Bioaccumulation of sediment heavy metals in Bellamya aeruginosa and its relations with the metals geochemical fractions
铜锈环棱螺对沉积物中重金属的生物积累及其与重金属赋存形态的关系

A 28-day sediment bioaccumulation test was conducted to study the bioaccumulation of river sediment heavy metals iri Bellamya aeruginosa,and its relations with the geochemical fractions of the metals.A higher bioaccumulation of Cd,Pb,Cu,Cr,Zn,and Mn was found in the hepatopancreas of B.aeruginosa,with the greatest accumulation of Zn(84.32% ±4.36%),followed by Cu(7.67% ±2.84%),Pb(3.62% ± 1.84%),Cr(2.22% ± 1.03%),Mn(1.33% ±0.15%),and Cd(0.83% ± 0.53%).No significant correlations were observed between the heavy metals accumulations in B.aeruginosa hepatopancreas,but the significant positive correlation between the metals pollution index of hepatopancreas and the Nemerow pollution index of sediments suggested that B.aeruginosa could be used as a potential bioindicator for sediment heavy metals pollution.The biota-sediment accumulation factors(BSAFs)for Cd,Cr,Zn,and Mn from different sediments showed a higher variability,while the BSAFs for Cu and Pb were relatively constant.The bioaccumulation of Cd had significant correlations with exchangeable Cd,weak acid soluble Cd,and oxidizable Cd; Pb bioaccumulation had significant correlation with reducible Pb; Cu bioaccumulation had significant correlation with oxidizable Cu; while Cr and Mn bioaccumulation had no correlations with the total concentrations and geochemical fractions of the two metals.Therefore,it would be inappropriate to use the BSAF as the indicator for the bioaccumulation of heavy metals in B.aeruginosa.