Abstract:
Objective In this paper, by simulating the pond water ecosystem, degradation rule in water and sediment and the impact on aquatic ecosystem of arsanilic acid were studied.
Method Four mini-aquatic pond ecosystems were established; the control was added 100 g pig manure and treated with different mass concentrations of 50, 150 and 500 mg/L of arsanilic acid. Samples of water and 2 cm-depth-sediment were taken. Arsanilic acid was determined by HPLC and the total arsenic contents were determined by HG-AFS.
Result and conclusion The half-life of arsanilic acid increased with the extension of the delivery drug concentration in pond water and surface sediment, which was 3.73 to 16.04 d and 35.17 to 61.27 d, respectively, and the total arsenic showed a distinguished subsidence trend in sediment and degraded slowly. The values of dissolved oxygen(DO), pH, primary productivity(P/R), activities of sediment alkaline phosphatase and catalase, and the content of total nitrogen and phosphorus indicators were regularly detected. The results showed that 500, and 150 mg/L arsanilic acid could cause irreversibly detectable effects on the ponds. High mass concentration of arsanilic acid obviously inhibited catalase activities. The total nitrogen content of sediment showed an inhibition-promotion-change process, and all mass concentrations of the total phosphorus content declined and presented a concentration dependent relationship.