| Used old-aged recycling leachate from semi-aerobic landfill as the studyobject, through the laboratory test, compared the influence of anodes on theelectrolytic treatment result, seek for optimal operating conditions of each anodein the electrochemical process and a total optimal electrolysis treatment schemefor leachate. A preliminary quantities analysis on conversion of high chlorideion concentration (Cl-) in leachate in electrochemical process were given andprovided a theoretic basis and technical parameters for engineering application.The experiment results indicated that①electrochemical technology is veryeffective for leachate treatment,and leachate treatment efficiency is different byuseing different anode in electrolysis.chloride concentration value act asignificant function for removal of pollutant when use different anode toelectrolyze leachate in the same operating conditions. When use same anode toelectrolysis ,the treatment result is different with the difference of chloride ionconcentration. the choice of anode material attributed to chloride concentration.Use Ru-Ir/Ti to electrolytic treat for high chloride ion concentration leachateand useβ-PbO2 to electrolytic treat for low chloride ion concentrationleachate.②the optimum operating condition for leachate COD removal isRu-Ir/Ti as anode, pH9,13.2g/l chloride concentration, 12A/dm2 currentdensity ,operating time 60min orβ—PbO2 as anode,pH12,11g/lchlorideconcentration, 12A/dm2 current density,operating time 60min.in above twooptimum operating condition, leachate COD removal efficiency can extendedover 96.9%.③if consider the removal result of COD,colour,Pb2+ .leachatequality as pH,chloride concentration, and energy consumption,the total optimalscheme is Ru-Ir/Ti as anode, pH9,8.8g/l chloric ion concentration, 12A/dm2current density,operating time 45min. under the optimal operating condition,removal efficiency for COD,colour, Pb2+ concentration can reach 94.3%,96.4%, 74.4%, respectively. COD concentration of leachate could be reducedfrom initial concentration of 1369mg/L to 78mg/L,got the first class of landfillleachate dischargeing standard.④the main oxidation formation of Cl- is ClO- and Cl2 in the electrolysis process ,and almost all Cl- concentration stay in leachate by the formation of Cl- and ClO-. When electrolysis in adverse condition, many Cl- can convert to Cl2 and discharged to atmosphere from leachate. The main factor that affect the production of ClO- is anode material and Cl- concentration.⑤different anode and different pH can lead to different product ratio of Cl2. It is essential that decreasing the production of Cl2 to the minimum or decreasing the quantity of discharging Cl2 to outside by engineering measures in electrochemical process,⑥indirect oxidation effect of ClO- is very effective for organic contaminant removal in the electrochemical process,there is a synergistic activity between oxidation of ClO- and anode material. when Ru-Ir/Ti as anode,the oxidation can reach top for organic contaminant removal efficiency.The research of this thesis is a beneficial attempt to promote electrochemical treatment technology of landfill leachate . It not only deepened the understanding of leachate treatment by electrochemical technology,but also provided a technical support for practical engineering applications.
|
PDF Full Text Request