Abstract
Seawater intrusion has become one of serious environmental problems in coastal areas. During the replacement of saline water by fresh water in the aquifers, in-situ clay could be released, transport and deposit in the porous media due to the change of hydrodynamic and geochemical conditions, which resulted in the increasing of particle size, plugging of pores and reduction of the permeability. Batch experiments and sand column experiments were explored to study the relationships between the flocculation of in-situ clay and geochemical conditions, by changing ionic strength and ionic type of clay suspension. Column outflow was analyzed for suspended particles and electrical conductivity. The total percentage of colloid straining and interception distribution in porous media was calculated. The results indicate that porous media had an effect on the interception of clay colloid particles with about 10 percent clay colloids captured due to the rough surfaces and spatial structure of porous media. Ionic strength played a key role on the permeability reductions. The higher ionic strength is, the greater the amount of colloidal particles trapped. Ionic type also had a significant effect on the interception of clay colloid particles. Ripening was the main mechanism for the interception within porous media when the bulk solution was potassium chloride while blocking happened when the bulk solution was sodium chloride. The distribution of clay colloids in porous media was heterogeneous. The closer to the sand column inlet was the less interception of clay colloids was. The results can provide the scientific basis for preventing the water sensitivity during the process of salty aquifer restoration.
Similar content being viewed by others
References
Abadzic, S. D., and Ryan, J. N., 2001. Particle release and permeability reduction in a natural zeolite (clinoptilolite) and sand porous medium. Environmental Science & Technology, 35 (22): 4502–4508, DOI: 10.1021/es001868s.
Auset, M., and Keller, A. A., 2006. Pore-scale visualization of colloid straining and filtration in saturated porous media using micromodels. Water Resources Research, 42 (12): 401–414, DOI: 10. 1029/2005WR004639.
Bradford, S. A., Kim, H. N., Haznedaroqlu, B. Z., Torkzaban, S., and Walker, S. L., 2009. Coupled factors influencing concentration-dependent colloid transport and retention in saturated porous media. Environmental Science and Technology, 43 (18): 6996–7002, DOI: 10.1021/es900840d.
Du, Y., Ma, T., Chen, L. Z., Shan, H. M., Xiao, C., Lu, Y., Liu, C. F., and Cai, H. S., 2015. Genesis of salinized groundwater in Quaternary aquifer system of coastal plain, Laizhou Bay, China: Geochemical evidences, especially from bromine stable isotope. Applied Geochemistry, 59: 155–165, DOI: 10. 1016/j.apgeochem.2015.04.017.
Godinez, I. G., Darnault, C. J. G., Khodadoust, A. P., and Bogdan, D., 2013. Deposition and release kinetics of nano-TiO2 in saturated porous media: Effects of solution ionic strength and surfactants. Environmental Pollution, 174 (5): 106–113, DOI: 10.1016/j.envpol.2012.11.002.
Goldenberg, L. C., Magaritz, M., and Mandel, S., 1983. Experimental investigation on irreversible changes of hydraulic conductivity on the seawater-freshwater interface in coastal aquifers. Water Resources Research, 19 (1): 77–85, DOI: 10. 1029/WR019i001p00077.
Grolimund, D., and Borkovec, M., 1999. Long term release kinetics of colloidal particles from porous media. Environment Science and Technology, 33 (22): 4054–4060, DOI: 10.1021/es990194m.
Grolimund, D., Elimelech, M., and Borkovec, M., 1998. Transport of in situ mobilized colloidal particles in packed soil columns. Environmental Science and Technology, 32 (22): 3562–3569, DOI: 10.1021/es980356z.
Han, Z. Y., Zheng, X. L., Chen, J. H., and Li, T., 2007. Factors affecting the water sensitivity of saltwater-freshwater interface. Hydrogeology & Engineering Geology, 34 (6): 24–27.
