Ultrasound-Fenton Method To Landfill Leachate

Sanitary landfill is the main method for processing municipal landfill these days,but it will produce landfill leachate which is very harmful to our environment.The leachate is a kind of liquid which contains lots of toxic and nocuous inorganic and organic matters,its COD is very high while biodegradability(B/C)is low.Pollutant concentration of the landfill leachate used to change largely.If the landfill leachate is discharged into the environment,the soil and groundwater environment will be polluted severely. Currently,all of the processing craft in domestic and foreign are divided into three segments;the biological treatment is taken as the main body craft,the physical-chemical treatment and land method are taken as the pretreatment craft and the post-processing craft,respectively.The leachate used in this dissertation comes from Asuwei Municipal Wastes Sanitary Landfill which is located at Xiao Tangshan,Beijing.Firstly, the leachate is processed by ultrasonic technology or(and)Fenton reagent oxidation.It is found that effect of the degradation and B/C by ultrasonic technology or Fenton reagent oxidation alone is insignificant,while the great improvement can be achieved when the two processes combined,with shorter processing time and better result(with B/C rate up to 0.51),which showed that the combination of these two processes presented better effect than each method alone.Then,the combination processing of ultrasound and Fenton is used. The influence of main factors to processing result is studied,these factors including ultrasonic power,initial pH,probe diameter,quantity of Fe²⁺and H₂O₂.The result shows that,the combination processing can get much better degradation than each method alone,but not prior to other Physic-chemical method.Experimental results indicated that the biodegradability decreased dramatically with the increasing of the initial pH; biodegradability will be increased with the increasing of the ultrasonic power,but at some level of power,the increasing of the probe diameter means the losing of ultrasounic energy,which will destroy ultrasounic cavitation and reduce its biodegradability;With the increasing of H₂O₂, biodegradability will also be increased,but when the magnitude of H₂O₂ is higher than 600 mg/l,the biodegradability will reduce a little;the same as H₂O₂.Fe²⁺will also benefit to biodegradability,but the increment will be reduced when Fe²⁺is higher than 10 mg/l.