Blending phosphogypsum to mitigate radionuclide leaching for sustainable road base applications.

Production of phosphoric acid generates a calcium sulfate byproduct known as phosphogypsum (PG). PG is not considered a suitable standalone road base material because of concerns such as strength and presence of radionuclides. This paper investigates the latter, specifically the influence of blending PG with common alkaline road base aggregates - limerock (LR) and recycled concrete aggregate (RCA) - on radionuclide leaching.

Opportunities and challenges with implementing a recycling program for municipal solid waste incineration (MSWI) bottom ash as a construction aggregate: A programmatic review.

The incineration of municipal solid waste (MSW) produces byproducts known as MSW incineration (MSWI) ash. The reuse of MSWI ash as a construction material prevails in several areas of the world, namely Europe and Asia, however, reuse in the United States (US) lags due to regulatory requirements for disposal practices. Developing a recycling program for MSWI ash provides an alternative end-of-life disposal scenario for material currently landfilled and supplements the reliability of mining of natural aggregates.

Impacts of advanced metals recovery on municipal solid waste incineration bottom ash: aggregate characteristics and performance in portland limestone cement concrete.

The optimization of alternative materials in concrete production continues to garner considerable attention in order to meet sustainability goals and supplement natural materials. Portland limestone cement (PLC) and municipal solid waste incineration (MSWI) bottom ash (BA) have been proposed separately as green cement and coarse aggregate supplement in low-strength concrete production, creating sustainable products and alternative disposal scenario for a waste material. This study discusses the impact of advanced ash processing techniques on aggregates and presents the performance of concrete incorporating both of these products with PLC for the first time.

FAIR reporting of clinical trials for public health practice.

The number of clinical trials is rapidly growing, and automation of literature processing is becoming desirable but unresolved. Our purpose was to assess and increase the readiness of clinical trial reports for supporting automated retrieval and implementation in public health practice. We searched the Medline database for a random sample of clinical trials of HIV/AIDS management with likely relevance to public health in Africa.

Reducing overdose deaths among persons with opioid use disorder in connecticut.

Background: People in Connecticut are now more likely to die of a drug-related overdose than a traffic accident. While Connecticut has had some success in slowing the rise in overdose death rates, substantial additional progress is necessary.

Methods: We developed, verified, and calibrated a mechanistic simulation of alternative overdose prevention policy options, including scaling up naloxone (NLX) distribution in the community and medications for opioid use disorder (OUD) among people who are incarcerated (MOUD-INC) and in the community (MOUD-COM) in a simulated cohort of people with OUD in Connecticut.

Analysis of ammonia-nitrogen removal kinetics by stage in pilot scale vertical flow wetlands treating landfill leachate in series.

This study explored the effect stage number and plant type have on ammonia-nitrogen (NH-N) removal kinetics in a two-stage pilot-scale vertical flow constructed wetland (VFCW) system treating landfill leachate. Half of the VFCW columns were planted with Typha latifolia and the other half Scirpus californicus, and half of the columns were loaded with municipal solid waste landfill leachate (diluted to 1 part leachate to 2 parts total) with the effluent from these columns was collected in two separate barrels. The remaining columns were loaded with the effluent collected from the first columns, creating a two-stage VFCW system with four unique pairs to be tested.

Per- and polyfluoroalkyl substances (PFAS) in construction and demolition debris (CDD): discerning sources and fate during waste management.

As regulatory frameworks for per- and polyfluoroalkyl substances (PFAS) evolve, the solid waste community seeks to manage PFAS risks effectively. Despite extensive research on PFAS in municipal solid waste (MSW) and wastewater sludge, there is limited information on a major global waste stream which seldom gleans regulatory oversight - construction and demolition debris (CDD). This study sampled a CDD processing facility to provide material-specific information on the PFAS profile within CDD.

Investigating the partitioning behavior of per- and polyfluoroalkyl substances (PFAS) during thermal landfill leachate evaporation.

Thermal landfill leachate evaporator systems can reduce the volume of leachate by up to 97%, while releasing water vapor and producing residuals (volume-reduced leachate and sludge) that are managed on-site. On-site thermal evaporators offer landfill operators leachate management autonomy without being subject to increasingly stringent wastewater treatment plant requirements. However, little is known about the partitioning of PFAS within these systems, nor the extent to which PFAS may be emitted into the environment via vapor.

