Performance Enhancement of Solar Water Distillation and Reuse for Sustainable Water Resources Management

Abstract

The waste water purification system combining nanofiltration (NF) membranes, solar- powered settling pretreatment ponds, and a multi-stage polishing chain. The aim is to treat combined pond and harvested rainwater contaminated with suspended solids, organics, nutrients and micropollutants, while using renewable energy to reduce operational carbon footprint. A detailed design of the experimental pilot is presented, along with proposed performance metrics, energy balance, and fouling control measures. Based on recent studies, nanofiltration offers high removal of micro-pollutants and hardness while solar-driven pretreatment and photocatalysis can substantially reduce organic loading, improving membrane lifetime. Expected outcomes include reduction in turbidity and BOD, significant micropollutant rejection, and a feasible low-carbon treatment pathway for decentralized pond/rainwater systems.

Introduction

The text presents a pilot-scale, solar-assisted decentralized wastewater treatment system aimed at addressing freshwater scarcity and pollution through energy-efficient and sustainable treatment for non-potable and indirect potable reuse. The study proposes integrating renewable-energy-driven pretreatment with nanofiltration (NF) and advanced polishing units to achieve high contaminant removal while reducing reliance on fossil fuels.

The system combines solar-assisted thermal settling, coarse filtration, NF membrane separation, activated carbon adsorption, and UV/photocatalytic disinfection. This hybrid approach addresses key challenges such as membrane fouling, variable feed water quality (pond and rainwater), and operational costs in decentralized settings. Solar water distillation principles are also discussed as a complementary low-cost, off-grid purification strategy, though conventional solar stills suffer from low productivity—prompting the need for system enhancements.

A detailed literature review highlights recent advances in decentralized water treatment, wastewater reuse, energy-efficient purification technologies, and climate-resilient water systems. Building on this background, the methodology describes the design and operation of a laboratory-scale pilot plant powered by photovoltaic energy. The system treats mixed pond and rainwater under varying operating pressures and recovery ratios, with performance assessed through water quality monitoring, membrane flux analysis, fouling behavior, cleaning protocols, and energy consumption metrics.

Results demonstrate substantial water quality improvement, including over 90% turbidity removal, 80–85% BOD reduction, 75–80% COD reduction, around 70% hardness reduction, and >99% microbial removal. The study confirms that solar-assisted pretreatment significantly reduces membrane fouling and energy demand. Overall, the integrated solar–NF treatment system shows strong potential as a sustainable, decentralized solution for water reuse, particularly in rural and water-stressed regions.

Conclusion

This experimental investigation confirms that integrating solar the al pretreatment with nanofiltration and post-treatment polishing enhances overall system performance. The system effectively treats pond and rainwater for non-potable reuse while minimizing energy consumption and membrane fouling. The proposed configuration is technically feasible, environmentally sustainable, and suitable for decentralized water treatment systems. 1) Solar thermal pretreatment effectively reduced turbidity and TSS by more than 60%. 2) Nanofiltration achieved high removal efficiencies for BOD, COD, hardness, and microorganisms. 3) Membrane fouling was significantly reduced due to staged pretreatment. 4) Solar-assisted operation reduced energy consumption and CO? emissions. 5) The system is technically feasible, economical, and environmentally sustainable for decentralized water reuse.

