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文獻名： Concurrent transport and removal of nitrate, phosphate and pesticides in low-cost metal- and carbon-based materials

 

作者： Dongli Tong^a,b, Jie Zhuang^a,c,d, Jaehoon Lee^c, John Buchanan^c, Xijuan Chen^a

^aKey Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, 110016, China

^bUniversity of Chinese Academy of Sciences, Beijing, 100039, China

^cDepartment of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, TN, 37996, USA

^dCenter for Environmental Biotechnology, University of Tennessee, Knoxville, TN, 37996, USA

 

摘要：Low-cost magnesium- and/or carbon-based materials have a great potential to remove soluble contaminants from surface and ground water. This study examined mechanisms that control the removal of nitrate, phosphate and pesticides (tricyclazole, malathion and isoprothiolane) during their transport through calcined magnesia (MgO) and corn stalk biochar. Various miscible column breakthrough experiments were carried out and morphology and crystallographic structures of reactive materials were examined. Approximately 96% (78,950?mg-NO3-/kg) and 48% (27,455?mg-NO3-/kg) of nitrate were removed from biochar and MgO columns, respectively. Chemical adsorption dominated nitrate removal during early phase (i.e., <11?PVs for biochar and <100?PVs for MgO, respectively), and microbial denitrification dominated during the following phase. 92% of the applied phosphate (6168?mg-PO43-/kg) was removed in MgO column, while much less in biochar column (4%, 347?mg-PO43-/kg). Mineral surface analyses confirmed that electrostatic attraction, ligand exchange, and chemical precipitation were responsible for phosphate removal. For the three pesticides, biochar exhibited larger removal capacity (1260–2778?mg/kg) than MgO (28–2193?mg/kg) due to the functional groups on biochar. The removal of pesticides based on their physico-chemical properties. Malathion had highest removal rate (98–100%), attributing to chemical sorption and bio-degradation, followed by isoprothiolane (47–79%) and tricyclazole (6–64%).