González Patricia, Zaror Claudio, Carrasco Virginia, Mondaca Maria Angelica, Mansilla Hector
Department of Public Health, University of Concepcion, Concepción, Chile.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2003;38(10):2201-8. doi: 10.1081/ese-120023352.
Effluents from small and medium sized chemical plants may contain significant amounts of poorly biodegradable aromatic compounds, which could negatively affect water quality and public health. This is a key environmental issue, particularly in areas where effluents are discharged into drinking water sources. Unfortunately, conventional biological treatment may not be able to meet discharge standards, and combined systems should be implemented. In this context, this paper presents experimental results on the application of a combined sequential ozonation-activated carbon-biological system to treat effluents containing chlorinated aromatic contaminants from chlorine based pulp bleaching. The experimental system consisted of an ozone bubble column reactor (0.3 dm3), an activated carbon fixed bed reactor (0.2 dm3), and an aerobic bioreactor (20 dm3). Ozone was produced from pure O2 using a generator rated at 2 mmol O3 h(-1). The bleaching effluent was pretreated and fed into the aerated sequencing batch bioreactor containing preconditioned biological sludge (3-4 g VSS dm(-3)), and cultured for 24 h. Samples of raw and treated effluents were assayed for biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total organic carbon (TOC), total phenols, and adsorbable organic halogens (AOX), using standard techniques. The presence of potential genotoxic activity in untreated and treated samples was assessed using the Ames tests. Results show that biological treatment of raw samples could not remove mutagenic activity on its own. On the other hand, ozonation followed by activated carbon treatment and biological treatment successfully removed genotoxicity in all cases. Reductions in BOD, COD, TOC, AOX, and phenols by biological treatment increased when samples were pretreated with ozone/activated carbon.
中小型化工厂的废水可能含有大量难生物降解的芳香族化合物，这可能会对水质和公众健康产生负面影响。这是一个关键的环境问题，尤其是在废水排放到饮用水源的地区。不幸的是，传统的生物处理可能无法达到排放标准，因此应采用组合系统。在此背景下，本文介绍了应用组合式序批式臭氧化-活性炭-生物系统处理含氯纸浆漂白产生的含氯芳香族污染物废水的实验结果。实验系统由一个臭氧鼓泡塔反应器（0.3立方分米）、一个活性炭固定床反应器（0.2立方分米）和一个好氧生物反应器（20立方分米）组成。使用额定产率为2毫摩尔臭氧/小时的发生器由纯氧气产生臭氧。对漂白废水进行预处理后，将其送入装有预处理生物污泥（3-4克挥发性悬浮固体/立方分米）的曝气序批式生物反应器中，并培养24小时。使用标准技术对原废水和处理后废水的样品进行生化需氧量（BOD5）、化学需氧量（COD）、总有机碳（TOC）、总酚和可吸附有机卤素（AOX）的测定。使用艾姆斯试验评估未处理和处理后样品中潜在的遗传毒性活性。结果表明，原样品的生物处理本身无法去除诱变活性。另一方面，臭氧化后进行活性炭处理和生物处理在所有情况下都成功地去除了遗传毒性。当样品用臭氧/活性炭预处理时，生物处理对BOD、COD、TOC、AOX和酚的去除率增加。
