Inhibitory effect of 2,4-dichlorophenol on nitrogen removal in a sequencing batch reactor

• Published in: The Korean journal of chemical engineering Vol. 29; no. 7; pp. 886 - 890
• Main Authors: Lim, Jun-Wei, Ng, Si-Ling, Khor, Siok-Moi, Seng, Chye-Eng
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.07.2012; 한국화학공학회
• Subjects: Biotechnology; Catalysis; Chemistry; Chemistry and Materials Science; Environmental Engineering; Industrial Chemistry/Chemical Engineering; Materials Science; 화학공학; Nitrogen Removal; Inhibitory Effect; 2,4-Dichlorophenol; Sequencing Batch Reactor; Nitrification
• ISSN: 0256-1115; 1975-7220
• DOI: 10.1007/s11814-011-0267-2

We examined the inhibitory effect of 2,4-dichlorophenol (2,4-DCP) on nitrogen removal in the sequencing batch reactor (SBR) system. The reactor was operated with FILL, REACT (nitrification: denitrification), SETTLE, DRAW and IDLE phases in the duration ratio of 2: 12 (9: 3): 1: 1: 8 for a 24 h cycle time. The deterioration of 2,4-DCP removal efficiency from 100 to 41% was observed when the influent concentration of 2,4-DCP was increased to 30mg/L. The residual 2,4-DCP remaining in the mixed liquor was found to inhibit the nitrification process, resulting in the decrease of nitrogen removal efficiency to 25 %. For kinetic study, the result showed that the experimental data of ammoniacal nitrogen (AN) removal at every stage fitted well to the first-order kinetics equation with high R 2 values. The rate constant of AN removal, k AN , decreased with increasing influent concentration of 2,4-DCP, from 0.053 to 0.0006/min when 2,4-DCP concentration increased from 0 to 30 mg/L, respectively. However, the observed gradual recovering of AN removal with respect to the removal efficiency and kinetics during the recovery stage indicated that the inhibitory effect of 2,4-DCP on the nitrification process was reversible.