Combined Oxidative and Bio Method for Removal, Degradation or Disposal of Chlorinated Persistent Organic Pollutants

Modern environmental technologies face massive challenges in dealing with persistent organic pollutants (POPs). The storage and disposal of POPs is now strictly controlled in most countries. However, sustainable techniques for POPs disposal are still lacking. This article discusses new approaches in hazardous waste management.

The performed degradation tests focus on chlorinated hydrocarbons, more precisely on polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT), pollutants that are prevalent worldwide. Both compounds are extremely toxic and bioaccumulating substances. Production and use of PCBs are strictly prohibited in most countries, while DDT is still produced and used in some states. In regards to land restoration of contaminated soils a remediation method is needed that both sustainably degrades the pollutants and at the same time promotes the selfregeneration of the ecosystem.

The experiments on the decontamination of PCB-loaded substrates were carried out in a close-loop reactor using the patented chemical oxidation method Arvox. The original contamination could be degraded by more than 90%, while conventional methods usually do not reach more than 70%.

Degradation tests with DDT-contaminated soil were carried out in situ. Chemical oxidation using Arvox was also applied, followed by a three-month biological post-treatment. In this case, 97% of the DDT compounds were degraded. Analyses of the treated soil showed a pH normalization and a high microflora activity in the substrate. The remediation process can be considered sustainable according to the current state of remediation practices.

The innovative approach of this research is to combine effective on-site chemical oxidation techniques with biological treatment as a new method for the efficient remediation of soils contaminated with halogenated POPs. In the experiments described below, the ecological, economic and social dimensions are taken into account as essential factors for sustainable remediation. 

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