Analyse et traitement par plasma froid des eaux de rejet de « l’abattoir des Brasseries » à Yaoundé

Des echantillons des eaux usees de á lfabattoir des Brasseries â a Yaounde, preleves ont ete analyses et traites par plasma froid. Les resultats dfanalyse revelent que lesdites eaux sont basiques (pH = 8.65), tres conductrices (conductivite electrique = 1625 ƒÊScm-1), fortement polluees (DBO5 = 1000 mgL-1 dfO2, DCO = 2390 mgL-1 dfO2 et 200 mgL-1 dfammonium) et biodegradables (DBO5/DCO = 0.42). La teneur elevee en chlorures (1347 mgL-1) et lfabsence des metaux lourds ont ete notees. Apres traitement par plasma, on observe une reduction de 50% de la DBO5 en 10 minutes, le debit du gaz plasmagene etant fixe a 1000 Lh-1. Lfefficacite du plasma froid a decharge electrique rampante (glidarc) a ete une fois de plus prouvee pour la reduction de la pollution environnementale.Mots cles: Eaux usees, biodegradables, glidarc, pollution

Acid activation and bleaching capacity of some Cameroonian smectite soil clays

International audienceThree Cameroonian clay materials with high smectite content were used for decolouration of palm oil with a clay / oil ratio of 2%. Particle size distribution, mineralogical and chemical analyses were done. The activation parameters (temperature, acid concentration and activation time) permitting the optimisation of their bleaching capacities have been determined. Their performances were compared to those of a commercial bleaching earth before and after acid activation

Talc based cementitious products: Effect of talc calcination.

AbstractThis study reports the use of calcined talc for cementitious products making. The calcination is used to enhance the availability of magnesium from talc to react with phosphate for cement phase formation. It is shown that previous calcination of talc leads to products having enhanced mechanical performance due to the formation of more cement phase than in products based on raw talc. Talc fired at 900°C was found to be the one in which magnesium release was maximal. Firing at temperature higher than 900°C leads to the stabilization of enstatite, which decreased the magnesium availability. The cement phase is struvite, which was better detected on the X-ray patterns of the products involving fired talc. All the products have very rapid setting time and low shrinkage

Preliminary study on the use of corn cob as pore forming agent in lightweight clay bricks: Physical and mechanical features

International audienc

Talc as raw material for cementitious products formulation

This study reports the characterization of a talc from Cameroon as a possible source material for cement formulation. To that end, the talc sample was characterized and mixed with a solution of sodium polyphosphate to formulate the cementitious products. Addition of magnesia (MgO) was done to analyze the effect of available MgO on the products. Fourier transform infrared, X-rays diffraction, linear shrinkage, compressive strength and scanning electron microscopy were used to analyze the products. The compressive strength increased with addition of MgO and the linear shrinkage decreased. All the analyses indicate that talc is a raw material of interest in cementitious products formulation; however, the inclusion of the MgO is a key factor for a better performance of the products

Comparative effect of bovine bone ash and cassava starch on the microstructure of porous ceramics using kaolinite clays from Cameroon

International audienc