Performance and treatment assessment of a pilot-scale decentralized greywater reuse system in rural schools of north-central Chile

• Published in: Ecological engineering Vol. 174; p. 106460
• Main Authors: Rodríguez, Carolina, Carrasco, Fernanda, Sánchez, Rafael, Rebolledo, Natalia, Schneider, Nicolás, Serrano, Jennyfer, Leiva, Eduardo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2022; Elsevier BV
• Subjects: Activated carbon; Adsorption; Arid climates; Arid regions; Carbon; Domestic wastewater; Drought; Greywater; Installation costs; Irrigation; Legislation; Organic matter; Recreation areas; Recreational areas; Recreational use; Removal; Sand; Schools; Semiarid climates; Sorbents; Turbidity; Wastewater; Water demand; Water quality; Water reuse; Water scarcity; Zeolites; Chile; Greywater; Adsorption; Water reuse; Water scarcity
• ISSN: 0925-8574; 1872-6992
• DOI: 10.1016/j.ecoleng.2021.106460

The problem of water scarcity in the world has gained great relevance in recent decades. One of the fields of study that has been developed as an ecological alternative to combat the water demand is the reuse of greywater. Greywater corresponds to domestic wastewater that excludes water from the toilet. These waters have the potential to be reused after simple treatments for non-potable uses. In the last decade, Chile has gone through the most intense mega-drought in its history. One of the most affected regions is the Coquimbo Region, located in the north-central zone, with a semi-arid climate and extensive agricultural activity. This paper presents the first results of pilot greywater treatment systems installed in rural public schools in the Coquimbo Region. In the first instance, different sorbent materials such as sand, zeolite, acid-activated carbon (AAC), base-activated carbon (BAC) and heat-activated carbon (HAC) were studied for the removal of organic matter and turbidity. It was found that the adsorbent materials based on carbon were more efficient for the removal of organic matter, registering maximum mean sorption capacities of 107.7 mg/g, 77.5 mg/g and 78.5 mg/g, for AAC, BAC and HAC, respectively. On the one hand, the treatment columns composed HAC, zeolite and sand, were very effective for removing turbidity, reaching removal percentages over 90%. On the other hand, pilot treatment systems were efficient in reaching the water quality levels required by Chilean legislation for the use of irrigation of recreational areas and services, and in some cases for the use of ornamental irrigation. The advantage of these systems is their simplicity and low installation cost. These systems have allowed savings of between 840 and 26,000 L per month, depending on the size of the school, which has allowed the watering of gardens. [Display omitted] •Heat-activated carbon and acid-activated carbon were effective for the adsorption of organic matter.•Sequential treatments columns containing heat-activated carbon, sand and zeolite had a great capacity for removing turbidity.•The pilot treatment systems installed in rural schools exhibited good results in greywater treatment.•Low-cost pilot treatment systems allowed the irrigation of gardens and green areas in rural schools.