The water resources management has been a challenge for the industries. The urban and industrial development has been leading to a significant increase in the demand for water, in contrast to the limited supply of fresh water for consumption on the planet. In this context, it becomes necessary to search technologies for water treatment and reuse in order to obtain supply autonomy and consumption rationalization. This paper intended to design two units for the tertiary treatment of effluents, one of which using carbon activated and ionic exchange beds (U-100), and the other using ultrafiltration and reverse osmosis membranes (U-200). The water generated by these units must be within the specifications for the use in boilers, water cooling towers and direct use in the process streams. For a feedwater flow of 1002.97 m3/h, U-100 generated 619.16 m3/h of water for the cooling towers, 200.59 m3/h for use in the process streams and 100.30 m3/h for the boiler; for the same flow, U-200 generated 619.16 m3/h of water for the cooling towers, 83.16 m3/h for use in the process streams and 41.58 m3/h for the boiler. The annual cost obtained for U-100, without considering the purchase of effluent, was 2,000,698.80 dollars, whilst for U-200 the cost was 2,430,971.19 dollars. Considering the purchase of effluent, the costs for U-100 and U-200 are, respectively, 14,520,773.31 dollars and 14,951,045.70 dollars.