Neurorehabilitation across the Continuum: From the Neurocritical care unit to home.

Children admitted to neurocritical care units often experience new neurodevelopmental disabilities due to both their acquired neurologic injuries and deconditioning from prolonged hospitalizations. Rehabilitation for critically ill children is multifactorial and begins in the intensive care unit itself. The goals of rehabilitation include prevention of complications associated with immobilization and evolving tone, comprehensive evaluation and treatment of functional deficits, and implementation of adaptive strategies with the goal of maximizing recovery.

Characterization of per- and polyfluoroalkyl substances (PFAS) and other constituents in MSW landfill leachate from Puerto Rico.

Elevated per- and polyfluoroalkyl substance (PFAS) concentrations have been reported in municipal solid waste (MSW) landfill leachate with higher levels in wet and warmer subtropical climates. Information about landfill leachate characteristics is much more limited in tropical climates. In this study, 20 landfill leachate samples were collected from three MSW landfills on the tropical island of Puerto Rico and results were compared against landfills nationally and within Florida, USA.

Assessing the suitability of leachability-based screening levels for per- and polyfluoroalkyl substances (PFAS) risk assessment.

In recent years, soil screening levels have been adopted by regulatory agencies for certain per- and polyfluoroalkyl substances (PFAS) to assess the risk of groundwater contamination through leaching. These soil screening levels, determined using an established equilibrium-based partitioning equation, have high variability among regulatory groups largely attributed to the diverse reported partitioning coefficients in the literature. This variability between reported partitioning coefficients, and subsequently soil screening levels, is due to the complex leaching behavior of PFAS not being predicted well by the standard equilibrium-based model.

Investigating the sources and fate of per- and polyfluoroalkyl substances (PFAS) in food waste compost.

Composting municipal food waste is a key strategy for beneficially reusing methane-producing waste that would otherwise occupy landfill space. However, land-applied compost can cycle per- and polyfluoroalkyl substances (PFAS) back into the food supply and the environment. We partnered with a pilot-scale windrow composting facility to investigate the sources and fate of 40 PFAS in food waste compost.

Evaluation of per- and polyfluoroalkyl substances (PFAS) in landfill liquids from Pennsylvania, Colorado, and Wisconsin.

PER: and polyfluoroalkyl substances (PFAS) have been measured in aqueous components within landfills. To date, the majority of these studies have been conducted in Florida. This current study aimed to evaluate PFAS concentrations in aqueous components (leachate, gas condensate, stormwater, and groundwater) from four landfills located outside of Florida, in Pennsylvania, Colorado, and Wisconsin (2 landfills).

Evaluation of per- and polyfluoroalkyl substances (PFAS) released from two Florida landfills based on mass balance analyses.

Per- and polyfluoroalkyl substances (PFAS) have been found at high levels within landfill environments. To assess PFAS distributions, this study aimed to evaluate PFAS mass flux leached from disposed solid waste and within landfill reservoirs by mass balance analyses for two full-scale operational Florida landfills. PFAS mass flux in different aqueous components within landfills were estimated based on PFAS concentrations and water flow rates.

Comparison of the PFAS and physical-chemical parameter fluctuations between an ash landfill and a MSW landfill.

Studies of per- and polyfluoroalkyl substances (PFAS) fluctuations at landfills have focused on municipal solid waste (MSW) leachate. Few studies exist that evaluate fluctuations (defined by the coefficient of variation, CV) in MSW incinerator ash (MSWA) landfill leachate and that evaluate PFAS fluctuations in stormwater, groundwater, and treated liquids on-site. In this study, aqueous landfill samples (leachate, treated leachate, stormwater, gas condensate, ambient groundwater, and effluent from a groundwater remediation system) were collected from a MSW and an MSWA landfill geographically located within close proximity (less than 40 km).

Assessing construction and demolition wood-derived biochar for in-situ per- and polyfluoroalkyl substance (PFAS) removal from landfill leachate.

With regulations for per-and polyfluoroalkyl substances (PFAS) impending, the abundance of these chemicals of emerging concern in municipal solid waste (MSW) landfill leachate increasingly challenges landfill operators to seek on-site leachate pre-treatment options. This two-staged study explores the potential reuse of biochar derived from construction and demolition debris (CDD) wood as an in-situ PFAS sorbent for application within MSW landfill leachate collection systems. Batch leaching tests were first used to examine the feasibility of capturing PFAS from landfill leachate using two sources of CDD-wood-derived biochar.

