Detoxification of Kraft pulp ECF bleaching effluents by catalytic hydrotreatment
In: Water research (Oxford), Jg. 41 (2007), Heft 4, S. 915-923
academicJournal
- print, 3/4 p
Zugriff:
Two different effluents from the D1 and E1 stages of the ECF bleaching of Eucalyptus globulus kraft pulp were treated by catalytic hydrogenation in a trickle bed reactor using commercial and homemade Pd/AC catalysts. The reactor was fed with the bleaching effluent and a H2/N2 gas stream. The variables studied were space-time (1.4-5 gcatmin/mL), gas to liquid flow ratio (286-1000 vol.), gas feed concentration (H2:N2, 1:1-1:7.3 vol.), temperature (25-100 °C) and pressure (1-11 bar). Hydrotreatment performance was evaluated in terms of ecotoxicity, adsorbable organic halogen (AOX), chemical oxygen demand (COD), biological oxygen demand (BOD5) and colour removal. In all the runs, the ecotoxicity of the effluents decreased as a result of the treatment, achieving reductions that ranged from 70% to 98%. Simultaneously to the reduction of toxicity, the hydrotreatment led to a decrease of the colour of the effluents, being the decrease significantly higher in the case of E1 effluent. The AOX content was reduced by 85% and 23% for E1 and D1 effluents, respectively. In the case of D1 effluent the removal of ecotoxicity was significantly higher than that of AOX, which indicates that much of the toxicity of the effluent must be associated to non-chlorinated organics. In spite of the important reduction of ecotoxicity, the biodegradability of the effluents only increased slightly. The homemade catalysts, prepared from activated carbons with a high external or non-microporous surface area and mesopore volume and a convenient surface chemistry showed a higher efficiency than the commercial one.
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Detoxification of Kraft pulp ECF bleaching effluents by catalytic hydrotreatment
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Autor/in / Beteiligte Person: | CALVO, L ; GILARRANZ, M. A ; CASAS, J. A ; MOHEDANO, A. F ; RODRIGUEZ, J. J |
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Zeitschrift: | Water research (Oxford), Jg. 41 (2007), Heft 4, S. 915-923 |
Veröffentlichung: | Oxford: Elsevier Science, 2007 |
Medientyp: | academicJournal |
Umfang: | print, 3/4 p |
ISSN: | 0043-1354 (print) |
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