Experiment Study On Advanced Oxidation Processes For Landfill Leachate

With the development of the city, the landfill leachate was produced in thecollection, transfer and transport, transformation and disposal of municipal solidwaste. Because leachate contains variety of pollutants and the quantity of leachatevaries greatly,leachate treatment becomes a major problem. Biochemical treatmenthas a better removal effect, but the effluent is still difficult to meet the more strictdischarge standards,Physical and chemical method received more and more attentionbecause of its low requirement for water quality and quantity, remarkable removalettcet on nonbiodegradable organism.First, in this thesis, the leachate after biological treatment which is from aTransfer Station, a Refuse Incineration Plant and a Sanitary Landfill in Beijing wasadvanced treated of electro-fenton. In the experiments, the optimization conditionswere decided and three dimensional fluorescence spectroscopy and ultravioletspectrum scanning were used to analyzed the removal characteristics of the leachate.The results showed that:when electro-fenton process was used to treat theleachate of COD<500mg/L, the effluent could meet the level1B standard limit ofDischarge Standard of Water Pollutants of Beijing(DB/307-2005); When leachate ofCOD﹥500mg/L, the effluent needs futher processing in order to meet the dischargestandards.Three dimensional fluorescence spectrum and ultraviolet spectrumscannning annlysis indicated that electro-fenton process had a better removal ofmacromolecular humic acid and fulvic-like with conjugated and polycyclichydrocarbons structure. Most of the organic matters could be degraded into CO2andwater, small bits generated protein-like substances(such as tryptophan-like).Then, in this thesis, the landfill leachate taken from one Transfer Station inBeijing was treated by wet hydrogen peroxide oxidation and catalytic wet hydrogenperoxide oxidation which uses Fe2+as catalyst. Through the experiment,the optimalconditions of each process were determined, three dimensional fluorescencespectroscopy and ultraviolet spectrum scanning were used to analyzed the removalcharacteristics of the leachate in the two kinds of process.The experimental results showed that:in the best experimental conditions of wet hydrogen peroxide oxidation method, the removl rate of COD could be up to68%, butthe removal rate of NH3-N is not obvious, the best removal rate was18%. Bycomparing three dimensional fluorescence spectroscopy analysis,it is found that wethydrogen peroxide oxidation has a good removal effcet on dissolved organic mattersin the leachate such as humic acid-like which could be degraded into fulvic acid oflower molecular weight and a kind of protein-like substances. In catalytic wethydrogen peroxide oxidation,under the optimal condition, the removal rate of CODcould be reacheh to more than90%, but the removal effect of NH3-N is notsignificant,the optimal removal rate was2%. Through analysis of three dimensionalfluorescence spectroscopy on various factors under the various levels, the resultsindicted that reaction temperature and time had a significant effect on the removal oftyrosine-like, the dosage quantity of hydorgen peroxide(the equivalent ratio of CODand H2O2) had a obvious removal effect on tyrosine-like and tryptophan-like, theadding number of times of hydrogen oxidation had a best effect on the removal rate offulvic acid-like.