Adsorption Removal Effect Of Atrazine In Water By Granular Activated Carbon And Its In-situ Regeneration With Ozone Microbubbles

Atrazine causes harm to the environment and organisms due to its long half-life and large amount of application.For the economically underdeveloped areas such as villages and towns,the commonly used adsorption technology has the problems that the adsorption material is easily saturated and becomes invalid and the regeneration efficiency is low.The ozone microbubble regeneration method can effectively avoid the generation of brominated disinfection by-products and reduce the treatment cost.At present,there are relatively few studies on ozone microbubble regeneration of activated carbon.This study compares the adsorption performance of different types of activated carbon and uses ozone microbubbles for in-situ regeneration experiments to provide a feasible method and theoretical basis for the effective operation of the atrazine removal process in water plants.In this paper,coal-based activated carbon,coconut shell activated carbon and nut shell activated carbon are used as adsorbents.Various characterization methods are used to observe the surface morphology and other characteristics,and to investigate the initial concentration of atrazine solution,activated carbon dosage,particle size,water quality background and temperature The removal effect of activated carbon on atrazine under various influencing factors,and the adsorption thermodynamics and kinetic analysis were carried out.The results show that coal-based activated carbon and coconut shell activated carbon have a large specific surface area and a large number of micropores.The adsorption of atrazine on activated carbon is more in line with the quasi-second-order kinetic model and Langmuir model.The removal rate and adsorption of atrazine by coal-based activated carbon are The amount is better than the other two activated carbons.The increase in the dosage of activated carbon causes an increase in the removal rate.With the increase in the particle size of the activated carbon,the adsorption capacity decreases slightly.The effect of using activated carbon to adsorb atrazine solution under the background of deionized water quality and the actual groundwater quality of villages The removal effect is closer,and the high temperature conditions are conducive to the adsorption of atrazine by activated carbon.The dynamic adsorption efficiency and law of the fixed bed under the conditions of different influent flow rate,activated carbon bed height and influent atrazine concentration are studied,and different dynamic adsorption models are used to simulate.Then the saturated activated carbon was regenerated in situ using ozone microbubbles,the regeneration efficiency of activated carbon under different conditions was studied,and the activated carbon before and after regeneration was characterized and its regeneration mechanism was discussed.The results show that with the decrease of the height of the activated carbon adsorption bed,the increase of the initial concentration of atrazine and the increase of the influent flow rate,the time to saturation is shortened.When the concentration of atrazine is 100μg/L,the activated carbon fixed bed can effectively remove the Trazine also makes the effluent water concentration lower than 2μg/L,which meets my country’s"Drinking Water Sanitary Standard",and the dynamic adsorption law conforms to the Bed Depth Service Time model and Yoon-Nelson model.Compared with ordinary aeration and ordinary ozone water regeneration activated carbon,the regeneration effect of ozone microbubbles under the same conditions is better.With the extension of the regeneration time and the increase of the amount of ozone,the regeneration effect is enhanced.When the flow rate of the ozone generator is0.4 L/min,the microbubble generator is aerated for 1 hour,the ozone water concentration is 11.70 mg/L,the regeneration flow rate is 66.7 m L/min,and the ozone consumption per unit activated carbon is 0.020 g O₃/g GAC,When the regeneration time is 3 h,the regeneration efficiency of ozone microbubbles can reach 87.73%.Therefore,activated carbon fixed bed adsorption and ozone microbubble in-situ regeneration is a low-cost and efficient method for removing atrazine in drinking water,which is feasible in practical engineering applications.