LI Dong, CAO Ruihua, YANG Hang, et al. Two-stage bio-purification technology of low temperature groundwater containing high concentration of iron, manganese and ammonia nitrogen[J]. 2018, 50(2): 2018-2.
LI Dong, CAO Ruihua, YANG Hang, et al. Two-stage bio-purification technology of low temperature groundwater containing high concentration of iron, manganese and ammonia nitrogen[J]. 2018, 50(2): 2018-2.DOI: 10.11918/j.issn.0367-6234.201611124.
The effluent manganese (Mn) and ammonia nitrogen (NH3-N) concentration were found excessive when the low-temperature (5-7.8 ℃) groundwater containing high NH3-N
iron (Fe) and Mn contents (NH3-N>3.0 mg/L
Total Fe>12 mg/L
Fe2+>8.0 mg/L
Mn2+>3.0 mg/L) was purified by "one-stage aeration combined with one-stage filtration" process. To improve the purification efficiency
the start-up of "two-stage aeration combined with two-stage filtration" purification process and the oxidation-removal active sites (ORAS) of Fe
Mn and NH3-N were investigated. Two-stage bio-purification process successfully started after 133 days and the start-up period was mainly related to the Mn content. The results showed that the removal capacity of NH3-N and Mn was 29.66 g/(m2·h) and 27.08 g/(m2·h) respectively
and the water yield was a double of one-stage bio-purification process. According to the ORAS
Fe was removed to trace levels in the 0-50 cm section of the primary filter column
and the NH3-N was removed by 55.23% and 44.10% respectively in the 0-135 cm segment of the primary filter column and 0-50 cm segment of the secondary filter column. There were significant removal classification between Mn and NH3-N during the oxidation-removal process. The activity of Mn-oxidizing bacteria (MnOB) was significantly inhibited by NH3-N in concentration greater than 2.25 mg/L. The removal ratio and ORAS of Mn in both filter columns were affected by the concentration of NH3-N in raw water as well as the filtration rate. After a successful start-up
the Mn was removed by 5.53% and 89.34% respectively in the primary and secondary filter columns.