3.3. DO in sediments
In the SRP release experiment, the DO concentration in the release treatment group was higher than in the control group (p < 0.05) ( Fig. 3). The average DO concentration at 1.5 mm depth in sediment was 1.05 ± 0.47 mg/L in the control group and 4.08 ± 0.97 mg/L in the release treatment group. The maximal depth of the oxic layer in sediment cores was about 4.0 mm in the release treatment group and about 2.0 mm in the control group.