Evaluation of Lead-Bearing Phases in Municipal Waste Combustor Fly Ash

Electrolytic recovery of lead in used lime leachate from municipal waste incinerator

“…(1)). In the same time, ferrous or aluminium ions were produced by anodic dissolution, which reacted immediately with hydroxide ions in solution to produce Fe(OH) 2 or Al(OH) 3 . These metallic hydroxides were produced up to a sufficient concentration, inducing the formation of a green precipitate and white gelatinous precipitate using Fe and Al electrodes respectively, which contributed in removing a high amount of Pb according to the Eq.…”

“…Indeed, in the first 10 min, Pb was mainly removed by cathodic reduction. It took 10 min for the electrolytic cell to produce enough Al(OH) 3 or Fe(OH) 2 and initiate the polymerization reaction and the subsequent solid formation, which contributes in accelerating Pb removal from UL leachate. The mechanism of metal removal from an acidic solution has been clearly put into evidence while treating an acidic leachate (strongly loaded with Cd) from waste alumina beads using electrochemical technology [41].…”

“…In comparison, a decrease of pH was recorded in the electrolytic cell using aluminium electrodes, when the current intensities increased (1.5 and 2.0 A). Indeed, as the current intensity increased, high amount of Al(OH) 3 was generated. Hydroxide aluminium reacted with water to form H + involving a slight decrease of pH (Eq.…”

“…In Canada, more than 1.7 kg of domestic wastes are produced per capita each day for an equivalent of 16 millions of t annually [2], whereas 196 millions t of municipal wastes are generated each year in the United States [3].…”

“…This practice allows reducing up to 90% the volume of wastes [3,4]. Overall, urban waste incineration generates two types of residues: bottom ash and the residues provided by the air pollution control devices, which are comprised of fly ashes and used lime (UL).…”