Assessment of Municipal Solid-Waste Landfill Liner Performance.

The leachate collection system (LCS) and leak detection system (LDS) flow rate data from 240 cells (or a combination of cells) at 54 municipal solid-waste landfills (located in seven US states) with double-liner systems were analyzed to assess the performance of the primary liner system. The average LCS leachate collection rates for the study sites ranged from 380 L ha day (40.7 gal.

Insights on volatile metals in landfill gas as determined from advanced treatment media.

This study analyzed spent activated carbon (AC) from a landfill gas (LFG) treatment system for an expanded suite of lesser studied volatile metals, revealing elevated levels of As and Sb in the LFG, exceeding those previously reported, with minimum average concentrations of 640 µg m and 590 µg m, respectively. The annual release of As and Sb through landfill gas was found to be significant, surpassing leachate emissions by an order of magnitude. Extrapolating these findings to all US landfills suggests that the release of As and Sb through landfill gas could be a major, previously overlooked source of these metals in global emission estimates, underscoring the need to include them when developing future inventories.

Expanding Per- and Polyfluoroalkyl Substances Coverage in Nontargeted Analysis Using Data-Independent Analysis and IonDecon.

Per- and polyfluoroalkyl substances (PFAS) are widespread, persistent environmental contaminants that have been linked to various health issues. Comprehensive PFAS analysis often relies on ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC HRMS) and molecular fragmentation (MS/MS). However, the selection and fragmentation of ions for MS/MS analysis using data-dependent analysis results in only the topmost abundant ions being selected.

Extrusion and characterization of recycled polyethylene terephthalate (rPET) filaments compounded with chain extender and impact modifiers for material-extrusion additive manufacturing.

The continuous growth of annual production and consumption of polyethylene terephthalate (PET) is coined with increasing waste that leaks into the environment, landfills and oceans as microplastics and nano plastics fragments. Upcycling the recycled PET to make a feedstock for the fast-growing material-extrusion additive manufacturing (MEX-AM) technology can contribute to the solution and supports the concept of sustainable materials. In this work, extrudable filaments comprising recycled polyethylene terephthalate (rPET) with low-cost additives, such as pyromellitic dianhydride (PMDA) as a chain extender, styrene-ethylene-butylene-styrene terpolymer functionalized with maleic anhydride (SEBS-g-MA), a thermal modifier and toughening agent, ethylene-ethyl acrylate-glycidyl methacrylate terpolymer (E-EA-GMA), a functional reactive elastomeric impact modifier and ethylene-ethyl-acrylate (EEA), a non-reactive elastomeric impact modifier, have been fabricated using the twin-screw extruder.

Isothermal Dual-Phase Flow Modeling to Assess the Impact of Gas Collection on Geotechnical and Hydraulic Performance of Landfills.

Liquid addition to landfilled municipal solid waste (MSW) is a practice employed to accelerate the biodegradation of the organic fraction of MSW and ensuing gas generation. Pore landfill gas (LFG) and leachate pressure from the added moisture and enhanced gas generation are expected to impact the geotechnical stability of landfill slopes. The impact of moisture addition and gas collection on the stability of landfills was numerically modeled using transient isothermal dual-phase flow and slope stability modeling.

Effect of waste-derived soil amendments on mitigating leaching impacts from municipal solid waste incineration (MSWI) ash.

This study explores modifying a sandy soil with a low solid to liquid partitioning coefficient (K) by adding amendments including iron-rich industrial slag byproducts and biochars, which contain sorption sites for trace metals present in MSWI ash leachate (notably Sb, cited as a concern for reuse applications). K values for Sb were determined for the sandy soil to be as low as 1.6 ± 0.

Pathways to racial disparities in the effects of Good Samaritan Laws: A mixed methods pilot study.

Background: Drug overdose deaths continue to rise, and considerable racial inequities have emerged. Overdose Good Samaritan laws (GSLs) are intended to encourage overdose witnesses to seek emergency assistance. However, evidence of their effectiveness is mixed, and little is known regarding racial disparities in their implementation.