Session 3 - Circular Water Management: Resource Recovery and Reuse Potentials

Convener - Serena Caucci, Peter Krebs, Tran Viet Nga, Edeltraud Guenther

Speaker Titel Abstract Kind of presentation
Catalin Stefan Using wastewater to recharge the aquifers: from limitations to opportunities and practical implementation 

The number of success stories about the wastewater use for non-potable purposes increased significantly in the last decade due to technological advances, knowledge dissemination and increased necessity (natural and human-induced pressure on water systems). The intentional recharge of aquifers (independent of influent water quality) for later abstraction or ecological benefits is widely known as managed aquifer recharge (MAR). Sporadically, recharging the aquifers with treated wastewater via soil aquifer treatment (SAT) is mentioned as potential solution against water scarcity, especially in arid countries where water conservation is a necessity. Despite their obvious benefits, best practice examples of MAR/SAT systems using treated wastewater are not many due regulatory, cultural, technical and economic limitations. At the EU level, a major bottleneck is represented by the lack of a regulatory risk assessment framework while in some other countries, religious and cultural implications can slow down the SAT implementation. The absence of an adequate aquifer for storing the water or the costs associated with the wastewater collection, pre-treatment, and transport to the infiltration site represent further additional obstacles. Nevertheless, presence of emerging contaminants in the municipal wastewaters and their potential micro-bacteriological contamination of the receiving aquifer can represent a reality and thus monitoring of wastewater should be constantly provided. Other wastewater types such as from food and beverage industries or industrial service waters (i.e. cooling process waters) could be excellent sources for SAT and MAR. The present paper describes the state-of-the-art in wastewater use for groundwater recharge and discusses the opportunities and prospects for future development. Best-practise examples will be given, together with considerations on planning, operation and maintenance of such schemes.

Lightning talk in the session and a poster
Caro Mooren, Stefania Munaretto, Piero Morseletto Tangling the circular economy to the nexus approach: a conceptual framework for wastewater circular solutions for water, energy and food  This paper investigates which circular solutions applied to waste water can contribute to maximise synergies, minimise trade-offs, and improve resource use efficiency in the water-energy-food (WEF) nexus. The study draws upon several case studies from both the academic literature and projects developed by water research institutes the authors work/are connected to. The case studies are selected according to three criteria: a) they deal with wastewater treatment/management (e.g. smart water systems, wastewater treatment plants as energy and resources factories); b) they reflect a meaningful array of circular economy solutions (e.g. avoid use, reduce use, reuse, recycle, replenish); c) they address the WEF nexus (e.g. reuse of treated wastewater for irrigation, energy production and nutrient recovery, circular water solutions for agriculture, food processing/consumption). Through the cases, the paper elicits relevant knowledge on resource recovery (e.g. water, energy, nutrients, materials), technological applications (e.g. bio-membranes, photo-bioreactors, forward osmose, rainwater harvesting and underground storage), operations/processes (e.g. closing loops, concentration and upcycling, extraction of water, energy and raw materials), technical design choices (e.g. centralisation vs decentralisation, advanced chemical vs biological oxidation), economics (e.g. value retention and value creation in the WEF nexus), and management (e.g. stakeholder engagement, regulatory requirements, nexus symbiosis). Furthermore, the case studies allow understanding the interlinkages in the WEF nexus while plotting out synergies, trade-offs, and efficiency gains. On these bases, the paper advances an initial conceptual framework for circular (waste) water and the WEF nexus. The aim is to initiate an academic conversation for the development of a consolidated conceptual framework to guide the design and implementation of circular solutions for reducing the pressure on WEF systems. In the same vein, the paper aims to sketch a preliminary research agenda for future academic, practice and policy research. Oral (normal length)
Attilio Toscano Use of non-conventional water resources in the Mediterranean agricultural sector: the FIT4REUSE project  FIT4REUSE is a recently funded PRIMA project with the main objective of providing safe, sustainable and accepted ways of water supply for the Mediterranean agricultural sector by exploiting non-conventional water resources, namely treated wastewater and desalted water. Therefore, the project aims to achieve a paradigm shift in the area of wastewater management. Instead of being regarded as waste, it is a valuable resource that the society and especially agricultural sector can benefit from. Moreover, sea water can also be used in a number of ways, and the project will offer novel solutions for the Mediterranean region (Southern Europe, North Africa and Middle East) including partners from 7 different countries (Italy, Spain, France, Greece, Israel, Tunisia and Turkey). Non-conventional water resources can be used to fill the gap that exists between water availability and water needs in the Mediterranean region and its agricultural sector as the major water consumer. However, in order to prevent any negative effect and achieve sustainable cycle of this resources, it is important to provide innovative technologies that can enable reaching standards that regulate this area. Apart from recycling only water resource, FIT4REUSE will also provide the know-how needed to recycle nutrients. Non-conventional water resources will be treated in a way to retain nutrients, enabling both irrigation and fertigation, and consequently improving crop growth with minimal investment. However, FIT4REUSE will also focus on the recovery of calcium, magnesium and phosphorus in form of salts or struvite through concentration, chemical precipitation or ion exchange process. The results obtained during the first year of the project will be discussed. Through achievement of this objectives but also through holistic assessment of proposed solutions that will involve different stakeholders, FIT4REUSE it is targeted to have a tangible positive impact on society, economy and environment of the Mediterranean region and beyond. Oral (normal length)
