Heavy Metal Remediation by Dry Mycelium Membranes: Approaches to Sustainable Lead Remediation in Water.

Lead contamination poses significant and lasting health risks, particularly in children. This study explores the efficacy of dried mycelium membranes, distinct from live fungal biomass, for the remediation of lead (Pb(II)) in water. Dried mycelium offers unique advantages, including environmental resilience, ease of handling, biodegradability, and mechanical reliability. The study explores Pb(II) removal mechanisms through sorption and mineralization by dried mycelium hyphae in aqueous solutions. The sorption isotherm studies reveal a high Pb(II) removal efficiency, exceeding 95% for concentrations below 1000 ppm and ∼63% above 1500 ppm, primarily driven by electrostatic interactions. The measured infrared peak shifts and the pseudo-second-order kinetics for sorption suggests a correlation between sorption capacity and the density of interacting functional groups. The study also explores novel surface functionalization of the mycelium network with phosphate to enhance Pb(II) removal, which enables remediation efficiencies >95% for concentrations above 1500 ppm. Scanning electron microscopy images show a pH-dependent formation of Pb-based crystals uniformly deposited throughout the entire mycelium network. Continuous cross-flow filtration tests employing a dried mycelium membrane demonstrate its efficacy as a microporous membrane for Pb(II) removal, reaching remediation efficiency of 85-90% at the highest Pb(II) concentrations. These findings suggest that dried mycelium membranes can be a viable alternative to synthetic membranes in heavy metal remediation, with potential environmental and water treatment applications.

Spaces of market politics: Retailscapes and modernist planning imaginaries in African cities.

This article interrogates the spatial, economic, and cultural underpinnings of traditional retailscapes in sub-Saharan Africa to understand how they intersect with contemporary urban planning policies. It does so by deploying a multi-step investigation of the issues from four perspectives: transportation corridors, spheres of influence, centrality, and observed spatial patterns - each leading us to connections between retail spaces and planning of African cities. Our analyses of 22 traditional satellite markets in Kumasi are distilled into four key findings. First, these markets emerge along, and at the intersection of, intra- and inter-urban road networks as a means of granting local access to indigenous goods and services. Second, the spatial distribution and spheres of influence of the markets partly support Christaller's hypothesis regarding the willingness of people to travel far distances to access higher-order goods and services. The hypothesis fails, however, to recognize that some traditional markets can still have high spheres of influence without providing higher-order goods and services because they constitute vital nodes in the rural-urban food networks. Third, we find a spatial clustering of these markets, suggesting agglomerative tendencies among the markets. Finally, we argue that the observed spatio-social patterns of Kumasi's retailscape only make sense if they are situated within the city's modernist urban planning imaginaries. Specifically, the city's retailscape embodies ongoing placemaking strategies, which involve the expropriation of urban spaces from traders to modernize the cityscape.

A multilevel scenario based predictive analytics framework to model the community mental health and built environment nexus.

The built environment affects mental health outcomes, but this relationship is less studied and understood. This article proposes a novel multi-level scenario-based predictive analytics framework (MSPAF) to explore the complex relationships between community mental health outcomes and the built environment conditions. The MSPAF combines rigorously validated interpretable machine learning algorithms and scenario-based sensitivity analysis to test various hypotheses on how the built environment impacts community mental health outcomes across the largest metropolitan areas in the US. Among other findings, our results suggest that declining socio-economic conditions of the built environment (e.g., poverty, low income, unemployment, decreased access to public health insurance) are significantly associated with increased reported mental health disorders. Similarly, physical conditions of the built environment (e.g., increased housing vacancies and increased travel costs) are significantly associated with increased reported mental health disorders. However, this positive relationship between the physical conditions of the built environment and mental health outcomes does not hold across all the metropolitan areas, suggesting a mixed effect of the built environment's physical conditions on community mental health. We conclude by highlighting future opportunities of incorporating other variables and datasets into the MSPAF framework to test additional hypotheses on how the built environment impacts community mental health.