Yale University
225 Prospect Street
New Haven, CT 06520
phone: 203.432.5215
greenchemistry@yale.edu

Water

  • Sustainable Remediation of Metal Contaminants from Wastewater: A Novel Nano Metal Oxide Impregnated Chitosan-Based Adsorbent

     Details...
    The goal of this research is to design an adjustable system that be adapted for wastewater streams of any composition and continuous flow design, currently focusing on remediation of selenium.

    Photo: Sustainable Remediation of Metal Contaminants from Wastewater: A Novel Nano Metal Oxide Impregnated Chitosan-Based Adsorbent

    Given the environmental challenges associated with wastewater remediation and the desire to design a technology to address this challenge with a solution that is itself sustainable, we have developed a chitosan-based nano-metal impregnated adsorbent. This technology exploits the high surface area and affinity of nano-metal oxides for many target contaminants (like arsenic and selenium) while being simple and sustainable during the implementation phase. We have already demonstrated improved remediation of arsenic, and hope to use similar ideas for successful remediation of and reduction of selenium. We are also looking for innovative methods of selective removal of these target contaminants in the presence of background ions that have been known to inhibit removal efficiency.

     

  • Civil Infrastructure Systems: Fostering Leapfrog Adoption of Green Infrastructure through Optimization of Urban Storm Water and Nitrogen Cycles

     Details...
    Comprehensively evaluating and modeling green and grey stormwater systems to optimize environmental function, geospatial placement, and social and economic benefit to leapfrog current costly infrastructure design and support local, state, and federal policy-making for sustainable stormwater systems investments.

    This project brings together students, faculty, citizens, and local, state and federal policy-makers in partnership to meet four aims: 1) critical review of current green infrastructure knowledge and implementation; 2) place-based characterization of hydrologic/nitrogen cycling by and socio-economic function of green infrastructure (south-, central- and northeastern urban seaboard); 3) GIS-supported geospatial optimization of hydrologic/nitrogen cycles by varying location of green infrastructure practices; 4) development of decision-support and policy recommendations for best-practice in green infrastructure investment.

  • MUSES Project - A Systems Dynamics Approach for Urban Water Reclamation-Reuse Planning: A Case Study from the Great Lakes Region

     Details...
    The project involves creating a systems dynamics computer model of the water/wasterwater system, extending the system to include water reuse and determining if water reuse is cost effective under different scenarios.

    Appropriate water reclamation and reuse practices are critical due to increasing water scarcity, concerns about the effect of wastewater discharges on receiving water, and availability of high-performing and cost-effective water reuse technologies.  However, incorporation of water reuse schemes into water/wastewater infrastructure systems is a complex decision-making process, involving various economical, technological, and environmental criteria.  System dynamics allows modeling of complex systems and provides information about the feedback behavior of the system.  We are applying our comprehensive system dynamics model of water/wastewater systems to various cities’ scenarios to determine potential for water reuse.

  • Sustainable Urban Stormwater Management: Critical Review and Path Forward

     Details...
    A critical review of the science of sustainable stormwater management, including definition of best management practices and low impact developments for stormwater, green infrastructure, as well as sustainable stormwater management; modeling to inform stormwater practice; optimized watershed scale design; and implementation.

    Literature from both academic and public sources is considered in order to provide a holistic perspective.  There are many tools available for stormwater management, but there is little evidence of systematic design processess and outcomes due to the lack of 1) large-scale environmental performace data; 2) cost-effectiveness studies that include life cycle costs; and 30 pricin and policy structures that engage broader stakeholders.  We presented a decision process based on systems thinking and show where current literature meets decision-making needs, where research gaps exist, and how research needs should be prioritized to support sustainable stormwater infrastructure implementation.  We are aslo starting data collection and model development of hydrology in the city of New Haven to test best management practices in model setting.

  • Life Cycle Assessment of Green and Gray Stormwater Infrastructures

     Details...
    To better inform decision makers for greener and sustainable stormwater management, this research assessed and compared life-cycle environmental impacts of green, gray, and integrated green & gray stormwater infrastructures, accounting the influences of variable local characteristics and future dynamics.

    Major results from this life cycle analysis research have shown that new stormwater infrastructures can significantly improve water quality and aquatic ecosystem health, but at the cost of added resource consumption and elevated GHG emissions and human toxicity impacts during the infrastructures’ construction, operation, and maintenance phases. Given the impacts of climate change, infrastructures with larger treatment capacity and higher resiliency are needed in order to effectively alleviate the impacts associated with more intense, more frequent stormwater events.  Also, improvement in infrastructure design and engineering (e.g. using low-impact or recycled materials or enhancing treatment efficiency) can largely offset the extra environmental impacts caused by the need of infrastructure upsizing. Reducing land imperviousness is an effective substitute to building new stormwater infrastructures. Finally, results have also shown, the assessment and implementation of integrated stormwater infrastructure systems and integrated wastewater and stormwater management can better assist decision makings with tradeoff dilemmas.  

     

  • Energy-Water Nexus Analysis

     Details...
    Energy-Water Nexus Analysis of Enhanced Water Supply Scenarios in Tampa Bay, Florida and San Diego, California

    Increased water demand and scarce freshwater resources have forced communities to seek non-traditional water sources. These challenges are exacerbated in coastal communities where population growth rates and densities in the US are the highest. 


    To understand the current management dilemma between constrained surface and groundwater sources and potential new water sources, Tampa Bay, FL (TB) and San Diego, CA (SD) were studied through 2030 accounting for changes in population, water demand, and electricity grid mix. 

    These locations were chosen based on their similar population, land area, economy, and water consumption characters, as well as their coastal locations and rising contradictions between water demand and supply. 

    Three scenarios were evaluated for each study area:

    1. Maximize traditional supplies
    2. Maximize seawater desalination
    3. Maximize non-potable water reclamation; and three types of impacts were assessed: embodied energy, greenhouse gas (GHG) emission and energy cost.  


    SD was found to have higher embodied energy and energy cost, but lower GHG emission than TB in most of its water infrastructure systems due to the differences in electricity grid mixes and water resources between the two regions.  Maximizing water reclamation was found to be better than either increasing traditional supply or seawater desalination in both regions in terms of the three impact categories.