Experimental study on treatment of oxytetracycline hydrochloride in high salinity wastewater by electrochemical oxidation
As the high salinity wastewater from pharmaceutical and fine chemical industry contains high concentration of oxytetracycline hydrochloride and is hard to be biodegraded,an electrochemical oxidation reac-tion system based on titanium-based coated tin dioxide doped with antimony grid anode plate was constructed.The influence of operating conditions and water quality on the degradation effect were investigated;besides,the treatment effect and energy consumption of single-stage reaction and three-stage series reaction under the same plate area,influent flow rate and reaction time conditions were compared and analyzed.The results showed that,oxytetracycline hydrochloride in wastewater could be effectively degraded by electrochemical method,and the re-moval rate reached 100%when the salt concentration was 20 g/L,the electrode spacing was 8 mm,the electric current density was 25.0 mA/cm2 and the reaction time was 100 min.Excessive initial concentration of oxytetra-cycline hydrochloride or excessive salinity will lead to the decrease of the removal rate;Compared to single-stage reaction,three-stage series continuous flow reaction has higher oxytetracycline hydrochloride removal rate and current efficiency,the energy consumption was lower.Under the condition that the electric current density was 25.0 mA/cm2,the reaction time was 40 min,the removal rate of oxytetracycline hygrochloride by three-stage se-ries continuous flow reaction could reach 84.7%;the current efficiency was 71.9%and the energy consumption for organic substance removal was 24.9 kW·h/kg.