Title:  Coupling Zero-Valent Iron and Sulfate Radical (ZVI + SO₄^●–) for Removing Emerging Contaminants

Summary:  The Ministry of Science, Technology, and Innovation (MCTIC) Decree # 1.122/2020 prioritized five Technology Areas.  This research project fits into two of those areas:  (a) Technologies for the Sustainable Development (Pollution Treatment and Environmental Preservation) and (b) Technologies for the Quality of Life (Water Safety).  The removal of some of the most prevalent Contaminants of Emerging Concern (CEC) in water bodies of São Paulo state, Brazil, will be studied.  For doing so, two processes will be coupled in a sole continuous, single-pass reactional system, at steady-state regime:  a reductive process (Zero-Valent Iron, ZVI) and an advanced oxidation one (sulfate radical production from persulfate ion).  A solution containing the contaminants will percolate through a reactor filled with steel wool, reacting with it.  The Fe(II), which is a residue of that reaction, will activate the persulfate ion homolysis, turning it into sulfate radical.  First, a multiresidue chromatographic method  will be developed, to simultaneously identify and quantify the selected contaminants.  The reactional system will undergo a multivariate optmization, using the Response Surface Methodology (RSM), aiming at maximizing the joint removal of the contaminants.  Besides the chemical tests necessary to follow up the coupling performance, biological tests will also be performed — ecotoxicology (test-organism:  Raphidocelis subcapitata) and strogenic activity (MCF-7 cells) —.  If the contaminants are removed and the effluent of the reactional system still has significant biological activity, the optmization routine will be repeated aiming at reducing this activity.  It is expected that the processes coupling be capable of removing the selected contaminants, without any significant biological activity.  One also expects this research project to have a great positive impact (as it proposes a simple, low-cost treatment system, which does not require a close watch by operators) on the removal of CECs — currently a true challenge for Water and Wastewater Treatment Stations (WTS and WWTS) worldwide.

Funding:  The National Council for Scientific and Technological Development (CNPq)