References

[1] Livinus A. Obasi, Cornelius O. Nevo et. al (2024)- Evaluating the predictive potential0 of RSM and ANN models in treatment of greywater-syrup mixture using Ekowe clay- PEM microbial fuel cell, Research Academia Green Energy Article Published 72273. [2] M.D. Gómez et. al (2022)- Industrial wastewater treatment by anaerobic digestion using a solar heater as renewable energy for temperature Academia Green Energy l50200. [3] M Elliott et. al (2024)- A Conceptual Framework to Assess Post-Wildfire Water Quality, State of the Science and Knowledge Gaps 036260. [4] N H Pakharudin et. al (2023)- Water treatment process using conventional and advanced methods, A comparative study of Malaysia and selected countries 012017. [5] S. Rossi et. al (2025)- Recent advances and challenges in mechanistic modelling of Photosynthetic processes for wastewater treatment Martin Škerlep, Science direct 123216. [6] Livinus A. Obasi, Cornelius O. Nevo et. al (2024)- Evaluating the predictive potential0 of RSM and ANN models in treatment of greywater-syrup mixture using Ekowe clay- PEM microbial fuel cell, Research Academia Green Energy Article Published 72273. [7] M.D. Gómez et. al (2022)- Industrial wastewater treatment by anaerobic digestion using a solar heater as renewable energy for temperature Academia Green Energy l50200. [8] M Elliott et. al (2024)- A Conceptual Framework to Assess Post-Wildfire Water Quality, State of the Science and Knowledge Gaps 036260. [9] N H Pakharudin et. al (2023)- Water treatment process using conventional and advanced methods, A comparative study of Malaysia and selected countries 012017. [10] S. Rossi et. al (2025)- Recent advances and challenges in mechanistic modelling of [11] photosynthetic processes for wastewater treatment Martin Škerlep, Science direct 123216. [12] Samra Naz et. al (2025)- Innovative Approaches in Wastewater Management: A Comprehensive Review, Environmental Science Advance, 2319-7706. [13] Jorge Alejandro Silva et. al (2023)- Wastewater Treatment and Reuse for Sustainable Water Resources Management, International Journal for Research Trends and Innovation, 151410940. [14] Ana Soares et. al (2020)- Wastewater treatment in Challenges ahead and future vision in a European context. Elsevier B.V. on behalf of Chinese, Environmental Science and Ecotechnology 102016 (2020). [15] Cinzia Da Ros, Vincenzo Conca et. al (2024)- Sieving of municipal wastewater and recovery of bio-based volatile fatty acids at pilot scale, Science Direct 115633. [16] Marlies J. Kampschreur et. al (2021)- Nitrous oxide emission during wastewater treatment, Science Direct 102016 (2021). [17] Borhane Mahjoub et. al (2025)- Green chemistry and sustainable chemistry related to water challenges Solutions and prospects in a changing climate, Green chemistry and sustainable chemistry, 101000. [18] Stef H.A. Koop et. al (2022)- Integrated water resources management in cities in the world: Global solutions. Science Direct 104137. [19] Ayla Ahmadi et. al (2022)- Pyrolysis of municipal waste: Effect of waste type and co- pyrolysis on the formation of products and coke over zeolite catalyst. Chemical Engineering Research and Design, 101016. [20] Mariana Marselina et. al (2025)- The water quality of the Upper Citarum: Applying the overall index of pollution, Said-WQI, and pollution index methods, Published by Elsevier Ltd, Science direct, 41690. [21] Leidy Marcela Ulloa, Murillo et. al (2025)- Pyrolysis of municipal waste with synthesized zeolite from steel making factory waste, Scientific report 951794. [22] C. Raghunathan, G Tamal Mondal et. al (2025)- Filter-feeding, Pharmaceutical, Coastal and marine ecosystem, Pondicherry, Science of the Total Environment 700053. [23] Liu Jiahe Ying Chunyang He et. al (2024)- Scarcity and quality risks for future global urban water supply, Landsc Ecol 018320. [24] Tushaar shah, Hugh Tural and B.K. Anand et. al (2023)- India’s Water Future to Business-as-Usual Scenario and Deviations, 10260862. [25] Lia Wang et. al (2025)- A Mini-Review of Sludge-Derived Biochar (SDB) for Wastewater Treatment Recent Advances in, Water Research 61703. [26] Marin Ugrina et. al (2024)- Advances in Wastewater Treatment, National Level Conference on Water Management Scenario 17061400. [27] Asma El Golli et. al (2024)- Advancing solar wastewater treatment: A photocatalytic process via green and concentrated sunlight 123178. [28] H. Sharon et. al (2024)- Solar Thermal Wastewater Treatment Systems, Journal of Environmental Management 283301. [29] N H Pakharuddin et. al (2023)- Water treatment process using conventional and advanced methods: A comparative study of Malaysia and selected countries, Earth and Environmental Science, 012017.

Copyright

Copyright © 2026 Ravindra Gautam, Dr. Parag Mishra, Prof. Bhagwat Dwivedi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.