Process for removing nitrogen compounds from a liquid
AssigneeEuropean Atomic Energy Community (Euratom)
InventorsDaniel Van Velzen, Heinrich Langenkamp, Ariel Moryoussef
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Abstract
The invention concerns a device and a method for removing nitrogen compounds from an aqueous liquid containing nitrogen oxides (NO.sub.x) and/or nitrates (NO.sub.3.sup.-). It comprises an electrochemical cell (10) with a cathode and an anode and a current source applied thereto. According to the invention, the cell is divided by a cation selective membrane into a cathode compartment (2) to be filled with said liquid, and an anode compartment (3) to be filled with an anolyte containing an aqueous solution of an alkali or hydrogen halide such as sodium bromide or sodium chloride, and the membrane (1) is constituted by a microporous fabric of PTFE.
Claims9
A process for removing nitrogen compounds from an aqueous liquid containing at least one of nitrogen oxides (NO.sub.x) and nitrates (NO.sub.3.sup.-), using a device comprising an electrolytic cell divided into a cathode compartment and an anode compartment by a cation selective membrane constituted by a microporous fabric, comprising the steps of:
- i) supplying the liquid to be treated as a catholyte to the cathode compartment of the electrolytic cell;
- ii) circulating an anolyte containing an aqueous solution of an alkali or hydrogen halide through the anode compartment of the cell;
- and
- iii) applying an electric current to the cell,
- wherein nitrogen oxide and nitrates contained in the liquid to be treated are reduced to ammonia at the cathode, halogen gas is formed at the anode by electrolytic oxidation of the halide, ammonia formed in the cathode compartment is transported through the cation selective membrane to the anode compartment, and the transported ammonia electrolytically reacts with halogen gas in the anode compartment to form nitrogen.
Dependencies are inferred from the claim text.