School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China.
South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China; Guangdong Key Laboratory of Water and Air Pollution Control, Guangzhou 510655, China.
Sci Total Environ. 2024 Mar 10;915:169937. doi: 10.1016/j.scitotenv.2024.169937. Epub 2024 Jan 8.
Papermaking wastewater contained various of toxic and hazardous pollutants that pose significant threats to both the ecosystem and human health. Despite these risks, limited research has addressed the detoxification efficiency and mechanism involved in the typical process treatment of papermaking wastewater. In this study, the acute toxicity of papermaking wastewater after different treatment processes was assessed using luminousbacteria, zebrafish and Daphnia magna (D. magna). Meanwhile, the pollution parament of the corresponding wastewater were measured, and the transformation of organic pollutant in the wastewater was identified by three-dimensional fluorescence and other techniques. Finally, the possible mechanism of toxicity variation in different treatment processes were explored in combination with correlation analyses. The results showed that raw papermaking wastewater displayed high acute toxicity to luminousbacteria, and exhibited slight acute toxicity and acute toxicity effect to zebrafish and D. magna, respectively. After physical and biochemical processes, not only the toxicity of the wastewater to zebrafish and D. magna was completely eliminated, but also the inhibitory effect on luminousbacteria was significantly reduced (TU value decreased from 11.07 to 1.66). Among them, the order of detoxification efficiency on luminousbacteria was air flotation > hydrolysis acidification > IC > aerobic process. Correlation analyses revealed a direct link between the reduced of Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) and the detoxification efficiency of the different processes on the wastewater. In particular, the removal of benzene-containing aromatic pollutant correlated positively with decreased toxicity. However, the Fenton process, despite lowering TOC and COD, increased of the acute toxicity of the luminousbacteria (TU value increased from 1.66 to 2.33). This may result from the transformation generation of organic pollutant and oxidant residues during the Fenton process. Hence, oxidation technologies such as the Fenton process, as a deep treatment process, should be more concerned about the ecological risks that may be caused while focusing on their effectiveness in removing pollutant.
造纸废水含有各种有毒有害物质，对生态系统和人类健康构成重大威胁。尽管存在这些风险，但针对造纸废水典型工艺处理的解毒效率和机制，相关研究仍然有限。在本研究中，采用发光细菌、斑马鱼和大型溞（Daphnia magna）评估了不同处理工艺后造纸废水的急性毒性。同时，测量了相应废水的污染参数，并通过三维荧光等技术鉴定了废水中有机污染物的转化。最后，结合相关分析，探讨了不同处理工艺中毒性变化的可能机制。结果表明，原生造纸废水对发光细菌具有高急性毒性，对斑马鱼和大型溞分别表现出轻微急性毒性和急性毒性效应。经过物理和生化处理后，不仅废水对斑马鱼和大型溞的毒性完全消除，而且对发光细菌的抑制作用也显著降低（TU 值从 11.07 降低到 1.66）。其中，气浮>水解酸化>IC>好氧工艺对发光细菌的解毒效率依次提高。相关分析表明，TOC 和 COD 的降低与不同工艺对废水的解毒效率直接相关。特别是含苯芳香族污染物的去除与毒性降低呈正相关。然而，尽管 Fenton 工艺降低了 TOC 和 COD，但发光细菌的急性毒性却增加了（TU 值从 1.66 增加到 2.33）。这可能是由于 Fenton 工艺过程中有机污染物和氧化剂残留的转化生成所致。因此，Fenton 工艺等氧化技术作为深度处理工艺，在关注其去除污染物有效性的同时，应更加关注其可能带来的生态风险。
