Water scarcity and insufficient sanitation create a major negative impact on public health. Lack of water is a severe problem in several states in India, as 77.6% of the country is exposed to drought resulting from irregulated monsoons, which has happened in four out of the last ten years (Patil & Eslamian, 2017). Many of the rural wastewater ponds do not have treatment, while others may have primary treatment only, where untreated sewage from the ponds is eventually discharged into the ground or a nearby water stream. Conventional wastewater treatments are energy demanding, thus, improving the efficiency of wastewater ponds, typically through aeration, will constitute a massive energy demand. In rural areas, decentralized systems are more flexible and can suit a wider range of site conditions, including topography where conventional sewage treatment cannot be implemented (Kumar & Tortajada, 2020), however, conventional centralized systems can reach a higher quality of treatment. Environmental indicators refer to the environmental efficiency of the wastewater technology in terms of quality of the effluent, resources used, emissions created process flexibility, and carbon footprint for the energy consumed to carry out the treatment. For a system to be environmentally sustainable, it should ensure the conservation of resources, such as the recycling of nutrients and energy.
Our innovation is a decentralized wastewater treatment method, working as natural remediation carried out through harnessing the synergic relations between microalgae and bacteria, which naturally exist in wastewater. We developed a specially designed biodegradable carrier, which serves as a medium platform through which a natural-based remediation process can occur in wastewater, turning it into water appropriate for reuse, to be utilized mainly for agricultural irrigation. Our joint research is conducted the state of Punjab, India, which suffers significantly from water & sanitation (WASH) challenges, alongside having a largely rural and agriculturally based population. Punjab’s agriculture sector is the largest in the state, with 36% of the population directly dependent on it as their main income and source of livelihood. Conclusions: Currently, we are in its pre-pilot stage (demo of 10 m3 of sewage pond at Thapar university), following 3-4 years of lab-based R&D, alongside social and financial evaluations which are being researched, with the aim of implementing this solution for 500 villages in a future pilot stage, to take place in the wastewater ponds of rural Patiala and Ludhiana districts, Punjab. The CMBB technology enhanced the removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), ammonium, phosphates, and micropollutants. For example, with our process, the COD reduction, compared with control reached a value of 50 mg/L, below the PPCB Standards (Discharge for treated water for Irrigation) of <150 mg/L COD. When addressing solutions in the field of sanitation, the importance of facilitating and following the social context of the adoption process should be especially emphasized. In comparison to innovations in other fields and sectors such as energy, transportation, or communication systems, the adoption of new sanitation solutions has a higher level of complexity due to intimate end-user interaction with the technology, which makes social acceptance a critical factor for success. We are conducting further research including alternative substrate designs, long-term studies, social aspects, and early adopters and financial aspects.
