Sludge Amendment Affect the Persistence, Carbon Mineralization and Enzyme Activity of Atrazine and Bifenthrin.

Abstract

Atrazine and bifenthrin persistence study was carried out in three sludge amended soil under laboratory condition. Atrazine persisted shorter in sludge amended soil sludge-3 (half-life 23.4days) followed by sludge-2 (half-life 30.1days) and sludge-1 (half-life 37.1days) than unamended control (half-life 150.5days). Bifenthrin followed the similar pattern with sludge-3 (half-life 43.1days) which increased to 50.3, 60.2 and 75.2days, respectively in sludge-2, sludge-1 and unamended control representing an immense influence of sludges on degradation. Duncan's Multiple Range Test revealed that carbon mineralization process was significantly influenced by all the sludges (p < 0.0001). Sludge-3 indicated highest Cmin (initial 118.16 to final 133.64mg CO2-C/kg) in bifenthrin and 129.91mg CO2-C/kg in atrazine. The relatively high Cmin rate in sludge amended soil than unamended control suggested a lower persistency of both the pesticides and thus decreasing its potential ecological risk. Sludge-3 sludge amended soil increased the dehydrogenase enzyme activity as compared to sludge-1 and sludge-2 sludge in atrazine.