Studied On Removal Process Of Cyanuric Acid In Aqueous Solution

Cyanuric acid,an important organic chemical intermediates,has been widely used in the synthesis of trichloroisocyanuric acid bleach,antioxidants,corrosion inhibitors and synthetic resins and other fields.However,due to its stable carbon-nitrogen heterocyclic structure,it is difficult to decompose under natural conditions.On the one hand,in the industrial production,cyanuric acid and chlorine compounds will produce explosive materials.It is a direct threat to industrial production safety.On the other hand,if the accumulation of cyanuric acid in the human body,which will produce toxicity to the kidneys and endanger human life and health.Therefore,the efficient and low-cost removal of cyanuric acid in aqueous solution has gradually became one of the important problems of industrial production and daily life.In this thesis,some methods including catalytic oxidation decomposition and resin adsorption are used respectively to remove the cyanuric acid in aqueous solution.For the more their mechanisms of its removal of cyanuric acid are studied.The process was in investigated by analyzing the molar ratio of melamine to cyanuric acid,reaction temperature,time and p H value.the results showed: CA: M = 1: 1,solution temperature was 0-80 ?,pH = 5 and he reaction time was 60 min.Under these conditions,the removal rate of cyanuric acid can reach about 97.8%.The structure of melamine cyanurate(MCA)synthesized by this experiment was characterized by IR,SEM and XRD.The thermal stability of MCA was determined by thermogravimetric analysis.The experiment further confirmed that melamine and cyanuric acid are intermolecular hydrogen bonds.The effects of separation and decomposition of trace cyanuric acid on nanofiltration membrane separation,catalytic oxidation and resin adsorption were investigated.The removal efficiency of cyanuric acid was the highest,which was 95%.The experimental results show that the resin has strong ability to repeat the adsorption of cyanuric acid.The experiment also stduy the effect of sodium chloride concentration on the removal of cyanuric acid in aqueous solution.The results showed that with the increase of sodium chloride concentration,the removal rate of nanofiltration membrane and resin adsorption method decreased obviously,but sodium chloride had no obvious effect on the decomposition of cyanuric acid by catalytic oxidation.The adsorption kinetic behavior and adsorption thermodynamics of the resin on the cyanuric acid were studied.Experiments show that: The adsorption kinetics of the resin is in accordance with the second order kinetic model,which is mainly chemical adsorption.Resin adsorption of cyanuric acid is consistent with the Freundlich isothermal model,which is multilayer adsorption.