DDT degradation efficiency and ecotoxicological effects of two types of nano-sized zero-valent iron (nZVI) in water and soil

Abstract

Nano-scale zero-valent iron (nZVI) has been conceived for cost-efficient degradation of chlorinated pollutants in soil as an alternative to e.g permeable reactive barriers or excavation. Little is however known about its efficiency in degradation of the ubiquitous environmental pollutant DDT and its secondary effects on organisms. Here, two types of nZVI (type B made using precipitation with borohydride, and type T produced by gas phase reduction of iron oxides under H2) were compared for efficiency in degradation of DDT in water and in a historically (>45 years) contaminated soil (24 mg kg(-1) DDT). Further, the ecotoxicity of soil and water was tested on plants (barley and flax), earthworms (Eisenia fetida), ostracods (Heterocypris incongruens), and bacteria (Escherichia coli). Both types of nZVI effectively degraded DDT in water, but showed lower degradation of aged DDT in soil. Both types of nZVI had negative impact on the tested organisms, with nZVI-T giving least adverse effects. Negative effects were mostly due to oxidation of nZVI, resulting in O2 consumption and excess Fe(II) in water and soil.

Human Risk Assessment of Organochlorine Pesticide Residues in Vegetables from Kumasi, Ghana

“…ough the levels never exceeded the EU MRL, the presence of residues of DDT in these vegetables shows that farmers are still illegally applying this pesticide on their farms. Under anaerobic conditions, DDTdegrades slowly to DDD and to DDE under aerobic conditions [45][46][47][48]. DDE and DDD were not detected in any vegetable sample analyzed in this study.…”

Environmental Nanoremediation under Changing Climate

“…Therefore, nanotechnology offers a new generation of nanomaterials for environmental remediation. This remediation has cost effective solutions in challenging the problems of the environmental cleanup from pollutants (El-Temsah et al 2016). For example, some nanoparticles can be used in remediation of soil or waste water or groundwater pollution because these nanomaterials have the following characterizations (1) the very small size of these nanoparticles can make the injection of them into very small spaces easy and remain active for a long time, (2) the large surface area can help to a high enzymatic activity, (3) the movement of these nanoparticles can be transported with the flow of water and is controlled by gravitational sedimentation, (4) and these nanoparticles can be adsorbed on the solid matrix (Araújo et al 2015;Guan et al 2015;Liu et al 2015;Louie et al 2016;Zhao et al 2016;Dasgupta et al 2017;Kaur et al 2017).…”

“…Thus, using of these nanoparticles in cleaning the environment from pollutants is called nanoremediation. Many studies have been published concerning the benefits of nanoremediation or nanotechnology for environmental clean-up including heavy metals removing from soils (Ingle et al 2014;Araújo et al 2105;Jain et al 2015;Fajardo et al 2015;Jain et al 2016;Gillies et al 2016;Gil-Díaz et al 2016a;Martínez-Fernández et al 2017), using plants in clean up (Ghormade et al 2011;Capaldi Arruda et al 2015;Gil-Díaz et al 2016b;Martínez-Fernández et al 2017), remediation of waste water (Hamza et al 2016;Peeters et al 2016;De Luca and Ferrer 2017;Shekarriz et al 2017;Xue et al 2017) degradation of pesticides in soil and water (El-Temsah and Joner 2013;Gomes et al 2014;El-Temsah et al 2016;Kaushik and Djiwanti 2017). Nanoremediation of soils, as a promising strategy in minimizing the entry of pollutants in plant parts, can be performed using nanoparticles such as zero-valent iron nanoparticles (nZVI), ZnO, TiO 2 , carbon nanotubes, fullerenes and bimetallic nano-metals.…”

Managing Risk in Nanotechnology

“…The enormous reactive surface area of NMs confers many NMs the ability to sorb and transform pollutants, a feature that has been exploited for bioremediation applications of, for example heavy metals, pharmaceuticals or pesticides using nanoscale zero valent Iron particles (El-Temsah et al, 2015 ;Kanel et al, 2006 ;Machado et al, 2013 ). Whether the presence of an NM in a polluted environment ameliorates (e.g.…”