Water is central to life itself. With the expansions in urban living, urban waste like household waste, pharmaceutical waste, agricultural waste, chemical waste, bacteriological pollution, virus transmission and solid waste has been the major sources of pollution. United Nations’ World Water Development Report 2017 was focussed on establishing wastewater as a valuable resource. African renewal magazine considered wastewater as the ‘new black gold’.
AIWW expands on these developments
Abovementioned developments, helped us shaping the second AIWW subtheme: Water reuse, recycle and recover. We determined these topics to further focus on:
- Reclaim and Reuse of wastewater
- Safe Resource recovery
- Central versus local/decentralised solutions for drinking water production & wastewater treatment
- Water for Food: water reuse & water efficiency
Current progression around waste treatment, reclaim, reuse and recycling of resources has paved the groundwork to implement resource recovery ideas. COVID-19 has especially unmasked the flaws in the system and lack of circularity within them. With the impacts of climate change, every summer is getting hotter, water scarcity is intensifying the environmental, political and economical effects. There are several regions of the world, still facing drought, with reserves of ground water that populations depend on have not yet fully recovered.
Groundwater, like surface water faces incremental pressure not only from population growth and recurring droughts but also from industries, utilities, from agriculture and also from the need to safeguard environmental flows.
What are the current global challenges? AIWW’s Focus
Wastewater reclamation has been a strategy to conserve resources for cities with continuous inflows and outflows of resources. It also the focal point of industries, cities and utilities as it reduces operational costs and reduces waste disposal and sludge generation.
Over the years, there are a variety of solutions implemented to reuse this waste-water and circulate it back into the system after treatment. Effective and efficient solutions for water treatment has driven technological advancements in the field, however challenges remain the same.
- Energy consumption holds largest share of operating costs for wastewater treatment plants and utilities. In most of the municipal water treatment plants, largest proportion of the energy is utilised for biological treatments. Biological treatments rely on organic decomposition of some waste substances by bacteria, nematodes, and others through cellular processes.
- Sludge is the residue generated during biological, chemical or physical processes used in treatment of waste. The disposal of sludge and/or re-se of the sludge is another major problem faced by cities, industries and utilities. Active sludge treatment solutions occupy larger areas, increasing the footprint. Both primary and secondary processes use larger process basins and aeration basins.
- Untreated sewage and inadequately treated wastewater continues to deplete water quality of the ecosystems. In some regions of the world, both sewerage and run-off water flows are through combined pipeline systems. This creates more complexity to segregate and higher potential of fresh-water being wasted. In separate sewerage and run-off systems, lack of proper maintenance and leakages leads to similar consequences.
- Informality and illegal connections add another dimension to the existing problem in water supply, distribution and treatment systems. This is a systemic and deep rooted issues which are severe concerns to attain good governance.
- Quantifications of the level of wastewater discharged into the environment is also an additional issue in ineffective sewerage systems and centralised water supply and treatment systems. ‘
- Higher pathogenic concentrations in domestic water if it is not treated properly, negatively affects the health of citizens and environment. Almost half of the world’s population doesn’t have a proper way of disposing black and grey water.
- Agricultural wastewater challenges further accentuate the current issues. Nutrient run-off, sediment run-off, chemical run-off and microbial run-off from traceable point and non-point sources are major concerns for policy, governance and technological solutions.
What are the global agendas on wastewater reuse, recycle and recovery?
Sustainable Development Goals 3 (Good health and well-being), 6 (Clean water and Sanitation), 11 (Sustainable cities and communities), 12 (Responsible consumption and production), and 15 (Life on land) consider the challenges and consequences of wastewater treatment related issues.
In 2018, the World Bank launched “Wastewater: From waste to resource” initiative. The goal of the initiative is to create awareness and provide guidance on improved planning, implementation, decision-making and financing of wastewater treatment and resource recovery. In order to achieve this, participatory processes were included for stakeholders in the Latin America and Caribbean regions.
United Nations Economic and Social Commission for Asia and the Pacific (ESCAP), United Nations Human Settlements Programme (UN-Habitat) and Asian Institute of Technology (AIT) in 2015, developed a policy manual on Wastewater Management with a Special Emphasis on Decentralized Wastewater Treatment Systems. The guidance focussed on decentralised wastewater treatment systems (DEWATS) development and implementation with a set of financial schemes, market opportunities, investment and potential impacts.
Global Water Partnership released a policy brief on “Managing the other side of the water cycle: making wastewater an asset”. By ‘other side’ , the brief explains is the municipal, industrial wastewater and storm drainage. The policy brief focussed on an integrated approach that encompasses the whole water cycle – water resources availability and water supply, treatment, and reuse options. Some of the recommended ideas by the initiative include participatory technology development, multi-stakeholder dialogues, social learning, linking waste management with other economic sectors for cost recovery and risk reduction.
United Nations Environment Program also developed an initiative to regulate wastewater treatment, legislations, policies and standards. The e-book also contains case studies in localised good practices, emerging trends, operational challenges and provides generic solutions.
The Organisation for Economic Co-operation and Development (OECD) developed an online tool based on wastewater indicators for 40 countries.
What are the existing solutions to address these challenges?
- Reuse of treated wastewater: The treated wastewater can be reused in irrigation, textile industries and other industrial secondary processes, production of biogas and drinking water. Agriculture- forestry system also makes productive use of drainage water. The quality of water recovered from the treatment process determines the potential of reuse.
For example Singapore’s ‘four taps’ policy on water reclamation through NEWater initiative, water harvesting methods like rainwater collectors in public spaces, and seawater desalination. The production of drinkable water quality after reclamation and treatment of wastewater.
Another example is EU-funded Thatuang Marsh wastewater management project in Laos. The project includes a centralised treatment system followed by decentralised wetlands-based secondary treatment system.
- Resource recovery and Circular economy “Closing the loop”: Water resource recovery facilitates reduced energy demands, lower costs and increased production of renewable energy and other valuable products like nutrients, biosolids, water.
As International Water Association in their project on “Water utility pathways in a circular economy” the concept is described as aiming to decouple economic growth and development from consumption of finite resources.
One of the example is an innovative low-cost, self-powered decentralised desalination plant established in Columbia. The plant provides clean drinking water to residents at zero operating costs. The scaling up of the pilot is planned in several other locations across Columbia. The goal is to operate and monitor decentralised, stand-alone and CO2 -free drinking water systems via a centralised, cloud-based platform, powered by renewable energy.
Another such example is Zero Brine project which aims to close the loop and improve environmental impacts of industries through recovery of resources from industrial wastewater. Use of constructed wetlands is also part of the green solution to treatment of water.
- Wastewater as an information resource: Wastewater reveals a lot of information that can be monitored and evaluated over a period of time for informed decisions. Tools like World Business Council for Sustainable Development’s Circular transition indicators. CTI is a simple, objective and quantitative framework that can be applied to businesses of all industries, sizes, value chain positions and geographies. It is a digitised, smart software solution enabling companies to accelerate their transition towards circular economy.
Another example is the USA Environmental Protection Agency’s “Workshop in a box” tool for small and medium communities on water and wastewater systems. The resource enables conducting workshops at multi-stakeholder level based on sustainable utility management framework.
More smart and digitised solutions can be found here.