3 research outputs found
Bio-weathering Using Shewanella oneidensis MR-1 Enhances Selective Recovery of Rare Earth Elements from Alaskan Coal Mines
Coal mines in Alaska with high rare earth elements (REEs) levels (286-524 mg/kg) serve as an alternative domestic source for REEs. Existing leaching/separation technologies fail to selectively recover REEs from the feedstock and require downstream multiple purification stages that increase the overall operational cost. This study aims at bio-weathering coal from two Alaskan coal mines (Wishbone Hill and Healy) at three density fractions (1.3 float, and 1.3 and 1.5 sink) using Shewanella oneidensis MR-1 for achieving higher selective REEs recovery in one-step process. Optimizing the bio-weathering process by varying solids percentages (5.7 to14.3% w/v), particle size (-14 to -200 M), incubation temperatures (30 to 34 °C), and inoculum dosing (0.2 to 1% v/v) resulted in highest recovery of Neodymium (75.3%) and total REEs (98.4%) from 1.3 float Wishbone Hill and 1.3 sink Healy coal, respectively. When compared to the chemical leaching process, bio-weathering enhanced selective recovery of REEs including Scandium, Yttrium, Ytterbium, Terbium, Erbium, and Lutetium from Healy coal at low density, and Yttrium from Wishbone Hill coal at high density. The results indicate the future scope for developing cost-effective selective REEs recovery processes that may address the global critical minerals supply chain risk
Rural Alaska Water Treatment and Distribution Systems Incur High Energy Costs: Identifying Energy Drivers Using Panel Data Analysis for 78 Communities
The energy consumption for water treatment and distribution
in
rural Alaska communities that represent one of the coldest and most
isolated regions in the US has been unexplored. Using energy audits
data from Alaska Native Tribal Health Consortium (ANTHC), we investigate
the annual energy consumption patterns for water treatment and distribution
in 78 rural Alaska communities (average population < 500 people)
along with seasonal, regional, and population impacts, and water treatment/distribution
system types. Regional trends of per capita annual energy consumption
are as follows: Interior > Northern > Southwest > Gulf coast
> Southeast
regions of Alaska. Our results indicate that the per capita energy
consumption is highest during the winter and lowest during the summer.
Generally, the per capita energy consumption decreases with an increasing
population. The variation of per capita energy consumption based on
water distribution types shows that piped circulating systems consume
the most energy, followed by washeteria, piped pressure, and closed
haul. At the water treatment plant, space heating and electrical motors
have the highest per capita energy consumption, followed by domestic
hot water, tank heating, and lighting. The findings in this work suggest
that per capita energy consumption (kWh/p) for water treatment and
distribution in rural Alaska is about 12–26 times higher than
the national average and about two orders of magnitude higher economic
costs for the same. Overall, this work sheds light on energy use for
water treatment and distribution in rural Alaska and establishes a
baseline that would be useful for the rural Alaska communities’
adaptation to climate change efforts, specifically in planning for
and designing new water systems or updating existing systems