| Water is the source of human existence,the base of life.Without the water,as leaving the air,it is difficult to persist for a long time.In the 21st century,with the development of the economic,the progress of society,and now our water resources have been contaminated terrible.There are few freshwater resources that can be cited by us,and a large number of inorganic organic pollutants in drinking water have been detected,.Seawater desalination is a new type of water-making and water-saving technology,which can alleviate the serious shortage of freshwater resources.It is widely used in the world and coastal areas of China,and it also can produce a lot of concentrated seawater.Boric acid is a special pollutant,because of its relatively small molecular weight,as water molecules can freely through the reverse osmosis membrane in reverse osmosis seawater desalination,so it affecting the water quality.Generally the concentration of reverse osmosis water desalination of boric acid is 0.9mg/L in water,Chinese water quality standard is 0.5mg/L.In order to achieve our drinking water standards,we need to combine with other methods.In this study,Amberlite IRA-743 resin was selected.And its surface structure and internal functional groups were analyzed by scanning electron microscopy and infrared spectroscopy.The dosage of Amberlite IRA-743 resin was 4g and the adsorption time was 200min.The experimental results show that the boron removal efficiency of Amberlite IRA-743 resin can reach more than 90%when it is 4g in 1mg/L boric acid solution.Secondly,Amberlite IRA-743 resin was used to study the removal of boron from reverse osmosis seawater desalination in three aspects:adsorption thermodynamics,adsorption kinetics,adsorption and regeneration.The adsorption isotherms of Amberlite IRA-743 resin were found to be in accordance with the Freundlich adsorption isotherm model.The study of adsorption kinetics of boron on Amberlite IRA-743 resin was belong to quasi-second-order kinetics.According to Amberlite IRA-743 resin regeneration and multi-periodic adsorption experiments of boric acid available,the contribution of ion exchange is slightly larger than microporous adsorption,probably accounted for 55%of the adsorption process,microporous adsorption accounted for about 45%.So the physical adsorption Possession of a large part.Besides,the effect of Amberlite IRA-743 resin on the adsorption of boric acid on the temperature and pH value was also studied.It was found that the temperature had little effect on the adsorption of boron by Amber-lite IRA-743 resin.The adsorption of boron was not accelerated by temperature increase.It was found that the temperature had little effect on the adsorption of boron by Amberlite IRA-743.The adsorption of boron was not accelerated by temperature increase.But the higher the pH value is,the higher the adsorption rate is,and the adsorption capacity of boron at pH 11 is the highest,which can reach above 85%.Due to the pH of the effluent is a certain requirement,so choose the pH between 8 to 9 the best.Finally,the effect of humic acid(HA)on the removal of boron in reverse osmosis desalination by Amberlite IRA-743 resin was also considered.In natural water,humic acid is a typical organic matter.It is found that HA has certain adsorption to boric acid,but when the presence of HA,Amberlite IRA-743 resin not only does not promote the removal of boron,but also has certain inhibitory effect. |
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