Study Of Phenolic Wastewater Treatment By Cu/Fe/C As Heterogeneous Fenton Catalyst

Phenolic wastewater is a serious threat to human and the environment which originates from a variety of sources.Phenol has a stable chemical structure and is toxic,so phenolic wastewater is difficult to be disposed by conventional methods.The treatment of phenolic wastewater has been a hot research topic for many years.Fenton oxidation is widely used in treatment of persistent organic pollutant,because the·OH which produced by Fenton reagent has a strong oxidizing ability and has no selective oxidation.But traditional Fenton reaction produces a huge amount of iron mud.To solve this problem,heterogeneous Fenton catalyst has gotten more and more attention.The main research direction focuses on preparation of catalyst and the mechanism of the reaction process.Compared with traditional Fenton reagent,the catalytic efficiency of heterogeneous catalysts is lower,which limits their application.So improving the catalytic efficiency of heterogeneous catalyst is an important research direction in the future.It is reported that heterogeneous catalyst prepared by loading Fe2+ onto active carbon has a good catalytic efficiency.To improve the catalytic efficiency of this materials,we prepared a new active carbon catalyst loaded with copper and iron.We use Scanning electron microscope(SEM)and X-ray photoelectron spectroscopy(XPS)to characterize these materials.The result indicate that copper and iron load onto the active carbon successfully.In the bimetallic system,there exists some interaction between copper and iron,which is beneficial to improve the amount of loading.It also suggests that iron loaded on active carbon mainly exist by Fe(II)form.The catalytic efficiency of these materials has been inspected through oxidation experiment with phenol solution.The result suggests that the efficiency of copper-iron-loaded catalyst is better than single metal-loaded ones.0.5g copper-iron-loaded catalyst and 0.5mL hydrogen peroxide are used to oxidate 50mL phenolic solution(1000mg/L).After 3 hours,the removal rate of phenol and COD are more than 95%and 80%respectively.In order to explore the catalytic efficiency of this catalyst under different conditions,we investigate the effect of copper/iron capacity,pH,reaction time,ratio of oxidant/catalyst,additive dosage and additive speed by controlled variable experiment.The results show that when pH is 3-4,reaction time is 3 hours,additive dosage is lOg/L,ratio of oxidant/catalyst is 0.6-0.8 and hydrogen peroxide is added continuously,the catalytic performance is the best.In addition,the catalyst efficiency increases with the copper/iron mass ratio in a certain range.When this ratio is 1:6,the removal rate of phenol and COD are 99.9%and 91%respectively.The two indicators remained about 61%and 47%after repeated 5 times.To explore whether this catalyst has a good efficiency when used for practical wastewater treatment,we ues it to treat salicylaldehyde produces effluent with a resource process,which consists of distill and Fenton oxidation mainly.Phenol,formaldehyde and COD of this effluent are 760mg/L,430mg/L,20000mg/L respectively.After treatment,their removal rate are 96.8%,100%,73.3%respectively.As a preliminary conclusion,copper-iron-loaded catalyst has a high catalytic performance.It is worth further research on mechanism and regeneration to lay the foundation for industrialized application.