Abstract

In the industrial production of the explosive 2,4,6-trinitrotoluene (TNT), purification steps are required to ensure the quality of the product, procedures that generate wastewater of a complex nature and with eco-toxicological potential, called red water, which consists of soluble sulfonates, TNT isomers, and other typical nitro aromatic compounds. The present work aimed to study the effects of integrating heterogeneous photocatalysis based on commercial TiO₂, with a biological process, based on activated sludge, for red water treatment. For the photocatalytic treatment, a 72% reduction in the typical absorption of nitro aromatic compounds (the region between 195 − 275 nm), a 36% reduction in chemical oxygen demand (COD), and a 68% reduction in total phenols were obtained. In the biological treatment, there was a 60% reduction in absorbance in the typical nitro aromatics region (NA), 10% reduction in COD, and 36% reduction in total phenols (FT). The integration of photocatalytic and biological treatments showed promising results compared to the individual processes. Having 94% reduction in NA absorbance, 72% reduction in FT, and 89% reduction in COD with an association of photocatalytic pretreatment followed by biological, and reductions of 88% in NA absorbance, 62% in FT, and 87% in COD for a biological pretreatment followed by the photocatalytic process. In general, when comparing the chemical and biological processes, isolated and integrated, both types of integration showed significantly superior results. They were able to remove the main nitro aromatic constituents of the Red Water effluent.

摘要

在爆炸性 2,4,6-三硝基甲苯 (TNT) 的工业生产中，需要进行纯化步骤以确保产品质量，这些程序会产生性质复杂且具有生态毒理学潜力的废水，称为红水，由可溶性磺酸盐、TNT 异构体和其他典型的硝基芳香族化合物组成。本工作旨在研究基于商业 TiO _{2的非均相光催化的集成效果。}，采用基于活性污泥的生物工艺处理红水。对于光催化处理，硝基芳族化合物的典型吸收降低了 72%（195-275 nm 之间的区域），化学需氧量 (COD) 降低了 36%，总酚类降低了 68%。在生物处理中，典型硝基芳烃区域 (NA) 的吸光度降低了 60%，COD 降低了 10%，总酚 (FT) 降低了 36%。与单独的过程相比，光催化和生物处理的整合显示出有希望的结果。NA 吸光度降低 94%，FT 降低 72%，COD 降低 89%，与光催化预处理和生物处理相关，NA 吸光度降低 88%，FT 降低 62%，和 87% 的 COD 用于生物预处理，然后是光催化过程。一般来说，在比较化学和生物过程、分离和集成时，两种类型的集成都显示出明显优越的结果。他们能够去除红水流出物中的主要硝基芳烃成分。