Study On Treatment Of Sludge Dewatering Liquid From Landfill Leachate Plant By Electrochemical Ozone Oxidation

The sludge dewatering liquid produced by Jiangcunggou landfill leachate plant was taken as the research object.COD removal rate and ammonia nitrogen removal rate were used as degradation indicators.Two-dimensional electrode method,three-dimensional electrode method,and three-dimensional electrode method combined with ozone were used to treat sludge dewatering liquid.In the experiment,the single factor method,orthogonal method and response surface method were used to optimize the experiment.Response surface method was used to establish the mathematical model of influencing factors on sludge dewatering liquid degradation,and the interaction between various factors was analyzed to obtain the optimal operating parameters of the process.Three-dimensional fluorescence spectroscopy(3D-EMM)and gas chromatography-mass spectrometry(GC-MS)were used to analyze the content changes of organic pollutants before and after sludge dewatering treatment.In the experiment of sludge dewatering liquid treated by two-dimensional electrode method,the influence degree of the selected influencing factors on pollutant removal rate was as follows:current density>plate spacing>reaction time>aeration volume.The COD removal rate was 60.20%when the plate spacing was 3 cm,the current density was50 mA/cm~2,the aeration rate was 0.4 L/min and the electrolysis time was 100 min.The removal rate of ammonia nitrogen was 98.66%when the plate spacing was 3 cm,the current density was 50 mA/cm~2,the aeration rate was 0.5 L/min and the electrolysis time was 100 min.For the treatment of sludge dewatering liquor by three-dimensional electrode method,the results of the response surface test were analyzed.The influence degree of selected influencing factors on the pollutant removal rate was as follows:current density>aeration quantity>activated carbon addition quantity.The removal rates of COD and ammonia nitrogen were 64.69%and 96.21%under the conditions of plate spacing 3 cm,current density 60 mA/cm~2,active carbon addition 20.85 g,aeration 0.62 L/min and electrolysis time 70 min.Compared with the two-dimensional electrode method,the three-dimensional electrode method can achieve a higher removal efficiency of organic pollutants under the same experimental conditions.The feasibility of three-dimensional electrode method combined with ozone for sludge dehydration was studied by changing the aeration source.The removal rates of COD and ammonia nitrogen reached 80.73%and 98.28%respectively under the conditions of plate spacing 3 cm,ozone aeration 0.8 L/min,current density 60 mA/cm~2,active carbon addition 22 g and electrolysis time 180 min.Three-dimensional fluorescence and GC-MS spectra of raw water and water samples treated by three methods were analyzed.The results showed that the three methods had better removal effect on fluorescent organic matter.Compared with the two-dimensional electrode method,the three-dimensional electrode method had stronger removal effect on area IV(soluble microbial metabolites).After the three-dimensional electrode combined with ozone treatment,V(humic acid-like acids)was removed.The removal efficiency of organic matter was obviously enhanced.After three-dimensional electrodes combined with ozone treatment,the content of organic matter in water samples decreased significantly,and the degradation of organic pollutants was more thorough.