The issues of reducing CO₂ levels in the atmosphere, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenging opportunities for sustainable development in energy and the environment. The latest advances in CO₂ mineralization technology involving natural minerals and industrial waste are summarized in this paper, with great emphasis on the advancement of fundamental science, economic evaluation, and engineering applications. We discuss several leading large-scale CO₂ mineralization methodologies from a technical and engineering-science perspective. For each technology option, we give an overview of the technical parameters, reaction pathway, reactivity, procedural scheme, and laboratorial and pilot devices. Furthermore, we present a discussion of each technology based on experimental results and the literature. Finally, current gaps in knowledge are identified in the conclusion, and an overview of the challenges and opportunities for future research in this field is provided.

Global water security is a severe issue that threatens human health and well-being. Finding sustainable alternative water resources has become a matter of great urgency. For coastal urban areas, desalinated seawater could serve as a freshwater supply. However, since 20%–30% of the water supply is used for flushing waste from the city, seawater with simple treatment could also partly replace the use of freshwater. In this work, the freshwater saving potential and environmental impacts of the urban water system (water-wastewater closed loop) adopting seawater desalination, seawater for toilet flushing (SWTF), or reclaimed water for toilet flushing (RWTF) are compared with those of a conventional freshwater system, through a life-cycle assessment and sensitivity analysis. The potential applications of these processes are also assessed. The results support the environmental sustainability of the SWTF approach, but its potential application depends on the coastal distance and effective population density of a city. Developed coastal cities with an effective population density exceeding 3000 persons·km^–2 and located less than 30?km from the seashore (for the main pipe supplying seawater to the city) would benefit from applying SWTF, regardless of other impact parameters. By further applying the sulfate reduction, autotrophic denitrification, and nitrification integrated (SANI) process for wastewater treatment, the maximum distance from the seashore can be extended to 60?km. Considering that most modern urbanized cities fulfill these criteria, the next generation of water supply systems could consist of a freshwater supply coupled with a seawater supply for sustainable urban development.

Coal is the dominant primary energy source in China and the major source of greenhouse gases and air pollutants. To facilitate the use of coal in an environmentally satisfactory and economically viable way, clean coal technologies (CCTs) are necessary. This paper presents a review of recent research and development of four kinds of CCTs: coal power generation; coal conversion; pollution control; and carbon capture, utilization, and storage. It also outlines future perspectives on directions for technology research and development (R&D). This review shows that China has made remarkable progress in the R&D of CCTs, and that a number of CCTs have now entered into the commercialization stage.

The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power (CCHP) systems have the potential to improve the energy generation efficiency of a city or urban region by providing energy for heating, cooling, and electricity simultaneously. The purpose of this study is to estimate the water consumption for energy generation use, carbon dioxide (CO₂) and NO_x emissions, and economic impact of implementing CCHP systems for five generic building types within the Atlanta metropolitan region, under various operational scenarios following the building thermal (heating and cooling) demands. Operating the CCHP system to follow the hourly thermal demand reduces CO₂ emissions for most building types both with and without net metering. The system can be economically beneficial for all building types depending on the price of natural gas, the implementation of net metering, and the cost structure assumed for the CCHP system. The greatest reduction in water consumption for energy production and NO_x emissions occurs when there is net metering and when the system is operated to meet the maximum yearly thermal demand, although this scenario also results in an increase in greenhouse gas emissions and, in some cases, cost. CCHP systems are more economical for medium office, large office, and multifamily residential buildings.

Thermal treatment technologies hold an important niche in the remediation of hydrocarbon-contaminated soils and sediments due to their ability to quickly and reliably meet cleanup standards. However, sustained high temperature can be energy intensive and can damage soil properties. Despite the broad applicability and prevalence of thermal remediation, little work has been done to improve the environmental compatibility and sustainability of these technologies. We review several common thermal treatment technologies for hydrocarbon-contaminated soils, assess their potential environmental impacts, and propose frameworks for sustainable and low-impact deployment based on a holistic consideration of energy and water requirements, ecosystem ecology, and soil science. There is no universally appropriate thermal treatment technology. Rather, the appropriate choice depends on the contamination scenario (including the type of hydrocarbons present) and on site-specific considerations such as soil properties, water availability, and the heat sensitivity of contaminated soils. Overall, the convergence of treatment process engineering with soil science, ecosystem ecology, and plant biology research is essential to fill critical knowledge gaps and improve both the removal efficiency and sustainability of thermal technologies.

