Experimental Study On The Effect Of Organic Contaminant On The Physical And Mechanical Properties Of River Sediments

In this study,the physical-mechanical properties of river sediments were systematically studied through laboratory tests,so as to provide reference for practical engineering.The river sediments used in this study were collected from Pu-dong river,Feng-ban river and lake of Shui-shang Park in jin 'an east district of Fuzhou city,Fujian province,and Qi-li river in Yangzhou city,Jiangsu province.Firstly,the physical-mechanical properties of sediments in different areas were compared and analyzed.After that,distilled water and hydrogen peroxide solution were used to leach the sediment,and the effect of contaminant content on the physical-mechanical properties of the sediment was studied.Finally,the change of physical-mechanical properties of artificial contaminated sediments with the types and properties of soluble organic matter was studied.The main works in this study are as follows:(1)A series of physical-chemical tests were carried out on the sediment before and after treatment to investigate the effect of the content of contaminant on the physical properties of the sediments.(2)A series of one-dimensional consolidation and falling head hydraulic conductivity tests were carried out on the remolded river sediment before and after hydrogen peroxide leaching treatment.The variation rules of the sediment compression and hydraulic conductivity behaviors with the content of organic matter were studied,and the key factors affecting the sediment compression and hydraulic conductivity behaviors were clarified.(3)The pore fluids with different concentrations of soluble organic matter(glycerol,urea,potassium humate)were added to prepare artificial contaminated sediments.Sediments samples to carry out a series of physical experiments,discussing physical properties of sediments with different organic matter.Comparing the effect of soluble organic matter on the viscosity,conductivity,and adsorption quantity change of pore fluid,the reason of the change of the physical property of river sediment caused by the decrease of organic matter content was discussed.(4)A series of one-dimensional consolidation and falling head hydraulic conductivity tests were carried out on artificially contaminated sediments samples to investigate the effect of organic matter content on the compressive and hydraulic conductivity of river sediments.Based on the p properties of soluble organic matter and the physical properties of organic soil,the mechanism of the effect of organic matter content on the compression and permeability behavior river sediment was discussed.