Speciation Distribution of Heavy Metals in Sewage Sludge of Jiaozuo and Ecological Risk Assessment
CUI Ying
WANG Hai-lin
LI Yong
WANG Mei
LI Zi-qiang
Abstract：In order to understand the speciation of heavy metal elements in sewage sludge and their ecological risk to agricultural usage,grit chamber sludge and de-watering sludge of Jiaozuo sewage treatment plant were sampled.The speciation analysis of Cr,Pb,As,Cu,Zn and Ni were performed using a modified BCR extraction procedure.Index of geoaccumulation and potential ecological risk index were calculated to assess the potential ecological risk induced by heavy metal elements in the sewage sludge. The results showed that the concentrations of the six heavy metal elements in grit chamber sludge and de-watering sludge of Jiaozuo sewage treatment plant met the requirements of state standards set for sewage sludge of agricultural use.Compared with the grit chamber sludge,the total content of heavy metal elements and the percentage of exchangeable fraction of six heavy metal elements in de-watering sludge were higher;except Cr,percentages of residual fraction of the other heavy metal elements were lower.Among six heavy metal elements,Pb in the sludge showed the highest chemical stability and the lowest bioavailability with the highest percentage of residual fraction(85.69% in grit chamber sludge and 82.25% in de-watering sludge),the lowest percentage of exchangeable fraction(0.29% in grit chamber sludge and 1.2 5% in de-watering sludge );Ni showed the highest highest transport capability and bioavailability with the highest percentage of exchangeable fraction(4.00% in grit chamber sludge and 15.53% in de-watering sludge)and the lowest percentage of residual fraction(24.34% in grit chamber sludge and 1 9.5 6% in de-watering sludge).The index of geoaccumulation indicated that Cr,Pb,As,Cu, Ni belonged to clear level,while Zn belonged to moderate pollution level.The potential ecological risk index indicated that the six heavy metal elements in sludge of Jiaozuo sewage treatment plant had low potential ecological risk,and might be applied to farm land after suitable treatments.
Keywords：sewage sludgeheavy metalfraction analysisindex of geoaccumulationecological riskJiaozuo
Publication Date：2014-01-01
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：7( 65-71 )