UV radiation had different effects on HgCl2 and Hg(NO3)2 suggesting that the coexisting negative ion is of great importance to mercury reduction in water.
Introducing KNO3 and CH3OH to this study indicated that OH, which was produced via photolysis of NO3 , should be responsible for the unexpected decreasing reduction
of Hg(NO3)2 under UV radiation.
Study of the Hg(NO3)2 reduction under different UV radiation conditions indicated that UVB induced the highest Hg(NO3)2 reduction, followed by UVA and then UVC, and mercury reduction increases with increasing light intensity.
The pseudo first order rate constant was determined to be 7 104 min1 through concentration gradient method and trail method.
The relative higher rate constant in this study suggested that the abiotic reduction of mercury in the environment deserves some more attention.