Research On The Technologcial Conditions And Surfactants In Oil Sludge Washing By Thermochemical Method

This thesis reviews the definition,source,category and hazards of oil sludge,and the related laws and statutes in environment protection.It introduces the burning, thermal desorption, solvent exhaustion, biological treatment, thermochemical cleaning and other methods,compare and evaluate on the its technology characters, application, economic feasibility and the futurity of this novel technology.Taken oily sludge of Liao River Oil field as the sample, new test approachs was attempted on the base of traditional analytical means to study its nature and chemical compositions.Starting from the cleaning of oily sludge via pure water (no cleaning solution) ,we observe the influence of different parameters such as temperature,cleaning time, agitation speed,pH,liquid-to- solid ratio and other monofactors to determine the initial technologcial conditions.Under the initial technologcial conditions,we select different ratios of the ingredients such as Na₂SiO₃,anion surfactant LAS and non-ionic surface active agent AEO-9 and select optimal ratio as LAS:Na₂SiO₃=1:2 (mass ratio) .After two-stage cleaning,the residue oil rate reduces to 0.3%.One-factor analysis of variance and orthogonalizing methods were intiated to optimize technological parameters and decide the main influential parameters.We tested the residue oil rate in the soil and solution COD with the cycle of cleaning solutions.It is observed that thermochemical washing system can adjust the gradation of cleaning unit and cycling times of washing solution and simplify technological process bsed on the specific requirements of residual oil rate.In the flocculation experiment for the waste water, Zeta potential and COD were measured to select the optimum inorganic flocculate solution PFS and organic macromolecule CPAM. Excellent results can be achieved when they were combined.Meanwhile,we improve multi-stage cleanig system partially in the earlier stage,and bring forth the closed circuit cleaning technological conditions to save ingredients,reduce energy,decrease exhaustation and decline the running cost to about 10%.