Study On The Manganese Removal In Groundwater With The Ceramic Flat Membrane Combined With Manganese Sand

Used as the source of drinking water,underground water has the advantages of good quality,safety,sanitary and so on.The exceed concentration of Manganese and Iron in underground water can harm health and cause manufacture problems.The Oxidation reduction potential of Manganese is higher than Iron,this results that compared with Fe???,Mn???is more difficult to be oxidized.This paper focus on the underground water Manganese removal problems with the target flow rate of 5L/h,using experimental instruments combined of Manganese sand and ceramic flat membrane,operating Manganese removal experiment,research on the removal effect of Manganese.Research on the single factor of the Manganese removal effect.The single factor is determined as aeration,pH and Fe²⁺ concentration.That is,adjusting aeration rate,pH and Fe²⁺concentration,observing the removal effect of Manganese.Experiment result shows,as aeration rate increasing,the Manganese concentration of outlet water is decreasing.When the dissolved oxygen is 5.16 mg/L,the Manganese concentration of outlet water is 0.108 mg/L.The value is at the lowest level and above the standard value.With the concentration of Fe²⁺ increasing,the Manganese concentration of outlet water increasing,the Iron concentration of outlet water increasing.When the concentration of Fe²⁺ is 0.205 mg/L,the Manganese concentration of outlet water is the lowest,0.124 mg/L,above the standard value.The concentration of Fe²⁺ increasing.the Manganese concentration of outlet water increasing.When the concentration of Fe²⁺ is 0.998 mg/L,the Iron concentration of outlet water is 0.114 mg/L,under the standard value.Research on the multi factors of the Manganese removal effect.The multi factors is determined as fixed the concentration of Manganese and Iron in the inlet water,adjust aeration rate and pH.That is.fixed the concentration of Manganese and Iron in the inlet water,adjust aeration rate and pH,observing the removal effect of Manganese and Iron.When the aeration rate adjusted,the result of Manganese concentration shows,when the dissolved oxygen increasing,the Manganese concentration of outlet water maintains stability,under the standard value.When the dissolved oxygen is 4.45 mg/L,the Manganese concentration of outlet water is under the standard value.The concentration of Iron in balancing water tank and outlet water are equal,this can imply that before the balancing water tank,the Iron concentration decreased from 0.60 mg/L to 0.0186 mg/L.During this procedure,Fe²⁺ is oxidized to Fe3+ then Fe3+ formed Ferric hydroxides,which were absorbed on the pipe wall,container wall and then,removed.When the pH adjusted,the experiment result shows,the pH of inlet water increasing gradually,the pH of outlet water maintains stability.The Manganese concentration in balancing water tank decreasing,this can imply that increased pH accelerated the oxidation procedure of Manganese.Manganese was oxidized and removed,the Manganese concentration of water decreased.When the pH is 9.75,the Manganese concentration of outlet water is 0.0268 mg/L,under the standard value.When pH increasing,the Manganese concentration of outlet water maintains stability and under the standard value.When pH increasing,the Iron concentration of outlet water maintains stability and under the standard value.Research also focused on the membrane cleaning.Membrane cleaning conduct two times and the removal effect test conduct three times.The membrane flow rate of the end period,in the first test conduct,decreased to one quarters of the initial value.In the second test conduct,membrane flow rate decreased to and maintained at 34mL/min.In the third test conduct,membrane flow rate maintains stability and maintains at 48mL/min.In three times test conduct,the stability value increased.After one cleaning,the penetration ability of membrane increased.Transmembrane pressure,in the first test conduct,the end period of transmembrane pressure value increased to 4.4 times of the initial value.In the second test conduct,the transmembrane pressure increased and maintained at 30kPa.In the third conduct,transmembrane pressure maintains stability and at 21kPa.In three test conducts,transmembrane pressure decreased gradually,the penetration ability of membrane increased.