Urea removal from aqueous solutions-a review

The abundance of urea in the natural environment is dictated by the fact that it is one of the major products of mammalian protein metabolism. Due to the extensive use of urea in many branches of industry, it is produced in large quantities. Urea enters into the environment not only with wastewater from the production plants but also by leaching from the fields, agro-breeding farms, and the effluents from the plants using it as a raw material. There are many methods of urea removal, but most of them are still being developed or are very new. The methods themselves differ in terms of physicochemical nature and technological ingenuity. Many wastewater treatment methods include processes such as hydrolysis, enzymatic hydrolysis, decomposition in the biological bed, decomposition by strong oxidants, adsorption, catalytic decomposition, and electrochemical oxidation. In this work, methods of urea removal from aqueous solutions have been reviewed. Particular attention was paid to electrochemical methods. [GRAPHICS]