Prioritization of Early-Stage Research and Development of a Hydrogel-Encapsulated Anaerobic Technology for Distributed Treatment of High Strength Organic Wastewater.

This study aims to support the prioritization of research and development (R&D) pathways of an anaerobic technology leveraging hydrogel-encapsulated biomass to treat high-strength organic industrial wastewaters, enabling decentralized energy recovery and treatment to reduce organic loading on centralized treatment facilities. To characterize the sustainability implications of early-stage design decisions and to delineate R&D targets, an encapsulated anaerobic process model was developed and coupled with design algorithms for integrated process simulation, techno-economic analysis, and life cycle assessment under uncertainty. Across the design space, a single-stage configuration with passive biogas collection was found to have the greatest potential for financial viability and the lowest life cycle carbon emission.

Quantification of depth-dependent microbial growth in encapsulated systems.

Encapsulated systems have been widely used in environmental applications to selectively retain and protect microorganisms. The permeable matrix used for encapsulation, however, limits the accessibility of existing analytical methods to study the behaviour of the encapsulated microorganisms. Here, we present a novel method that overcomes these limitations and enables direct observation and enumeration of encapsulated microbial colonies over a range of spatial and temporal scales.

The potential for bacteria from carbon-limited deep terrestrial environments to participate in chlorine cycling.

Bacteria capable of dehalogenation via reductive or hydrolytic pathways are ubiquitous. Little is known, however, about the prevalence of bacterial dechlorination in deep terrestrial environments with a limited carbon supply. In this study we analyzed published genomes from three deep terrestrial subsurface sites: a deep aquifer in Western Siberia, the Sanford Underground Research Facility in South Dakota, USA, and the Soudan Underground Iron Mine (SUIM) in Minnesota, USA to determine if there was evidence to suggest that microbial dehalogenation was possible in these environments.

Contaminants of Emerging Concern in the Lower Volta River, Ghana, West Africa: The Agriculture, Aquaculture, and Urban Development Nexus.

Contaminants of emerging concern (CECs) are ubiquitous in aquatic environments across all continents and are relatively well known in the developed world. However, few studies have investigated their presence and biological effects in low- and middle-income countries. We provide a survey of CEC presence in the Volta River, Ghana, and examine the microbial consequences of anthropogenic activities along this economically and ecologically important African river.

Unraveling encapsulated growth of Nitrosomonas europaea in alginate: An experimental and modeling study.

Encapsulation is a promising technology to retain and protect autotrophs for biological nitrogen removal. One-dimensional biofilm models have been used to describe encapsulated systems; they do not, however, incorporate chemical sorption to the encapsulant nor do they adequately describe cell growth and distribution within the encapsulant. In this research we developed a new model to describe encapsulated growth and activity of Nitrosomonas europaea, incorporating ammonium sorption to the alginate encapsulant.

Dissolved oxygen concentrations affect the function but not the relative abundance of nitrifying bacterial populations in full-scale municipal wastewater treatment bioreactors during cold weather.

This study aimed to understand the effect of different dissolved oxygen (DO) concentrations on the abundance and performance of nitrifying bacteria in full-scale wastewater treatment bioreactors, particularly during the winter when nitrifying bacterial activity is often negligible. Biomass samples were collected from three parallel full-scale bioreactors with low DO concentrations (<1.3 mg/ L) and from two full-scale bioreactors with higher DO concentrations (~4.

Diverse dechlorinators and dechlorination genes enriched through amendment of chlorinated natural organic matter fractions.

In uncontaminated environments, chlorinated natural organic matter (Cl-NOM) can act as an electron acceptor for organohalide-respiring bacteria. It is unknown, however, whether different types of Cl-NOM are preferentially dechlorinated or whether enrichment with Cl-NOM affects the ability of bacteria to dechlorinate contaminants. In this research NOM was extracted from sediment, fractionated based on hydrophobicity, and either amended to polychlorinated biphenyl-contaminated soil directly or chlorinated and then amended to soil.

Aqueous film forming foam and associated perfluoroalkyl substances inhibit methane production and Co-contaminant degradation in an anaerobic microbial community.

Aqueous film forming foams (AFFF) can contain gram per liter concentrations of per- and polyfluoroalkyl substances (PFAS) and are often released in large quantities directly to the environment as they are used to fight fires. AFFF composition is complex and contains many unknown PFAS in addition to ingredients such as hydrocarbons, solvents, and corrosion inhibitors. While biological effects of single PFAS have been studied, the effects of PFAS-containing mixtures, such as AFFF, are unknown.

Modeling alginate encapsulation system for biological hydrogen production.

Wastewater treatment using encapsulated biomass is a promising approach for high-rate resource recovery. Encapsulation matrices can be customized to achieve desired biomass retention and mass transport performance. This, in turn, facilitates treatment of different waste streams.

