Cuiying Liu;Xin Jiang;Yuan Ma;Barbara J. Cade-Menu

Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Jiangsu Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044 (China);State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China);Agriculture and Agri-Food Canada, Semiarid Prairie Agricultural Research Centre, Swift Current SK S9H 3X2 (Canada

pecb;the application;adsorbents;hcb;decreased;activated carbo

Persistent organic pollutants (POPs) in soils are an environmental concern due to their long-term bioavailability, which could be reduced by adding adsorbents. However, testing of these adsorbents is necessary prior to widespread field application. The effects of three adsorbents, nano-organic montmorillonite, nano-organic silicon dioxide (SiO2), and activated carbon, on hexachlorobenzene (HCB) and pentachlorobenzene (PeCB) accumulation in rice (Oryza sativa L.) plants were tested in a greenhouse experiment using two soils, a Hydragric Acrisol (Ac) and a Gleyi-Stagnic Anthrosol (An). The bioconcentration factors (BCFs) of HCB and PeCB to rice roots were 2.3-3.7 and 2.0-3.0 times those to rice shoots, respectively. The applications of the three adsorbents decreased HCB and PeCB extractability in Ac, while only the application of activated carbon decreased their extractability in An. The bioavailability of HCB and PeCB to rice plants in Ac was higher than that in An. In Ac, the applications of nano-organic SiO2 and activated carbon decreased the BCF of HCB to rice roots by 16.1% and 26.8%, respectively, whereas only the application of activated carbon decreased the BCF of PeCB to rice roots by 31.4%, compared to the control. In An, only the application of activated carbon decreased the BCFs of HCB and PeCB to rice roots by 22.9% and 18.2%, respectively, compared to the control. However, the application of nano-organic montmorillonite inhibited rice growth in both soils. The results of this study suggested that the effectiveness of adsorbents would vary with pollutant and soil types, providing a reference point for developing efficient adsorbents to reduce the ecological risk of POPs.