Application Of Giant Magnetic Separation Technology In Baiyangdian Watershed Management

With the enhancement of people’s awareness of environmental protection,our country’s efforts in water environment governance are constantly increasing,and watershed comprehensive management has gradually become the mainstream trend of environmental governance.Our country is vigorously developing Xiongan New Area,Baiyangdian as it’s important water,it’s governance is attracting much attention.This paper is expected to design a suitable process for Baiyangdian Lake water treatment,and by carrying out experiments to determine the optimal process parameters for the purpose of the problems of insufficient construction area and short treatment period of Baiyangdian Lake.It’s found that the super-magnetic separation technology can complete the whole treatment process within 5～10 minutes,the hydraulic retention time is short,the structure is compact,the construction area is small（1/8～1/6 of the conventional process）,the recovery rate of magnetic powder can reach 99%,the treatment cost is low,the effect is good.So that it has an incomparable advantage over other processes in river management of main urban areas.This paper designed the super-magnetic separation technology combined with the actual situation of Baiyangdian water.This paper focuses on the study of the flocculants polyaluminum chloride（PAC）,polyacrylamide（PAM）and magnetic powder selection,dosing sequence,water velocity,stirring conditions and other key process parameters on the Baiyangdian water treatment effect.The results show that:（1）The type of polyacrylamide（PAM）suitable for the ultra magnetic separation process of Baiyangdian Lake water is cationic polyacrylamide（CPAM）with a molecular weight of 11.2 million.When PAM and polyaluminum chloride（PAC）are mixed,the treatment effect is better than when PAM and PAC are used alone.（2）In the water treatment of the super magnetic separation process,the treatment effect of alkali immersed magnetized ferrous carbonate（Fe CO₃）as magnetic powder is better than that of Fe₃O₄ as magnetic powder.The removal rate of suspended solids（SS）,chemical oxygen demand（COD）and total phosphorus（TP）in the effluent with alkali leaching Fe CO₃ is higher than that with Fe₃O₄。（3）When the flow rate of the incoming water body is 8.07 m3/min The stirring conditions are as follows:the first dosing（PAC and alkali leaching Fe CO₃are added simultaneously）,stirring（240 r/min）for 3 minutes,and the second dosing（PAM）,stirring（60 r/min）for 4 minutes.This not only achieves the treatment effect,but also takes into account the economic benefits.（4）When the dosage is PAC 45 mg/L,PAM 2 mg/L,and magnetic powder（alkali immersed Fe CO₃）240 mg/L,the water inlet rate is 8.07 m3/min When the first dosing（PAC and alkali leaching Fe CO₃ are added simultaneously）and stirred（240 r/min）for 3minutes and the second dosing（PAM）and stirred（60 r/min）for 4 minutes,the removal rate of SS in the raw water is above 90%,the removal rate of COD can reach 81%,and the removal rate of TP is basically stable at over 70%.From the sensory perspective of the effluent,the visibility of the water increases and the odor of the water significantly decreases.This study conducts experimental research on the design and key parameters of the super magnetic separation process,indicating that the super magnetic separation process is feasible in the governance of the Baiyangdian River Basin.By optimizing the process parameters,the effectiveness of the super magnetic separation process in the governance of the Baiyangdian River Basin can be greatly improved,which is of great significance for the governance of the Baiyangdian River Basin and the construction of Xiong’an New Area.