# Degradation

Pesticides in both the particulate and dissolved forms are subject to degradation. The amount of pesticide that is removed from the sediment via degradation is:

         $$pst\_{deg,sed}=k\_{p,sed}\* pst\_{lksed}$$                        8:4.2.8

where $$pst\_{deg,sed}$$ is the amount of pesticide removed from the sediment via degradation (mg pst), $$k\_{p,sed}$$ is the rate constant for degradation or removal of pesticide in the sediment (1/day), and $$pst\_{lksed}$$ is the amount of pesticide in the sediment (mg pst). The rate constant is related to the sediment half-life:

         $$k\_{p,sed}=\frac{0.693}{t\_{1/2,sed}}$$                                              8:4.2.9

where $$k\_{p,sed}$$ is the rate constant for degradation or removal of pesticide in the sediment (1/day), and $$t\_{1/2,sed}$$ is the sediment half-life for the pesticide (days).