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Atrazine (ATR) continues being one of the most frequently detected pesticides in natural waters and soils. In this work, an electrokinetic-assisted phytoremediation pot test (EKPR) was performed for the remediation of an atrazine-spiked soil; a low electric voltage gradient (1 V cm -1 ) with two different electric field operation times (6 and 24 h per day) was used in combination with ryegrass (Lolium perenne L.). EKPR increased up to 27% and 7% the overall ATR removal from soil as compared to natural attenuation and phytoremediation treatments, respectively. ATR soil concentration vs time curves were fitted to a pseudofirst-order kinetic equation, obtaining ATR half-life values of 8.2, 7.1 and 5.4 days for the treatments corresponding, respectively, to 0, 6 and 24 h day -1 of electric current application. It clearly showed that the ATR removal from soils was enhanced by the electric field. ATR plant accumulation was significantly improved with respect to phytoremediation when the electric current was continuously applied throughout the experiment (24 h day -1 ); most of the ATR residues were accumulated in the shoot biomass of the ryegrass plants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

An electrokinetic-assisted phytoremediation test using maize (Zea mays L.) was conducted in order to assess the role of the electric field on the enhancement of plant uptake and degradation of the moderate polar pesticide atrazine in spiked soils. Twelve different treatments, including two different initial atrazine soil doses (5 and 10 mg kg -1 ) and two different values of the electric field applied (2 and 4 V cm -1 ), together with the corresponding control treatments without plants and/or without electric current, were tested. The application of an electric field during a period of 4 h a day and with periodical polarity inversion (each 2 h) did not caused significant changes in soil pH; moreover, maize plants increased the buffering capacity of the soil. The application of an electric field of 2 V cm -1 led to a slight decrease on maize biomass while the accumulation of atrazine and its main metabolites in plant tissues was significantly enhanced. On the overall, the yield of atrazine removal by electrokinetic-assisted phytoremediation with maize was increased up to 36.5% with respect to the phytoremediation process without electricity. On our knowledge, this work is the first one specifically focused on the removal of organic pollutants from soils by using the combination of phytoremediation and electrokinetic remediation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Pollution of soil and groundwater by atrazine has become an increasing environmental concern in the last decade. A phytoremediation test using plastic pots was conducted in order to assess the ability of several crops and grasses to remove atrazine from a soil of low permeability spiked with this herbicide. Four plant species were assessed for their ability to degrade or accumulate atrazine from soils: two grasses, i.e., ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea), and two crops, i.e., barley (Hordeum vulgare) and maize (Zea mays). Three different doses of atrazine were used for the contamination of the pots: 2, 5 and 10 mg kg -1 . 16 days after spiking, the initial amount of atrazine was reduced by 88.6-99.6% in planted pots, while a decrease of only 63.1-78.2% was found for the unplanted pots, thus showing the contribution of plants to soil decontamination. All the plant species were capable of accumulating atrazine and its N-dealkylated metabolites, i.e., deethylatrazine and deisopropylatrazine, in their tissues. Some toxic responses, such as biomass decreases and/or chlorosis, were observed in plants to a greater or lesser extent for initial soil doses of atrazine above 2 mg kg -1 . Maize was the plant species with the highest ability to accumulate atrazine derivatives, reaching up to 38.4% of the initial atrazine added to the soil. Rhizosphere degradation/mineralization by microorganisms or plant enzymes, together with degradation inside the plants, have been proposed as the mechanisms that contributed to a higher extent than plant accumulation to explain the removal of atrazine from soils., (Copyright © 2017 Elsevier Ltd. All rights reserved.)