Research And Design Of Solid-Liquid Separation Of Contaminated Soil By Pressure Filtration

Long-term industrial production has been caused a large amount of heavy metals and other harmful substances remain in the land of factory which made the soil contamination seriously.After the relocation of the old industrial estate,the land needs reclamation.Therefore,it is extremely urgent that to restore soil fundamental characteristics and remove soil pollutants.This paper is mainly developed from the following work on the pressure filtration in solid-liquid separation in the contaminated soil ectopic leaching method:The first aspect: through experiments to find the relationship between soil moisture content and filtration parameters in pressure filtration solid-liquid separation.That is,the relationship between soil moisture content and filtration pressure;the relationship between soil moisture content and filtration rate.The second aspect: Aiming at the phenomenon of soil component loss during solid-liquid separation,soil loss is quantitatively described by experiments.In addition,the force of solid-liquid separation equipment is uneven due to gravity settlement of mud.In this paper,the gravity settlement of mud in 30 minutes was measured by experiments.The third aspect : Fluent software was used to simulate the mud flow field in the filter chamber of the filter press,which can be know about the pressure distribution,velocity distribution and Filter cake formation process in the filter chamber.The forth aspect is design the equipments of leaching and pressure filtration solid-liquid separation.According to the experimental data,a horizontal filter press was designed,including the filter press system,feed system,filtrate collection system and hydraulic system,which realize the connection and cooperation between leaching system and solid-liquid separation system,and the function of recycle and reuse of leacheate.The fifth aspect: carried out finite element analysis on the main components of the horizontal press filter.When the push plate works,the force is not uniform.Through the force analysis,the force of the push plate is determined,and the ANSYS software is used to carry out the static analysis of the push plate,and the optimized design is based on the analysis result.By consulting the literature,it is known that there are few studies on the influence of gravity settlement on horizontal pressure filtration process at home and abroad.The content of this paper reveals the relationship between cake moisture content,filtration efficiency and filtration pressure,filtration speed and the influence of gravity settlement on horizontal pressure filtration.It provides the solid-liquid separation equipment and experimental data for practitioners who engaged in contaminated soil remediation and mud-solid-liquid separation,and also provides a reference for future design of pressure-filtered solid-liquid separation system.