Numerical Simulation On β-Hexachlorocyclohexane In The Arctic Ocean

Beta-Hexachlorocyclohexane(β-HCH),as a representative substance,has received extensive attention in Arctic research due to its strong ocean current transport ability.However,there is no research to quantitatively describe the transport route ofβ-HCH into the Arctic Ocean.The Arctic Mass Balance Box Model(AMBBM)is a concentration model used to assess the transport pathways of POPs in the Arctic Ocean.It has been successfully applied to the Arctic fate analysis of α-HCH.This study will use the widely used fugacity method to reconstruct and optimize AMBBM,to calculate the concentration of β-HCH in the Arctic multi-medium environment,to quantitatively analyze the transportation path and fate of β-HCH in the Arctic Ocean,and to explore the relationship between the environmental phase interface.Before the construction of AMBBM,this study used OCED software to calculate the long-distance transportation potential(LRTP)to explain that the transportation path of β-HCH should be mainly liquid phase fluid,while the transportation ofα-HCH is mainly atmospheric.In this study,an AMBBM model under the fugacity method was established,and the environmental behavior differences betweenβ-HCH and α-HCH in the Arctic Ocean were compared by analyzing the results of the model.The model has passed the model evaluation process of mass balance verification,concentration comparison and sensitivity analysis.L ong-distance transportation in the atmosphere is highly efficient,and β-HCH over the Arctic is highly correlated with emissions from countries around the world.The concentration of β-HCH in the Arctic seawater changes more gradually than the concentration of β-HCH in the atmosphere,and the peak appears later.Correspondingly,the concentration of β-HCH in the Arctic biological phase also changes more gradually than the concentration in the dissolved phase of the Arctic Ocean,and the peak appears later.Based on the statistical analysis of the flow,this study shows that during the period from 1945 to 2020,during the path of β-HCH entering the Arctic Ocean,ocean current transportation is the most important transportation path(57.22%),followed by atmospheric transportation(24.52%).In the atmospheric transportation,wet dissolution caused by precipitation occupies an absolute dominant position(92.31%).Due to the small flow,the amount of β-HCH transported by rivers is the least(18.26%).In the fate of β-HCH,78.45% of β-HCH leaves the Arctic Ocean through ocean currents,and about 10% of β-HCH is removed from the Arctic Ocean through biodegradation and seawater diving,respectively.The volatility of the Arctic Ocean is Very low.During 1945-2020,only 0.2% of β-HCH left the Arctic Ocean in volatile form.As of 2020,2.18% of β-HCH remains in the Arctic Ocean environment.There are four interfaces in this model,of which the gas-water interface is the most complex,precipitation is the main transportation path,and the flow of dry and wet sedimentation and gas diffusion is very small.The concentration of β-HCH in the Arctic atmosphere has gone through two stages.In the first stage,the β-HCH in the atmosphere is emitted by the world and enters the Arctic atmosphere through long-distance transportation(LRAT).In the second stage,part of the β-HCH in the atmosphere is volatilized into the atmosphere from the Arctic Ocean,and part of the β-HCH in the atmosphere is still provided by LRAT.;The water-particle interface is in a state of equilibrium with no net exchange;the water-biological interface maintains a large fugacity difference with the environment through the nutrient intake process of organisms,and also removes from the biological phase through biological respiration,excretion and metabolism.Remove.The gas-particle interface is calculated using the steady-state theory of gas-particle distribution.