The Study Of Dynamics Mechanism For DP Isomers Bio-accumulation In Ulva Pertusa

Dechlorane plus (DP) is a kind of synthetic chlorinated flame retardant, and it has been widely used in high polymer materials such as fiber, plastic and cable. DP has two isomers (syn-DP and anti-DP), the abundance fraction fsyn is used to indicate the proportion of syn-DP in total DP.DP is widely used and released into the environment medium, then absorbed by organisms and accumulated in organisms.In the process of enrichment, the value of f fsyn within the organism and environmental exposure may be different, the organism has a selective enrichment between DP isomers.Ulva pertusa is a kind of common large on intertidal zone, it belongs to low trophic level. Ulva pertusain nature and juvenile Ulva pertusa under lab cultivation are used in the research, then put them under different DP concentrations for exposure and eliminating experiment, it aims to determine the effect of developmental stage and DP exposure concentration on its selective enrichment. The experimental period is for 42d (exposing 21d, eliminating 21d), when 21d the Ulva pertusawas transferred to seawater without DP.The Ulva pertusand seawater were determined on 0,7,14,21,28,35 and 42d. In the statistical analysis, "two-box model" was used for simulating the data to calculate the volatilization rate kv, absorption rate k1, eliminating rate k2, metabolic rate KM and half-life t0.5 of syn-DP and anti-DP, analyzing the metabolic kinetic mechanism in Ulva pertusa.The main results in this research were as follows:1. Under the exposure concentration of 105ng/L, both the juvenile Ulva pertusa and Ulvapertusa adult enrich anti-DP selectively.2. Under the exposure concentration of 105ng/L, the dynamic parameters between juvenile Ulva pertusa and Ulva pertusa adult are different.But the t0.5 of anti-DP is higher than syn-DP, which is in accordance with the result of enriching anti-DP selectively.3. When it is under high concentration (1.3×105ng/L) exposure, Ulva pertusa adult enrich anti-DP selectively; when it is under low concentration (78ng/L) exposure, it showed no selective bioaccumulation of DP isomers.4. Under different exposure concentration to Ulva pertusa, the kinetic parameters of two DP isomers are different. When it is under high concentration (1.3×105ng/L) exposure, the t0.5 of anti-DP is higher than syn-DP, which is in accordance with the result of enriching anti-DP selectively; when it is under low concentration (78ng/L) exposure, the t0.5 of anti-DP is lower than syn-DP, showing no selective enrichment of syn-DP.