An Overview on the Organic Contaminants | Author : Moustafa Gamal Snousy | Abstract | Full Text | Abstract :Pollution can be defined as the introduction of elements, compounds or energy into the environment at levels that impair its functioning or that present an unacceptable risk to humans or other targets that use or linked to that environment. Soils may affect the hydrosphere compromising the quality of drinking water resources and threatening the aquatic ecosystems. When the problem of groundwater pollution began to be discovered, the initial approach to remediation was based on the assumption that most of contamination was actually in the soil at the site of the spill; from where it was reasoned that the contaminated soil could be treated, and also contaminated water. |
| EFFECT OF IN VIVO CONTAMINATION BY EFFLUENT FROM PHOSPHATE TREATMENT INDUSTRY ON THE CLAM RUDITAPES DECUSSATUS | Author : Rim Ladhar-Chaabouni | Abstract | Full Text | Abstract :This study focused on industrial effluent characterization and determination of its effects on the clam Ruditapes decussatus. The analysis results revealed that the effluent having acid pH and high concentrations of some chemicals, comparing to the norms, such as SO42-, NO3-, K+, Mg2+, F and Cd. The effect of the effluent on the clam R. decussatus was reflected by the LT50 determined after an exposition to different doses (5%, 10%, 20%, 30%) during 25 days and by the concentration/activity of two biomarkers: malondialdehyde (MDA) and acetylcholinesterase (AChE) determined after a contamination by effluent (1%) during 16 days. The stress on stress results showed that animals were stressed even with le lowest effluent concentration. An increase of MDA concentrations was observed in digestive glands of exposed clams. Nevertheless, no significant variation of AChE activity was observed. |
| The remediation method of sandy land in the feldspathic sandstone area - a review | Author : Jichang Han | Abstract | Full Text | Abstract :This review presented a remediated technology that sand was remediated by feldspathic sandstone to convert to usable land and synthesized formation mechanism of remediated soil (sand remediated by feldspathic sandstone), highlighting the effect of remediated soil on the agriculture as well as pointing out the effect of sand stabilization of remediated soil. This paper could be helpful to guide the remediation method on sandy land where feldspathic sandstone was associated with sand and widely distributed, such as Mu Us feldspathic sandstone area, as well as to suggest useful avenues to improve the physical and chemical properties of the sandy land which was favorable for sustainable crops growth. Sand remediated by feldspathic sandstone, could be fixed, and soil erosion could be effectively prevented as well as its surrounded ecological environment could be well protected. This research has important theoretical and practical significance in the feldspathic sandstone area, for the sand remediated by feldspathic sandstone is proved to be a sustainable way to comprehensively improve the sandy land, and to solve soil erosion problems in feldspathic sandstone areas with remarkable economic, social and ecological efficiency. |
| X-ray Photoelectron Spectroscopy study of so-called “Larimar”, blue pectolite from the Dominican Republic | Author : J. THEO KLOPROGGE | Abstract | Full Text | Abstract :A detailed analysis was undertaken of the X-ray photoelectron spectra of the blue variety of pectolite known by the tradename Larimar from the Dominican Republic in an attempt to elucidate the origin of the blue colour. The survey scan confirmed the chemical composition of pectolite. The O 1s showed a complex set of bands associated with Si-O-Si, Si-O-(Na,Ca) and OH in the crystal structure of pectolite. From the possible elements suspected to cause the colour, such as Cu, Fe, Mn, and V, only Cu and Fe were observed above the detection limit of the XPS instrument. For the first time about 0.02 atom% of Pb was observed was observed in one sample, while another sample from the same block showed the presence of 1.05 atom% Sb. The possible presence of [Pb-Pb]3+ pairs can act as a chromophore analogous to that observed in the blue-green feldspar variety amazonite. This would explain the till now unexplained optical band at 630 nm as well as part of the high hydroxyl concentration. Though other chromophores cannot be excluded, the observation of Pb adds a new possible explanation for the blue colour of Larimar. |
| Spatial pattern of ciliates in relation to environmental factors at Sfax south coast (Gulf of Gabes, Tunisia) | Author : Ben Salem Zohra | Abstract | Full Text | Abstract :Data for ciliate abundance, biomass composition, with relevant physicochemical parameters, were studied in the south of Sfax from twenty stations during winter 2008. A total of 18 ciliate taxa representing 10 different genera were identified during the monitoring periods. The Tintinnida group is the most diversified (11 species) accounting for 77% and 92% of the total abundance and biomass, respectively, followed by Choreotrichida and Strombidiida. The ciliate assemblage is dominated by the medium-sized (from 30 µm to 60µm) species and T. beroidea, T. balechi and T. nana are the most abundant. High chlorophyll-a concentration, N/P ratio lower than the Redfield and low Shannon index of ciliate indicated that the water quality of the south coast of Sfax is degraded. So, the coupling of the chemical and biological parameters may serve as good tools to monitor the marine ecosystems. |
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