Study On The Application Of Nano-catalytic Electrolysis In Disinfection Of Tail Water

With the rising of water biological pollution,the electrochemical technique,as a more efficient,cleaner and safer advanced oxidation method to protect the public health and safety has been widely used in the disinfection of tail water.This paper studied electrochemical disinfection technique by using the titanium as cathode and ruthenium-tin-iridium metal oxide nanocoating titanium electrode as anode.Firstly,the effects of electrolysis time,current intensity,pH,conductivity and electrolyte type on the removal rate of fecal coliform,residual chlorine and energy consumption were studied by the single factor and multi-factor orthogonal experiment,and the optimum experimental conditions are:the electrolytic time 10 s,the current intensity 3 A and the electrical conductivity 3000 uS/cm adjusted by FeCl₃.Under the optimized conditions,the fecal coliform（FC）was less than 30 MPN/mL and its removal rate reached 99.99%,the residual chlorine was 3.4 mg/L,while the energy consumption was also relatively low with 0.043 kw·h/m³.Based on the orthogonal experiment,the electrolysis disinfection improves standards engineering application in the 1000 m/d tail water by running two reactors in series.The results indicated that the FC was less than 30 MPN/mL and its removal rate was 99.99%,and the residual chlorine was 9.86 mg/L,and the operating cost was only 0.013 Y/m³,when the dosage of FeCl₃ was 40 mg/L,the energy consumption was 1.031 kw·h,the electrolysis time was 2.74 s and the hydraulic retention time was 147 s.Due to the precipitation and flocculation effects of FeCl₃,the effluent COD was reduced to 30 mg/L and its removal rate was 32.52%,the T-P reduced from 0.85 mg/L to 0.28 mg/L and its removal rate was 77.60%.The effluent water is better than A of primary standard in Discharge standard of pollutants for municipal wastewater treatment plant（GB18918-2002）,and reached the class Ⅳ standard in Environmental quality standards for surface water（GB 3838-2002）.According to the experimental results,the nano catalytic electrolysis disinfection technology can be applied in engineering practice.Under the optimal operation conditions,it exhibits better disinfection efficiency and lower operating cost.Therefore,it has the potential value for engineering application.