Discoloration and detoxicification of a Congo red dye solution by means of ozone treatment for a possible water reuse.

The objective of this study was to investigate the degradation and mineralization of an azo-dye, the Congo red, in aqueous solutions using ozone. Phytotoxicity and the inhibitory effects on the microbial activity of the raw and the ozonated solutions were also carried out with the aim of water reuse and environment protection. Decolorization of the aqueous solutions, disappearance of the parent compound, chemical oxygen demand (COD) and total organic carbon (TOC) removal were the main parameters monitored in this study. To control the mineralization of the Congo red, pH of the ozonated solution and heteroatoms released from the mother molecule such NH(4)(+), NO(3)(-) and SO(4)(2-) were determined. It was concluded that ozone by itself is strong enough to decolorize these aqueous solutions in the early stage of the oxidation process. Nonetheless, efficient mineralization had not been achieved. Significant drops in COD (54%) were registered. The extent of TOC removal was about 32%. Sulfur heteroatom was totally oxidized to SO(4)(2-) ions while the central -NN- azo ring was partially converted to NH(4)(+) and NO(3)(-). Results of the kinetic studies showed that ozonation of the selected molecule was a pseudo-first-order reaction with respect to dye concentration. The obtained results also demonstrate that ozone process reduced the phytotoxicity of the raw solution and enhanced the biodegradability of the treated azo-dyes-wastewater. Hence, this show that ozone remains one of the effective technologies for the discoloration and the detoxification of organic dyes in wastewater.

[Traumatic hip dislocations in children]. / Les luxations traumatiques de la hanche chez l'enfant.

PURPOSE OF THE STUDY: Traumatic hip dislocation is a rare event in children. Appropriate management remains a subject of debate. The purpose of this study was to investigate the epidemiological, therapeutic features of this situation and the long-term outcome after treatment. MATERIAL AND METHODS: This was a retrospective analysis of 15 traumatic hip dislocations collected over a period of 20 years in pediatric patients with at least two years follow-up. We searched for predisposing factors and factors affecting prognosis. RESULTS: The series included 11 boys and three girls, mean age eight years. Dislocation was posterior in 13 hips and anterior in two. Time to reduction was less than 3h in eight cases, 3-6h in five and greater than 6h in two. After reduction, traction was performed in nine children, for 20 days on average, followed in five cases by immobilization for 40 days on average. Five hips were immobilized directly after reduction. We identified two groups by age: group 1 with dislocations in children aged less than six years (seven children) were characterized by low-energy trauma. Dislocation was not associated with other lesions. Predisposing factors (overt ligament hyperlaxity, insufficient superolateral head cover, coax valga) were noted in six children. Reduction was simple. Later treatment consisted in immobilization with a pelvispedious cast for 30-45 days. Group 2 were dislocations in children aged over six years (seven children) victims of high-energy trauma. Associated injuries were frequent. Predisposing factors were not present. At mean 11 years follow-up, all hips are considered normal clinically. The radiograph was normal for 14 hips. In one case, there was a slight coax magna. In three patients, defective femoral head cover persisted. Coxa valga persisted in two patients. DISCUSSION: Traumatic dislocation of the hip joint is rare in very young children, but results from a minimally traumatic event. This suggests the presence of predisposing factors in this category of patients, particularly capsuloligamentary hyperlaxity. After reduction, immobilization can be recommended. Traumatic hip dislocations in children are different from the adult variety due to their rarity, the general absence of associated fractures, easy reduction and better prognosis. The epidemiological and therapeutic features in children older than six years are however similar to those in adults.

Hydrocarbon contamination of coastal sediments from the Sfax area (Tunisia), Mediterranean Sea.

The coastal area off the city of Sfax (730,000 inhabitants), well-known for fisheries and industrial activities, receives high inputs of organic matter mostly anthropogenic. Eighteen stations were selected in the vicinity of the direct discharge of industrial sewage effluents in the sea in order to study the spatial distribution of the organic contamination. Surface sediments sampled in the shallow shelf were analysed for hydrocarbons by Fourier transform infrared spectroscopy, gas chromatography and gas chromatography/mass spectrometry. Total hydrocarbon distributions revealed high contamination as compared to other coastal Mediterranean sites, with an average concentration of 1865 ppm/dry weight sediment. Gas chromatographic distribution patterns, values of unresolved mixture/n-alkane ratio and distributions of steranes and hopanes confirmed a petroleum contamination of the Arabian light crude oil type. Biogenic compounds were also identified with a series of short-chain carbon-numbered n-alkenes in the carbon range 16-24.