THE OPERATIONAL CHALLENGE

A chemical industry located in Belford Roxo believed it was operating an efficient water reuse system. The operation used treated water for washing floors and equipment, and this effluent returned to the system, completing the cycle.

The system concealed a serious structural flaw. With each reuse cycle, the pollutant load of the water progressively increased. There was no effective removal of contaminants between cycles. In practice, the system stopped treating and began concentrating.

The direct consequence was the growing need for external disposal of the effluent, already at high levels of contamination, via containers for offsite treatment. This introduced a second problem: operational dependence on third parties and a continuous increase in cost as the problem worsened.

The client needed a solution that would interrupt this cycle of concentration and allow for true reuse, not just recirculation of contaminated water.

GIGWATER conducted an in-depth characterization of the effluent, and the results revealed a system completely out of balance, with multiple simultaneous risk vectors.

BOD was above 8,000 mg/L. The soluble fraction of this contaminant was significant, indicating low removal efficiency in the existing treatment. Sulfides and ammoniacal nitrogen were also detected in relevant concentrations, in addition to the presence of metals, including chromium in the initial analyses. Electrical conductivity and total dissolved solids were elevated, resulting from regeneration currents in the chemical process.

The system adopted until then was based on a batch physicochemical process, with limited capacity and low operational frequency. GIGWATER identified three limitations that, combined, made the stability of the treatment unfeasible.

The first limitation was the absence of true equalization. The second limitation was the low capacity for removing soluble load. Finally, the system's stability depended on the operator, not the process. The result was a system that worked sporadically, but could not sustain continuous operation with stability.