For site ASYC160, a small amount of As(V) (about 6 μg/L) was released from both the original sterilized and nonsterilized sediments after 1 month of aerobic incubation, whereas As(V) became insignificant after 4 months of aerobic incubation (Figure 2B). An addition of 100 mg/L dipotassium phosphate increased As(V) release from both sterilized and nonsterilized sediments with a mean value of 26 μg/L As(V) for 1 month of aerobic incubation and 12 and 2 μg/L As(V), respectively, for 4 months of aerobic incubation (Figure 2B). The addition of 500 mg/L ammonium sulfate (inorganic nitrogenous fertilizers) only slightly increased As(V) release (about 5−7 μg/L) in both sterilized or nonsterilized sediments after 1 month of incubation, whereas As(V) became insignificant after 4 months of aerobic incubation (Figure 2B).