Municipal wastewater treatment has long been known as a high-cost and energy-intensive process that destroys most of the energy-containing molecules by spending energy and that leaves little energy and few nutrients available for reuse. Over the past few years, some wastewater treatment plants have tried to revamp themselves as “resource factories,” enabled by new technologies and the upgrading of old technologies. In particular, there is an renewed interest in anaerobic biotechnologies, which can convert organic matter into usable energy and preserve nutrients for potential reuse. However, considerable technological and economic limitations still exist. Here, we provide an overview of recent advances in several cutting-edge anaerobic biotechnologies for wastewater treatment, including enhanced side-stream anaerobic sludge digestion, anaerobic membrane bioreactors, and microbial electrochemical systems, and discuss future challenges and opportunities for their applications. This review is intended to provide useful information to guide the future design and optimization of municipal wastewater treatment processes.

China’s green investment needs up to 2020 are ¥1.7 trillion—2.9 trillion CNY ($274 billion—468 billion USD) per year. Estimates of financing requirements are provided for multiple sectors, including sustainable energy, infrastructure (including for environmental protection), environmental remediation, industrial pollution control, energy and water efficiency, and green products. The context to China’s green financing is discussed, covering urbanization, climate change, interactions between infrastructure sectors, and the transformation of industry. Much of the infrastructure financing will occur in cities, with a focus on equity, environmental protection, and quality of life under the National New-Type Urbanization Plan (2014—2020). China has implemented many successful policies in the building sector, but there is still considerable scope for improvement in the energy efficiency of Chinese buildings. China is currently pursuing low-carbon growth strategies that are consistent with its overall environmental and quality-of-life objectives. Beyond 2020, China’s future as an ecologically balanced civilization will rest on the implementation of a central infrastructure policy: China 2050 High Renewable Energy Penetration Scenario and Roadmap Study. As exemplified by the Circular Economy Development Strategy and Near-Term Action Plan, an essential part of China’s green industrial transformation involves engineering systems that conserve materials, thereby reducing or even eliminating wastes. To better understand changes to China’s economy under its green transformation and to unlock large potential sources of finance, it is necessary to undertake a fuller examination of all of China’s infrastructure sectors, particularly freight rail infrastructure and ports. Large investments are required to clean up a legacy of environmental contamination of soil and groundwater and to reduce industrial pollution. Transformation of the power sector away from coal will avoid some industrial treatment costs. The contribution of engineers in planning, designing, and constructing China’s new green infrastructure will be furthered by understanding the broad policy context and the interactions between land use, infrastructure, and environmental performance.

The 2030 Agenda for Sustainable Development outlines 17 individual Sustainable Development Goals (SDGs) that guide the needs of practice for many professional disciplines around the world, including engineering, research, policy, and development. The SDGs represent commitments to reduce poverty, hunger, ill health, gender inequality, environmental degradation, and lack of access to clean water and sanitation. If a typical reductionist approach is employed to address and optimize individual goals, it may lead to a failure in technological, policy, or managerial development interventions through unintended consequences in other goals. This study uses a systems approach to understand the fundamental dynamics between the SDGs in order to identify potential synergies and antagonisms. A conceptual system model was constructed to illustrate the causal relationships between SDGs, examine system structures using generic system archetypes, and identify leverage points to effectively influence intentional and minimize unintentional changes in the system. The structure of interactions among the SDGs reflects three archetypes of system behavior: Reinforcing Growth, Limits to Growth, and Growth and Underinvestment. The leverage points identified from the conceptual model are gender equality, sustainable management of water and sanitation, alternative resources, sustainable livelihood standards, and global partnerships. Such a conceptual system analysis of SDGs can enhance the likelihood that the development community will broaden its understanding of the potential synergistic benefits of their projects on resource management, environmental sustainability, and climate change. By linking the interactions and feedbacks of those projects with economic gains, women’s empowerment, and educational equality, stakeholders can recognize holistic improvements that can be made to the quality of life of many of the world’s poor.