Failing to reduce greenhouse gas (GHG) emissions is one of the greatest risks facing the world today. However, even dramatic cuts in emissions at this stage will only begin to slow the rate of climate change. As of the middle of 2021, ever dramatic impacts of climate change are already here, and we need to aggressively cope with additional impacts that will occur in the coming decades, potentially even centuries.
Resilience is a journey, not a destination. As the climate has changed, so too have the approaches needed to understand and proactively address associated risks and opportunities. Utilities, governments and corporations across all sectors are realizing that looking to the past is no longer sufficient to plan for our future in a changing climate.
The Water Climate Discussion series creates a space to come together and help the water sector build its leading role in addressing the climate crisis. The series is the result of close collaboration between water institutions who recognise climate change as an
existential threat and wish to have a voice promoting a key message: water is climate. This report is based on the recorded third discussion of
the series: Energy Transitions, which was aired on Thursday, 1 July 2021. The discussion was hosted by Martin Currie and led by Ivan Vølund of VCS Denmark, John Sammon of Scottish Water Horizons and the interaction of the participants.
Nearly 50% of electricity-related emissions from the global wastewater sector could be abated at negative cost by investing in readily available technologies This report investigates greenhouse gas abatement opportunities from energy efficiency in the wastewater sector.
Nitrous oxide (N2O) is a greenhouse gas with a global warming potential 265 times stronger than carbon dioxide on a 100-year time horizon (Eickemeier et al., 2014) and therefore, even emitted in small amounts, it can contribute significantly to global warming. In addition, nitrous
oxide is acknowledged as an important threat to the ozone layer (Ravishankara et al., 2009). N2O is an undesired bioproduct emitted during the biological nitrogen removal process in wastewater treatment systems and despite the recent efforts in understanding nitrous oxide
emissions from wastewater treatment, data from full-scale plants is still scarce.
As the world recognizes the growing impacts of climate change, there is a sense of urgency to accelerate the transition to energy, transport and industrial systems with fewer greenhouse gas emissions and effectuate more sustainable modes of production
and consumption. To enable this transition, new energy carriers will be needed to transfer the increased levels of decarbonized energy
to consumers, without impacting the quality of service to residential, industrial and transportation users. Hydrogen offers
a versatile solution and is emerging as an increasingly important energy vector for decarbonized fuel sources, as well as for the storage and transport of renewable energy. Hydrogen is expected to play a critical role in decarbonizing power generation and transport, heating domestic and commercial buildings, and supporting industrial feedstock and industrial processes — including hard-to-abate sectors such as
steel, refining, cement and agriculture.
Engineered biological nutrient removal (BNR) processes have been identified by the Intergovernmental Panel on Climate Change (IPCC) as potential contributors to atmospheric nitrous oxide (N2O) emissions. This is a significant concern to wastewater utilities because the greenhouse impact of nitrous oxide emissions on a mass equivalent basis is 300 times that of carbon dioxide. This study differs from other studies in that it characterizes the microbial pathways for N2O formation in addition to measurement of emission rates from several BNR and non-BNR plants across the U.S. As the production and emission pathways are understood, operational strategies to minimize N2O emissions appear highly likely.
This study aimed at evaluating the nitrous oxide (N2O) emissions from membrane bioreactors (MBRs) for wastewater treatment. The study investigated the N2O emissions considering multiple influential factors over a two-year period: (i) different MBR based process configurations; (ii) wastewater composition (municipal or industrial); (iii) operational conditions (i.e. sludge retention time, carbon-to-nitrogen ratio, C/N, hydraulic retention time); (iv) membrane modules. Among the overall analysed configurations, the highest N2O emission occurred from the aerated reactors. The treatment of industrial wastewater, contaminated with salt and hydrocarbons, provided the highest N2O emission factor (EF): 16% of the influent nitrogen for the denitrification/nitrification-MBR plant. The lowest N2O emission (EF = 0.5% of the influent nitrogen) was obtained in the biological phosphorus removal-moving bed-MBR plant likely due to an improvement in biological performances exerted by the co-presence of both suspended and attached biomass. The influent C/N ratio has been identified as a key factor affecting the N2O production. Indeed, a decrease of the C/N ratio (from 10 to 2) promoted the increase of N2O emissions in both gaseous and dissolved phases, mainly related to a decreased efficiency of the denitrification processes
Working together, infrastructure organizations have the power to use PAS 2080 to transform the benefits that a national economy gains from its infrastructure systems and to provide a sustainable legacy. If all parties involved across the value chain work collaboratively, towards a common goal to reduce carbon, the following outcomes can be achieved:
• Reduced carbon, reduced cost infrastructure;
• More collaborative ways of working will promote innovation, delivering benefit to society and communities served by economic infrastructure;
• Effective carbon management in infrastructure will make an important contribution to tackling climate change and leave a positive legacy for future generations;
• Delivering more sustainable solutions, at lower cost, will enhance the reputation of the infrastructure industry, generating pride for those who work in it and attracting new people and skills;