Centrifuge test modeling of impact of sediment consolidation on contaminant transportation
ZHENG Jian1,2,LI Yu chao1,2,CHEN Yun min1,2
1. MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China; 2. Institute of Geotechnical Engineering, Zhejiang University, Hangzhou 310058, China
The impact of sediment consolidation induced by capping on velocity of contaminant migration and outflow amount was analyzed in order to study the process of consolidation of sediment and the pore water release accelerate contaminant transport through the cover via advection in sediment capping technology. The special and temporal scaling effects of centrifuge tests were used, and the tests were simulated using numerical method. 1) The relationship between chloride mass concentration in the overlying water and time had a good correlation with that between sediment settlement induced by consolidation and time. The pore water squeezed by sediment consolidation remarkably accelerated the contaminant migration towards the overlying water.The design of contaminated sediment capping is unconservative if only contaminant diffusion is considered. 2) Tests for caps with varied thicknesses showed that the capping layer retained the migration of contaminant. The chloride concentration in the overlying water of 1 cm capping layer was 857% higher than 3 cm capping layer, and a thicker capping layer can significantly reduce the amount of contaminant moving into the overlying water. 3) The sediment settlements calculated by the layer wise summation method simulations are close to the experimental measurements with an average difference of 87%. The sediment consolidation time of centrifuge test was between the time calculated by two different drainage paths (the sediment height before and after consolidation was completed for capping). Sediment consolidation induced by capping can be simulated by centrifuge tests. 4) The numerical results of the sediment settlement under different thickness capping layer were higher than experimental measurements with an average difference of 109%, while those of the chloride mass concentration in the overlying water were lower than experimental measurement with an average difference of 166%. 5) The numerical results show that the breakthrough time can be shortened by 407 times if sediment consolidation is considered compared to diffusion.
ZHENG Jian,LI Yu chao,CHEN Yun min. Centrifuge test modeling of impact of sediment consolidation on contaminant transportation. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2016, 50(1): 8-15.
［1］ 敖静. 污染底泥释放控制技术的研究进展［J］. 环境保护科学, 2005, 30(6): 29-32．
AO Jing. Reviews on development of release control techniques of contaminated sediment ［J］. Environmental Protection Science, 2005, 30(6): 29-32．
［2］ 朱广伟, 陈英旭. 水体沉积物的污染控制技术研究进展［J］. 农业环境保护, 2002, 21(4): 378-380.
ZHU Guang wei, CHEN Ying xu. Reviews on development of pollution control techniques of sediment ［J］. Agro Environmental Protection, 2002, 21(4): 378-380．
［3］ 胡小贞,金相灿,卢少勇,等. 湖泊底泥污染控制技术及其适用性探讨［J］. 中国工程科学, 2009, 11(9): 28-33.
HU Xiao zhen, JIN Xiang can, LU Shao yong, et al. Techniques for sediment pollution control and discussion on the applicability in lakes of China ［J］. Engineering Sciences, 2009, 11(9): 28-33．
［4］ AZCUE J M, ZEMAN A J, MUDROCH A, et al. Assessment of sediment and porewater after one year of subaqueous capping of contaminated sediments in Hamilton Harbour, Canada ［J］. Water Science and Technology, 1998, 37(6): 323-329．
［5］ PALERMOM R. Design considerations for in situ capping of contaminated sediments ［J］. Water Science and Technology, 1998, 37(6): 315-321．
［6］ U.S.EPA. Contaminated sediment remediation guidance for hazardous waste sites ［R］. \[S.l.\]:EPA, 2005．
［7］ 唐艳, 胡小贞, 卢少勇. 污染底泥原位覆盖技术综述［J］. 生态学杂志, 2007, 26(7): 1125-1128．
TANG Yan, HU Xiao zhen, LU Shao yong. In situ capping technology for remediation of contaminated sediment ［J］. Chinese Journal of Ecology, 2007, 26(7): 1125-1128．
