Application of hydrodynamic cavitation for leachate of municipal landfill site

Abstract

Landfill leachate is generated as a result of rainwater percolating through the landfilled waste and leaching organic and inorganic compounds formed during landfill transformation. Typically, landfill leachate is characterized by a high concentration of organic carbon (with an average COD of about 8000 mg O2/L) and total nitrogen, mainly in the form of ammonia nitrogen (with an average NH3-N of about 1600 mg/L). There are also present some toxic refractive compounds, like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals. Usually conventional treatment such as activated sludge method is insufficient to effectively remove contaminants contained in landfill leachate. Thus in recent years advanced oxidation processes have been more widely applied to oxidize these contaminants. One of these methods, in which reactive hydroxyl radicals with a high oxidizing potential are formed, is hydrodynamic cavitation. The paper presents preliminary research concerning the application of hydrodynamic cavitation in landfill leachate treatment. During the experiment the influence of changes of temperature on the process efficiency was examined. Moreover, changes in essential process parameters, namely TOC and COD were analyzed.