Study On Denitrification Of Electrochemical Applications In High Chlorine Secondary Effluent

Due to the high groundwater level in coastal areas,the uneven settlement of pipelines often occur,which result in the leakage of sewage pipelines.Due to the infiltration of seawater into the sewage pipeline,the content of chloride ion in the influent water of the sewage plant is relatively high.However,biochemical treatment has little removal efficiency for chloride ions.In order to effectively utilize the chloride ion in sewage,the technology of electrochemical synchronous oxidation-reduction was introduced to treat the high chloride secondary effluent.The effect and mechanism of electrochemical denitrification were explored by using three electrode reaction system.The results show that Ti/IrO₂ is more suitable for electrochemical denitrification than Ti/RuO₂-SnO₂ and Ti/RuO₂-IrO₂.When exploring the influence of different factors on denitrification effect,the results show that the cathode potential,initial nitrate concentration,initial ammonia concentration,initial p H and initial chloride ion concentration have a great influence on the electrochemical denitrification effect,while the concentration of organic nitrogen has little influence on the denitrification effect.The optimized operation parameters of the experiment determine that the cathode potential is-1.6V,initial p H is 9,initial chloride ion concentration is 3000mg/L.When the simulated high chlorine secondary effluent was used as the treatment object,Cu was the cathode,Ti/IrO₂ was the anode,and in the water sample with the initial ammonia concentration of 10mg/L and the initial nitrate concentration of 20mg/L.The technology of electrochemical oxidation of ammonia and simultaneous cathodic reduction of nitrate nitrogen was carried out by optimizing the operation parameters.After 60 minutes,the removal rate of ammonia is more than 99%,nitrate is 57.26%,total nitrogen is 67.93%,reach the standard of ammonia and total nitrogen in quasi class IV water.Taking the actual high chlorine secondary effluent as the treatment object,it is found that the optimize operation parameters are better than the electrolytic denitrification effect under the raw water condition,and after electrolysis for 60 minutes,the total nitrogen removal rate is 71.22%.In the secondary effluent,humic acid and aromatic protein are the main components of organic matter.Electrolysis wouldn't only remove nitrogen,but also remove some dissolve organic matter.It is found that amines in organic nitrogen is converted into nitriles or amine salts by electrolysis,and then further oxidized into ammonia and nitrogen,reducing the concentration of organic nitrogen.The removal process of ammonia and nitrate conform to the characteristics of the first-order reaction kinetic model.Figure 37;Table 12;Reference 73...