［8］ PALERMO M R, MAYNORD S, MILLER J, et al. Guidance for in situ subaqueous capping of contaminated sediments ［R］. Chicago: Great Lakes National Program Office, 1998．
［9］ GIDLEY P T, KWON S, YAKIREVICH A, et al. Advection dominated transport of polycyclic aromatic hydrocarbons in amended sediment caps ［J］. Environmental Science and Technology, 2012, 46(9): 5032-5039．
［10］ THOMA G J, REIBLE D D, VALSARAJ K T, et al. Efficiency of capping contaminated sediments in situ. 2. mathematics of diffusion adsorption in the capping layer ［J］. Environmental Science and Technology, 1993, 27(12): 2412-2419．
［11］ ZEMAN A J. Subaqueous capping of very soft contaminated sediments ［J］. Canadian Geotechnical Journal, 1994, 31(4): 570-577．
［12］ FOX P J. Coupled large strain consolidation and solute transport. I: model development ［J］. Journal of Geotechnical and Geoenvironment Engineering, 2007, 133(1): 3-15．
［13］ FOX P J. Coupled large strain consolidation and solute transport. II: model verification and simulation results［J］. Journal of Geotechnical and Geoenvironment Engineering, 2007, 133(1): 16-29．
［14］ FOX P J, LEE J. Model for consolidation induced solute transport with nonlinear and nonequilibrium sorption ［J］. International Journal of Geomechanics, 2008, 8(3): 188-198．
［15］LEE J, FOX P J. Investigation of consolidation induced solute transport. II: experimental and numerical results ［J］. Journal of Geotechnical and Geoenvironmental Engineering, 2009, 135(9): 1239-1253．
［16］ LEE J, PARK J W. Numerical investigation for the isolation effect of in situ capping for heavy metals in contaminated sediments ［J］. KSCE Journal of Civil Engineering, 2013, 17(6): 1275-1283．
［17］ LYNDON A, SCHOFIELD A N. Centrifugal model tests of the Lodalen landslide ［J］. Canadian Geotechnical Journal, 1978, 15(1): 113．
［18］ Geotechnical centrifuge technology ［M］. London: CRC, 2003:22-25．
［19］ ARULANANDAN K, THOMPSON P Y, KUTTER B L, et al. Centrifuge modeling of transport processes for pollutants in soils ［J］. Journal of Geotechnical Engineering, 1988, 114(2): 185-205．
［20］ KUMAR P R. Scaling laws and experimental modeling of contaminant transport mechanism through soils in a geotechnical centrifuge ［J］. Geotechnical and Geological Engineering, 2007, 25(5): 581-590．
［21］ NAKAJIMA H, HIROOKA A, TAKEMURA J, et al. Centrifuge modeling of one dimensional subsurface contamination ［J］. Journal of the American Water Resource Association, 1998, 34(6): 1415-1425．
［22］ MOO YOUNG H, MYERS T, TARDY B, et al. Determination of the environmental impact of consolidation induced convective transport through capped sediment ［J］. Journal of Hazardous Materials, 2001, 85(1): 53-72．
［23］ MOO YOUNG H, MYERS T, TARDY B, et al. Modeling contaminant transport through capped dredged sediment using a centrifuge ［J］. Journal of Soils and Sediments, 2002, 2(3): 117-128．
［24］ TANG G P, ALSHAWABKEH A N, SHEAHAN T C. Experimental study of nonreactive solute transport in fine grained soils under consolidation ［J］. Waste Containment and Remediation, 2005, 168: 36-46．
［25］ LEE J, FOX P J. An experimental investigation of consolidation induced solute transport ［C］∥Proceedings of GeoCongress. New Orleans: ［s.n.］, 2008: 806813．
［26］ 中华人名共和国建设部. GB/T50123 1999,土工试验方法标准［S］. 北京: 中国计划出版社,1999．
［27］ MCKINLEY J D, PRICE B A, LYNCH R J, et al. Centrifuge modeling of the transport of a pulse of two contaminants through a clay layer ［J］. Geotechnique, 1998, 48(3): 421-425．
［28］SHARMA H D, REDDY K R. Ceoenvironmental engineering: stie remediation, waste containment, and e merging waste management technologies ［M］. New Jersey: Wiley, 2004．
［29］ 谢海建. 成层介质污染物运移机理及衬垫系统防污性能研究［D］. 杭州：浙江大学,2008．
XIE Hai jian. A study on contaminant transport in layered media and the performance of landfill liner sytems ［D］. Hangzhou: Zhejiang University, 2008．
