BACKGROUND: Biobeds have been well studied in northern Europe, whereas little is known regarding their use in southern Europe. The degradation and adsorption of terbuthylazine (TA) and chlorpyrifos (CP) were studied in three different biomixtures composed of composted cotton crop residues, soil and straw in various proportions, and also in sterilised and non-sterilised soil. RESULTS: Compost biomixtures degraded the less hydrophobic TA at a faster rate than soil, while the opposite was evident for the more hydrophobic CP. These results were attributed to the rapid abiotic hydrolysis of CP in the alkaline soil (pH 8.5) compared with the lower pH of the compost (6.6), but also to the increasing adsorption (K(d) = 746 mL g(-1)) and reduced bioavailability of CP in the biomixtures compared with soil (K(d) = 17 mL g(-1)), as verified by the adsorption studies. CONCLUSIONS: Compost had a dual but contrasting effect on degradation that depended on the chemical nature of the pesticide studied: a positive effect towards TA owing to increasing biodegradation and a negative effect towards CP owing to increasing adsorption. Overall, composted cotton crop residues could be potentially used in local biobed systems in Greece, as they promoted the degradation of hydrophilic pesticides and the adsorption of hydrophobic pesticides.
BACKGROUND: Biobeds have been well studied in northern Europe, whereas little is known regarding their use in southern Europe. The degradation and adsorption of terbuthylazine (TA) and chlorpyrifos (CP) were studied in three different biomixtures composed of composted cotton crop residues, soil and straw in various proportions, and also in sterilised and non-sterilised soil. RESULTS: Compost biomixtures degraded the less hydrophobic TA at a faster rate than soil, while the opposite was evident for the more hydrophobic CP. These results were attributed to the rapid abiotic hydrolysis of CP in the alkaline soil (pH 8.5) compared with the lower pH of the compost (6.6), but also to the increasing adsorption (K(d) = 746 mL g(-1)) and reduced bioavailability of CP in the biomixtures compared with soil (K(d) = 17 mL g(-1)), as verified by the adsorption studies. CONCLUSIONS: Compost had a dual but contrasting effect on degradation that depended on the chemical nature of the pesticide studied: a positive effect towards TA owing to increasing biodegradation and a negative effect towards CP owing to increasing adsorption. Overall, composted cotton crop residues could be potentially used in local biobed systems in Greece, as they promoted the degradation of hydrophilic pesticides and the adsorption of hydrophobic pesticides.
Authors: Juan Salvador Chin-Pampillo; Karla Ruiz-Hidalgo; Mario Masís-Mora; Elizabeth Carazo-Rojas; Carlos E Rodríguez-Rodríguez Journal: Environ Sci Pollut Res Int Date: 2015-02-03 Impact factor: 4.223
Authors: Maria Marinozzi; Laura Coppola; Elga Monaci; Dimitrios G Karpouzas; Evangelia Papadopoulou; Urania Menkissoglu-Spiroudi; Costantino Vischetti Journal: Environ Sci Pollut Res Int Date: 2012-09-11 Impact factor: 4.223