Development of a sustainable, green, and solar-powered filtration system for E. coli removal and greywater treatment

Jordan's limited water resources have reduced daily water consumption, leading to a highly concentrated greywater production rate of 54 million cubic meters per year. The presence of nitrate ions, total dissolved solids, total suspended solids, chemical oxygen demand, and biological oxygen demand in greywater poses excellent environmental and health risks when disposed untreated. Water scarcity directly impacts water and food security and is expected to intensify at the current resources management practices. The significance of the current and predictable water shortage in the context of sustainable development and the presence of new technologies brought further attention to utilizing non-conventional water sources. Reclamation of treated wastewater, greywater, brackish, and seawater desalination is Jordan's water budget's only non-conventional water resource. This study aims to address Jordan's water scarcity crisis by developing a low-energy, solar-powered greywater filtration system using natural materials while ensuring compliance with Jordanian standards for safe agricultural applications. Several treatment methods have been proposed; however, most of these systems require high to medium energy levels for treatment purposes. Hence, the running cost of the system is relatively high. To address this issue, a four-stage, low-energy, green, and decentralized solar filtration system for greywater treatment has been developed, which uses natural materials available in Jordan and activated carbon to reduce organic and solids content and remove pathogens. The system also uses hot water generated by a Photovoltaic solar system to sanitize the greywater, a novel concept of approach for sanitization. This innovative system is powered entirely by solar energy and can be installed in individual homes.  The results of the developed solar filtration system were very efficient in reducing turbidity, chemical oxygen demand, and Escherichia coli removal: 92, 95, and 100 percent, respectively. Furthermore, the system showed a high potential for total coliforms and Escherichia coli inactivation, reaching 4.64 and 3.15 log units, respectively. Product water meets Jordan standards, ensuring safe reuse for irrigation applications. The findings of this study highlight the satisfactory performance of the developed greywater solar filtration setup. The economic feasibility analysis demonstrates that the proposed system is economically viable and financially sound. The system’s reliance on solar energy and the absence of consumables contribute to its sustainability. They are addressing sustainable practices in greywater treatment in addition to water scarcity concerns. The treated greywater, obtained through the series of treatment steps, including solar disinfection, successfully met the Jordanian standards for safe reuse. The substantial reduction of Escherichia coli and total coliforms to acceptable levels demonstrates the treatment system's effectiveness in generating pathogen-free greywater, suitable for a wide range of applications. The study concludes that the solar filtration setup consistently delivers high-quality, pathogen-free greywater, meeting stringent regulatory requirements. This innovative, sustainable system offers a viable solution to Jordan’s water scarcity, introducing a new non-conventional water resource that requires no consumables (non-chemical, non-hazardous materials), thereby addressing sustainability concerns in greywater treatment.