淤泥固化后氮的形态变化及撒规律.doc

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摘  要

湖泊底泥（淤泥）的固化技术已经日渐成熟，并进入了实践工程应用阶段，但有机质含量较高的底泥在固化之后，其中含有的氮元素仍然可能对周围的环境造成二次污染。为了深入地了解固化处理对底泥中的氮形态及浸出的影响，本文研究了普通水泥、硫铝酸盐水泥、膨润土单独作为固化材料固化处理太湖底泥后，底泥中氮的形态和氮的浸出量改变情况；并分析了氮的浸出量与氮的形态之间的关系，以此来分析氮的浸出行为、浸出过程形态变化与外界条件之间的关系。目的在于探视底泥中氮的的潜在迁移规律，预测底泥中氮的的环境污染风险，为含氮的底泥的固化处理提供理论依据。本文得出的主要结论包括：

    （1）底泥固化处理后，氮的的形态变化规律研究。普通水泥作为稳定化材料处理时，根据不同的添加量和养护泥龄，稳定态氮含量增加量在10%~50%之间；硫铝酸盐水泥作为稳定化材料处理时，根据不同的添加量和养护泥龄，稳定态氮含量增加量在5%~40%之间；膨润土作为稳定化材料处理时，根据不同的添加量和养护泥龄，稳定态氮含量增加量在-5%~40%之间。三种材料对太湖底泥进行固化处理时，对氮的的稳定化效果不相同，这可能与材料的性质、氮的的特性有关。

（2）底泥固化处理后，氮的的浸出规律研究。用普通水泥、硫铝酸盐水泥和膨润土分别固化处理底泥后，底泥中氮的的浸出量都得到了不同程度的降低。

（3）在底泥的固化处理过程中，固化材料除了通过降低氮的非稳定态的含量来降低氮的的浸出量外，还存在一些其他作用，如：包裹作用、物理吸附、化学吸附等；而且对于降低氮的的浸出量来说，这些作用要比改变氮的形态有更好的效果。

关键词：湖泊底泥、固化处理、氮的形态、浸出毒性

 

ABSTRACT

The lake sediment (silt) curing technology has matured, and has entered into the stage of practical engineering application, but high organic matter content of the sediment after curing, which contain nitrogen may still cause secondary pollution to the surrounding environment. To in-depth understanding of the solidification treatment of sediment nitrogen forms and leaching effect, this paper studies the ordinary cement,sulphoaluminate cement, bentonite alone as curing curing treatment of sediment in Taihu Lake, sediment nitrogen forms and nitrogen leaching amount of change； and to analyze the relationship between the amount of nitrogen leaching and nitrogen forms, in order to analyze the relationship between the leaching behavior of nitrogen and leaching process of morphological change and external conditions. The aim is to predict the potential migration of nitrogen in sediment, and to predict the environmental pollution risk of nitrogen in sediment,and provide a theoretical basis for the curing and treatment of nitrogen containing sediment. The main conclusions of this paper include：

(1) After curing the sediment, the morphology of the nitrogen was studied. Portland cement as a stabilizing material handling, according to the different adding amount and curing sludge age, stable nitrogen content increased amount between 10% to 50%；sulphoaluminate cement as the stability of materials processing, according to the different adding amount and curing sludge age, stable nitrogen content increased between 5% ~ 40%；bentonite as the stability of materials processing,according to the different adding amount and mud maintenance age, stable nitrogen content increased between the -5%~40%. The effect of the stabilization of nitrogen on the nitrogen was different when the sediment was cured in Taihu by the three materials, which could be related to the properties and the properties of the material.

(2) Leaching law of nitrogen after curing sludge curing. With ordinary cement, sulphoaluminate cement and bentonite are respectively solidified sediment, sediment  

nitrogen leaching amount have been reduced in different degree.

(3) In sediment curing process, curing materials except through non stable state of reduced nitrogen content to reduce nitrogen leaching amount, there are still some of the other effects, such as encapsulation, physical adsorption and chemical adsorption； and to reduce nitrogen leaching amount to say, these effects to better than the change of nitrogen forms.

Key words：Lake sediment, Curing treatment, Nitrogen form, Leaching toxicity