Experimental study of a circular economy system for the oxidation treatment of organochlorine compounds

The acknowledgment of the serious hazard caused by the massive use of pesticides and other industrial and commercial products containing organochlorine compounds has prompted the search of the best strategy for the remediation of aquatic and terrestrial environments. Organochlorine compounds are persistent contaminants present in soils and water that easily bio-accumulate and bio-magnify becoming a threat for human health¹.  The in situ chemical oxidation (ISCO) has proven to be an effective method for the decontamination of chlorinated solvents². The ISCO implementation needs specific oxidant-activation conditions that are often difficult to maintain. In a previous study, inert urban waste (concrete residue) was used in a pilot system of circular economy to induce alkaline conditions in interception trenches installed in the unsaturated zone of a contaminated bedrock aquifer³. In the present study, a scaled down set-up was used to produce preliminary data on the solid reactivity and solution changes upon the application of an oxidant, persulfate, which requires alkaline activation. Flow-through columns were filled with grinded concrete waste that was allowed to react with water extracted from the trenches and enriched with persulfate. The results set the basis for the correct in situ application of the planned remediation method.  

1. Islam, M. A.; Amin, S. M. N.; Rahman, M. A.; Juraimi, A. S.; Uddin, M. K.; Brown, C. L.; Arshad, A. Environmental Nanotechnology, Monitoring & Management 2022, 18, 100740.

2. Krembs, F. J.; Siegrist, R. L.; Crimi, M. L.; Furrer, R. F.; Petri, B. G. Groundwater Monitoring & Remediation 2010, 30, (4), 42-53.

3. Torrentó, C.; Audí-Miró, C.; Bordeleau, G.; Marchesi, M.; Rosell, M.; Otero, N.; Soler, A. Environmental Science & Technology 2014, 48, (3), 1869-1877.