Study On Sludge Solidification Technology And Heavy Metal Pollution Control

Because of the problems of economic feasibility, material stability and secondary pollution in solidification treatment of sludge, the studies which include skeleton constructing solidification technology, biochemical effect on material stability of solidification sludge, stabilization for heavy metal, forecast and control for secondary pollution were carried out The particular content includes:(1) The new solidification technology and theory was proposed based on using the silt constructing the skeleton. The XRD, adsorption and pore water analysis experiment were carried out to explain the theory of skeleton constructing solidification technology.(2) The calcium ion was assumed the representative ion in hydration products and the chemical dynamics model was established which describes the chemical reaction between hydration products in solidification sludge and acid. On the other hand, the kinetic model of organic in solidification sludge was established by bioreactor which strengthens the activity of microorganism. The long-term strength was estimated by the above models under the action of acid rain and microorganism.(3) The flexible-wall permeameter was adopted to simulate the acid rain and action of microorganism which influences the long-term permeability of solidification sludge, moreover, the mechanism of permeability change was analyzed.(4) The effect on leaching of heavy metal was studied by three ways. Firstly, pH and Eh value of extraction solution were changed to simulate the chemical condition. Secondly, bioreactor was adopted to reflect the change of chemical condition because of the action of microorganism. Finally, grain diameter of solidification sludge was changed to reflect physical closed action.(5) The breakthrough curves for heavy metals of solidification sludge were obtained by flexible-wall permeameter and the hydrodynamic dispersion parameters were acquired by genetic inverse method.(6) The secondary pollution of heavy metal of solidification sludge was forecast. The pollution control project was provided by the way of summarizing the secondary pollution problem to a inverse problem of source item control and a parameters optimization item.