2022-07, Breitenmoser, Lena, Cuadrado Quesada, Gabriela, N, Anshuman, Bassi, Nitin, Dkhar, Nathaniel Bhakupar, Phukan, Mayuri, Kumar, Saurabh, Naga Babu, Andraju, Kierstein, Anjin, Campling, Paul, Hooijmans, Christine Maria

Abstract Wastewater treatment and reuse practices are limited in India despite the known benefits of preventing water resources pollution and contributing to sustainable production and consumption systems. We identify the perceived key drivers and barriers to wastewater treatment and reuse governance in a two-round Delphi study, including literature and case study analyses and consultation with 75 panelists. Panelists indicated that the most significant driver for wastewater treatment and water reuse is persistent water scarcity that necessitates diversification to alternative water supplies. In contrast, the most significant barriers are the lack of enforcement of pollution monitoring and control, the lack of an umbrella directive for integrated water resources management, and insufficient collaboration between responsible governmental organizations, central and state water authorities. Given the absence of central guidelines, only a few Indian states such as Maharashtra, Gujarat or Punjab have adopted effective governance structures. These states showcase that defined reuse standards can create successful wastewater treatment and reuse practices but require target-based regulations which are enforced and regularly monitored and financing mechanisms for their long-term operation. The new effluent discharge standards by the National Green Tribunal, the government support programmes, and increasing water scarcity in many parts of India will supposedly drive innovative wastewater treatment and reuse structures. Panelists agreed that efforts are needed to develop technology guiding frameworks following the fit-for-purpose principle and that strengthening institutional and monitoring capacity is crucial to increase confidence in the quality of recovered water resources, create demand, and ultimately safeguard human health and the environment.

2019-04-15, Breitenmoser, Lena, Gross, Thomas, Huesch, Ragini, Rau, Julius, Hugi, Christoph, Wintgens, Thomas

The quest for improved living conditions in rapidly growing Indian communities puts pressure on natural resources and produces emissions which harm the environment, society and the economy. Current municipal solid waste (MSW) practices are an important example, as most waste remains untreated and is often deposited on unsafe dumpsites or burned on open fires. Anaerobic digestion (AD) is an option to treat the large biodegradable fraction ('biowaste'). In rural parts of India, the technology to supply energy from biogas has been promoted for 30 years. Biowaste treatment in urban MSW management and organic fertilizer ('digestate') production for agriculture via AD have more recently gained attention but with limited success so far. Recent environmental policies in waste, energy, agricultural and other sectors have, however, set important cornerstones for a broader diffusion in the coming years. On the basis of peer-reviewed literature and governmental reports, we identify barriers and enabling factors along the AD chain (biowaste to technology to product utilization), and analyse relevant boundary conditions for the new multi-sector policies. We show that AD implementation has repeatedly failed due to unrealistic assumptions on biowaste quantity and quality, underestimation of the complex biowaste supply chain, unsuitable AD designs and overestimation of economic returns from biogas and digestate. Local knowledge and capacities for planning and process control are lacking in many places and resources required for operation and maintenance in the long run have often been ignored. We found that the multi-facetted value propositions of AD - including biowaste treatment, energy and fertilizer products - have only been partially tapped due to the exclusive focus on biogas. The new sector policies provide important enabling factors for change. Decentralized AD plants operating on a few tons biowaste per day from reliable and manageable sources (e.g. fruit and vegetable markets) could be a more promising step forward than large-scale investments which rely on large biowaste volumes from various sources. The parallel development of biowaste management, planning tools for municipalities, standardized digestate monitoring protocols and studies on simple, low-cost optimization measures for methane recovery from a wide range of biowastes and innovative high-solid AD digester designs will be prerequisites for the long-term future of AD projects.

2018-04, Breitenmoser, Lena, Dhar, Hiya, Gross, Thomas, Bakre, Milan, Huesch, Ragini, Hugi, Christoph, Wintgens, Thomas, Kumar, Rakesh, Kumar, Sunil

Anaerobic digestion (AD) of biowaste can generate biogas with methane (CH4) as energy source and contribute to sustainable municipal solid waste management in India. Characteristic municipal biowastes sampled seasonally from household, fruit and vegetable market and agricultural waste collection points in villages, towns and cities in Maharashtra were analysed to assess the potential as substrate for AD. The mean biochemical methane potential (BMP, at 37 °C) across seasons and community sizes was between 200-260, 175-240 and 101-286 NLCH4 kgvs-1 for household, market and agricultural biowaste, respectively. CH4 yields were comparable in villages, towns and cities. Seasonal variations in CH4 yields were observed for market and agricultural biowaste with highest values during pre-monsoon season. Results underpin that municipal biowaste is a suitable substrate for AD in India. However, low purity of available biowaste resulted in lower CH4 yields compared to recent studies using source-segregated biowaste.