| Environnement, ingénierie & développement |  |
N° 84 - EID
Ce volume est le premier de la revue EID, Il succède aux 83 volumes de DST parus précédemment. Il lui est attribué le numéro 84 en continuité de la série des 83 volumes de DST.
1. ETAT DES LIEUX ET IMPACTS SOCIO-ENVIRONNEMENTAUX DE LA GESTION DES DECHETS HOSPITALIERSSOLIDES DANS LA VILLE DE YAOUNDE, CAPITALE DU CAMEROUN
This paper presents an overview on biomedical wastes(BWs) management in the capital city of Cameroon andrelated socio-environmental impacts. Four elementsconstitute major axes in this study: (i) the general viewof BWs management in five health centers (HCs) inYaoundé city, (ii) the among of BWs produced in eachHC, (iii) the management method used in various HCsand (iv) resulted social and environmental impacts.Field observations and data analysis collected from themedical staff and users have shown that BWs producedin those HCs of our choice regroup household waste(76.79 %), pathological waste (12.43 %), prickly andcutting waste (9.58 %), anatomical waste (0.60 %) andspecial waste (0.30 %). The management system ofthese wastes still in his embryonic state due to lack ofreal waste management plan, lack of information andtraining of medical staff, lack of qualified staff in wastemanagement and also lack of financial issues. Asconsequences, one attends poor BWs management ateach step of waste management, with consequence theexposure of the populations to numerous possibleillnesses. The environmental pollution is also sensitivebecause of BWs deposit on soil, their transportation bywater streaming and also of poisonous gas dismissal inair during their decomposition.
2. VALORISATION DE LA POUDRE DE MARBRE COMME ADDITIF DANS LA FORMULATION DE BETONS AUTOPLAÇANTS
The cement industry is a greenhouse gas-generatingactivity since approximately one ton of carbondioxide (CO2) is emitted into the atmosphere per tonof cement produced. Many mineral products can beadded to concrete to modify their technicalcharacteristics for particular applications and/or toimprove the environmental balance of their lifecycle. This article reports the study of the influenceof the addition of waste marble on the properties ofself-consolidating concrete (SCC). Several additionrates were tested Concrete were prepared with aWater/Binder (W/L) ratio of 0.33 and an equalPortland cement dosage of 400kg/m3. Used alone asa reference composition (white), or with additions ofmarble powder at dosages of 15, 20 and 30% relativeto the mass of the cement. The properties of theself-compacting concrete in the fresh and hardenedstate were tested using specific tests, by varying thefineness of the marble powder at 3000, 7000 and9000 cm2/g and the Superplasticizer content at 1 .5%and 1.75%. The results obtained show that the use ofmarble powder improves the properties of selfconsolidatingconcrete and is consistent with therecommendations of the French Association of CivilEngineering.
3. GESTION DES DECHETS SOLIDES DU CENTRE HOSPITALIER REGIONAL DE DALOA (CENTRE-OUEST DE LA COTE D’IVOIRE) ET DES RISQUES ASSOCIES
Health facilities generate multiple wastes on a dailybasis, which constitute a health and environmentalproblem in the event of poor management. Theobjective of our study was to improve wastemanagement at the Daloa Regional Hospital (CHR). Toachieve this, surveys were conducted with DaloaRegional Hospital (CHR) staff and users. Sharp andcutting waste at the level of each department and therisks associated with this waste has been quantified.The results showed that the waste produced withinthe Daloa Regional Hospital is of two types, namelyhealthcare waste (39.1 %) found in specialized serviceand waste treated as household waste (60.9 %) foundin all service. 71.1 % of CHR staff do not sort the wastecollected. The collected waste is transported inwheelbarrows contrary to the recommendations ofthe World Health Organization (WHO). In the absenceof a functional incinerator, sharps waste,pharmaceutical waste, no-sharps waste andhousehold waste are burned in the open air andanatomical waste is buried in landfill pits. The methodand process of waste management produced at DaloaRegional Hospital (CHR) could result in significant risksof HIV-AIDS infection and hepatitis infection,estimated at 40.8 % and 28.7 % respectively. Theacquisition of a banalizer by Daloa Regional Hospital(CHR) staff raises hopes for an improvement in wastemanagement at this important health facility inCentral West-Ivorien.
4. VALORISATION DE DECHETS PLASTIQUES ET D'INDUSTRIE DU BOIS EN COMPOSITE MOULE A FROID : EFFET DES PARAMETRES DE FABRICATION SUR LES PROPRIETES MECANIQUES
This work concerns the field of recycling of waste intobuilding materials. It reports on the possibility ofrecovering plastic waste and related products fromthe wood industry, in construction. The objective ofthe study is to give added value to wood-plasticcomposites produced using the cold compressionmolding process, by improving their mechanicalproperties. Through the bending test, the influence oftwo manufacturing parameters - compactionpressure and drying temperature after molding - onthe mechanical properties, was evaluated for the caseof a composite based on tropical wood sawdustcoming from Benin and recycled polystyrene (CBPo).It appears that the compaction pressure and thedrying temperature are essential factors to considerwhen evaluating the mechanical performance of thecomposite. Increasing the compaction pressure to alimit value significantly improves the properties of thematerial. The optimal properties of CBPo wereobtained at a pressure of 7 MPa. Post-forming dryingat 100 ° C also significantly improved the performanceof the composite. In addition, thanks to its enhancednew mechanical properties, the CBPo is repositionedrelatively to other existing materials, thus making itpossible to think about new applications inconstruction.
5. TRAITEMENT PAR EVAPORATION SOLAIRE DE LIXIVIATS DE DECHETS MENAGERS AU MAROC
The aim of our work was the development of evaporation techniques for the treatment of leachate from household waste in the city of Kasba Tadla to avoid rejection permanently in nature. Taking into account the characteristics of the selected site which has a warm climate with temperatures that exceed 50°C during the summer period we favored a forced evaporation processing mode. Several models have been tested, the alternatives given on the position of the evaporation pans relative to the ground, coverage evaporation pans by glass plates and their angle of inclination and the presence or absence of systems agitation and ventilation. The tests were used to develop a final evaporation model forced with glass plates inclined with a stirring system of leachate. forced evaporation of leachate testing have helped reduce the time of evaporation of leachate by 50% approximately relative to natural evaporation and 30% compared to evaporation with plates of horizontal glass. The power evaporating of this technique from a value of 3.06 mm/day to reach a value of 10.25 mm/day during the summer period. The model developed shows evaporation performance and effectiveness for the treatment of leachate so it stands out as alterative techniques for the treatment of leachate.