Bae, JH Lee, IS Jang, MS Ahn, KH Lee, SH 2024-01-21T06:34:51Z 2024-01-21T06:34:51Z 2021-09-02 2004-09 0273-1223 https://pubs.kist.re.kr/handle/201004/137298 Nitrogen removal efficiency of a pilot-scale system consisted of Modified Ludzack-Ettinger (MILE) followed by sulfur-utilizing denitrification (SUDNR) process was evaluated with a landfill leachate. For SUDNR, a down-flow mode sulfur packed bed reactor (SPBR) filled with sulfur and limestone particles was used. Although total nitrogen removal efficiency of the MLE process was about 80% at the recycle ratio of 4, effluent contained 350-450 mg/L NO3--N. Up to a loading rate of 1.2 kg NO3--N/m(3)-day, the SPBR could achieve complete removal of nitrate, and nitrate removal rate was kept to that level even at higher loading rate. When a COD/N ratio of MLE process was maintained at 2 instead of 4, more organics with molecular weight less than 500 were utilized for heterotrophic denitrification although denitrification was not complete with the lack of electron donors. Clogging in the SPBR, mainly by the accumulation of nitrogen gas in the pores, could easily be removed by introducing the effluent in an upward direction for 1 min at 1 hr intervals. The proposed treatment system could achieve nitrate free effluent with a slight increase in chemical cost. Furthermore, depending on further COD removal requirement after biological treatment, the proposed treatment system can be an economical solution. English IWA PUBLISHING UTILIZING AUTOTROPHIC DENITRIFICATION ELEMENTAL SULFUR LIMESTONE Treatment of landfill leachate by a pilot-scale modified Ludzack-Ettinger and sulfur-utilizing denitrification process Article 10.2166/wst.2004.0370 1 WATER SCIENCE AND TECHNOLOGY, v.50, no.6, pp.141 - 148 WATER SCIENCE AND TECHNOLOGY 50 6 141 148 scie scopus 000224952400021 2-s2.0-7244232913 Engineering, Environmental Environmental Sciences Water Resources Engineering Environmental Sciences & Ecology Water Resources Article; Proceedings Paper UTILIZING AUTOTROPHIC DENITRIFICATION ELEMENTAL SULFUR LIMESTONE clogging COD denitrification leachate nitrification sulfur