| Desalination is an important way to solve the shortage of potable water resources.However,the concentration of boron in desalination water after first stage reverse osmosis still exceeds the potable water standard,so the concentration of boron in desalination water should meet the potable water standard(GB5749—2006).First,five commercial resins were screened and studied in this study.The safety,stability,adsorption and desorption properties of the resin were studied to select a better resin for the study of static adsorption.Kinetics and thermodynamics,dynamic adsorption experiments were also carried out,and then the fitting comparison between Yoon-Nelson model and Thomas model was made.Finally,based on the pilot test,a set of resin boron removal device was designed which can solve the problem that the boron concentration exceeds the potable water standard in the first stage reverse osmosis desalination water.The specific research results are as follows:(1)Based on the surface morphology,safety,stability,adsorption and desorption properties of the resin,D564 resin was selected as the raw material for the subsequent desalination water boron removal experiment.D564 resin surface was relatively smooth,resin strength was higher,chemical stability was better.The resin can be used in drinking water treatment;mechanical,chemical,thermal stability was in a better level.Under different experimental conditions(pH,temperature,initial boron concentration,resin dosage),D564 resin had better adsorption performance.(2)The batch adsorption experiment of D564 resin showed that the best adsorption resin temperature was about 35 ?;the optimum adsorption performance of D564 resin has achieved for boron was at pH = 9;Under certain experimental conditions,the boron removal rate of the resin could reach more than 99%,and the adsorption capacity was about 0.99 mg g-1;The resin had high boron selectivity.The batch desorption and regeneration of D564 resin were studied that the desorption equilibrium time of the resin was shorter,which was beneficial to improve the regeneration process efficiency of the resin.It would be better that the concentration of hydrochloric acid controlled at 0.5 mol L-1.The ratio of washing volume(L)and resin mass(g)after resin transformation could be controlled as 1:1.D564 resin conformed to Lagergren's pseudo-second-order model and Freundlich equation.The mechanism of D564 resin was studied that the adsorption principle of resin was mainly by the resin with N-methyl glucosamine chelated boron,and formed a stable complex.(3)Under the single variable control of the experiment,the adsorption effect of the resin was negatively correlated with the inflow rate and the initial boron concentration of the solution,and positively correlated with the height of the resin layer.The desorption and washing effect of resin were positively correlated with the inflow rate;D564 had good regeneration performance.Under the condition of single variable,the dynamic adsorption of D564 resin was more consistent with Thomas model when the flow rate and resin dosage were changed.When the initial boron concentration of the solution was changed,the dynamic adsorption of D564 resin was more consistent with Yoon-Nelson model.According to pilot test and related design requirements,the device consists of three size with ? 0.15×1.65 m resin column,proposal resin regeneration period of 30 days,the device can produce 4320 L of water on a daily basis,which could satisfy about 200 people for potable water needs.The study based on the status quo of boron exceeded in desalination water,D564 resin was screened out to achieve effective boron removal,and a set of resin device was designed to provide reference theoretical basis and relevant parameters for the removal of excess boron in desalination water and making it reach the potable water standard. |
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