Presence, Diversity, and Enrichment of Respiratory Reductive Dehalogenase and Non-respiratory Hydrolytic and Oxidative Dehalogenase Genes in Terrestrial Environments.

Organohalide-respiring bacteria have been linked to the cycling and possible respiration of chlorinated natural organic matter (Cl-NOM) in uncontaminated soils and sediments. The importance of non-respiratory hydrolytic/oxidative dechlorination processes in the cycling of Cl-NOM in terrestrial soil and sediment, however, is still not understood. This research analyzes the dechlorination potential of terrestrial systems through analysis of the metagenomes of urban lake sediments and cultures enriched with Cl-NOM.

Partitioning and Accumulation of Perfluoroalkyl Substances in Model Lipid Bilayers and Bacteria.

Perfluoroalkyl substances (PFAS) are ubiquitous and persistent environmental contaminants, yet knowledge of their biological effects and mechanisms of action is limited. The highest aqueous PFAS concentrations are found in areas where bacteria are relied upon for functions such as nutrient cycling and contaminant degradation, including fire-training areas, wastewater treatment plants, and landfill leachates. This research sought to elucidate one of the mechanisms of action of PFAS by studying their uptake by bacteria and partitioning into model phospholipid bilayer membranes.

Novel Microbial Assemblages Dominate Weathered Sulfide-Bearing Rock from Copper-Nickel Deposits in the Duluth Complex, Minnesota, USA.

The Duluth Complex in northeastern Minnesota hosts economically significant deposits of copper, nickel, and platinum group elements (PGEs). The primary sulfide mineralogy of these deposits includes the minerals pyrrhotite, chalcopyrite, pentlandite, and cubanite, and weathering experiments show that most sulfide-bearing rock from the Duluth Complex generates moderately acidic leachate (pH 4 to 6). Microorganisms are important catalysts for metal sulfide oxidation and could influence the quality of water from mines in the Duluth Complex.

Rapid Enrichment of Dehalococcoides-Like Bacteria by Partial Hydrophobic Separation.

Organohalide-respiring bacteria can be difficult to enrich and isolate, which can limit research on these important organisms. The goal of this research was to develop a method to rapidly (minutes to days) enrich these organisms from a mixed community. The method presented is based on the hypothesis that organohalide-respiring bacteria would be more hydrophobic than other bacteria as they dehalogenate hydrophobic compounds.

Sources and transport of contaminants of emerging concern: A two-year study of occurrence and spatiotemporal variation in a mixed land use watershed.

The occurrence and spatiotemporal variation of 26 contaminants of emerging concern (CECs) were evaluated in 68 water samples in 2011-2012 in the Zumbro River watershed, Minnesota, U.S.A.

Contaminants of Emerging Concern: Mass Balance and Comparison of Wastewater Effluent and Upstream Sources in a Mixed-Use Watershed.

Understanding the sources, transport, and spatiotemporal variability of contaminants of emerging concern (CECs) is important for understanding risks and developing monitoring and mitigation strategies. This study used mass balances to compare wastewater treatment plant (WWTP) and upstream sources of 16 CECs to a mixed-use watershed in Minnesota, under different seasonal and hydrological conditions. Three distinct CEC groups emerged with respect to their source proportionality and instream behavior.

The Effect of Perfluorooctane Sulfonate, Exposure Time, and Chemical Mixtures on Methanogenic Community Structure and Function.

A plethora of organic micropollutant mixtures are found in untreated municipal wastewater. Anaerobic digesters receive large loadings of hydrophobic micropollutants that sorb to wastewater biosolids. Despite micropollutants being pervasive as mixtures, little research is available to explain the impact that mixtures of compounds, as well as exposure time, have on microbial communities in anaerobic digesters.

Sediment-water distribution of contaminants of emerging concern in a mixed use watershed.

This study evaluated the occurrence and distribution of 15 contaminants of emerging concern (CECs) in stream water and sediments in the Zumbro River watershed in Minnesota and compared these with sub-watershed land uses. Sixty pairs of sediment and water samples were collected across all seasons from four stream sites for over two years and analyzed for selected personal care products, pesticides, human and veterinary medications, and phytoestrogens. Spatial and temporal analyses indicate that pharmaceuticals and personal care products (urban/residential CECs) are significantly elevated in water and/or sediment at sites with greater population density (>100 people/km(2)) and percentage of developed land use (>8% of subwatershed area) than those with less population density and land area under development.

Estrone degradation: does organic matter (quality), matter?

Understanding the parameters that drive E1 degradation is necessary to improve existing wastewater treatment systems and evaluate potential treatment options. Organic matter quality could be an important parameter. Microbial communities grown from activated sludge seeds using different dissolved organic matter sources were tested for E1 degradation rates.