Department of Hydraulic and Sanitary Engineering, Sao Carlos School of Engineering, University of Sao Paulo, Av Trabalhador São-carlense 400, Sao Carlos SP, Brazil.
Water Sci Technol. 2010;62(6):1312-9. doi: 10.2166/wst.2010.944.
As part of an experimental project on the treatment of bleach plant effluents the results of biodegradability and toxicity assessment of effluents from a bench-scale horizontal anaerobic immobilized bioreactor (HAIB) are discussed in this paper. The biodegradability of the bleach plant effluents from a Kraft pulp mill treated in the HAIB was evaluated using the modified Zahn-Wellens test. The inoculum came from a pulp mill wastewater treatment plant and the dissolved organic carbon (DOC) was used as the indicator of organic matter removal. The acute and chronic toxicity removal during the anaerobic treatment was estimated using Daphnia similis and Ceriodaphnia silvestrii respectively. Moreover, the evaluation of chromosome aberrations (CA), micronucleus frequencies (MN) and mitotic index (IM) in Allium cepa cells were used as genotoxicity indicators. The results indicate that the effluents from the anaerobic reactor are amenable to aerobic polishing. Acute and chronic toxicity were reduced by 90 and 81%, respectively. The largest CA and MN incidence in the meristematic cells of A. cepa were observed after exposure to the raw bleach plant effluent. The HAIB was able to reduce the acute and chronic toxicity as well as chromosome aberrations and the occurrence of micronucleus.
本文讨论了一个关于处理漂液厂废水的实验项目，其中包括评估水平式厌氧固定生物反应器（HAIB）处理后废水的可生物降解性和毒性。使用改良的 Zahn-Wellens 试验评估了在 HAIB 中处理的 Kraft 浆厂漂液厂废水的可生物降解性。接种物来自纸浆厂废水处理厂，溶解有机碳（DOC）用作有机物去除的指标。使用大型溞（Daphnia similis）和绿蝇（Ceriodaphnia silvestrii）分别评估了厌氧处理过程中的急性和慢性毒性去除。此外，还使用洋葱根尖细胞的染色体畸变（CA）、微核频率（MN）和有丝分裂指数（IM）评估作为遗传毒性指标。结果表明，厌氧反应器的出水适合进行好氧抛光。急性和慢性毒性分别降低了 90%和 81%。在 A. cepa 的分生细胞中观察到最大的 CA 和 MN 发生率是在暴露于原始漂液厂废水后。HAIB 能够降低急性和慢性毒性以及染色体畸变和微核的发生。
