The consolidated drained tests and numerical analysis on sewage sludge by using sand well

Abstract-The dewatered municipal sewage sludge is very difficult to re-dewatered, and becomes an important issue in wastewater treatment progress. As an effective soft foundation treatment technology, sand well foundation treatment technology could accelerate the rate of consolidation. It is extremely worth exploring whether making use of the sand wells to shorten the distance of drainage can increase the properties of dewatering. In this paper, the test device was first designed and a indoor sludge dewatering of the experiment was completed by using sand well, study the effects and laws of dehydration, enhance the efficiency of dehydration by the numerical analysis and optimization. The results showed that: the role of sand wells can improve the efficiency of sludge dewatering, sand well spacing, load size, load time, and such factors as the initial thickness of the sludge affect the deep dewatering. Through numerical analysis and optimization, this paper argues that the sand well spacing should be 5cm, load may be 800kPa about the size, duration of load could be 2~5h so as to the water content getting down to 60%.