Membranas de fibra sintética de poliamida e híbridas aplicadas na separação água/óleo

Abstract

One of the major causes of environmental impacts is the improper disposal of effluents, whether they originate from domestic or industrial sources. When oil spills occur, the oil remains on the water's surface, forming a layer that inhibits the penetration of sunlight, hindering the photosynthesis process of algae, affecting the plants and animals in mangroves, and causing financial losses to the affected population. To minimize environmental damage, some techniques are used to address water pollution. Membrane separation processes (MSP) have emerged as an efficient alternative for treating oily effluents among various techniques. In light of this, this research aims to produce membranes from recycled synthetic polyamide fiber and hybrids with activated carbon using the phase inversion technique for oil/water separation in the petroleum industry. Microporous membranes were obtained from pure polyamide 66 waste dissolved in formic acid, and hybrids with the addition of 1, 3, and 5% by weight of activated carbon (AC), both introducing calcium chloride salt through the phase inversion technique using the immersion-precipitation method. The polymeric and hybrid solutions were characterized by viscosity. The membranes were characterized using atomic force microscopy (AFM), water absorption, porosity, contact angle, water vapor permeation, average and maximum pore sizes, and permeate flux. Crude oil was evaluated for density, API gravity, sulfur content, and viscosity. Effluents were analyzed for temperature, pH, electrical conductivity, apparent color, and turbidity. Factorial design was used to assess the influence of membrane composition, effluent concentration, and pressure on flux rates, selectivity, and the physicochemical parameters of permeates. It was possible to obtain membranes from polyamide 66 synthetic fiber waste, and the introduction of the inorganic load AC altered the microstructure of the hybrid membranes compared to the polymeric membrane, achieving results generally exceeding 95% in the removal of effluent oil for both pure PA66 and its hybrids. Statistical analysis (ANOVA) indicated that the membrane factor was significant for flux, color, and pH, with the membrane containing 3% by weight of AC showing the best results in the studied responses.