The development of optimization projects and the new facilities implemented in the ETS led to quality assurance and stability of the treated effluents over the whole year. The emission levels were rigorously kept within the limits specified by the legislation in force. Besides the technological resources, the team spirit prevailing among the operation, maintenance and engineering departments has decisively contributed to the exceptional results achieved over the years.
The main final effluent control parameters are temperature, pH, sedimentary solids and suspended matter, Chemical and Biochemical Oxygen Demand (respectively COD and BOD), specific raw water consumption, and Adsorbable Organic Halides (AOX).
Environmental investments in the ETS and the elimination of elemental chlorine as a bleaching agent in the pulp bleaching stage (100% ECF – Elemental Chlorine Free pulp) in 2002 have led to continuous improvement in the quality of CENIBRA’s liquid effluents.
The Company has been developing a number of projects with an aim to ensure and highlight its superior environmental performance in terms of liquid effluents, with particular emphasis on biomonitoring surveys of Doce River involving the quantification of biologic variables upstream and downstream the plant’s sewer outfall, as well as in the mixture zone. Furthermore, works have been carried out to assess the toxicity of specific effluents that make up the raw effluent and to characterize the existing microbiological organisms in the biological treatment. Moreover, operational measures have been taken to lower the amount of residual nutrients in the treated effluents.