| Title |
Regeneration of used zeolite by biological nitrification |
| Authors |
손대희 ( Son Dae Hui ) ; 정윤철 ( Jeong Yun Cheol ) ; 유명진 ( Yu Myeong Jin ) ; 정진영 ( Jeong Jin Yeong ) |
| Keywords |
Zeolite; Nitrogen; Biological regeneration; Chemical regeneration |
| Abstract |
Zeolite is well known material for its ability to preferentially remove ammonium ions from wastewater. However, its usage has been limited by high cost for chemical regeneration on this purpose. As an alternative, biological regeneration of zeolite has been suggested by some researchers. In this study, the characteristics of biological regeneration of zeolite was studied at various conditions, i.e. changes in microorganism and Na^(+) concentration. In the first test, the percentage of bio-regeneration via nitrification in the columns(MLVSS 2,250㎎/ℓ and 4,500㎎/ℓ) was 2.6 times higher than the column with NaHCO₃(2M980 ㎎/ℓ) addition only. In the second test MLVSS were changed(400, 800 and 3,200㎎/ℓ) but, for alkalinity supply, NaHCO₃ concentration was fixed at 745㎎/ℓ. The regeneration rates were proportional to the MLVSS concentration, but the same amounts of total regenerated nitrogen were achieved in all columns tested. In the third, test the regeneration tests were performed to evaluate effects of Na^(+) concentration on regeneration were tested. The regeneration effficiency was enhanced about 5% when Na^(+) concentration increased from 342 to 734㎎/ℓ. There was no difference in regeneration rate by nitrification. Therefore the higher regeneration efficiency of zeolite could be obtained by nitrification than by chemical methods. The regeneration rates with the fixed Na^(+) concentration were proportional to nitrification rate, and the regeneration efficiencies with the fixed microorganism concentration were highly dependent on cation concentrations such as Na^(+) |