Green practices in wastewater treatment: Upcycling avocado waste for enhanced water sanitation. Case study: WWTP in San Francisco Pichátaro, Michoacán

Potable water and sanitation are priorities since pollutants pose health risks in Mexican rural communities. In this study, the San Francisco Pichataro (Michoacán) WWTP effluent was subjected to a post-bioadsorption treatment. For this purpose, activated bioadsorbents from avocado waste were developed. Avocado waste represents ∼34 metric tons per day in the considered municipality. The WQI tool was used to assess the water quality for the WWTP influent, effluent, and the post-bioadsorption effluent (permeate). The application of the activated bioadsorbent increased the WQI from 30 to 70, removing about 1600 to 1900 mg L −1 of COD and ≈50% of hardness (Mg 2+ and Ca 2+ ), and enhancing the quality of the WWTP effluent. This improvement means the permeate flux could be used for crop irrigation or sanitation activities, improving water resource management. • Use avocado waste (the municipality generates ∼34 metrics tons per day) to develop activated bioadsorbents for enhanced water sanitation. • Application of the bioadsorbents improved the WQI from 30 to 70, removing about 1600 to 1900 mg L −1 of COD and ∼50% of hardness (Mg 2+ and Ca 2+ ). • Upcycling agricultural waste and addressing local water treatment challenges. • Findings have practical implications for the indigenous community of San Francisco Pichátaro, Michoacán.