TY - GEN
T1 - Chemical forms and bioavailability of Cu, Zn, Ni and Cd in fly ash and calcium oxide stabilized sewage sludge
AU - Su, Dechun
AU - WONG, Jonathan W C
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012
Y1 - 2012
N2 - Coal fly ash at 10 and 35% (m/m) was mixed with dewatered sewage sludge (on fresh weight basis) and then the ash-sludge mixture was mixed separately with 1 and 2% (m/m) calcium oxide to kill the entrained pathogens and to suppress the availability of heavy metals enriched in sludge. A sequential extraction method was used to determine chemical forms of Cu, Zn, Ni and Cd in the sludge and fly ash and CaO stabilized sludge. A loamy acid soil amended with sludge and stabilized sludge was used to grow corn under greenhouse conditions. The results showed that sewage sludge amended with coal fly ash and CaO could reduce the availability of Cu, Zn, Ni and Cd in the sludge. Increasing fly ash and CaO amendment rate significantly increased pH and reduced DTPA extractable Cu, Zn, Ni, Cd contents and EC of the sludge. Fly ash and CaO addition significantly reduced the Zn and Cd concentration in exchangeable and total fraction. But add CaO significantly increase the Cu concentration in exchangeable fraction. Majority of Cu was associated with organic form, but Zn and Ni were associated with Fe-Mn oxide and residual forms. Fly ash and CaO addition significantly increase the percentage of Zn and Ni in residual fraction. Addition of 10% fly ash amended sludge and 10% fly ash then 1% CaO amended sludge significantly increased the dry weight yield and decreased the concentrations of Zn, Cu and Cd in shoot of corn. The results demonstrate the beneficial effects of fly ash and CaO addition on suppress the availability of heavy metals enriched in the sludge.
AB - Coal fly ash at 10 and 35% (m/m) was mixed with dewatered sewage sludge (on fresh weight basis) and then the ash-sludge mixture was mixed separately with 1 and 2% (m/m) calcium oxide to kill the entrained pathogens and to suppress the availability of heavy metals enriched in sludge. A sequential extraction method was used to determine chemical forms of Cu, Zn, Ni and Cd in the sludge and fly ash and CaO stabilized sludge. A loamy acid soil amended with sludge and stabilized sludge was used to grow corn under greenhouse conditions. The results showed that sewage sludge amended with coal fly ash and CaO could reduce the availability of Cu, Zn, Ni and Cd in the sludge. Increasing fly ash and CaO amendment rate significantly increased pH and reduced DTPA extractable Cu, Zn, Ni, Cd contents and EC of the sludge. Fly ash and CaO addition significantly reduced the Zn and Cd concentration in exchangeable and total fraction. But add CaO significantly increase the Cu concentration in exchangeable fraction. Majority of Cu was associated with organic form, but Zn and Ni were associated with Fe-Mn oxide and residual forms. Fly ash and CaO addition significantly increase the percentage of Zn and Ni in residual fraction. Addition of 10% fly ash amended sludge and 10% fly ash then 1% CaO amended sludge significantly increased the dry weight yield and decreased the concentrations of Zn, Cu and Cd in shoot of corn. The results demonstrate the beneficial effects of fly ash and CaO addition on suppress the availability of heavy metals enriched in the sludge.
KW - Availability
KW - Calcium oxide
KW - Fly ash
KW - Heavy metal speciation
KW - Sewage sludge
UR - http://www.scopus.com/inward/record.url?scp=84869482703&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/AMR.573-574.560
DO - 10.4028/www.scientific.net/AMR.573-574.560
M3 - Conference proceeding
AN - SCOPUS:84869482703
SN - 9783037854952
T3 - Advanced Materials Research
SP - 560
EP - 567
BT - Environment Science and Materials Engineering
T2 - 2012 International Conference on Environment Materials and Environment Management, EMEM 2012
Y2 - 4 August 2012 through 4 August 2012
ER -