ire¯ecting their toxic-
ity to soil microbial communities. Among the three
types of wastewater, normal and medium strength
wastewater (IW and 5 IW) caused similar degree of
TABLE 2
Concentrations of total heavy metal in mangrove soils at the end of a 26-week wastewater-loading experiment (meanstandard deviation values of
3 replicates are shown).
Heavy metals conc.
(lg gÿ1 dw)
Background C IW 5 IW 10 IW
Total Cu 3.942.62 4.221.49 22.680.09 118.4637.20 172.026.34
Total Zn 16.061.20 17.192.83 51.933.50 232.75 50.70 389.0943.64
Total Cd ND 1.300.55 1.971.71 7.92 3.37 12.811.72
Total Cr 9.942.81 6.280.63 13.990.60 42.18 9.15 74.953.43
Total Ni ND ND 17.370.50 114.35 8.45 211.2723.50
ND: Not detected as the concentration is below the detection limit of AAS.
Fig. 5 Total amount of heavy metals accumulated in various plant
tissues at the end of the loading experiment (mean of three
replicates are shown).
184
Marine Pollution Bulletin