About
Information extracted from the main website: Energy and Environmental Sustainability Solutions for Megacities – E2S2
Phase II
Phase II intends to find Eco-Solutions (abbreviate as ES) to Sustainable Urban EcoCity from these aspects:
- construction of zero-emission waste loop in megacities;
- detection and management of algal blooms and anti-microbial resistances.
Projects
ES-1: Waste-to-Resource: Eco-Energy System towards Environmental Sustainability
The aim is to cultivate a culture of energy and environmental conservation by implementing systems that can educate, connect and service stakeholders in existing and new communities and townships.
Food waste
Increasing amounts of disposed food waste are posing environmental problems in megacities. Food waste accounts for nearly 25% of all solid waste disposed in Singapore.The main objective of this project is to provide a sustainable alternative to managing food waste in Singapore. Other than reducing the amount of wastes being disposed, the decentralised model of this treatment system eliminates the need for tipping fee and also generates renewable energy and resources for use within the community. Participation of the public through this project will also raise environmental awareness of citizens and therefore promote sustainable practices and standards in Singapore.
Gasification
High-temperature solar thermal energy is a renewable and clean source of energy that can be used to provide a highly efficient waste-to-energy process. Experimentation of gasification of wastes using solar radiation can produce high-quality syngas.
The experimental results will be used to validate the modeling and simulation of the reaction processes within the reactor. Syngas produced will be studied for conversion to dimethyl ether (DME), a liquid fuel. The ashes from the gasification process can be utilized as biochar, adsorbent, soil amendment and converted into other high value materials. The effects of the emissions from the gasification system on human health and environment requires evaluation, and establishing a standard protocol for rapid screening of gasification ashes on the basis of in vitro and in vivo testing.
DSS
In many industrial applications, waste can be effectively converted to useful resources with new and improved waste valorization technologies. This in turn, reduces the need for virgin material, potentially avoiding environmental impacts significantly. Hence, establishing effective coordination mechanism between potential waste generators and buyers is crucial.
However, designing such coordination schemes is challenging as uncertainties in waste characteristics may affect downstream production/utilization. Furthermore, effective schemes should achieve long term economic and environmental requirements.
Integrating stochastic optimization, agent-based modelling and environmental assessment tools, the team focuses on developing analytical and computational models for multi-operator waste-to-resource systems. Such models provide important support for decision makers to achieve environmentally sustainable and cost effective solutions for megacities.
Life cycle assessment
Currently, there are different technologies to convert waste to energy and resources. Thus extensive studies about the environmental impacts of these technologies should be done in order to help the decision makers determine which strategy to use to achieve sustainability goal. Life cycle assessment (LCA) is an international accepted tool to holistically evaluate the technologies by quantifying their potential environmental impacts. Therefore, LCA will be used in this project to offer environmental impact information of different scientific topics, such as waste collection method, anaerobic digestion, gasification, etc.
Urban metabolism analysis
Urban Metabolism Analysis (UMA) is an important tool for studying the use of energy and resources in urban ecosystems. Applying methods such as material flow analysis, substance flow analysis and energy flow analysis, UMA is able to quantify, describe and evaluate the sustainability of different flows and stocks (that is, accumulation) of energy and materials within an economy or geographical boundary. UMA is also effective in tracing any evolutions of these variables with time. Broadly speaking, large metabolic throughput, low metabolic efficiency, and disordered metabolic processes are known to cause an urban system to become “unhealthy” and unsustainable. State-of-art UMA methodology combines flow and stock analyses with top-down economic input-output analyses (an example is shown in the diagram above) and bottom-up process-based life cycle assessment (LCA), in order to evaluate the state of sustainability due to the use of materials and energy by the waste utilization technologies.
The comparison of environmental impacts due to the current and proposed technologies will be done based on a functional unit (e.g. 1 kg of the food waste recycled). This will form the basis for estimating the difference in impacts when our proposed technologies replaced current technologies.
Scenario analysis will be applied to help scale up the waste utilization, and understand the net environmental impacts caused by the technologies. An example of such a scenario may be that by 2020, Singapore will target to recycle and utilize an additional 20% of its horticultural waste into compost, by applying a combination of AD and composting technology.
ES-2: Detection, Assessment and Modelling of Emerging Contaminants in the Urban Environment
The overall outcomes of this project are detection methods, occurrence data, control methods, modeling and management tools which can provide an evaluation of environmental impact and health risks under different scenarios. Ultimately, these tools can assist policy makers and regulators to manage and reduce the emerging contaminants associated with algal blooms and antimicrobial resistance.
Algal blooms
We seek to develop an integrated ‘Monitoring, Modelling and Management’ (M3) system for algal blooms. Specifically, we will address the sources and fundamental mechanisms of bloom formation, from species composition to interactions with biotic and abiotic environmental factors. These will then be incorporated into models for prediction and risk assessment. In addition, novel physical, chemical and biological methods will also be developed to control algal blooms.
Antimicrobial resistance (AMR)
We plan to determine the relative importance of different components that contribute to the growing antimicrobial resistance problem in Singapore. We will also use metagenomics and phage isolation experiments to study possible new mechanisms of controlling antimicrobial resistance, which may offer possibilities for the discovery of new enzymes and mechanisms from phages that can attack specific bacteria, including antibiotic resistant ones.
Phase I (Aug 2012-Mar 2018)
Achievements
Projects
In Phase I, we focused on topics under two key problems that stressed megacities are facing
CS-A: Waste Management in Megacities for Sustainability and Energy Recovery
- Sustainable energy production;
- Waste management;
- Economical and life cycle assessments.
CS-B: Challenges of Emerging Contaminants on Environmental Sustainability in Megacities
- Urban contaminants detection;
- Water and air quality;
- Urban microclimate maintenance.
They are supported by two platform projects
SP-1: Mission-oriented Systems Model for Megacity Sustainability
- A software model advancing the toolboxes for WTE and MSW management system design;
- A software model silmulating reservoir systems in China and Singapore;
- A sustainability framework structure for rish prevention and assessment.
SP-2: Distributed Clouds: Peta-scale Urban Sensing and Data Management
- A virtualization software for supporting data management, analytics and system modeling.
- An open-source data analytic framework that can analyse large data very fast.
- A cloud software for mobile app to display sensor data in real time.
