Study On Biological Manganese Removal From Groundwater And Its Effecting Factors

Against the manganese concentration of the groundwater in many areas inChina, based on the laboratory and by the aid of model experiment, the subject wasconducted to study the characteristics of the biological manganese removal in thegroundwater. Tests of start-up of the biological manganese removal were conducted;The factors of filtering velocity、pH、organic matter、 filter out short-term werestudied to evaluate their efforts for biological manganese removal; Thecharacteristics of the biological manganese removal in the high concentration ofwater are also included in the tests. By experimental studies, the main conclusionsare as follows:1. Quick-Start Of Biological Manganese Removal test results showed that under theoperation of grafting mature filter material eluent into filter bed, the time needed forthe cultivation of biological manganese removal was37days, it could effectivelyremove manganese in raw water and the influent is stable qualified. However,training in the natural way, the removal ratio of manganese has been30%to40%bymore than two months of operation; it did not generate biological activatedmembrane. Microscope photographs of biological membrane showed that mostmanganese bacteria were rod-shaped bacteria; a considerable number of bacteriaconnected into chains and became dominant micro flora.2. The affecting factors such as filtration speed, pH, organic matter and filter outshort-term were analyzed. The results showed that the manganese concentration ofthe effluent from the lower part of filtration column was with increasing of thefiltration speed; Under this operation conditions, the filtration speed could only beincreased to a maximum speed13m/h, otherwise, the effluent will exceed thestandard.The affect of pH for biological manganese removal was studied, the testresults showed that: when pH was5.2—8.7, good manganese removal could beachieved and the manganese concentration of the effluent could remain steadilybelow0.lmg/L，but if pH was less than5.2，the manganese concentration of theeffluent increased greatly. After shutting down for23days, bio-filtration column and manganese can be quickly restored, it showed that the short-term filter leachingout had little impact on biological activity, although it produced a certain effect onbiological manganese removal efficiency, however,the effect was short-term. Theexperimental results show that: had advanced impacts on the biologicalmanganese-removal, the greater the concentration of organic substance was, and thehigher the eligible filter layer was; after adding organic matter, the filter periodbecame short. The higher the concentration of organic matter was, the shorter theperiod became; after adding organic matter, the apparent change happened on headloss, and along with the increase in concentration of organic matter, head loss curvebecame more steep; the removal ratio of organic matter was20%~40%, with theincreasing of the concentration of organic matter, the effluent becoming out of theCODMnstandard.3. The biological manganese removal of single-stage bio-filter in high concentrationof water was limited. Water quality was getting worse along with the concentrationof water becoming higher. When influent concentration was stable, the removal ratiohad the inverse relationship with filtration speed, the higher the filtration speed was,the lower the removal ratio became. At the same time, the higher the influentconcentration was, the shorter the filter period became.