Chromium Remediation from Tannery Wastewater in Arequipa, Peru: Local Experiences and Prospects for Sustainable Solutions

The release of tannery wastewater contributes to chromium (Cr) pollution globally. Herein, we conduct a novel consolidation of research from the Arequipa region of southern Peru that integrates university theses written in Spanish alongside peer-reviewed journal articles. The objective is to provide a place-based complement to existing research in English scientific journals focused on effective tools for Cr treatment from tannery wastewater. Our consolidation categorized a total of 75 publications (70 theses and five peer-reviewed) into five distinct strategies for Cr treatment: adsorption (twenty-three studies), phytoremediation (eighteen studies), bioremediation (thirteen studies), electrocoagulation (five studies), and other techniques (fifteen studies). This synthesis highlighted potentially promising approaches that could be sustainably tailored to regional resources and waste products. This includes sorptive materials derived from food waste such as native achiote peels ( B. orellana ) and avocado seeds ( P. americana ) either used directly or as a feedstock for biochar. Other technologies include phytoremediation using microalgae and resident vascular plants and microbial bioremediation that capitalizes on indigenous bacteria and fungi. Promise was also discerned in studies that incorporated a combination of abiotic and biotic mechanisms tailored toward the region, such as infiltration using selective and bioactive materials, wetlands, solar distillation, iron-based coagulation and flocculation, and bioreactors. These findings provide a sustainable complement to prior global investigations for effective attenuation strategies by adding novel materials and techniques that could be further explored to assess the viability of implementation at pilot and larger scales. These promising technologies and the ability to tailor sustainable treatments toward local resources highlight the opportunity to prioritize the treatment of tannery wastewater to ensure a cleaner environment by informing policy makers, academics, and industry on technologies that could be adopted for implementation in the region.