC) in textile wastewater, is not easily degradable by conventional methods of wastewater treatment. This study investigates the degradation of aqueous PVA in a continuous UV/H2O2 photoreactor since the feeding strategy of hydrogen peroxide proves to have considerable effects on the process performance. Response surface methodology involving the Box–Behnken method is adopted for the experimental design to study the effects of operating parameters on the process performance. Experimental analysis shows that the TOC removal varies from 16.11 to 42.70 % along with a reduction of the PVA molecular weights from 56.7 to 95.3 %. The TOC removal is significantly lower than the molecular weight reduction due to the generation of the intermediate products during oxidation. Operating the UV/H2O2 process in a continuous mode facilitates the degradation of highly concentrated polymeric solutions using a relatively small hydrogen peroxide concentration in the feed with a small residence time ranges from 6.13 to 18.4 min. 相似文献
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Benoit Lebreton Pierre Richard Robert Galois Gilles Radenac Amel Brahmia Géraldine Colli Marig Grouazel Cyril André Ga?l Guillou Gérard F. Blanchard 《Marine Biology》2012,159(7):1537-1550
In an intertidal Zostera noltii Hornem seagrass bed, food sources used by sediment meiofauna were determined seasonally by comparing stable isotope signatures (δ13C, δ15N) of sources with those of nematodes and copepods. Proportions of different carbon sources used by consumers were estimated using the SIAR mixing model on δ13C values. Contrary to δ15N values, food source mean δ13C values encompassed a large range, from −22.1 ‰ (suspended particulate organic matter) to −10.0 ‰ (Z. noltii roots). δ13C values of copepods (from −22.3 to −12.3 ‰) showed that they use many food sources (benthic and phytoplanktonic microalgae, Z. noltii matter). Nematode δ13C values ranged from −14.6 to −11.4 ‰, indicating a strong role of microphytobenthos and/or Z. noltii matter as carbon sources. The difference of food source uses between copepods and nematodes is discussed in light of source accessibility and availability. 相似文献
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Sana Ben-Khedher Jamel Jebali Zohra Houas Hmida Nawéli Amel Jrad Mohamed Banni Hamadi Boussetta 《Environmental science and pollution research international》2014,21(6):4343-4357
Metals concentrations and histolopathological lesions of gills and digestive gland were investigated in Carcinus maenas crabs sampled from Bizerta Lagoon and Kuriat Island (Tunisia) as control site. The concentrations of trace metals varied between tissues, sites and sampling time. The highest levels of the analysed metals in gills and digestive gland were noted in Menzel Bourguiba and Cimentery sites at both sampling times (February and July). The higher metals loads were associated with severe and various tissues alterations in contaminated crabs. We particularly noted in the gills a haemocytic infiltration, distension and enlargement of the lamellae, lifting of lamellar epithelium, necrotic lesions and fusion of lamellae in the most polluted sites (Menzel Bourguiba and Cimentery). Moreover, others pathological alterations were observed in digestive gland of crabs collected from polluted sites and with a severity site dependent. We observed necrotic tubules containing tissue debris in the lumen with more intensity in crabs collected from Cimentery site in both sampling times. The thickened basal laminae and the walling off of the tubules by haemocytes around the thickened basal laminae were more abundant at Menzel Bourguiba than at others sites. The coagulation in the thickened basal laminae was observed only at Cimentery in February. Tissues histopathological lesions were sensitive to discriminate crabs of different sites and demonstrated its usefulness in this biomonitoring study. We recommend the association of histopatholocial lesions to biochemical biomarkers in future biomonitoring studies. 相似文献
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Rim Khlifi Pablo Olmedo Fernando Gil Molka Feki-Tounsi Bouthaina Hammami Ahmed Rebai Amel Hamza-Chaffai 《Environmental monitoring and assessment》2014,186(2):761-779
