Study On The Effect Of Effluent Organic Matter In Water Purification Plant On Ag/TiO₂ Photoelectrocatalytic Degradation Of Methyl Orange

Severe water pollution and water resources shortage attribute to the massive discharge of organic dye wastewater.Photocatalysis（PC）technology and photoelectric catalysis（PEC）technology,undisputedly,have caught much attention on account of the advantages of being operable,environmentally friendly and efficient in a variety of dye wastewater treatment technology.Ag-doped nano-Ti O₂ is capable of lifting the photocatalytic and photoelectric catalytic activities.In this paper,Sol-Gel approach is adopted to prepare Ag/Ti O₂ nanoparticles（Ag/TNPs）,while anodizing and electrochemical deposition approaches are to make Ag/Ti O₂ nanotube arrays（Ag/TNTAs）aiming to explore their photocatalytic performance and photoelectric catalytic performance of the degradation of methyl orange（MO）.Ag/TNPs prepared by condensation crystallization have the characteristics of the highest binding degree of Ag and Ti O₂,the highest photocatalytic efficiency and the highest reutilization rate.Ag/TNTAs have taken on a relatively highly organized nanotube structure,and Ag and Ti O₂ combine well with low impedance and high reutilization rates,and PEC degradation performance is much higher than PC,electrochemical oxidation and direct photolysis process.Effluent organic matter（EfOM）from the water purification plant can generate free radicals produced by photoexcitation for the promotion of photodegradation of pollutants,nevertheless,excessive EfOM will inhibit degradation.For this reason,this paper further studies the effect of EfOM on the PC and PEC properties of Ag/TNPs and Ag/TNTAs.Additionally,as it can be seen in the research results,separate EfOM can accelerate the photochemical degradation of MO.However,it can inhibit the photocatalytic performance of Ag/TNPs undoubtedly whether the concentration of EfOM is high or low,meanwhile,changes in p H and ionic strength will not impact the inhibition results.For the reason that EfOM wraps Ag/TNPs,it can cause the utilization rate of its active sites reduction.Simultaneously,EfOM will compete with MO for photons and inhibit the degradation of MO.When the initial concentration of EfOM is less than or equal to 1 mg C L^-1,it promotes the PEC activity of Ag/TNTAs;when the concentration is over 1 mg C L^-1,it inhibits the PEC activity otherwise.This study discloses that there being a non-synergistic effect of photocatalysis between EfOM and nanoparticles,and a synergistic effect between nanotubes at a specific concentration.It follows practices that EfOM will inhibit the photocatalytic degradation of Ag/TNPs of organic compounds in the aquatic environment for one thing,and promote the photocatalytic degradation of Ag/TNTAs for another.