Application of Hydrus -1D Model to Simulate the Transport of some Selected Heavy Metals in Paddy Soil in Thanh Tri, Hanoi

Title:	Application of Hydrus -1D Model to Simulate the Transport of some Selected Heavy Metals in Paddy Soil in Thanh Tri, Hanoi
Authors:	Chu, Anh Đào Khương, Minh Phượng Phạm, Vy Anh Nguyễn, Ngọc Minh Nguyễn, Mạnh Khải
Keywords:	Hydrus-1D;simulation;transport;heavy metal;paddy soil
Issue Date:	2014
Publisher:	ĐHQGHN
Series/Report no.:	Vol 30, No 1 (2014);
Abstract:	Application of fertilizers and pesticides or using waste water for irrigation can result in an accumulation of heavy metals (HM) in cultivation areas. Under flooding condition of the paddy soils, HM can be leached and result in a potential risk for groundwater. In this study, Hydrus – 1D was applied to simulate the infiltration of Cu, Pb and Zn in paddy soils (in Huu Hoa, Dai Ang and Ta Thanh Oai communes, Thanh Tri district, Hanoi) in the time span from 1 to 720 days. Simulations were based on input data of the soils: texture, bulk density, Freundlich constants (Kf and β), head pressure as 20 cm ± 10 cm and assummed concentrations of the HM in irrigated water as 0.5 mmol Cu cm-3, 0.1 mmol Pb cm-3 and 0.75 mmol Zn cm-3. Leaching rates of the HM were observed to decrease in the order: Zn > Cu > Pb. Under constant flooded conditions at a water table of 20 cm, Cu, Pb and Zn were estimated to reach 1 m deep in the soil domain within 193, 312 and 450 days, respectively. At water layers of 10 and 30 cm, the leaching rate of HM increase or decrease 17%, respectively. Speciation experiments revealed that Zn transport might be affected by the presence of Fe-, Al-oxides, while the factor prohibiting the leaching rate of Cu was soil organic matter. Pb showed a strong dependence on both Fe-, Al-oxides and organic matter. These results reinforce the necessity of using transport models to improve predictions of HM transport and more efficient remediation of contaminated aquifers. Uncertainties in modeling arise as several parameters in the simulation can be determined only with significant errors. However, Hydrus-1D is a suitable tool for simulation of the transport of HM in paddy soil.
Description:	p. 22-30
URI:	http://repository.vnu.edu.vn/handle/VNU_123/57275
ISSN:	2588-1094
Appears in Collections:	Earth and Environmental Studies