Ainul Firdatun Nisaa Using GRASP method for developing options of sanitation systems for an informal settlement in Lima  Only a small percentage of fecal sludge generated in Lima’s informal settlements is safely managed. Although efforts for improving sanitation accesses for informal settlements in Lima have gradually increased in the past two decades, the informal settlement of Quebrada Verde is yet to benefit from any urban sanitation programs. This research aims at using a GRASP procedure (Spuhler et al., 2018) to identify appropriate sanitation technologies and system options for Quebrada Verde. The technologies were chosen based on the literature review from informal settlements worldwide and based on the discussion with experts. The appropriateness of each technology for the given case study was assessed using 18 attributes developed within the sustainable sanitation objective, e.g. water and energy supplies. A total of 42 technologies were evaluated regarding their appropriateness and resulted in 265,185 valid sanitation system options. From these systems, a diverse set of 17 sanitation system options was selected which covers the full diversity of system options, providing the foundation to reveal major trade-offs among options for different decision objectives, as well as a quantitative comparison of the appropriateness of different options. The result shows that higher recovery ratio potentials were observed for sanitation system with urine diversion and biogas production as well as the system combining anaerobic filter and co-composting for the treatment. These options are recommended to be considered in the decision-making processes, promoting energy recovery and wastewater reuse for irrigation concept in the water-shortage region of Lima. The case of Quebrada Verde can be replicated in other settlements that have similar profiles. Poster only
Ali Aqlan Solar Powered Desalination Applied Solution In Yemen  Climate changes put more pressure on basic services. Access to clean water and energy became challenging particularly during disasters, such as the current crisis in Yemen. The lack of water/energy is critical to health and survival. Utilizing natural renewable resources, which rely on no fuel has more resilience and could mitigate climate change impact and solve a part of water/energy problems. So far purification/desalination device that can be deployed quickly and affordable to people in need of clean drinking water does not yet exist in the marketplace. There is a high need to create a hand-held, stand-alone, low-cost, purification/desalination device for rapid deployment mainly during humanitarian crises. Yemen is rich in solar energy. Solar radiation averaged in Yemen is 5.2 – 6.8 kWh/m2, and the average sunshine exceed 9 hours a day of clear blue sky. Utilizing solar energy in Yemen could solve a part of the current energy/water shortages. This paper discussed the fabrication and development process and the results of the newly developed solar still device combined with parabolic concentration. Fieldworks and manufacturing, laboratory experiments and water quality analysis, mathematical modeling and simulation using ANSYS (CFD) software were the tools used in this study. The clean water productivity of the second version of the developed device reached 5 L/ m2 a day. The study proposed further plans for a conical shape unit for the same device, which seems more promising and easier to handle, install and maintain. With this new shape/plan of device, the analysis results expect to increase the productivity to 8 L/m2 a day. This study showed feasible/ viable results and verifies the importance of renewable energy/water transition to achieve secure sustainable water and energy management. Keywords: Renewable Resources, Solar Energy, Water/ Energy crisis, Water Purification, Desalination Poster only
Anthony Njuguna Matheri Role of Green/Digital/Circular Economy Research in the Economic Emerging Market through Technology Station in Research and Development, Technology, Innovation and Commercialization  University of Johannesburg, Process Energy Environment and Technology Station is the National Green Economy Award Winner National Science and Technology Forum (NSTF) 2018/2019. The primary mandate of the UJ-PEETS is to contribute towards improving the competitiveness of industry and small, medium scale enterprises (SMEs) through the application of specialized knowledge, technology and facilitating the interaction between industry (especially SMEs) and academia, to enable innovation and technology transfer to grow the green economy. The UJ-PEETS was established in 2010 under the support of University of Johannesburg. The technology station is funded by Technology Innovation Agency (TIA), which is an agency of the Department of Science and Technology (DST) to fulfil the sustainable green economy mandate. The transition towards the fourth industrial revolution (4IR) otherwise called Industry 4.0 (I4.0) across virtually all sectors, is already upon us. Industry 4.0, as it developed from automation and data exchange in manufacturing technologies, is