Combined electrochemical processes for the efficient degradation of non-polar organochlorine pesticides. (15th October 2019)

• Record Type: Journal Article
• Authors: Raschitor, A.; Llanos, J.; Rodrigo, M.A.; Cañizares, P.
• Is Part Of: Journal of environmental management. Volume 248(2019)
• Publication Date: 2019-10-15
• Subjects: Organochlorine pesticides -- BDD -- Concentration -- Electro-oxidation -- Electro-fenton; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2019.109289
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: This study deals with the development of efficient and economic electrochemical treatment processes to confront the treatment of liquid wastes containing non-polar organochlorine pesticides. In previous works, it was demonstrated that it is possible to use electrocoagulation (EC) as a concentration technique for a model organochlorine pesticide (oxyfluorfen). Within this framework, the present work describes a process for the degradation of wastes containing non-polar organochlorines (oxyfluorfen or lindane) in two consecutive stages: 1) a first stage of concentration by electrocoagulation; 2) a second stage of electrochemical degradation by electro-oxidation (EO) or electro-Fenton (EF). The first result reached in the present work is that it is possible to remove close to 50% of both pollutants using EO and more that 94% using EF. Additionally, it was proved that the addition of a pre-concentration stage decreases by a factor of 20 the power consumption needed to deplete by EO the same amount of the initial pollutant. Moreover, when EF process is performed to the concentrated stream, the power consumption is further reduced, getting values (for 1-log removal) as low as 14.51 kWh m −3 for oxyfluorfen decrease and 49.7 kWh m −3 for lindane. These results strengthen the fact that the removal efficiency increases with the concentration of the pollutant and demonstrate that the combination of concentration steps and electrochemical degradation technologies is an efficient and promising alternative for the degradation of non-polar organochlorines. Graphical abstract: Image 1 Highlights: A concentration step reduces by 20 the specific power consumption. The electric energy per order is 14.5 kWh m −3 for oxyfluorfen decrease. The electric energy per order is 49.7 kWh m −3 for lindane decrease. The process allows maximum removal degrees of 94% for both oxyfluorfen and lindane.