The human health impact of the historic and current mining and industrial activities in Tunisia is not known. This study assessed the exposure to metals in the population of Southern Tunisia, using biomonitoring. The aim of this pilot study was to evaluate metal exposure on 350 participants living near mining and active industrial areas in the South of Tunisia. Blood specimens were analyzed for metals (Cd, Cr, As, and Ni) by Atomic Absorption Spectrometer equipped with Zeeman background correction and AS-800 auto sampler by graphite furnace and graphite tubes with integrated L'vov platform. The sample population was classified according to different age groups, sex, smoking habit, sea food and water drinking consumption, occupational exposure, amalgam fillings and place of residence. The blood As, Cd, Cr and Ni values expressed as mean?±?SD were 1.56?±?2.49, 0.74?±?1.15, 35.04?±?26.02 and 30.56?±?29.96 μg/l, respectively. Blood Cd and Ni levels in smokers were 2 and 1.2 times, respectively, higher than in non-smokers. Blood Cd levels increase significantly with age (p?=?0.002). As, Cd and Ni were significantly correlated with gender and age (p?<?0.05). Cd level in blood samples of subjects occupationally exposed was 1.3 times higher than that of non-exposed. Blood metals were not significantly affected by amalgam fillings, place of living and sea food and drinking water consumption. This first biomonitoring study of metal exposure in the South of Tunisia reveals a substantial exposure to several metals. The pathways of exposure and health significance of these findings need to be further investigated. 相似文献
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Zied Marzougui Amel Chaabouni Boubaker Elleuch Abdelhamid Elaissari 《Environmental science and pollution research international》2016,23(16):15807-15819
In this study, magnetic polydivinylbenzene latex particles MPDVB with a core-shell structure were tested for the removal of bisphenol A (BPA), copper Cu(II), lead Pb(II), and zinc Zn(II) from aqueous solutions by a batch-adsorption technique. The effect of different parameters, such as initial concentration of pollutant, contact time, adsorbent dose, and initial pH solution on the adsorption of the different adsorbates considered was investigated. The adsorption of BPA, Cu(II), Pb(II), and Zn(II) was found to be fast, and the equilibrium was achieved within 30 min. The pH 5–5.5 was found to be the most suitable pH for metal removal. The presence of electrolytes and their increasing concentration reduced the metal adsorption capacity of the adsorbent. Whereas, the optimal pH for BPA adsorption was found 7, both hydrogen bonds and π–π interaction were thought responsible for the adsorption of BPA on MPDVB. The adsorption kinetics of BPA, Cu(II), Pb(II), and Zn(II) were found to follow a pseudo-second-order kinetic model. Equilibrium data for BPA, Cu(II), Pb(II), and Zn(II) adsorption were fitted well by the Langmuir isotherm model. Furthermore, the desorption and regeneration studies have proven that MPDVB can be employed repeatedly without impacting its adsorption capacity. 相似文献
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Barka Sabria Gdara Imene Ouanes-Ben Othmen Zouhour Mouelhi Samia El Bour Monia Hamza-Chaffai Amel 《Environmental science and pollution research international》2020,27(6):5670-5680
Environmental Science and Pollution Research - Dams represent large semi-closed reservoirs of pesticides and various organic and inorganic pollutants from agricultural and human activities, and... 相似文献
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Amelène El-Mufleh Béatrice Béchet Véronique Ruban Michel Legret Blandine Clozel Sylvie Barraud Carolina Gonzalez-Merchan Jean-Philippe Bedell Cécile Delolme 《Environmental science and pollution research international》2014,21(8):5329-5346
Urban stormwater infiltration basins are designed to hold runoff from impervious surfaces and allow the settling of sediments and associated pollutants. However concerns have been expressed about the environmental impacts that may be exerted by the trapped pollutants on groundwater, soils and ecosystems. In this context, sediment characterization represents a key issue for local authorities in terms of management strategies. During the last two decades, several studies were launched including either physical or chemical characterization of stormwater sediments but without real synthesis of data and methods used. Consequently, there is an important need for reviewing the current experimental techniques devoted to the physico-chemical characterization of sediment. The review is based on the outcomes of two experimental sites for which long term monitoring and data collection have been done: the Cheviré basin (near Nantes) and the Django Reinhardt basin (near Lyon). The authors summarize the studies dealing with bulk properties, pollutant contents, their potential mobility and speciation. This paper aims at promoting the significant progresses that were made through a multidisciplinary approach involving multi-scaled and combined experimental techniques. 相似文献