changing the way Industry is evolving. We offer new opportunities for SMEs, corporates, municipalities, national government by creating new business models and integrate into global value chains. UJ PEETS endeavors to promote cross-disciplinary knowledge transfer that supports the development of the green economy by building on relationship with researchers and developing networks within the university, National System of Innovation (NSI) as it relates to sustainable development in the energy-water-waste nexus. Our focus is on process optimization, specifically in the energy, water, food and environmental sectors that supports I4.0 business strategies. In the energy sector, our focus is on energy efficiency and renewable energy solutions, waste to energy conversion, microgrids and energy storage, supported by data driven decision making and industry 4.0 business process optimization. In the environmental sector, our focus is on waste utilization and optimization, air and water quality management, water loss management. Poster only
Damilare Ogundipe Mass Cultivation of Euglena: MBR And Outdoor Fermenter Using Cassava Starch Waste  Cassava (Maniot esculenta)- a woody shrub cultivated for its edible, starchy, tuberous root is a major staple in Nigeria, the worlds largest producer of the crop. Nigeria presently has 5 funtioning Cassava Starch factories with combined annual production capacity of 35,000 Metric Ton Per Annum (MTPA). The crop is drought tolerant and rich in carbohydrate, it is also lifeline to the countrys 30 million smallholder farmers. But the roots exceptionally short shelf-life means that more than 40% of its yield is lost before it is processed and the effluent discharge (Cassava Starch Pulp) of about 200,000MTPA is channeled to the environment and streams within the host communities (FMITI, 2018). The effluent discharge from these factories is negatively affecting both the flora and fauna on its path. This is due to the deformation of the top soil, increased acidity, cyanogen and foul odour. This research work will study the potentials of euglena gracilis as a bioreactor to convert the effluent waste to protein and other metabolites that can be useful as food ingredients and use the cassava pulp as biomass for the in order to reduce the carbon footprint of the Cassava Starch Factory. The dewatered pulp is dried to 20-30 % moisture content with the aid of a rotary dryer. The dried pulp is the mixed with sawdust (Another waste from sawmill) and black oil and pelletized biomass will serve as feedstock for the biomass boiler to generate steam. Lightning talk in the session and a poster
Donald Kasongi Horizontal Learning on Circular Economy within Water Governance in Africa–Lessons from Upstream of River Nile in Tanzania  The global development Agenda 2030 provides a framework for engagement on sustainability from global through national to local level. Adoption of circular economy approaches demands unraveling the complex alignment between policies, technical and economic ecosystems. Within Africa, the route to a sustainable water future through circular economy is desired. Within the Nile Basin, shared commitments for integrated Water, Sanitation and Hygiene (WASH) are evident, but plausible actions are maligned. The failure to institutionalize horizontal learning at national level appears to be replicated at local level. An analysis of transitions to circular water economy across 30 local authorities in Tanzania section of the Nile Basin was conducted between 2017 and 2019. Results from the analysis indicate that: about 60% indicated that there was growing awareness on the threats to water resources but incentives for translating this reality into knowledge and solution seeking were missing, All local authorities asserted that joint learning on promoting resilient water governance through risk responsive approaches is a missed opportunity, hardly 20% of the authorities were involved in cross learning on articulating the evolving waterscape governance, 60% demonstrated that sectoral appetite for sustainable water resources management was being fuelled by climate change but actions dragged by chronic lack of institutional frameworks for cross- learning. We conclude that the uptake of local horizontal learning in implementing a nexus approach to sustainable water governance in the context of SDG is urgent but new tools for turning commitments into action are required. Key recommendations from the analysis call for review existing WASH policies and regulatory frameworks to align with the need for risk responsive water governance, building consensus on water sector proofing to emerging threats at basin level and transferring science-informed recommendations to local level for action and incentivizing cross-learning across local authorities, water utilities and regulatory institutions. Poster only
Jorge Ivan Cifuentes Waste water treatment trough carbon nanotubes to get drinking water  In this research, a simple application of carbon nanotubes to filtrate water is explained. Nanomembranes were assembled using MWCNT and cotton to create a mesh and fiber support to remove pollutants and meet the World Health Organization (WHO) parameters for drinking water. After the nanofiltration process the following results were obtained: Escherichia Coli was reduced from 6.8 per 100 ml to 2.0 per 100 ml, Turbidity obtained after nanofiltration was reduced from 4.04 to 0.23 mg/l; Magnesium content was reduced from 93.14 mg/l to 13.62 mg/l, total hardness was reduced from 450 mg/l to 132 mg/l, the color diminished from 58 units to 1.0 units, Ph got reduced from 6.87 to 6.44. The results show that the quality of water can be improved using multi wall carbon nanotubes to meet drinking water requirements. In addition, electric current was used through membranes to create electro separation of pollutants and let filtrated water to pass. The resultsalso showed water with less pollutants and less turbidity after the nano filtration process. This is an approach in the use of nanotechnology for waste water treatment and increase the access to drinking water to more people around the World. This research was performed at School of Mechanical Engineering and Engineering research center from University of San Carlos of Guatemala. Poster only
