(a): The allowable limit for the disposal of benzene contained in a mixed sludge from a treatment process is 5 µg/L. Sixty days after disposing of some sludge waste, a sample was collected and analyzed for benzene. The concentration of benzene found in the sludge was 1.37 µg/L. If the first-order removal rate constant for benzene is 0.00345/hr, determine whether the sludge could have been disposed of in the landfill if a sample had been analyzed at the time the sludge was brought to the landfill.

(b); Solve the above problem assuming that the second-order removal rate constant for benzene is 0.0029/hr.