Electrochemical / ultrasound / electromagnetic treatment of mature landfill eluate

The purpose of this paper is to develop a treatment system for leachate from old municipal landfills by means of electrochemical, ultrasound and electromagnetic methods in laboratory conditions and at a pilot plant. The leachate was taken from two sanitary landfills (Piskornica and Tarno) and subjected to electrochemical treatment by implementing electrodes made of stainless steel, iron and aluminium, and a simultaneous treatment with ultrasound and recirculation through electromagnetic field. The reactions of pollutants from the leachate with the electrochemically generated hypochlorite, chromates and free radicals as well as thermal decomposition in cavitation bubbles are responsible for fast, efficient removal of organic matter and ammonium. The removal efficiency of COD, BOD5 and ammonium is over 99 % after 85-minute treatment. The removal of heavy metals up to 99.93 % is mostly achieved by means of electrocoagulation with iron and aluminium electrodes. All measured indicators in treated water, both in laboratory conditions and at the pilot plant, were significantly lower with respect to their maximum permitted concentrations in waters that can be discharged into a natural receiving body.