Manzoor Qadir Global and regional potential of resource recovery and recycling from municipal wastewater  With the increase in municipal wastewater volumes and innovations in resource recovery, there is a proactive interest in recovering water, nutrients and energy from waste streams. The synthesis of wastewater data suggests that 380 billion m3 (m3 = 1000 L) of water can be recovered from wastewater produced annually across the world; a volume 5-fold the volume of water passing through Niagara Falls annually. Wastewater production globally is expected to increase by 24% by 2030 and 51% by 2050 over the current level. Among major nutrients, 16.6 tera-gram (Tg = million metric ton) of nitrogen are embedded in wastewater produced worldwide annually; phosphorus stands at 3.0 Tg and potassium at 6.3 Tg. The full nutrient recovery from wastewater would offset 13.4% of the global demand for these nutrients in agriculture. Beyond nutrient recovery and economic gains, there are critical environmental benefits, such as minimizing eutrophication. At the energy front, the energy embedded in wastewater would be enough to provide electricity to 158 million households (474 million to 632 million people) or to support the energy needs of wastewater treatment plants. These estimates and projections are based on the maximum theoretical amounts of water, nutrients, and energy that exist in the reported municipal wastewater produced worldwide annually. Supporting resource recovery from wastewater will need a step-wise approach to address a range of constraints to deliver a high rate of return in direct support of Sustainable Development Goals (SDG) 2, 6, 7 and 12, but also other goals, including the adaptation to climate change (SDG 13) and efforts in advancing ‘net-zero’ energy processes towards a green economy. As an essential component of a circular economy, resource recovery from municipal wastewater can generate new business opportunities while helping in improved water supply and sanitation services. Poster only
Mauro Lafratta At the nexus of water and energy sectors: flexible electricity generation from anaerobic digestion of sewage sludge  In achieving a net-zero carbon emissions system the contribution of the energy sector to decarbonisation is crucial. Energy production, and specifically electricity generation, is currently a major contributor to global carbon emissions. Given the large potential contribution of wind and solar power generation, the electricity sector is considered easy to decarbonise. However, security of electricity supply is threatened by a large use of such intermittent renewable energy sources. Therefore, other renewable technologies are needed to provide flexible electricity generation. Among other technologies, anaerobic digestion is able to produce energy (in the form of biogas) that can usefully be used as a flexible source of electricity. The water sector uses this technology extensively to treat sewage sludge for resource recovery and energy production. For the latter, the common practice is to use this technology as baseload provider of electricity. This contribution will show that appropriate feeding management allows demand-driven biogas production to make energy available when needed. Experimental results carried out in this project at different scales demonstrate its feasibility for stability and performance of the process. Demand-driven biogas production is suitable to support the participation of the water industry as generator in electricity market’s balancing services. However, in order to unlock the full flexible potential of electricity generation from sewage sludge, a number of factors in the water and energy sectors needs to be considered. This contribution will explore necessary synergies between wastewater treatment technologies, operational strategies of anaerobic digestion, flexible energy management for electricity generation, electricity market’s balancing services requirements and national policies to transform the water industry into a full scale flexible renewable electricity provider. Additionally, potential economic and environmental benefits for the water industry to contribute to balancing services in the electricity sector will be presented. Poster only
Norbert F. TCHOUAFFE TCHIADJE Ecological engineering to mitigate eutrophication in the flooding zone of river Nyong, Cameroon  The problems of pollution caused by liquid and solid waste, as a result of demographic and socio-economic development along the River Nyong, as well as the climatic conditions and particularly the irregularity of the rain, have repercussions on the quality of the water resources of the said River. Popolation growth within the river Nyong's basin has led to exacerbated deforestation, recurrent pollution and sedimentation of the river bed. It follows that the sedimentation accentuates the growth of floating macrophytes and in turn causes a gradual reduction in the flow of the river. These complex interactions between uses and ecological functions are the heart of the challenges of the sustainability and balanced management of the due river's ecosystem. This the main purpose of the ecological engineering that we want to apply for this work using the risk, attitudes, norms, abilities and self-regulation ( Ranas) model to build up a framework of active actor's aiming at overcoming eutrophication through repatriation or creation of buffer zones. Poster only
Rued Soeren Linking water and climate: Experiences from the WaCCliM project on closing the urban water cycle N.A. Oral (normal lenght)