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.
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Greenhouse gas emissions from membrane bioreactors: analysis of a two-year survey on different MBR configurations
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
Carbon Management in Infrastructure
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;
ADAPT NOW: A GLOBAL CALL FOR LEADERSHIP ON CLIMATE RESILIENCE
Climate change is one of the greatest threats facing humanity, with far-reaching and devastating impacts on people, the environment, and the economy. Climate impacts affect all regions of the world and cut across all sectors of society. People who did the least to cause the problem—especially those living in poverty and fragile areas—are most at risk.
CIWEM The Environment Urban Water Shortages
COMPARISON OF SUITABLE LEAK DETECTION METHODS
This publication is intended to support water utilities, especially in EMDEs, (Emerging Markets and Developing Economies), to broaden their knowledge of the currently available methods, including their advantages, disadvantages, application possibilities and limitations to be
able to make an initial pre-evaluation of the methods under the respective local conditions.
2nd Edition Smart Water Management
Digitalization is transforming the way water and wastewater utilities plan and manage their infrastructure and interact with their customers and their staff. Globally, digital technologies have been playing a role in resource efficient water management for some time, including in the management of water losses and the energy efficiency of utilities. Digital applications have been developed for customer engagement, leak detection, pressure management, energy efficient pumping, energy management and wastewater treatment.
This document addresses these differences, from tariff structures to levels of water losses, and identifies opportunities for digitalization in resource-efficient water management that can work especially well in EMDEs. It also discusses some digital applications that are already in widespread use in high-income countries, but due to economic, technical or other factors are not currently suited to the needs of EMDEs.
WaCCliM case study – SEDACUSCO
National Greenhouse and Energy Reporting (Measurement) Determination 2008
Wastewater treatment process impact on energy savings and greenhouse gas emissions
The objective of this research was to assess the energy consumption of wastewater treatment plants (WWTPs), to apply a mathematical model to evaluate their carbon footprint, and to propose energy saving strategies that can be implemented to reduce both energy consumption and greenhouse gas (GHG) emissions in Greece. The survey was focused on 10 WWTPs in Greece with a treatment capacity ranging from 10,000 to 4,000,000 population equivalents (PE). Based on the results, annual specific energy consumption ranged from 15 to 86 kWh/PE. The highest energy consumer in all the WWTPs was aeration, accounting for 40–75% of total energy requirements. The annual GHG emissions varied significantly according to the treatment schemes employed and ranged between 61 and 161 kgCO2e/PE. The highest values of CO2 emissions were obtained in extended aeration systems and the lowest in conventional activated sludge systems. Key strategies that the wastewater industry could adopt to mitigate GHG emissions are identified and discussed. A case study is presented to demonstrate potential strategies for energy savings and GHG emission reduction. Given the results, it is postulated that the reduction of dissolved oxygen (DO) set points and sludge retention time can provide significant energy savings and decrease GHG emissions.