Tratamento de resíduos sólidos de laboratório uilizando a técnica de estabilização por solidificação.

Abstract

The generation of solid waste occurs in all sectors, the chemical industry being one of the most outstanding in the production of industrial solid waste due to the high volume and the lack of use of its raw material. In the same way, however, to a lesser extent, we have the Federal Institutions of Higher Education, where there is a complex generation of solid waste with very diverse origins. Much of the waste is generated mainly in chemistry laboratories, due to the use of highly dangerous products producing hazardous waste, such as heavy metals. The treatment of Laboratory Solid Waste (RLS) by means of the solidification stabilization technique using cement matrix has been recognized as the best process for the treatment of hazardous waste before final disposal. The present work aimed to carry out the treatment of solid laboratory residues (RSL) through the analysis of integrity / durability and immobilization of contaminants in materials with heavy metals using the technique of stabilization by solidification, using cement matrices subjected to different temperatures of cure (°C) and different concentrations of RSL (% ). In the experiment, a 2k factorial design with the factors T and % RSL was applied, and the compressive strength (RC), hydrogen potential analysis was performed ( pH), water absorption capacity (CAA), humidification and drying (U/S), total solids (ST) and their fractions, and chemical oxygen demand (COD). Based on the analyzes carried out, it is possible to observe that the RSL used is a dangerous material due to the high percentage of total solids; cementitious matrices with a high percentage of RSL were not approved in the contaminants Durability / Integrity tests and the temperature variation and the increase in RSL concentration directly influenced the responses of the analyzes performed. As the percentage of RSL and the cure temperature increased, there was an increase in the COD concentration, obtaining the best result from the treatment using the lowest cure temperature of 6°C and the lowest percentage of 10% of RSL (50898.2 mg.k g -1). While the experiment with the highest COD concentration was obtained using the highest cure temperature (50°C) and the highest RSL concentration (45%), reaching a concentration of 65868.2 mg.kg -1 of COD. From the mass balance it was observed that all treatments retained an amount of residue in the cementitious matrix, with the highest retention obtained in the treatment subjected to the lowest curing temperature and the lowest percentage of RSL obtaining a contaminant mass retention of 109,82g. All experiments showed efficiency in retaining the residue in the cementitious matrix, reducing the leaching of the RSL into the environment, and the treatment with the lowest percentage of residue and the lowest cure temperature showed the highest efficiency inimmobilizing the contaminant (95,84% ).