| With the development of China's industrialization and modernization,the environmental problems have been paid increasing attention from society.The composition of organic wastewater is complex,and it comes from many sources and routes.In addition to containing a large amount of organic matter,it also contains metal cations,suspend solids,ammonia nitrogen,etc.If it is discharged without treatment,it will cause water pollution and do harm to environment.The conventional treatment of organic wastewater is mostly costly,the process is complicated,and the wastewater cannot be uniformly treated.Therefore,it is necessary to develop a new technology for resource utilization of organic wastewater with low cost and uniform treatment.Coal water slurry(CWS)is a new type of coal-based fuel.It has been widely used in the field of power boilers in China.The application of CWS technology to treat organic wastewater can transform and utilize organic matter from wastewater,and achieve the purpose of organic wastewater's resource utilization.However,due to the complex composition of organic wastewater,these components will have certain effects on the slurry and additives during the preparation of coal water slurry,thus affecting the properties of coal wastewater slurry.In this paper,the slurry properties of coal wastewater slurry,the adaptability of dispersant,the influence of metal ions on slurry properties and dispersants,and the effects of complex components of organic wastewater on stabilizers were studied.Impact.The main work is as follows:The experiment selected four kinds of wastewaters,such as gasification wastewater,carbonized wastewater,sulfur wastewater and external wastewater,and different dispersants for the preparation of coal wastewater slurry.The coal type was selected as Shenhua coal.The effect of wastewater on the slurry properties of CWS and the adaptability of dispersants were studied.The results showed that different wastewaters had different effects on CWS.Carbonized wastewater was not conducive to pulping because of a large amount of contained ammonia nitrogen.Other wastewaters contained reducing substances that changed the surface characteristics of coal to promote slurry formation.Compared with deionized water,the incorporation of wastewater used in the experiment enhanced the pseudoplasticity of the slurry.The rheological curve was fitted to the power rate model.The consistency coefficient increased and the rheological index decreased,which means an increase in pseudoplasticity.In the stability experiment,the incorporation of carbonized water enhanced stability,while the incorporation of other wastewaters was detrimental to stability.The adaptability of the dispersant was studied.The results showed that the law of "polynuclear aromatic hydrocarbons > mononuclear aromatic hydrocarbons > alkane hydrocarbons" appeared in deionized water,but there was little difference in wastewater.In wastewater the impact on coal water slurry is dominated by the composition of wastewater,and the difference caused by dispersants is not obvious.The effects of six metal ions on the properties of CWS and the action mechanism with dispersants were studied.It was found that Fe3+ increased the apparent viscosity of CWS and Cu2+ decreased the apparent viscosity.However,Mg2+,Ca2+,K+ and Na+ showed no significant change.The effect of the addition of Fe3+ and Cu2+ in the stability experiment improved the stability of CWS,and the remaining ions had no significant effect.The effect of the addition of Fe3+ and Cu2+ from the stability experiment improved the stability of the slurry,and the remaining ions had no significant effect.The adsorption behavior of metal ions at the coal-water interface was analyzed by ICPOES and EDS.It was found that the concentration of Fe3+ and Cu2+ decreased significantly after adsorption,and the content of iron and copper element was obviously increased on the coal surface.The experiment also found that the mixture of Fe3+ and the dispersant solution produced flocculent insoluble matter.It was considered to be a complex combined with the change of the content of Fe3+.The complex was analyzed by FTIR and compared with the infrared spectroscopy of original dispersant.The change and shift of the peak were found to have the formation of bound water and the complexation of sulfonic acid groups and Fe3+ during the reaction.The results indicated that the incorporation of Fe3+ and the dispersant were generated and the complex caused the dispersant to "inactivate".In addition,the zeta potential was measured on CWS with metal ions.It was found that the zeta potential of CWS-Fe increased significantly while the zeta potential of CWS-Cu decreased significantly,which was consistent with the experimental results.The effects of different components in organic wastewater on stabilizers were studied.The preparation of coal water slurry was carried out by mixing ammonia nitrogen,COD and inorganic electrolyte into the slurry.The properties of CWS were studied.It was found that the incorporation of ammonia nitrogen resulted in the decrease of stability.The incorporation of COD had no obvious effect on stability.The incorporation of inorganic electrolyte led to a significant decrease in stability,and the results showed that the higher the ion valence state,the more obvious the decrease.In addition,the amount of stabilizer in CWS was also studied.It was found that with the increase of the amount of stabilizer added,the pseudoplasticity of the slurry was stronger and the stability was better.According to comprehensive analysis,if the coal slurry requires longer storage time,0.10% xanthan gum can be incorporated and if the storage time is shorter,0.05% xanthan gum can be incorporated. |
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