Han, Z. Y., Zheng, X. L., and Chen, J. H., 2008. Water sensitivity characters of different clay minerals. Hydrogeology & Engineering Geology, 35 (1): 80–82, 89.
Han, Z. Y., Zheng, X. L., Chen, J. H., and Yang, T., 2008. Experimental study on the water sensitivity of the powder-silver sand. Advances in Water Science, 19 (5): 630–634.
Han, Z. Y., Zheng, X. L., and Chen, J. H., 2009. Applications of water sensitivity in situ remediation at saltwater-freshwater interface. Journal of Tianjin University (Science and Technology), 15 (2): 150–155.
Han, Z. Y., Zheng, X. L., and Zhang, X. H., 2008. Water sensitivity assessment of sand aquifer in saline-water intrusion area of Dagu river lower reach. Journal of China Hydrology, 28 (4): 34–37.
Han, Z. Y., Zheng, X. L., and Zhang, X. H., 2008. Determination of the critical salt concentration. Geotechnical Investigation & Surveying, 11: 37–40.
Huang, G., Zheng, X. L., Luan, X. M., and Li, Y. X., 2009. Experimental study of changes in hydraulic conductivity of aquifer medium in salt-freshwater displacement process. Hydrogeology & Engineering Geology, 36 (6): 21–25.
Johnson, W. P., Li, X. Q., and Yal, G., 2007. Colloid retention in porous media: mechanistic confirmation of wedging and retention in zones of flow stagnation. Environmental Science and Technology, 41 (4): 1279–1287, DOI: 10.1021/es061301x.
Masciopinto, C., 2013. Management of aquifer recharge in Lebanon by removing seawater intrusion from coastal aquifers. Journal of Environmental Management, 130 (1): 306–312, DOI: 10.1016/j.jenvman.2013.08.021.
Mesticou, Z., Kacem, M., and Dubujet, P., 2014. Influence of ionic strength and flow rate on silt particle deposition and release in saturated porous medium. Experiment and Modeling, 103 (1): 1–24, DOI: 10.1007/s11242-014-0285-8.
Romanazzi, A., Gentile, F., and Polemio, M., 2015. Modelling and management of a Mediterranean karstic coastal aquifer under the effects of seawater intrusion and climate change. Environmental Earth Sciences, 74 (1): 115–128, DOI: 10. 1007/s12665-015-4423-6.
Shammas, M. I., 2008. The effectiveness of artificial recharge in combating seawater intrusion in Salalah coastal aquifer, Oman. Environmental Geology, 55 (1): 191–204, DOI: 10. 1007/s00254-007-0975-4.
Shainberg, I., Goldstein, D., Mamedov, A. I., and Levy, G. J., 2011. Granular and dissolved polyacrylamide effects on hydraulic conductivity of a fine sand and a silt loam. Soil Science Society of America Journal, 75 (3): 1090–1098, DOI: 10.2136/sssaj2010.0293.
Witteveen, P., Ferrari, A., and Laloui, L., 2013. An experimental and constitutive investigation on the chemo-mechanical behaviour of a clay. Geotechnique, 63 (3): 244–255, DOI: 10. 1680/geot.SIP13.P.027.
Xu, S. P., Liao, Q., and Saiers, J. E., 2008. Straining of nonspherical colloids in saturated porous media. Environmental Science and Technology, 42: 771–778, DOI: 10.1021/es 071328w.
Zhou, J., Zheng, X. L., Flury, M., and Lin, G. Q., 2009. Permeability changes during remediation of an aquifer affected by sea-water intrusion: A laboratory column study. Journal of Hydrology, 376 (3): 557–566, DOI: 10.1016/j.jhydrol.2009.07.067.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhou, J., Qiu, L., Lin, G. et al. Chemical mechanism of flocculation and deposition of clay colloids in coastal aquifers. J. Ocean Univ. China 15, 847–852 (2016). https://doi.org/10.1007/s11802-016-3045-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11802-016-3045-2