ABSTRACT Graphical abstract summarizing reclaimed wastewater reuse for an industrial cooling tower. Municipal wastewater is treated and blended with Ebro River water at up to 40% reverse osmosis permeate before being supplied as cooling tower make-up water. The case study shows an increase in cycles of concentration from 4 to 7, a 22% reduction in total make-up water demand, a 50% reduction in blowdown, corrosion maintained within target limits, and no detection of Legionella pneumophila. This study presents a full-scale industrial case study on the reuse of reclaimed municipal wastewater as make-up water for cooling towers in a large petrochemical complex in Tarragona, Spain. Reverse osmosis permeate produced at the Camp de Tarragona Advanced Water Reclamation Plant is blended with Ebro river water at ratios up to 40% and supplied to an ethylene cracker cooling tower system, with the objective of reducing freshwater consumption while maintaining safe and stable operation. The use of reclaimed water enabled an increase in cooling tower cycles of concentration from 4 to up to 7, resulting in a 22% reduction in total make-up water demand and a 50% reduction in blowdown. Despite the low buffering capacity and calcium content of the reclaimed water, corrosion rates for carbon steel and copper alloys remained below 1 and 0.24 mils per year respectively, through optimized chemical treatment and real-time monitoring. Microbiological control was maintained throughout the study period, with aerobic bacteria counts below regulatory limits and no detection of Legionella pneumophila. These results demonstrate that reverse osmosis treated reclaimed water can be safely reused in industrial cooling systems, contributing to significant freshwater savings and reduced environmental pressure on stressed river basins.
Gilabert-Oriol et al. (Mon,) studied this question.