The Study On The Treatment Of Coking Wastewater By Modified Char And TiO₂

With the development of industrialization,the problem of water pollution is becoming more and more serious.More researchers have turned their attention to creating efficient water treatment technologies to improve the utilization of water resources.In order to improve the treatment effect,this experiment used pyrolysis furnace to prepare the birth material and titanium dioxide modified coal char,and at the same time,a new one-step hydrothermal method was used to prepare the new doped modified TiO₂,and the phenol solution was used as the simulated wastewater to explore this.The optimal preparation conditions,modification methods,reaction conditions and reaction mechanism of the two materials were also analyzed by XRD,BET,SEM,XPS,UV-VIS photocurrent and other means.In the experiment of adsorption of phenol by coal char,the upper coal was selected by comparison with 200mg/L phenol solution.The optimum treatment efficiency was 20%under the condition of pH=1.The coal char biomass is the best when the rape straw is used,and the efficiency can be increased by 60%.On the basis of this,the modification efficiency of the titanium dioxide can be further increased by10%,and the optimum titanium dioxide consumption is 5%by mass.The SEM characterization results show that the modified coal char is uniformly prepared by the experiment.BET indicates that the biomass and titanium dioxide modification can increase the specific surface area and pore volume of the coal char.In the TiO₂ photocatalytic experiment,the hydrothermal time?6 hours?and the optimum reaction pH?2?were found by comparing the catalytic efficiency with 20mg/L phenol solution.After 180 minutes of energy-saving lamp irradiation,the catalytic efficiency of pure titanium dioxide to phenol can reach 35.0%,far exceeding the microwave method and hydrothermal+calcined titanium dioxide?10%and 22%?.The metal doping modification was carried out,and the doping effect of La was the best among the three metals.The treatment efficiency of TiO₂ doped with 0.5%La was improved by about 30%compared with pure TiO₂.On this basis,non-metallic elements were introduced,and Br was compared and screened,and the treatment efficiency was increased by about 20%when the amount of doping was 20%.XRD,XPS and other characterizations proved that the crystalline titanium dioxide with anatase phase was prepared,and the doped atoms entered the TiO₂ unit cell,which improved the specific surface area of the material.UV-VIS DRS and photocurrent characterization indicate that the forbidden band width of the material after doping is reduced,and the absorption capacity for visible light is improved.Coal char can adsorb higher concentration of phenol wastewater,but can not reduce the biodegradability of organic wastewater.The modified coal char and titanium dioxide are combined to treat phenol wastewater,and the modified coal char and TiO₂ are combined to treat phenol solution?200mg/L?.The dosage of coal char and titanium dioxide is 4g/L and 2.5g/L,respectively.The final removal efficiency can reach more than 90%.At the same time,the BOD/COD can be increased to 0.3 or more.The foundation proves the feasibility of collaborative processing.