Preparation Of Iron Oxyhydroxide/activated Carbon Composite Material And Its Adsorption Capability To Mn(Ⅱ)

Groundwater is an important source of water supply for public drinking water in my country.At present,the groundwater in Northeast,East,and Central South in China is seriously polluted by manganese,which has adversely affected water safety in various regions.Therefore,researching on manganese removal technology and manganese removal materials is of great significance for people’s water safety.For this reason,this research intends to carry out researching on the preparation of composite materials and the removal of Mn（II）in drinking water,and provide technical guidance for the adsorption treatment of manganese-containing groundwater and the construction of an integrated system in the future.In this study,the iron oxyhydroxide/activated ca rbon composite material（Fe OOH@GAC）was prepared by the co-precipitation method.SEM,BET,XRD,FTIR were used to characterize the physical and chemical properties of activated carbon before and after loading.The iron loading and stability of iron oxyhydr oxide were analyzed.And its adsorption performance was exploring through static and dynamic adsorption experiments.The effect of different iron salt,concentration of iron salt,p H of preparation solution and aging time on the removal effect of Mn（II）wa s compared through experiments,and a composite material that efficiently adsorbed Mn（II）was obtained.Through SEM,XRD and FTIR characterization,it can be seen that Fe OOH is successfully loaded on GAC.Fe OOH has a needle-like or rod-like structure with a length of 50～500nm.Fe OOH is loaded successfully on GAC,and it has good p H stability,temperature stability and Oscillation stability.After modified activated carbon,the specific surface area and total pore volume were significantly reduced,and the p H_zpc decreased from 6.8 to 6.0.The static adsorption experiment shows that under the condition of initial concentration of 3mg/L and dosage of 1.0g/L,the removal rate can reach more than97%in the normal groundwater p H range（6.0～8.0）.Its equilibrium time is 300min,and the remaining concentration is 0.07mg/L,which can meet the requirements of drinking water standards.The adsorption behavior of Fe OOH@GAC for Mn（II）follows the Langmuir isotherm equation and quasi-second-order kinetics.The maximum adsorption capacity of Fe OOH@GAC fo r Mn（II）in water is 16.47mg/g,which is 3.25 times that of GAC.Dynamic adsorption experiments show that the adsorption capacity of Fe OOH@GAC is about 2.57 times that of GAC,and the adsorption performance is greatly improved.The change of the zero point potential p H_zpc before and after the modified activated carbon and the FTIR characterization show that the adsorption mechanism of Fe OOH@GAC on Mn（II）is mainly the combined effect of electrostatic attraction and Chemisorption.In summary,as an excellent adsorption material for removing Mn（II）from drinking water,the iron oxyhydroxide/activated carbon composite material provides a new solution for the purification of high manganese groundwater in villages and towns,and has broad application prospects.