Clarificação de águas de efluente de lavanderia hospitalar pelo emprego de cinzas de carvão mineral.

Abstract

The scarcity of water in the Agreste region of Pernambuco is a matter of concern for the communities and industries installed in this location. One of the activities developed in this area involves the central processing centers for hospital clothes, which are important service sectors, and the health segment, both of which are responsible for a significant share in the consumption of water, the main raw material. In this last segment, the effluents generated by the processing of clothes in hospital laundries represent a complex mixture, resulting from the products inserted during the washing and from the organic and inorganic load coming from the dirtiness of the processed clothes. Thus, in addition to the scarcity of aquatic springs, the region needs sustainable strategies for the use of existing aquatic resources, such as, for example, reducing the consumption of chemicals in the dosage of water sent to treatment processes aimed at reuse. In this context, the ashes generated in the combustion of mineral coal (CCM), considered a great environmental liability of the thermoelectric plants installed in regions close to Pernambuco, presented themselves as an adsorbent substance and with potential use in the clarification of hospital effluents. Ashes (CCM) are made up of silica and alumina, making it possible to convert them into zeolitic material. Commercial zeolitic material is already used successfully in the clarification stage of hospital laundries. The efficiency of this zeolitic microstructure material in the removal of pollutants that give color to the effluents generated by the hygiene processes of the hospital laundry located in a private hospital in the city of Caruaru, in the Agreste region of Pernambuco, was evaluated. Experimental clarification tests demonstrated efficiency above 98% for a CCM content of 20 g.L-¹. It was also demonstrated that when conveniently subjected to treatment to reduce the sulfur content at the exit of the combustion furnaces, as requested by cement companies (Portland Cement Manufacturer), the CCMs do not require synthesis processes to activate their zeolitic structure. In addition, the strong correlation between the CCM content in the treatment effluent and the pH at the outlet of the mixing tank (effluent + CCM), allowed the elaboration of a system for clarifying hospital laundry effluents, associating the adsorption step to hydrocyclone batteries - this process is characterized by its low complexity, due to simple equipment (mixing tank and hydrocyclones) and high efficiency of clarification and recovery of water for reuse.