Modified Nano Tio <sub> 2 </ Sub> Of Mine Water In The Photocatalytic Applications

As an advanced oxidation technology,the nano-TiO₂ photocatalytic technology can degrade the pollutants effectively without secondary pollution.But the photocatalytic performance of pure nano-TiO₂ is not good, so its application is limited.In order to improve the photocatalytic activity,modification of pure nano-TiO₂ is an effective way.While the mine water is a kind of reusable water,in this way,using the nano-TiO₂ in the treatment of mine water will be significant to alleviate the shortage of water resources and achieve sustainable economic development of the mining areas.The WO₃ modified and the PEG modified nano-TiO₂ were prepared with the sol-gel technology.Both were characterized or tested with XRD,SEM,XPS, IR,TG-DTA,etc.Research of the degradation of methyl orange caused by the photocatalysis of modified nano-TiO₂.The kinetics of photocatalysis in methyl orange were studied.The influence factors such as the amount of photocatalyst,initial concentration of the solution,reaction time, temperature and the pH on the degradation of methyl orange were also investigated and the optimum amount of WO₃ and PEG were determined.The dynamics of the degradation of methyl orange under photo-oxidation and photo-catalyze was compared.The influences of 7 kinds of inorganic ions to the activity of the modified TiO₂ on catalyzing and degrading the COD in the water were studied. It is found that HCO₃^-,SO₄^2-,Cl^-and Ca²⁺ all can restrain the two photocatalysts PEG400-TiO₂ and TiO₂ when they reach the actual concentration in the coal mine water,and the order of their restraining capacities is HCO₃^-＞SO₄^2-＞Cl^-＞Ca²⁺.The Cl^- can improve the performances of the two photocatalysts when its concentration is low(0.9～8.9mmol/l); Mn²⁺ has no influence on the photocatalysts when it reaches the actual concentration(0.0013mol/L),while when its concentration is more than 0.013mol/L,it could restrain the photocatalytic performance of TiO₂,and it can restrain the catalytic performance of PEG400-TiO₂ only when its concentration is more than 0.039mmol/L.The Cu²⁺ can improve the performances of the two photocatalysts when its concentration is 0.008～0.072mmol/L,while when its concentration is more than 0.072mol/L,it can restrain the photocatalytic performance;Like Mn²⁺ and Cu²⁺,Fe³⁺ has no influence on the photocatalysts when it reaches the actual concentration (0.0457mmol/L),and it can greatly improve the performances of the two photocatalysts when its concentration is 0.2～0.7mmol/L,but it can restrain the photocatalytic performance when its concentration is more than 0.8mmol/L.When the concentration of each ion is very close to the one in the actual mine water,it shows that HCO₃^- and SO₄^2-,HCO₃^- and Cl^-,SO₄^2- and Cl^- all have obvious influences on the degradation rate of the two photocatalysts through the two-factor analysis of variance;Both Mn²⁺ and Cu²⁺ have no influence on the degradation rate of the two photocatalysts;When the Mn²⁺ and Ca²⁺ coexist or Cu²⁺ and Ca²⁺ coexists,it is Ca²⁺ that influences the degradation rate of the both photocatalysts.Experimentation of the activated carbon load modified Ti₂ on the coal mine water has been researched.5d experiment on the serious against standard indicators,such as fluoride,nephelometer,chroma,Hg²⁺,Cr⁶⁺, coliform bacteria and parameters of the total number of the bacteria has been carried out.The results are satisfying and its stability and the economic benefits are preliminarily analyzed.