Treatment of the solution extracted from metal contaminated soils by reverse osmosis and chemical precipitation.
In this study a process for the remediation of soils contaminated by lead or copper is proposed, consisting of the operations in sequence: soil flushing, membrane treatment, acidification, and metal precipitation. Pb(II) and Cu(II) extraction from a synthetically contaminated soil using a 0.05 M EDTA aqueous solution were investigated in column. The metal removal efficiencies and the final soil metal concentration were 98.2% and 37.96 mg/g respectively for lead and 95.4% and 59.20 mg/kg for copper. The extracted solutions were concentrated through a membrane treatment to reduce the water content up to the 75% and to obtain a permeate metal concentration in compliance with the Italian Environmental Regulation. The recovery of the used EDTA from the retentate solution, with recovery yield of at least 85.4%, was also obtained through acidification. Metal precipitation from the filtered solution was then performed according two different methods, achieving metal removal yield of more than 99.4%.
Di Palma
Luca
L
Dipartimento di Ingegneria Chimica, dei Materiali, delle Materie Prime, Metallurgia Università di Roma La Sapienza, via Eudossiana 18, 00184 Roma, Italy. luca.di.palma@ingchim.ing.uniroma1.it
Ferrantelli
Paola
P
Merli
Carlo
C
Petrucci
Elisabetta
E
D002614:Chelating Agents / Q000737:chemistry; D011232:Chemical Precipitation; D003300:Copper / Q000737:chemistry / Q000302:isolation & purification*; D004492:Edetic Acid / Q000737:chemistry; D004787:Environmental Pollution / Q000517:prevention & control*; D007854:Lead / Q000737:chemistry / Q000302:isolation & purification*; D009995:Osmosis; D012989:Soil Pollutants / Q000302:isolation & purification*
D002614:Chelating Agents; D012989:Soil Pollutants; D007854:Lead; D003300:Copper; D004492:Edetic Acid