Amplifying Progress toward Multiple Development Goals through Resource Recovery from Sanitation

The United Nations’ Sustainable Development Goals (SDGs) recognize that current sanitation gaps must be closed to better serve those without access to safely managed systems (Target 6.2: universal sanitation coverage) and those connected to sewers without wastewater treatment (Target 6.3: halving the proportion of untreated wastewater). Beyond mitigating environmental and health concerns, implementing resource recovery sanitation systems could simultaneously improve the availability of agricultural nutrients (SDG 2) and household energy (SDG 7). This study estimates the potential for global, regional, and country-level resource recovery to impact nutrient and household electricity use through 2030. We distinguish impacts from newly installed sanitation systems (to achieve universal coverage), newly treated wastewater systems (to halve the proportion of untreated wastewater), and existing system replacement, while also considering urban and rural disparities and spatial colocation of nutrients with agricultural needs. This work points toward country-specific strategies for deriving the greatest benefit from sanitation investments while also identifying overarching trends to guide international research efforts. Globally, potential nutrient gains are an order of magnitude larger than electricity (a small fraction of total energy), and considerable impacts are possible in the least-developed countries, six of which could double or offset all projected nutrient and electricity use through newly installed sanitation systems

Characterizing the Opportunity Space for Sustainable Hydrothermal Valorization of Wet Organic Wastes

Resource recovery from wet organic wastes can support circular economies by creating financial incentives to produce renewable energy and return nutrients to agriculture. In this study, we characterize the potential for hydrothermal liquefaction (HTL)-based resource recovery systems to advance the economic and environmental sustainability of wastewater sludge, FOG (fats, oils, and grease), food waste, green waste, and animal manure management through the production of liquid biofuels (naphtha, diesel), fertilizers (struvite, ammonium sulfate), and power (heat, electricity). From the waste management perspective, median costs range from −193 $·tonne–1 (FOG) to 251$·tonne–1 (green waste), and median carbon intensities range from 367 kg CO2 eq·tonne–1 (wastewater sludge) to 769 kg CO2 eq·tonne–1 (green waste). From the fuel production perspective, the minimum selling price of renewable diesel blendstocks are within the commercial diesel price range (2.37 to 5.81 $·gal–1) and have a lower carbon intensity than petroleum diesel (101 kg CO2 eq·MMBTU–1). Finally, through uncertainty analysis and Monte Carlo filtering, we set specific targets (i.e., achieve wastewater sludge-to-biocrude yield >0.440) for the future development of hydrothermal waste management system components. Overall, our work demonstrates the potential of HTL-based resource recovery systems to reduce the costs and carbon intensity of resource-rich organic wastes

Environmental and Economic Assessment of Electrothermal Swing Adsorption of Air Emissions from Sheet-Foam Production Compared to Conventional Abatement Techniques

A life-cycle assessment (LCA) and cost analysis are presented comparing the environmental and economic impacts of using regenerative thermal oxidizer (RTO), granular activated carbon (GAC), and activated carbon fiber cloth (ACFC) systems to treat gaseous emissions from sheet-foam production. The ACFC system has the lowest operational energy consumption (i.e., 19.2, 8.7, and 3.4 TJ/year at a full-scale facility for RTO, GAC, and ACFC systems, respectively). The GAC system has the smallest environmental impacts across most impact categories for the use of electricity from select states in the United States that produce sheet foam. Monte Carlo simulations indicate the GAC and ACFC systems perform similarly (within one standard deviation) for seven of nine environmental impact categories considered and have lower impacts than the RTO for every category for the use of natural gas to produce electricity. The GAC and ACFC systems recover adequate isobutane to pay for themselves through chemical-consumption offsets, whereas the net present value of the RTO is $4.1 M (20 years,$0.001/m³ treated). The adsorption systems are more environmentally and economically competitive than the RTO due to recovered isobutane for the production process and are recommended for resource recovery from (and treatment of) sheet-foam-production exhaust gas. Research targets for these adsorption systems should focus on increasing adsorptive capacity and saturation of GAC systems and decreasing electricity and N₂ consumption of ACFC systems

Evaluation of Life Cycle Assessment (LCA) for Roadway Drainage Systems

Roadway drainage design has traditionally focused on cost-effectively managing water quantity; however, runoff carries pollutants, posing risks to the local environment and public health. Additionally, construction and maintenance incur costs and contribute to global environmental impacts. While life cycle assessment (LCA) can potentially capture local and global environmental impacts of roadway drainage and other stormwater systems, LCA methodology must be evaluated because stormwater systems differ from wastewater and drinking water systems to which LCA is more frequently applied. To this end, this research developed a comprehensive model linking roadway drainage design parameters to LCA and life cycle costing (LCC) under uncertainty. This framework was applied to 10 highway drainage projects to evaluate LCA methodological choices by characterizing environmental and economic impacts of drainage projects and individual components (basin, bioswale, culvert, grass swale, storm sewer, and pipe underdrain). The relative impacts of drainage components varied based on functional unit choice. LCA inventory cutoff criteria evaluation showed the potential for cost-based criteria, which performed better than mass-based criteria. Finally, the local aquatic benefits of grass swales and bioswales offset global environmental impacts for four impact categories, highlighting the need to explicitly consider local impacts (i.e., direct emissions) when evaluating drainage technologies

Comparable nutrient uptake across diel cycles from three distinct algal communities

Three algal communities cultured from inocula sourced from geographically distinct locations within the continental United States were maintained under identical sequencing-batch growth conditions in photobioreactors and sampled over 82 days. Communities were sequenced via both V4 and V8-V9 18S rRNA gene sequencing. Mothur and R were used to analyze sequencing data and to describe and compare community dynamics within and between communities. This project includes both mothur and R script files used to analyze the data