Study On Orthophosphate And Nitrate Removal Of Micro-polluted Water By Electrocoagulation

Along with the development of industrial and agricultural production and urbanization, a large number of nitrogen and phosphorus discharged into water bodies, and cause eutrophication. Electrocoagulation in drinking water and wastewater treatment has been applied The study focus on the removal of nitrogen and phosphorus by means of electrocoagulation technology on various operating conditions, including the following sections:At first, traditional and electrocoagulation technology for nitrogen and phosphorus removal was investigated, research process was developed.Then, orthogonal test of L16(45) for orthophosphate and nitrate removal was carried out in order to analyze the sequence of factors on electrocoagulation. Orthophosphate removal under optimal conditions was 99.6%, nitrate removal under optimal conditions was 68.94%. Meanwhile, current, concentration of NaCl, pH, arrangement of eletrodes have been studied. Optimal conditions for each factor have been tested. Electrocoagulation and conventional means of orthophosphate removal was compared, AlCl3 was used as a coagulant to the conventional coagulation, there was an optimum ratio of pharmacy dosing, Al: P (molar ratio) was 2.6, however, the removal efficiency of electrocoagulation is improving with the increasing of Al dosing, and the electrocoagulation technology adapts to a wider range of pH. Water of the Songhua River was treated by electrocoagulation, in order to analyse the efficiency of electrocoagulation.At last, the energy consumption of electrocoagulation factors have been analyzed. Electrode polarization and passivation caused energy loss. The energy consumption caculating method was analysed, and the energy consumption of electrocoagulation under different conditions was calculated. The orthogonal analysis of energy results show that the lowest electrocoagulation power consumption in addition to orthophosphate was 0.09 kWh(gPO43--P)-1, and in addition to orthophosphate was 0.08 102 kWh(gNO3--N)-1. Based on the energy consumption calculation and analysis, discussed the low-power operating conditions of electrocoagulation.Electrocoagulation has certain efficiency on orthophosphate and nitrate removal. Considering energy consumption, optimize operating conditions, electrocoagulation has some potential applications in the special circumstances of small-scale applications.