Adsorption/desorption and degradation of bisphenol A in soils from the water-level-fluctuation zone
To investigate the environmental behavior of bisphenol A(BPA)in the water-level-fluctuation zone(WLFZ),soil samples were collected at different elevations(SL:155m,SM:160m,SH:165m)from the WLFZ in Qingxi Town,Fulin.Batch adsorption/desorption and simulated degradation experiments were conducted to study the adsorption,desorption,and degradation behaviors of BPA in these soil samples.At temperatures of 15℃,25℃,and 35℃,the adsorption isotherms of BPA on soils at various elevations conformed to the Freundlich model,exhibiting decreased adsorption capacity with increasing temperature and showing non-linear adsorption characteristics.The adsorption capacity of BPA in soil samples followed a trend consistent with soil organic matter content,increasing as elevation decreased(SL＞SM＞SH).The values of calculated thermodynamic data △G、△H and△S were all less than zero,indicating that the adsorption of BPA in tested soils was a spontaneous,exothermic process with decreased entropy,dominated by physical adsorption.The desorption hysteresis index HI(0.853-0.981)approached 1,suggesting minimal desorption hysteresis and easy release of BPA from the soils.Under 25℃,the half-life of BPA degradation in soils followed the sequence SL(4.88d)＜SM(6.68d)＜HS(10.07d),indicating slower degradation rates in soils from long-term exposed areas.At 10℃,the half-life of BPA degradation in soil SH extended to 12.01d,which was 1.19 and 1.20 times longer compared to 25℃ and 35℃,respectively,indicating inhibition of BPA degradation under low-temperature conditions.
万方数据
维普
