The Research On Removal Boron Through Adorption From Desalted Seawater

With the development of national economy, seawater desalting has become the main developing method in industry and agriculture in 21-century. However, there are many problems during the process of seawater desalting, in which boron removal is the most important one. This paper focus on boron adsorption using processed cotton as cellulose and a specific boron resin named D403 as sorbents and the thermodynamics and dynamics experiment for the two sorbents (cellulose and boron resin). The adsorption mechanism of cellulose is also included in the paper. This research will provide certain theoretic backgrounds for seawater boron removal.The first part of this paper tries to measure the adsorption isothermal curve, the time curve and the column curve of both cellulose and boron resin with the three curves optimized using models and find out the interfere affection to Na⁺, Ca²⁺, Mg²⁺-. SO₄^2- Cl^- in simulated seawater and the regeneration is affection on the adsorption. Through the research, it can find that the rule of cellulose and resin adsorption boron can be well described by Langmuir model;the boron adsorption using cellulose and as sorbents can be well described by two dynamics equation;the time columnar experiment can be well described by Thomas model and Yoon and Nelson model;Na⁺, Ca²⁺, Mg²⁺, SO₄^2- Cl^- have negative affection on the adsorption boron using the cellulose and boron resin and the affection to boron resin is more serious than cellulose and the regeneration has no affection on the sorbents when the regeneration of the sorbents is less than five times.The second part of this paper tries to analyze the adsorption mechanism by explaining the IR and XRD spectrogram, measuring the complexation proportion of boric acid-glucose, boric acid-mannitol, and boric acid-N-methylglucamine, mensurating a series of pH-concentration adsorption curve and founding the half experienced mathematics model, and to study the for cellulose. We can find from the research that the IR and XRD spectrogram shows the exists of H₃BO₃ on the surface of cellulose;there is H⁺ released form the solution and the complexation proportion of the boric acid-glucose in the solution is 1:1, the boric acid-mannitol is 1:2 and the boric acid-N-methylglucamine is 1:2;and the half experienced mathematics model experiment on analyzing PH shows that the cellulose's adsorption of the boracic acid is mainly chemical adsorption with a proportion of 1:1 while physical adsorption with the H⁺ released during the reaction plays a role as assistance.