The COD value in urban domestic sewage is very high. If it is directly discharged without oxidation treatment, it will inevitably cause environmental pollution. Sodium hypochlorite is used to treat sewage. Through the reaction of sodium hypochlorite with ammonia and amino acids in the sewage, nitrogen is decomposed to generate chloramine compounds, which not only eliminates ammonia nitrogen and COD, but also has disinfection and sterilization effects, so as to achieve the purpose of urban sewage treatment.

The sodium chloride solution with a concentration of 30-40g/l is injected into the electrolyzer after circulating pump, filter and heat exchanger, and electrolysis produces sodium hypochlorite. After circulating for a predetermined time, the product is collected in the product tank, and the sodium hypochlorite is removed by the product pump The product liquid is injected into the sewage to be treated。

The operating voltage of the electrolytic cell is about 160V (total voltage), the voltage between the electrodes is about 4V, the current load between the electrodes is 2A, the current density is 1400A/M2, the current efficiency is 65%-70%, and the concentration of sodium chloride solution is 30g/ l. The chlorine content of the finished solution (effective rate) is 1.5g/(LH), the salt conversion rate is 30%, the salt consumption of 1kg chlorine of the sodium hypochlorite generator is 1.6kg, and the electricity consumption of 1kg chlorine is 3.5kw.h, The cooling water consumption of 1kg of chlorine is 0.15m3 nd the cost of treating 1t of sewage is $0.031-0.062

The characteristics of the anode, choose titanium as the substrate, the surface is coated with ruthenium, iridium and other oxide coating electrode plates as the electrode. The anode has a higher oxygen evolution potential, withstand voltage, and can operate at a higher current density. At the same time, it has better resistance to sodium hypochlorite. High corrosion resistance, service life is more than 8 years.

Using bisexual titanium coated ruthenium and other oxide-coated electrodes, cylindrical flange head, and closed electrolytic cell process to electrolyze sodium chloride solution to produce sodium hypochlorite, high-quality sodium hypochlorite can be produced, which is suitable for urban sewage treatment and hospital sewage deal with.