Electrocoagulation treated waters

Further investigate relationships between the formation of Fe(II) and Fe(III) and their derivatives during the electrocoagulation process. Iron of a higher state of valence should be more optimal for precipitation, as well as produce a more neutral treated water (Fig. 2). 

Electrochemical technique (also electrocoagulation) is a simple and efficient method for the treatment of potable water. This process is characterized by a fast rate of contaminant removal, a compact size of the equipment, simplicity in operation and low capital and operating costs. Moreover, it is particularly more effective in treating wastewaters containing small and light suspended particles, such as oily restaurant wastewater, because of the accompanying electroflotation effect. 

Can, O.T. (2014) COD removal from fruit juice production wastewater by electrooxidation electrocoagulation and electro-Fenton processes. Desalin. Water Treat., 52, 65-73. 

Both the A1 and Fe trivalent ions form as proton donors, Al(H20)g and Fe(H20)g, which are only stable at low pH [1-3]. At higher pH, they lose protons to form the monomers A1(H20)5(0H) +, A1(H20)4(0H)+, A1(0H)3, and A1(0H)4 progressively as the pH increases. Some of these monomers are unstable and try to form the OH-bridged dimer A1(H20)4(0H)2(H20)4A1 ". These unstable monomers react best at a pH in the range of 5 < pH < 7. This process goes much faster when there are pollutants in the water onto which the dimer can easily form, binding to the pollutant at the same time. The Fe " reactions are similar. These are the standard chemical trivalent ion flocculation processes used in water treated by both chemical and electrocoagulation processes. 

Sahl JW, Gary MO, Harris JK, Spear JR (2011) A comparative molecular analysis of water-filled limestone sinkholes in north-eastern Mexico. Environ Microbiol 13 226-240 Sbizzaro D, Bota GB, Borri RB, Teran FJC (2012) Electrocoagulation/flotation followed by fluidized bed anaerobic reactor applied to tannery effluent treatment. Desalin Water Treat 37 359-363... 

This part describes the electrocoagulation and electroflotation as electrochemical methods to treat waste water. The conventional reactors used and the different disposition of electrodes are pointed out. It is also explained how innovative reactors can improve the process of waste water treatment. Thus, specific energy and electrode consumptions are even smaller without the need for mechanical agitation, pumping requirements and air injection, which could not be achieved in other kinds of conventional gas-Uquid contacting devices. 

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