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Simona Caprarescu Mihai Cosmin Corobe Violeta Purcar Catalin Ilie Spataru Raluca Ianchis Gabriel Vasilievici Zina Vuluga 《环境科学学报(英文版)》2015,35(9):27-37
Heterogeneous membranes were obtained by using styrene-acrylonitrile copolymer (SAN) blends with low content of ion-exchanger particles (5 wt.%). The membranes obtained by phase inversion were used for the removal of copper ions from synthetic wastewater solutions by electrodialytic separation. The electrodialysis was conducted in a three cell unit, without electrolyte recirculation. The process, under potentiostatic or galvanostatic control, was followed by pH and conductivity measurements in the solution. The electrodialytic performance, evaluated in terms of extraction removal degree (rd) of copper ions, was better under potentiostatic control then by the galvanostatic one and the highest (over 70%) was attained at 8 V. The membrane efficiency at small ion-exchanger load was explained by the migration of resin particles toward the pores surface during the phase inversion. The prepared membranes were characterized by various techniques i.e. optical microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis and differential thermal analysis and contact angle measurements. 相似文献
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Zina Armi Souad Turki Elbahri Trabelsi Naceur Ben Maiz 《Environmental monitoring and assessment》2010,164(1-4):423-433
Coolia monotis is a potentially toxic epiphytic dinoflagellate widespread along the Mediterranean coasts, where it is frequently detected year round at low concentrations. However, it only proliferates recurrently in some localities. The North Lake of Tunis is one of the affected areas in the southwestern part of the Mediterranean Sea. This site is one of the most productive aquatic Tunisian areas (Recreational Fisheries and shellfish collecting). In the south part of this area of study, recurrent C. monotis proliferation (5 ×105 cells per liter) took place in late spring and early summer of 2006. During this proliferation, the spatial distribution of C. monotis species, phytoplankton community, and abiotic factors were studied. The composition of the phytoplankton community exhibited a clear dominance of dinoflagellates over other genera. We suggest that proliferation development of C. monotis was linked to climatic conditions, water temperature (r?=?0.24, p?<?0.05) and high concentrations of nitrogenous nutrients, essentially NH4 ?+? (r?=?0.18, p?<?0.05) and NO3 ??? (r?=?0.21, p?<?0.05). 相似文献
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Awatef Aissaoui Zina Armi Souad Turki Oum Kalthoum Ben Hassine 《Environmental monitoring and assessment》2013,185(11):9361-9384
This study investigates spatio-temporal variations of in situ division rate (μ) of two species of the genus Dinophysis. Based on a postmitotic index approach, estimates of μ from net-haul samples were compared during five daily cell cycles studies in three stations of the Punic harbors of Carthage (Gulf of Tunis). To study the annual cycle of Dinophysis spp., weekly sampling were carried out from March 2008 to June 2010. In addition, sampling over 24 h was conducted on three-cycle studies in late spring and two-cycle studies in autumn, seasons characterized by Dinophysis proliferations. We recorded important abundances of Dinophysis sacculus stein (2.25?×?104 cells/l, June 2008) and Dinophysis cf. acuminata (3?×?104 cells/l, June 2009). Cellular division was phased in D. sacculus stein and D. cf. acuminata, but the division time, required for the population cohorts to pass from one phase to another, and values of estimated division rates varied between seasons and stations for the same species. D. cf. acuminata exhibit moderate (0.22 day?1) to high (0.68 day?1) value of μ. In contrast, D. sacculus shows very low μ values (0.02–0.17 day?1) in autumn season to moderate values (0.21–0.35 day?1) in late spring. The results presented here confirm that the postmitotic index approach allowed estimated of μ at low field depths and concentrations (102–103 cells/l). 相似文献
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Armi Z Turki S Trabelsi E Ceredi A Riccardi E Milandri A 《Environmental monitoring and assessment》2012,184(8):5085-5095
The main diarrhetic shellfish toxins, okadaic acid (OA) and dinophysistoxin-1, 2 (DTX-2, 2) were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) as pyrenacyl esters in clams (Ruditapes decussatus) collected in Tunis north lagoon from January 2007 to June 2008. Sample analyses by LC-MS/MS displayed OA and related congeners (DTX-2, 2) with a highest detected level of 21 μg OA eq/kg shellfish meat for the samples of January 2007. Nevertheless, all samples were MBA negative. During the study period, potentially toxic dinoflagellate Dinophysis sacculus was recorded all year, blooming at different times. Highest concentrations were recorded during January 2007 with 4.6?×?10(4) cells per liter and 4.10(4) cells per liter in the northern and southern districts, respectively. Results show that there is no significant correlation between D. sacculus densities in water column and diarrhetic shellfish poisoning (DSP) toxins concentrations unregistered in clams. These data reveal that DSP toxicity in clams of Tunis north lagoon is low according to European regulatory limit (160 μg OA eq/kg shellfish meat). However, a potential threat, in this area, is represented by DSP toxic species as D. sacculus and provides grounds for widen and reinforcing sanitary control of the phycotoxin measures in the region. 相似文献
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Zina Skandrani 《Journal of Agricultural and Environmental Ethics》2016,29(3):541-548
In this essay, I build on the article by Soulé that established the foundation for the field of conservation biology. I analyze the presuppositions that have guided the discipline’s ethics in the 30 years since that article first appeared. I argue that conservation biology’s normative postulates introduced a paradigm shift that placed the diversity of the biota instead of the biota itself at the center of its ethics. I show that the ensuing priorities in the valuation of nature entail several contradictions at the ethical level and are justifiable only through scientific postulates. Identifying potential revisions and latent ideological issues in science, I defend the position that such scientific legitimization of conservation measures becomes disputable when this option undermines the ethical status of non-human life. Furthermore, I explain the absence of social feedback regarding conservation measures from the perspective of this shift. I conclude with an invitation to critically rethink the ethical basis of conservation sciences so that these fields may achieve their intention of playing a key role in halting the destruction of nature and in encouraging society’s support. 相似文献
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Gasmi Salim Rouabhi Rachid Kebieche Mohamed Boussekine Samira Salmi Aya Toualbia Nadjiba Taib Chahinez Bouteraa Zina Chenikher Hajer Henine Sara Djabri Belgacem 《Environmental science and pollution research international》2017,24(19):16440-16457
Environmental Science and Pollution Research - The present work is to evaluate the neurotoxicity induced by pyrethroid insecticide “Deltamethrin” at 0.32 mg/kg/day in two main... 相似文献
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