DataSheet1_Stability of Acid Black 210 dye in Tannery Industry Effluent in Aqueous Solution Is Limited and Generates Harmful Subproducts.docx

The present work investigates the occurrence of the Acid Black 210 (AB210) dye and its subproducts in the tannery industry by analytical techniques. The AB210 is an important dye characterized by three azo groups as a chromophore and is one of the most used azo dyes in the tannery industry. The stability of AB210 in front of chlorination, sunlight exposition, and ambient conditions was investigated, as well as its occurrence and degradation products in the tannery wastewater. The stability study of AB210 showed a decrease in dye concentration of up to 45% after 14 days at room temperature. The exposure of the AB 210 by a solar simulator for 3 h showed discoloration of the dye. Furthermore, the chlorination of the AB210 caused a reduction of 25% in the intensity of the absorption band at the visible region after 300 s of treatment with sodium hypochlorite (NaClO). Studies based on high-performance liquid chromatography (HPLC-DAD), liquid chromatography-mass spectrometry (LC-MS/MS), and nuclear magnetic resonance (NMR) have indicated the occurrence of several harmful compounds such as benzene, cresol, naphthalene, phenol, 2-naphthylamine, and phenylacetic acid, and three aromatic amines, 2-naphthylamine, 2,6-dimethylaniline and 4-nitroaniline from the tannery industry. The cytotoxicity assay showed toxicity for the samples stored for a long period. Thus, the immortalized human keratinocyte (HaCAT) and 3T3 cells assays for the AB210 stored for 14 days showed 70% cell death in both strains evaluated. Our results demonstrated that the AB210 degradation is a great environmental concern due to increased toxicity for the body of living beings, especially for humans, as their biotransformation produces harmful compounds such as amines, which have been widely condemned by the International Agency for Research on Cancer.本研究采用分析技术，探究了制革工业中酸性黑210（Acid Black 210，AB210）染料及其副产物的赋存情况。酸性黑210（AB210）是一类重要的染料，以三个偶氮基团作为生色团，是制革工业中应用最广泛的偶氮染料之一。本研究同时探究了AB210在氯化、日光照射及自然环境条件下的稳定性，以及其在制革废水中的赋存状态与降解产物。AB210的稳定性实验结果显示，室温放置14天后，染料浓度最高可下降45%。采用太阳模拟器照射AB210达3小时后，染料发生了褪色现象。此外，采用次氯酸钠（sodium hypochlorite，NaClO）处理AB210达300秒后，其可见光区的吸收带强度下降了25%。本研究采用高效液相色谱-二极管阵列检测器（high-performance liquid chromatography-diode array detector, HPLC-DAD）、液相色谱-串联质谱（liquid chromatography-tandem mass spectrometry, LC-MS/MS）以及核磁共振（nuclear magnetic resonance, NMR）技术进行分析，结果表明制革工业废水中存在多种有害化合物，包括苯、甲酚、萘、苯酚、2-萘胺、苯乙酸，以及2-萘胺、2,6-二甲基苯胺、4-硝基苯胺三种芳香胺类物质。细胞毒性实验结果显示，长期储存的样品具有毒性。因此，针对储存14天的AB210样品开展的永生化人角质形成细胞（immortalized human keratinocyte, HaCAT）与3T3细胞毒性实验结果显示，两种被测细胞株的细胞死亡率均达到70%。本研究结果表明，AB210的降解会显著提升对生物体（尤其人类）的毒性，因此是一项重大的环境隐患。这是因为AB210经生物转化后会生成胺类等有害化合物，而此类物质已被国际癌症研究机构（International Agency for Research on Cancer, IARC）广泛认定为致癌物质。