Coagulation electrocoagulation

Floes formed by EC are similar to chemical floe. But, EC floe tends to be much larger, contains less bound water, is acid resistant, and is more stable. In the chemical coagulation process, it is always followed by sedimentation and filtration. While in the electrocoagulation process, it can be followed by sedimentation or flotation. The gas bubbles produced during electrolysis can carry the pollutant to the top of the solution where it can be more easily concentrated, collected, and removed. 

EC is a simple, efficient, and promising method to remove arsenic form water. Arsenic removal efficiencies with different electrode materials follow the sequence iron > titanium > aluminum. The process was able to remove more than 99% of arsenic from an As-contaminated water and met the drinking water standard of 10p,gL 1 with iron electrode. Compared with the iron electrodes, aluminum electrodes obtained lower removal efficiency. The plausible reason for less arsenic removal by aluminum in comparison to iron could be that the adsorption capacity of hydrous aluminum oxide for As(III) is much lower in comparison to hydrous ferric oxides. Comparative evaluation of As(III) and As(V) removal by chemical coagulation (with ferric chloride) and electrocoagulation has been done. The comparison revealed that EC has better removal efficiency for As(ni), whereas As(V) removal by both processes was nearly same (Kumar et al. 2004). 

Canizares, P., Martinez, P., Jimenez, C., Lobato, J., Rodrigo, M.A. (2006). Coagulation and electrocoagulation of wastes polluted with dyes. Environ. Sci. Technol. 40, 6418-6424. 

Zhu, B.T., Cliford, D.A., Chellam, S. (2005). Comparison of electrocoagulation and chemical coagulation pretreatment for enhanced virus removal using microfiltration membranes. Water Res. 39, 3098-3108. 

For technical applications, electrocoagulators are used to charge the solids in contaminated liquid effluents. Metal hydroxides are produced by a system of soluble electrodes (anodes) which, in suitable electrolytes, cause coagulation of particles into larger floes. 

Electrocoagulation Coagulation induced by exposing a dispersion to an alternating electric field gradient between two sacrificial metal electrodes. Electrocoagulation is apparently due to a combination of the alternating electric field and the adsorption on dispersed particles, or droplets, of ions solubilized from the electrodes. See also reference 17. 

M.M. Emamjomeh, M. Sivakumar, Review of pollutants removed by electrocoagulation and electro-coagulation/flotation processes, J. Environ. Mgmt. 90 (2009) 1863—1879. 

Another electrochemical method that has the potential to be an effective alternative to the various traditional techniques employed for the distillery and/or brewery effluent treatment is electrocoagulation. Electrocoagulation is based on the in situ formation of the coagulant as the sacrificial anode dissolves due to the applied current, while the simultaneous evolution of gases at the electrodes allows for organic pollutant ronoval by flotation (Khandegar Saroha, 2012). 

Ethanol injection,bipolar electrocoagulation therapy, and argon coagulation are all methods used to restore patency of the esophageal lumen by producing tumor necrosis without the need for expensive laser equipment and the stringent safety precautions required for laser therapy. 

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