Tratamento de água residuária proveniente do processo de lavagem de tecidos utilizando reator UASB

Abstract

The lack of quality in water is a theme that draws everyone's attention. As the years pass, laws and regulations become increasingly stringent as to the quality of the water discarded in the environment. Among the wastewater in question, the laundry effluents stand out, since they generate high volumes of liquid waste, characterized by high amounts of organic matter and surfactants. Because they have complex structures, the surfactants present low biodegradability, making their treatment difficult. The physico-chemical method for treatment is commonly used. Aiming for a more sustainable alternative, the present work had as objective the treatment of wastewater from the fabric washing process using the Upflow Anaerobic Reactor and Sludge Blanket, UASB. The inoculum used was from poultry slaughterhouse, DACAR. The reactor was fed with laundry wastewater (LW), collected at a local commercial laundry and diluted in a nutritional solution. The hydraulic detention time used was 48 hours, with a flow rate of 94 mL / h. The total time of reactor operation was 317 days. Physical and chemical analyzes were performed for chemical oxygen demand, anionic surfactants, total alkalinity, total acids, pH and total solids for control and monitoring of the reactor. Hydrodynamic trials and biogas production were also carried out. The hydrodynamic results showed experimental HRT (hydraulic retention time) close to the theoretical, besides identifying the flow regime as plug flow. Seven phases of operation were performed, changing the concentrations of the substrates present in accordance with the removal efficiency of COD and LAS (linear alkylbenzene sulfonate) (approximately 600 to 1000 mg COD/L and 2 to 10mg LAS/L). The removal efficiencies ranged from 85.83% to 95.46% for COD and from 35% to 64% for LAS. As for biogas production, a value of 16.32 ± 0.81 cm³ / h was found. In this way, it can be concluded that the reactor performed well in the treatment of LW according to the proposed conditions.