Microbiological biodeterioration of the structural materials in a solid waste/recycling plant in an urban Buenos Aires province

GUIAMET P.; MUGNOLO A.; GÓMEZ DE SARAVIA S.

Sant´Alessio Siculo-Messina, Italia

Simposio; 14 th. International Biodeterioration & Biodegradation Symposium IBBS-14; 2008

The solid waste treatment plant located in Tapalqué, Buenos Aires province, Argentine was created to eliminate open-air disposal of domiciliary waste. This plant recovers materials from domiciliary solid waste and recycles organic matter for vermicomposting. Biodeterioration, caused by lixiviates from organic matter and by the use of biocides and cleaning products, occurred in the unloading docks used for organic fraction of cement. Consequently, these structures were replaced by metallic conveyor belts, which are not exempt from biodeterioration risks. The goal of this work was to study the problems of biocorrosion that arise in this plant through the formation of biofilms and the use of biocides and cleaning products. Bioassays were carried out during six months. Series of test coupons made of the same material as the conveyor belt were placed in contact with the lixiviates and removed so as to estimate the recruitment of macro and microsessile biofilm-formation species, and immediately replaced by clean ones. The resulting data were compared in order to estimate microbiological colonization before and after treatment of the coupons with biocide. Possible causes of biocorrosion were studied by microbiological techniques of isolation and culture complemented with optical and scanning electron microscope (SEM) observation. The impact of biofilm formation and lixiviates on structural materials from the plant were studied by energy dispersion x-ray analysis (EDX) and different electrochemical techniques. We verified the presence of bacteria, fungi and other microscopic organisms. The lixiviates and acids produced by bacteria and fungi affected diverse structures in the treatment plant.