Research On Treatment Of Simulated Wastewater Containing Chromium With Graphite Rod

Leather production and other industries produce a large number of chromium containing wastewater,which seriously endangers the environment and human health.The electrolysis method has the advantages of thorough and convenient removal of pollutants and is suitable for the removal of chromium containing wastewater.This paper is divided into the steps of setting up electrolysis device,configuration and electrolysis simulation of chromium containing wastewater.The electrolysis equipment mainly includes electrode,electrolytic cell and DC power supply.The inorganic chromium in simulated wastewater contains chromium nitrate and potassium dichromate,while the organic chromium includes chromium oxalate and chromium picolinate.The factors affecting the removal rate of chromium include electrode type,current,voltage and reaction time.The results show that the electrode has the best electrolytic capacity,and the best condition for the adsorption of chromium ion is pH at 2,the initial voltage and current are 10V and 0.8A,respectively,and the removal rate is about 55%.The graphite rod material has good renewable recycling performance and can be reused for 5 times.The pre experiment of electrolytic simulation of chromium containing wastewater was carried out with iron block and aluminum block under the action of DC power supply.The optimal conditions for the treatment were pH 5.9,current and voltage at 0.9A and 11V,plate spacing 1.5cm,and chromium removal rate about 48%.With the increase of reaction time,voltage or pH,chromium removal first increased and then stabilized.With the increase of plate spacing,chromium removal first increased and then decreased.It is possible that the content of chromium is reduced by electrocoagulation.Hexavalent chromium is reduced to trivalent chromium by electrode and deposited on the electrode,which reduces the concentration of chromium in the solution.Organic chromium is oxidized and removed.According to the grey correlation theory,the main factors affecting the simulation of trivalent and hexavalent chromium wastewater are reaction time and temperature.