Method and device for removing trihalomethanes in drinking water by plasma

Abstract

The invention relates to a method and a device for removing trihalomethanes in drinking water by plasma, in particular to water treatment. The device comprises a reactor, a gas discharge tube, a gas circulating pump, an alkaline tank, electrodes, and a high frequency power supply. After water is introduced into the reactor, oxygen and argon are introduced; the gas circulating pump is started, and gas flow speed is regulated; the high frequency power supply is started, gaseous discharge is performed in the gas discharge tube to treat incoming gas, outgoing gas is automatically introduced into the alkaline tank during discharging, hydrogen halide and carbon dioxide are absorbed, residual gas returns to a reaction container, and trihalomethanes in the water are stripped continuously and are introduced into the discharge tube for degradation; when the content of the oxygen in the discharge tube, calculated by percentage, is lower than 0.05%, the oxygen is supplemented to 0.1-10% through a steel oxygen cylinder; When the concentration of alkaline in the alkaline tank is lower than 0.05mol / L, the alkaline is supplemented to 0.1-5mol / L.

Description

technical field [0001] The invention relates to water treatment, in particular to a device and method for removing trihalomethanes in drinking water by plasma. Background technique [0002] In recent years, the pollution of drinking water sources in my country has been increasing day by day. At present, water purification plants mainly adopt the traditional process of "coagulation-filtration-chlorine disinfection", which can effectively remove suspended solids, chroma and pathogenic bacteria in the water, but for the Dissolved organic matter removal is limited. During the chlorination disinfection process, these organic substances will react with disinfectants to produce a variety of toxic and harmful by-products, such as trihalomethanes (THMs), haloacetic acids (HAAs), etc. Among them, THMs are the most abundant and widely distributed substances in the disinfection by-products of drinking water, including chloroform, dichloromonobromomethane, monochlorodibromomethane, and t...

AI Technical Summary

Problems solved by technology

Activated carbon adsorption is to remove THMs through the principle of equilibrium control instead of decomposition. Activated carbon is easy to reach saturation and requires frequent regeneration. C.A., Tzoumerkas, F.K., & Lekkas, T.D. Pilot study of the removal of THMs, HAAs and DOC from drinking water by GAC adsorption. Desalination, 2007, 210(1), 215-224)

THMs belong to halogenated hydrocarbon compounds, which are characterized by low reaction rate with hydroxyl radicals, so advanced oxidation technologies such as ozone oxidation have long treatment time and low removal efficiency

Air stripping is a simple and effective method, but this method only transfers THMs from the liquid phase to the gas phase, which requires a large gas-water ratio ([2] Wu Fangtong; Su Qiuxia; Wu Shujuan. Air stripping method to remove THMs in drinking water Halomethanes, water supply and drainage, 2009, 35 (12) 26-30), and air pollution ([3] WANG, Gen-Shuh; DENG, Ya-Chen; LIN, Tsair-Fuh. Cancer risk assessment from trihalomethanes in drinking water. Science of the Total Environment, 2007, 387.1: 86-95)

Images