Electric-Catalytic Reduction Removing Nitrate Of Water

Nitrate is a wide spread contaminant of ground water and it is a potentialhuman health threat. Regarding to these facts, it stimulates people great concern onnitrate contamination in groundwater. WHO and USEPA have regulated themaximum nitrate concentration in drinking water not greater than 10mg NO₃^-N/I.There are ways to prevent high concentrations, but since it will take many years to seethe results of improved fertilizer management, nitrate removal may be the only optionfor many communities. The main removal nitrate technologies are discussed andcompared in this paper. Through comparing, electrical-catalytic reduction removingnitrate is considered as a promising technology of drinking water treatment, focusingon experimental research of removing nitrate.In the process of experiment, it is crucial to choose the right electrode. On theone hand, the right electrode will not be eroded and release contaminant to thetreating water, which is green and environmental; on the other hand, the catalyst willdevelop reacting rate and selecting rate. Regarding to these two standards, thisexperiment chooses several electrode:â‘ cathode non-porous titanium plated by Cu/Pd-Cu, anode carbon plate;â‘¡cathode titanium net+ACF( plated by Pd-Cu/Pd-Cu),anode the same titanium net;â‘¢cathode porous titanium plate/ACF( plated Pd-Cu),anode the same porous titanium plate. Through comparing and analysisingexperimental results, we choose cathode porous titanium plate, anode the sameporous titanium plate as the last electrode for continual experiment.In the continual experiment, the removing nitrate and influence under differentreacting situations are researched with electrode of porous titanium plated by 1:1 and4:1 Pd-Cu. The denitrification effect of 4:1 plate catalyst is a little less than 1:1,however, the reacting by-products will be reduced by 4:1 plate catalyst. Throughcomparing denitrification effect under different plating ratio, we choose 4:1 as thefinal ratio for the best reacting effect.To overcome single reacting room's drawback, this experiment has researchedreacting effect in separated reactor. We have researched denitrification effect and influent factors under different reacting situation with porous titanium plated by 4:1Pd-Cu and Pd-Sn. The experimental results show that electrode plated by 4:1 Pd-Snhas better denitrification effect and also reduce by-product. The effect of differentanion SO₄^2-, Cl^-, HCO₃^- to dinitrating has been researched, we get the order:SO₄^2--3^-. The effect of catalytic electrode to stimulant ground water is notmuch worse, however, the by-product ammonia increased and selecting nitrogendecreased.Through different experimental results, experimental theory and reacting kineticare researched. Sum up and compare catalytic theory of different catalysts.Electric-catalytic reduction removing nitrate of ground water is considered as aefficient and applied denitrification method in the future, especially for thesmall-scale application in the rural areas. Finally, we discuss existing problems andmethods dealing with these problems, point out the final developing direction.