Particulate matter
(PM) air pollution poses a risk to public health,
especially in rapidly industrializing countries. One major way to
protect individuals from PM exposure is to use fiber-based filters
for indoor air purification. In this study, a new low pressure drop
poly(vinyl alcohol) (PVA)/cellulose nanocrystals (CNCs) composite
nanofibrous filter was fabricated using electrospinning. This electrospun
PVA/CNCs filter was demonstrated as an air filter for the first time.
The CNCs not only contributed to the PVA/CNCs system as mechanical
reinforcement agents but also increased the surface charge density
of the electrospinning solution, thereby reducing fiber diameter.
The thinner fibers reduced pressure drop significantly and increased
the efficiency of PM removal. Our results indicate that high PM2.5 removal efficiency was achieved (99.1%) under extremely
polluted conditions (PM2.5 mass concentration > 500
μg
m–3) with low pressure drop (91 Pa) at an airflow
velocity of 0.2 m s–1. Considering that PVA and
CNCs are both nontoxic and biodegradable, this high-efficiency composite
filter with low air resistance is environmentally friendly and shows
promise in indoor air purification applications.
Short-rotation woody crops are an integral component of regional and national energy portfolios, as well as providing essential ecosystem services such as biomass supplies, carbon sinks, clean water, and healthy soils. We review recent USDA Forest Service Research and Development efforts from the USDA Biomass Research Centers on the provisioning of these ecosystem services from woody crop production systems. For biomass, we highlight productivity and yield potential, pest susceptibility, and bioenergy siting applications. We describe carbon storage in aboveground woody biomass and studies assessing the provision of clean and plentiful water. Soil protection and wildlife habitat are also mentioned, in the context of converting lands from traditional row-crop agriculture to woody production systems.
Laser-induced breakdown spectroscopy (LIBS) is being proposed more and more as a high-throughput technology to assess the elemental composition of materials. When a specific element is of interest, semiquantification is possible by building a calibration model using the emission line intensity of this element for known samples. However, a unique element has usually more than one emission line, and there are many examples where several emission lines used in combination give dramatically better results than any of the individual variables used alone. With a multivariate approach, models can be constructed that take into account all the emission lines related to a specific element; therefore more robust models can be developed. In this work, chemometric methods such as principal component analysis and partial least squares are proposed to resolve and extract useful information from the LIBS spectral data collected on biological materials.
Soil erosion, loss of productivity potential, biodiversity loss, water shortage, and soil and water pollution are ongoing processes that decrease or degrade provisioning (e.g., biomass, freshwater) and regulating (e.g., carbon sequestration, soil quality) ecosystem services. Therefore, developing environmental technologies that maximize these services is essential for the continued support of rural and urban populations. Genotype selection is a key component of these technologies, and characteristics of the species used in short rotation woody biomass systems, as well as the silvicultural techniques developed for short rotation woody crops are readily adapted to environmental applications. Here, we describe the development of such woody crop production systems for the advancement of environmental technologies including phytoremediation, urban afforestation, forest restoration, and mine reclamation. The primary goal of these collective efforts is to develop systems and tools that can help to mitigate ecological degradation and thereby sustain healthy ecosystems across the rural to urban continuum. Abbreviations B B o r o n C C a r b o n Cl Chloride Electronic supplementary material The online version of this article (
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