Indoor Model Test Study Of Electroosmotic Dewatering Mud

The urban infrastructure construction generates large amounts of slurrywastewater, whose safe disposal is becoming a major problem in the field ofenvironmental protection. Because of the high water content, reducing the size ofslurry by dewatering is the key to achieve its reduction, reducing disposal and re-use.Although the mechanical dewatering method is currently used and effective toremove the free water of slurry, it is subject to hydraulic conductivity of soil as theslurry contains a lot of silt and clay. Dewatered solid slowly in sludge treatmentresults into difficult to effectively remove the capillary water and bound water. Inrecent years, electroosmosis, the technique for reinforcement of soft soil, is alsointroduced into the slurry dewatering. The experiment found that this technique caneffectively remove this part of the pore water, but it costs high. Therefore, on thepremise of no evidently increase in the cost, researching the technology of rapidlyslurry dewatering by electroosmosis has very important economic and social benefits.In view of this, take the slurry of pile works produced in Ningbo area as example.Fabricate a indoor model test device, which can be carry out electro-osmoticdewatering test and weight dewatering test simultaneously. In order to deeply studythe mechanism for the electro-osmotic dewatering of slurry, the parameters such asthe timing of voltage, current, dehydration are measured in the test. The law ofenergy consumption is analysed, and influence of the potential gradient, moisture andother factors on the electro-osmotic dewatering and energy consumption coefficientsare discussed. Study shows that, at the beginning of electricity, dewatering rapidly,and low power consumption. And the greater the voltage gradient, the greater theamount of current and dehydration, electroosmosis relatively time is also shorter.To study the measures and means of speed up electro-osmotic dehydration ofslurry, jointly weight dehydration, load dehydration and adding chemicals and othermeans were also tried. Tests showed that electro-osmotic dehydration combined loadsis greater, while the weight dehydration is less effective, and the key of add chemicalsis to find the right type and dosage. To verify the effect of electro-osmotic dehydration, carried on the comparison ofthe amount of dehydration, electric current and energy consumption of direct passageof current and current after the permeability respectively. Analysis showed that thedirect electro-osmotic dehydration energized better, less power consumption.By analyzing the changes in the height of slurry during the test and the watercontent of later test, it is found that the settlement of slurry is obvious in the early.When the moisture content is close to30%, the dehydration effect was no longersignificant.Finally, the effect of electrode contact area with the slurry is discussed. It shouldbe as possible as to increase the electrode contact area with the slurry. So that thecurrent in slurry can be more uniform and the measured data can be more accurateduring the electroosmosis experiment. And it can increase the amount of dehydrationand the dehydration rate of speed, also the final dewatering better.