Effects of ozonation process on lignin-derived compounds in pulp and paper mill effluents.
The effect of ozonation process on pulp and paper mill effluents was investigated. The objectives were to: (1) identify various compounds in wastewater from a pulp and paper mill, (2) evaluate decolorization and organic removal efficiency by conventional bubble reactor and (3) evaluate the biodegradability at various progressive stages of ozonation. The qualitative GC/MS analyses were performed before and after the biological treatment and ozonation process. Two groups of compounds were observed in this wastewater: lignin-derived compounds and aliphatic compounds used in the pulp and paper production process (i.e. n-alkanes, fatty alcohols, fatty acid and ester). Treatment efficiency was measured by decolorization and TOC removal rates. Additionally, the utilization coefficient (k) and BOD/COD ratio were determined to observe the biodegradability of ozonized effluents. The results indicated that after 45 min, the ozonation of effluents yielded almost colorless effluent with over 90% decolorization efficiency and with corresponding ozone capacity rate of 20.0 mg O(3)L(-1). This decolorization was not always accompanied by the mineralization of the organic matters therefore ozonation was not related to TOC removal rates. The BOD/COD ratio increased from 0.10 to a maximum value of 0.32 with ozone flow rate (O/F) of 4.0 L min(-1). It was confirmed by the utilization coefficient as first order BOD equation, the magnitude k value increased from 0.21 day(-1) to maximum value of 0.47 day(-1) as the ozonation time was raised to 60 min with O/F 4.0 L min(-1).
Kreetachat
T
T
Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, 50 Phaholyothin Road, Chatuchak, Bangkok 10900, Thailand. g4685023@ku.ac.th
Damrongsri
M
M
Punsuwon
V
V
Vaithanomsat
P
P
Chiemchaisri
C
C
Chomsurin
C
C
D003116:Color; D008401:Gas Chromatography-Mass Spectrometry; D008031:Lignin / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D013783:Textile Industry; D014874:Water Pollutants, Chemical / Q000032:analysis*
D014874:Water Pollutants, Chemical; D010126:Ozone; D008031:Lignin