Hydraulic performance of HPMC modified bentonites against aggressive solution
Hydroxypropyl methylcellulose(HPMC)was used to enhance the hydraulic performance of natural sodium bentonite to aggressive solution.Hydraulic conductivity and free swell tests using 5000mg/L CuSO4 and 0.5mol/L H2SO4 solution were conducted to test the hydraulic performance and swell ability of the HPMC modified bentonite.The hydraulic conductivity test results show that the hydraulic conductivity of the bentonite to CuSO4 solution decreased by 32.28%to 77.40%after modification with 2%and 5%HPMC,respectively.Whereas,when permeated with H2SO4 solution,the hydraulic conductivity of the bentonite decreased by 73.42%to 92.83%when the mass loading of HPMC was 2%and 5%,respectively.When the HPMC loading reached 2%,the swell ability of the bentonite cannot be improved,whereas when the HPMC loading was up to 5%,the swell ability of bentonite can be enhanced by 2factors.These data illustrate that modification with HPMC could improve the hydraulic performance of bentonite to the aggressive solution,and the higher HPMC mass loading the higher hydraulic performance of bentonite.The improvement in the hydraulic performance should be attributed mainly to the clogging of the pore of the bentonite specimens.
geosynthetic clay liner(GCL)bentonitehydroxypropyl methylcellulose(HPMC)hydraulic conductivityswell index