为明确铅、汞、镉和砷在通辽地区土壤中的吸附-解吸特征,采用批量平衡法,研究通辽地区4种典型土壤(草甸土、盐碱土、风沙土和栗钙土)对Pb(Ⅱ),Hg(Ⅱ),Cd(Ⅱ)和As(Ⅴ)的吸附-解吸行为,并分析影响吸附与解吸的因素。结果表明:1)Langmuir模型适合描述Pb(Ⅱ)和Cd(Ⅱ)在这4种土壤中的吸附特征,Freundlich模型适合描述Hg(Ⅱ)和As(Ⅴ)在这4种土壤中的吸附特征。2)4种土壤对重金属离子的吸附顺序是Pb(Ⅱ)〉Hg(Ⅱ)〉Cd(Ⅱ)〉As(Ⅴ);4种土壤对4种重金属的吸附能力不同,对Pb(Ⅱ)的吸附量顺序是栗钙土〉盐碱土〉草甸土〉风沙土,对Hg(Ⅱ)和Cd(Ⅱ)的吸附量顺序是草甸土〉栗钙土〉盐碱土〉风沙土,对As(Ⅴ)的吸附量顺序是栗钙土〉草甸土〉盐碱土〉风沙土。3)二次幂函数可以较好地拟合重金属离子解吸量与吸附量的关系。4)4种土壤对4种重金属离子解吸量顺序是As(Ⅴ)〉Cd(Ⅱ)〉Pb(Ⅱ)〉Hg(Ⅱ);不同土壤对同一重金属离子的解吸量不同,对Pb(Ⅱ)和Cd(Ⅱ)的解吸量为:风沙土〉盐碱土〉栗钙土〉草甸土,对于Hg(Ⅱ)的解吸量为:风沙土〉草甸土〉盐碱土〉栗钙土,对于As(Ⅴ)的解吸量为:风沙土〉盐碱土〉草甸土〉栗钙土。通辽地区4种典型土壤对铅、汞、镉和砷4种重金属的吸附、解吸行为是不同的。
In order to ascertain the properties of adsorption and desorption of lead,mercury,cadmium and arsenic in soil from Tongliao,the behavior of adsorption-desorption of added Hg(Ⅱ),Pb(Ⅱ),Cd(Ⅱ)and As(Ⅴ)in meadow soil,saline alkali soil,aeolian sandy soil and chestnut soil was tested by using batch equilibrium method.And the influenctial factors were also investigated.The result showed:1)Langmuir equation could better fit the adsorption process of Pb(Ⅱ)and Cd(Ⅱ)in four soil,Freundlich equation could better fit the a desorption process of Hg(Ⅱ)and As(Ⅴ)in four tested soil;2)Adsorption capacities of heavy metal ions in 4tested soil were different.The adsorption capacity of Pb(Ⅱ)was in the order as chestnut soil 〉saline alkali soil〉 meadow soil 〉aeolian sandy soil;Adsorption quantity of Hg(Ⅱ)and Cd(Ⅱ)was ranked as meadow soil〉chestnut soil 〉saline alkali soil〉aeolian sandy soil;Adsorptionamount of As(Ⅴ)in 4 tested soil was chestnut soil〉 saline alkali soil〉meadow saline soil〉aeolian sandy soil.Adsorption quantity of the heavy metal ion in 4tested soil was Pb(Ⅱ)〉Hg(Ⅱ)〉Cd(Ⅱ)〉As(Ⅴ);(3)Power function could better fit the adsorption capacities and desorption capacities.Desorption quantity of the heavy metal ion in soil was As(Ⅴ)〉Cd(Ⅱ)〉Pb(Ⅱ)〉Hg(Ⅱ).Adsorption quantity of different soil for the same heavy metal ion was different.For Pb(Ⅱ)and Cd(Ⅱ),desorption quantity was aeolian sandy soil 〉saline alkali soil〉 chestnut soil〉meadow soil;for Hg(Ⅱ),Desorption quantity was aeolian sandy soil 〉meadow soil〉 saline alkali soil〉chestnut soil;for As(Ⅴ),desorption quantity was sandy soil 〉saline alkali 〉meadow soil〉chestnut soil and meadow soil.The behavior of adsorption and desorption of four typical soil from Tongliao for four heavy metal was different.