The total phenolic content dpph scavenging capacity

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Unformatted text preview: overy of better quality oil and protein from hempseeds. 1 ENV-O8 THE INHIBITORY EFFECT OF 2,4-DICHLOROPHENOL ON NITROGEN REMOVAL IN SEQUENCING BATCH REACTOR SYSTEM JW Lim, SL Ng and CE Seng School of Chemical Sciences, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia E-mail: ceseng@usm.my The objective of this study is to examine 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 FI LL, 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 and fed with synthetic wastewater. The mixed liquor suspended solids (MLSS) concentrations increased to 7700 and 9000 mg/L when the added 2,4-DCP concentrations were 5 and 15 mg/L, respectively, but decreased significantly to around 6800 mg/L when the concentration of 2,4-DCP was increased to 30 mg/L. The sludge volume index (SVI) value increased to 90 mL/g when the 2,4-DCP concentration added was 30 mg/L due to the increase of settled sludge volume (SV30). The results showed that increasing the 2,4-DCP concentration to 30 mg/L had resulted in the deterioration of nitrogen and 2,4-DCP removal efficiencies from 100 % to 25 an d 41 %, respectively, in the SBR system. This indicates that the unacclimated microorganisms might have already been inhibited when the 2,4-DCP concentration was above 30 mg/L. The kinetic study showed that the rate of ammoniacal nitrogen (AN) removal could be described by the first -order kinetics. The rate constant of -1 -1 AN removal (kAN) increased from 0.0008 min at 30 mg/L of 2,4-DCP concentration to 0.0277 min when no further addition of 2,4-DCP. This ascertain that, the inhibition effect of 2,4 -DCP was reversible for the nitrification process. 91 23rd-25th June 2010 3rd ICYC 2010 Universiti Sains Malaysia ENV-O9 ADSORPTION CHARACTERISTICS OF ELEMENTAL MERCURY ONTO PURE AND FUNCTIONALIZED -SILICA GELS 1 K Johari, N Saman and H M...
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This note was uploaded on 02/17/2011 for the course CHEMISTRY 101 taught by Professor Csr during the Spring '11 term at University of Louisville.

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