Transport velocities of aniline and nitrobenzene in sandy sediment
- 87 Downloads
The research aimed to determine the transport velocities of aniline (AN) and nitrobenzene (NB) in sandy sediment so as to predict the pollution plume in sandy aquifer. The transport velocities of organic compounds in aquifer depend on various factors. This research also evaluated the effects of compound type, single or mixture solute systems, pore-water velocity (v), and pH on the transport velocities of AN and NB. These results will facilitate more precise determination of transport velocities.
Materials and methods
Column experiments containing sorption and desorption periods were conducted using typical sandy sediment from JiangHan Plain, China. Special emphasis was placed on the variation of compounds, solute systems, v from 4.5 to 10 cm h−1, and pH from 5 to 8.5. The transport curves of AN and NB were simulated using different sorption models coupled in HYDRUS-1D and the partition coefficient, Kd, was determined by inverse solution. The retardation coefficient (R) and transport velocity (1/R) were calculated based on Kd and the basic properties of the column. The transport velocities of AN and NB in various experimental conditions were compared and discussed.
Results and discussion
The linear non-equilibrium two-site (L2Site) sorption model coupled in HYDRUS-1D best described the sorption of AN and NB during the transport process in the sandy sediment. The 1/R values of AN and NB were 0.47–0.67 m and 0.16–0.21 m, respectively. AN transported three times faster than NB in both single and mixture systems. Lower v enhanced the transport of AN but displayed limited impact on the transport of NB in single solute system. In mixture solute system, the 1/R values of AN tended to decrease and NB increase at lower v, which suggested an interference between AN and NB transports. Both transport velocities of AN and NB potentially increase with pH.
AN and NB can transport 0.47–0.67 m and 0.16–0.21 m, respectively, when groundwater flows 1 m at various experimental conditions. The transport velocities of AN and NB depend on the type of compounds, single or mixture solute system, v, and pH. All the factors should be considered when we determine the parameter, transport velocities, for prediction of pollution plume.
KeywordsAniline HYDRUS-1D Nitrobenzene Sandy sediment Transport
This study was supported by a grant from the National Natural Science Foundation of China (grant nos. 41830862, 41521001), Hubei Province for Innovative Research Groups (grant no. 2018CFA028), and the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (CUG170103).
- ATSDR (1990) Toxicological profile for nitrobenzene. Public Health Service, U.S. Department of Health and Human Services, AtlantaGoogle Scholar
- China News (2013) Local newspaper report, Hebei “Red color groundwater” aniline concentration exceeded more than 70 times the standard. Available at: http://www.chinanewscom/sh/2013/04–08/4710431shtml. Accessed 11 July 2015
- Hansch C, Leo A, Hoekman D (1995) Exploring QSAR hydrophobic, electronic and steric constants. ACS, Washington, DCGoogle Scholar
- Palma G, Demanet R, Jorquera M, Mora ML, Briceno G, Violante A (2015) Effect of pH on sorption kinetic process of acidic herbicides in a volcanic soil. J Soil Sci Plant Nutr 15:549–560Google Scholar
- Simunek J, van Genuchten MT, Sejna M (2005) The HYDRUS-1D software package for simulating the one-dimensional movement of water, heat, and multiple solutes in variably-saturated media. University of California, Riverside, RiversideGoogle Scholar