Abstract: A process for desulfurizing waste gas is described, wherein an SO.sub.2 containing waste gas is absorbed in an aqueous solution and the resultant solution containing sulfite is treated electrolytically which is much less expensive than the prior art methods, is simpler to implement and avoids the danger of producing explosive gases which is possible in prior art methods based on anodic O.sub.2 formation and cathodic H.sub.2 formation. In this process, electrochemical oxidation of SO.sub.3.sup.2- ions into SO.sub.4.sup.2- ions occurs at the anode as well as a simultaneous formation of H.sup.+ ions, thereby producing H.sub.2 SO.sub.4, while avoiding the production of oxygen. Apparatus suitable for carrying out this process is also described.

Abstract: An anticorrison protected small electric household water heating tank includes a metal tank having a passive anticorrosive layer provided on an inner wall thereof. A U-shaped electric immersion heating element is horizontally arranged in a lower region of the tank. A pair of electrodes are supplied with external current, one being an external current anode horizontally arranged above and perpendicular to the arms of the U-shaped heating element and the other being the tank itself. A reference electrode is also provided in the lower region of the tank. A potentiostat is connected to the reference electrode and tank for detecting the potential between the reference electrode and tank, for comparing the detected potential between tank and reference electrode to a reference voltage and for adjusting the current flow to the external electrodes to maintain an optimum potential between the tank and reference electrode.