Pintar Albin, Besson Michèle, Gallezot Pierre, Gibert Janine, Martin Dominique
Laboratory for Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, P.O. Box 660, Ljubljana SI-1001, Slovenia.
Water Res. 2004 Jan;38(2):289-300. doi: 10.1016/j.watres.2003.09.027.
Two Kraft-pulp bleaching effluents from a sequence of treatments which include chlorine dioxide and caustic soda were treated by catalytic wet-air oxidation (CWAO) at T=463 K in trickle-bed and batch-recycle reactors packed with either TiO2 extrudates or Ru(3 wt%)/TiO2 catalyst. Chemical analyses (TOC removal, color, HPLC) and bioassays (48-h and 30-min acute toxicity tests using Daphnia magna and Vibrio fischeri, respectively) were used to get information about the toxicity impact of the starting effluents and of the treated solutions. Under the operating conditions, complex organic compounds are mostly oxidized into carbon dioxide and water, along with short-chain carboxylic acids. Bioassays were found as a complement to chemical analyses for ensuring the toxicological impact on the ecosystem. In spite of a large decrease of TOC, the solutions of end products were all more toxic to Daphnia magna than the starting effluents by factors ranging from 2 to 33. This observation is attributed to the synergistic effects of acetic acid and salts present in the solutions. On the other hand, toxicity reduction with respect to Vibrio fischeri was achieved: detoxification factors greater than unity were measured for end-product solutions treated in the presence of the Ru(3 wt%)/TiO2 catalyst, suggesting the absence of cumulative effect for this bacteria, or a lower sensitivity to the organic acids and salts. Bleach plant effluents treated by the CWAO process over the Ru/TiO2 catalyst were completely biodegradable.
来自一系列包括二氧化氯和烧碱处理的两种硫酸盐浆漂白废水，在填充有TiO₂挤出物或Ru(3 wt%)/TiO₂催化剂的滴流床和间歇循环反应器中，于T = 463 K下通过催化湿式空气氧化(CWAO)进行处理。采用化学分析(总有机碳去除、颜色、高效液相色谱)和生物测定(分别使用大型溞和费氏弧菌进行48小时和30分钟急性毒性试验)来获取有关起始废水和处理后溶液毒性影响的信息。在操作条件下，复杂有机化合物大多被氧化成二氧化碳和水，以及短链羧酸。发现生物测定可作为化学分析的补充，以确保对生态系统的毒理学影响。尽管总有机碳大幅降低，但最终产物溶液对大型溞的毒性均比起始废水高2至33倍。这一观察结果归因于溶液中存在的乙酸和盐的协同作用。另一方面，实现了对费氏弧菌的毒性降低：在Ru(3 wt%)/TiO₂催化剂存在下处理的最终产物溶液的解毒因子大于1，表明该细菌不存在累积效应，或对有机酸和盐的敏感性较低。通过Ru/TiO₂催化剂上的CWAO工艺处理的漂白厂废水完全可生物降解。
