【作者】 马宁；

【导师】 王继红；

【作者基本信息】 吉林农业大学 ， 环境工程， 2011， 硕士

【摘要】 水体中的底泥污染,现在是世界范围内的一个重要的环境问题。通过以底泥作为研究对象,对氨氮在底泥中的吸附-解吸行为的研究进展进行较系统的阐述,通过实验研究揭示从底泥中提取的不同粒径有机无机复合体对氨氮的吸附-解吸的特征及影响因素。底泥不同粒径有机无机复合体对不同浓度氨氮溶液的吸附,在相同的环境条件下,能够反映有机无机复合体对氨氮吸附能力的强弱。有机无机复合体的粒径愈小,其吸附量愈大,粒径为0.001-0.005mm的有机无机复合体对氨氮的吸附量明显高于其它三个粒径。粒径为0.05-0.25mm的有机无机复合体对氨氮的吸附量最少,说明粒径愈大,其吸附能力愈弱,伊通河在不同河段的底泥有机无机复合体均呈现出此规律。有机质对不同粒径有机无机复合体吸附氨氮的影响,土壤中可变电荷主要来自有机质,而腐殖质中含有大量的负电荷,对土壤表面负电荷量有较大贡献,所以,粒径较小的复合体中含有较多的负电荷,它们对氨氮的吸附起了决定性作用。粒径愈小,有机质含量愈高,其负电荷对氨氮的吸附能力愈强。伊通河不同河段的有机无机复合体对氨氮的解吸量均随浓度的增加而升高,在浓度为0.001-0.005mol/1范围内,氨氮的解吸量升高的较快,浓度在0.005-0.026mol/1范围内,解吸量升高的较缓慢。在各个粒径中,粒径愈大,其解吸量愈高,即吸附量愈大的粒径,其解吸量愈低。粒径为0.05-0.25mm的复合体对氨氮的解吸量最多,且它们对氨氮的解吸量均呈现良好的线性关系。有机质是影响有机无机复合体对氨氮解吸的主要因素,有机质含量较低的有机无机复合体,其吸附结合能较小,而解吸率较高。伊通河不同河段底泥中有机无机复合体在不同pH值条件下,复合体对氨氮的吸附量均随pH值增加而逐渐升高,粒径为0.001-0.005mm复合体吸附量高于其它粒径,当pH值增加到8-12范围时,其对氨氮的吸附速率最快。在pH值条件下,不同粒径对氨氮的吸附均呈现较好的相关性,且复合体吸附速率的差异性与永久负电荷和可变负电荷关系较大。不同粒径有机复合体对氨氮的解吸量随pH值的增大而升高,粒径为0.001-0.005mm的复合体吸附量高,而解吸量较其它粒径要少很多,说明吸附性能较强的复合体其解吸性能较弱,所以,解吸量随着粒径的减小而降低。不同河段的底泥的复合体均呈现出上述的解吸规律。不同粒径有机无机复合体对于氨氮的吸附,其吸附等温线均以Freundlich型吸附等温线为最优,其次是Herry型吸附等温线,Langmuir型吸附等温线稍差,对于不同河段复合体的吸附等温线均呈现较好的拟合在氨氮吸附动力学实验中,四种方程拟合性的显著效果大小依次为,-级方程较为显,Elovich方程和双常数方程次之,扩散方程拟合性较差,所以一级方程为最优方程。更多还原

【Abstract】 Sediment pollution of water was a major environmental problem in the world. The sediment was research ed as the object of ammonia nitrogen in the sediment of the adsorption-desorption behavior of a systematic exposition of the progress, ammonia nitrogen adsorption-desorption in different size sediments extracted organo-mineral complex of characteristics and influencing factors was revealed in experimental studies.Ammonia solution in different concentrations was adsorbed in organo-mineral complex of different size in the sediment, in the same environmental conditions, the organo-mineral complex on the strength of ammonia adsorption capacity was refleced.The size of organo-mineral complex was smaller, its adsorption capacity was greater, particle size of organo-mineral complex was 0.001-0.005mm, its adsorption amount of ammonia nitrogen was significantly higher than the other three particle sizes, particle size of organo-mineral complex was 0.05-0.25mm, its the adsorption of ammonia nitrogen was the least, indicating that particle size was larger, the adsorption capacity was weaker,the different sections of organo-mineral complex were shown the law in the sediment of Yitong River.Organic matter on adsorption ammonia nitrogen in different size of organo-mineral complex, the impact of variable charge in soils mainly from organic matter, and large amounts of negative charge was contained in humus, negative charge in the soil surface had a greater contribution, therefore, more negatively charged was contained in smaller particle size of the complex, they played a decisive role in the adsorption. Smaller size, higher organic matter content, the stronger of the adsorption capacity on the negative charge.Ammonia nitrogen desorption in different sections of organo-mineral complex was increased with increasing concentration inYitong river, at a concentration of 0.001-0.005mol/L range, the desorption amount of ammonia nitrogen was rised rapidly,at a concentration of 0.005-0.026mol/L range, desorption was rised more slowly. In each size, the size was larger, the desorption was higher, particle size of the larger adsorption capacity, the desorption was lower. The size of complex was 0.05-0.25mm,its desorption of ammonia nitrogen was the most, and desorption of ammonia nitrogen was showed a good linear relationship.Desorption of ammonia nitrogen was affectted by organic matter in complex, it was major factor.The content of organic matter was lower, the adsorption binding energy of complex was smaller than the rate of desorption was higher.At different conditions of pH values, organo-mineral complex of different sections in sediment of Yitong river, the adsorption of ammonia nitrogen in organo-mineral complex was higher with the gradually increased of pH value, particle size was 0.001-0.005mm in complex,its adsorption was higher than other particle size, when the pH value to the range of 8 to 12, the fastest adsorption rate of ammonia nitrogen. In pH, and the adsorption of ammonia nitrogen in different particle size of complex was showed a good correlation, and complex differences in adsorption rate and variable negative charge had the larger relationship between a permanent and negative charge.Desorption amount of ammonia nitrogen in different particle size of complex was increased with the increasing of pH value, particle size was 0.001-0.005mm in complex,its adsorption was the highest, but the desorption was much less than other particle size, the adsorption performance of complex was stronger,but its desorption performance was weaker, so the desorption was decreased with the decreasing of particle size. Different sections of the complex were shown above the desorption regularity in sediment.The adsorption of ammonia nitrogen in organo-mineral complex, the adsorption isotherms were Freundlich and adsorption isotherm model was the best, followed by adsorption isotherm was Herry-type, Langmuir isotherm type was less, good simulation was presented for different sections of organo-mineral complex.In the kinetic experiments of the adsorption, the four equations fit the dominant effect of the order, first-order equation was obvious, Elovich equation and dual constant equation was the second than first-order equation, diffusion equation was poor, so first-order equation was the optimal equation.更多还原