Page 327 - e-Book

the algal scum followed by Anabaena cylindrica, Lemm. When compared to other species.

These algae showed luxuriant growth in the crop fields due to availability of all
nutrients in the irrigated water containing the effluent waste. The mixed algal scum after

collection was centrifuged and the residue was taken for analysis of pigments and dried
algal pellet was taken for heavy metal analysis. The mixed algal collection showed high

accumulation of mercury and cadmium in their tissues. The mixed algal culture collected
from the crop fields accumulated 3.2±0.7mg of mercury g -1 dry wt and 2.6±0.4mg of

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cadmium g dry wt (Table-2). Pigment analysis of these mixed algal scum indicated very
interesting results. The total chlorophyll content, phaeophytin content and carotenoid
content of the exposed algal scum significantly decreased by

54.1%; 46% and 40.7% respectively (Table-2).

Samples were collected from the crop fields to assess the stress in the crop fields.

Heavy metal analysis indicated significant accumulation of mercury and cadmium to the tune
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of 8.5±1.3mg of mercury g dry wt and 11.4±0.7mg of cadmium g dry wt in case of green
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gram plant leaves. Pigment analysis of green gram plant leaf indicated significant decrease in
parameters. Total chlorophyll content decreased by 54.9%, total phaeophytin content

decreased by 51.6% and carotene content decreased by 50%. Heavy metal analysis
indicated significant accumulation of mercury and cadmium to the tune of

7.8±0.9mg of mercury g -1 dry wt and 8.3±1.1mg of cadmium g -1 dry wt in case of black

gram plant leaves. Pigment analysis of black gram plant leaf indicated significant
decrease in parameters. Total chlorophyll content decreased by 54%, total phaeophytin

content decreased by 57.9% and carotene content decreased by 41.9%. Heavy metal

analysis indicated significant accumulation of mercury and cadmium to the tune of
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10.2±0.6mg of mercury g dry wt and 13.2±0.8mg of cadmium g dry wt in case of rice
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plant leaves. Pigment analysis of rice plant leaf indicated significant decrease in parameters.
Total chlorophyll content decreased by 48%, total phaeophytin content decreased by 49%

and carotene content decreased by 71.8%. Heavy metal analysis indicated significant
-1
accumulation of mercury and cadmium to the tune of 4.87±1.6mg of mercury g dry wt and
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4.32±0.7mg of cadmium g dry wt in case of ragi plant leaves. Pigment analysis of ragi
plant leaf indicated significant decrease in parameters. Total chlorophyll content
decreased by 68.9%, total phaeophytin content decreased by 69.8% and carotene content

decreased by 75% (Table-2).

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