【摘要】 以吉林省长春市新立城水库为对象,采用连续分级法研究土壤及底泥中的游离态氮(FN)、可交换态氮(EN)、酸解态氮(HN)和残渣态氮(RN)之间的关系,探讨土壤和底泥对氮的吸附等温线、吸附动力学、吸附热力学及不同pH和有机质对氮吸附量的影响。结果表明:富营养化湖库底泥中FN、EN和HN的含量均高于新立城水库底泥和土壤,试样中氮素的稳定性为新立城水库底泥>土壤>富营养化水库底泥。对NH+4-N的吸附动力学可通过准二级反应动力学方程来表示,新立城水库底泥、富营养化湖库底泥和土壤的吸附平衡时间大致为20min,平衡吸附量分别为375.887,156.287,364.966μg/g,等温线可以通过Langmuir方程进行描述,底泥对NH+4-N的平衡吸附量与底泥中游离态氮和可交换态氮含量之和呈显著负相关,相关性系数为0.901 6;吸附热力学表明,随着温度的升高,吸附量逐渐减少,说明样品在完成物理吸附的同时还存在一个弱放热反应。样品对NH+4-N吸附量随着pH的增加而增大,pH在平衡吸附量对土壤的影响要高于底泥,底泥对NH+4-N吸附量随着有机质含量及温度的升高而降低。更多还原

【Abstract】 The objective of the research was to study the relationship between free nitrogen(FN),the exchangeable nitrogen(EN),the acid hydrolysable nitrogen(HN)and the residual nitrogen(RN)of sediments and soil in Xinlicheng Reservoir by the sequential extraction method,explore the adsorption isotherms,the adsorption dynamics,the adsorption thermodynamics,different pH and organic matter on adsorption of nitrogen.The results showed that the concentration levels of FN,EN and RN in eutrophication sediments were higher than that in Xinlicheng sediments and soils,the order of stability of nitrogen was Xinlicheng sediments>soil>eutrophication sediments.The dynamic adsorption data of NH+ 4-N were well described by pseudo second order reaction rate model,the equilibrium adsorption capacity of Xinlicheng sediments,eutrophication sediments and soils were 375.887,156.287,364.966μg/g,adsorption equilibrium time was approximately 20min.The adsorption of NH+ 4-N on three kinds of samples could be well fitted by Langmuir isotherms equation,the equilibrium adsorption capacity of sediments were negatively correlated with the sum of FN and EN,the correlation coefficient was 0.901 6.Adsorption thermodynamics showed that with the temperature rose,the adsorption capacity gradually decreased.Since,there was a weak exothermic reaction beyond the physical adsorption.The NH+ 4-N absorption increased with the increase of pH,the effect of pH on the equilibrium adsorption capacity of the soils was higher than that of the sediments.The adsorption capability of NH+ 4-N decreased with increasing organic matters and temperature.更多还原