Impact of urban and industrial effluents on the coastal marine environment in Oran, Algeria

In Algeria most of the urban waste water is dumped without treatment into the Sea. It is tremendously important to assess the consequences of organic matter rich sewage on marine ecosystem. In this study we investigated the effects of industrial and urban sewage on the dissolved oxygen (O2), chemical oxygen demand (COD), biochemical oxygen demands (BOD5), pH, salinity, electrical conductivity (EC), Metal element (Hg, Pb, Cu, Ni, Cr, Cd), petroleum hydrocarbons (HC), oil and grease (OG) in Bay of Oran, Algeria. A ten-year follow-up research showed that the concentrations of oil and grease released into the bionetwork are of higher ecological impact and this needs to be given the desired consideration. Information on bathing water quality revealed that the most beaches in Oran are under the national environmental standard limit.

Simultaneous spectrophotometric determination of Fe(III), Al(III) and Cu(II) by partial least-squares calibration method

A spectrophotometric method for simultaneous determination of Fe(III), Al(III) and Cu(II) using Alizarin Red S as a chelating agent was developed. The parameters controlling behavior of the system were investigated and optimum conditions were selected. A partial least-squares multivariate calibration method was used for the analysis of ternary mixtures of Fe(III), Al(III) and Cu(II) over the range of 450-6000, 140-4000 and 450-15000 ng ml(-1), respectively. Absorbance data were taken between 400 and 800 nm. Applying this method to simultaneous determination of these metal ions in several synthetic alloy solutions with total relative standard error of less than 5% validated the proposed method.

A Novel Micellar Medium Using Triblock Copolymer for Cobalt Determination

This work proposes a new method for Co(II) determination based on the use of the triblock copolymer as micellar medium instead of chloroform. The proposed strategy is environmental friendly because the copolymer is biodegradable and nontoxic. The method is based on the formation of a cobalt-1-nitroso-2-naphthol complex, in the micellar triblock copolymer compound solution constituted by polyethylene oxide (PEO) and polypropylene oxide (PPO). Experimental conditions such as pH, the molecular weight and the PEO/PPO ratio of triblock copolymer were optimized. Results obtained for cobalt determination in vitamins with this novel method showed excellent agreement with those obtained using atomic absorption spectrometry. The relative standard deviation for a solution containing 0.125 mg L(-1) Co was 1.0% (n = 5); the relative error varied from 2.8 to 4.4%; the detection limit was 13.3 microg L(-1) and the quantification limit was 44.3 microg L(-1).

Coordination properties of 2-aminocyclopentene-1-dithiocarboxylic acid to transition metal ions as studied by ab initio calculations

The question of the(N, S) vs. (S, S) coordination mode on M x (ACDA)(2) complexes (ACDA=2-aminocyclopentene-1-dithiocarboxylic acid, M=Ni(2+), Pd(2+), Pt(2+)) was assessed through an extensive ab initio study, using the hybrid B3LYP density functional approach. The (S,S)coordination was found to be the most stable one, with an energy difference of ca. 50 kJ mol(-1) relative to the(N, S) coordination mode. Detailed analysis of the ab initio results indicates that this preference is a result of the combined effect of geometry constraints and electron distribution within the complex.