Background

In order to reduce emissions of micropollutants (MPs) via effluents of wastewater treatment plants (WWTPs), additional treatment steps are suggested and already deployed in selected WWTPs. Next to advanced oxidation processes, the application of powdered activated carbon (PAC) is considered a promising and suitable option as MP removal rates of 80% and more can be achieved. However, this method might also hold a drawback as a complete retention of PAC applied within the WWTP cannot always be guaranteed. Hence, small amounts of MP-loaded PAC can enter receiving waters with potentially negative consequences for aquatic organisms. The present study investigated possible effects of MP-loaded PAC from a WWTP as compared to unloaded, native PAC on the bivalve Corbicula sp. in a 10-week exposure experiment. The PAC types were administered in concentrations of 1, 10 and 100 mg/L in a semi-static sediment–water system.

Results

Molecular biomarker responses for xenobiotic metabolism (i.e., glutathione-S-transferase (GST)) and oxidative stress (i.e., catalase (CAT) activity and lipid peroxidation) were analyzed and in none of the treatments, significant differences to the control could be detected, except for the CAT activity in the 1 mg/L PAC_WWTP treatment. Moreover, the filtration rate of individual bivalves was measured after 5 and 10 weeks of exposure and compared to the initial filtration rate with the result that the presence of PAC did not affect the filtration rate of Corbicula sp. In summary, despite the selection of sensitive endpoints and a comparatively long exposure period, no significant effects were detected for unloaded and MP-loaded PAC even at the highest test concentration, which is far away from environmental relevance.

Conclusions

These results give an auspicious perspective for the application of PAC in WWTPs. Even when small PAC leakages from WWTPs occur, adverse effects for aquatic organisms appear to be neglectable based on our findings.

中文翻译：

---

来自废水处理厂的微污染物粉状活性炭是否对双壳类Corbicula sp。有毒？

背景

为了减少废水处理厂（WWTP）的废水中的微污染物（MPs）的排放，建议了一些额外的处理步骤，这些步骤已经在某些WWTP中部署。除了先进的氧化工艺，粉状活性炭（PAC）的应用被认为是一种有前途的合适选择，因为可以实现80％或更高的MP去除率。但是，此方法也可能存在一个缺点，因为不能始终保证在污水处理厂内完全保留PAC。因此，少量的装有MP的PAC可以进入接收水，对水生生物可能产生负面影响。本研究调查了从污水处理厂中装载MP的PAC与未装载的天然PAC相比对双壳类双壁珊瑚的可能影响 sp。在10周的暴露实验中。在半静态沉积物-水系统中，PAC的浓度分别为1、10和100 mg / L。

结果

分析了异种生物代谢（即谷胱甘肽-S-转移酶（GST））和氧化应激（即过氧化氢酶（CAT）活性和脂质过氧化）的分子生物标记反应，在任何一种处理中，均未检测到与对照的显着差异，除了1 mg / L PAC _WWTP处理中的CAT活性。此外，在暴露5周和10周后测量了单个双壳类动物的过滤速率，并将其与初始过滤速率进行了比较，结果是PAC的存在不影响Corbicula的过滤速率。 sp。总而言之，尽管选择了敏感的终点并且暴露时间相对较长，但即使在最高测试浓度下，对于卸载和MP装载的PAC也没有检测到显着影响，这与环境无关。

结论

这些结果为PAC在污水处理厂中的应用提供了有利的前景。根据我们的发现，即使当污水处理厂发生少量PAC泄漏时，对水生生物的不利影响似乎也可以忽略不计。