Characterizing the Impact of Cyanobacterial Blooms on the Photoreactivity of Surface Waters from New York Lakes: A Combined Statewide Survey and Laboratory Investigation.

Cyanobacterial blooms introduce autochthonous dissolved organic matter (DOM) into aquatic environments, but their impact on surface water photoreactivity has not been investigated through collaborative field sampling with comparative laboratory assessments. In this work, we quantified the apparent quantum yields (Φ) of reactive intermediates (RIs), including excited triplet states of dissolved organic matter (DOM*), singlet oxygen (O), and hydroxyl radicals (OH), for whole water samples collected by citizen volunteers from more than 100 New York lakes. Multiple comparisons tests and orthogonal partial least-squares analysis identified the level of cyanobacterial chlorophyll as a key factor in explaining the enhanced photoreactivity of whole water samples sourced from bloom-impacted lakes.

Suspect screening to support source identification and risk assessment of organic micropollutants in the aquatic environment of a Sub-Saharan African urban center.

Organic micropollutants (OMPs) are contaminants of global concern and have garnered increasing attention in Africa, particularly in urban and urbanizing areas of Sub-Saharan Africa (SSA). In this work, we coupled suspect screening enabled by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) with multivariate analysis to characterize OMPs in wastewater, surface water, and groundwater samples collected from Kampala, the capital and largest city of Uganda. Suspect screening prioritized and confirmed 157 OMPs in Kampala samples for target quantification.

Contrasting Impacts of Photochemical and Microbial Processing on the Photoreactivity of Dissolved Organic Matter in an Adirondack Lake Watershed.

Photochemical and microbial processing are the prevailing mechanisms that shape the composition and reactivity of dissolved organic matter (DOM); however, prior research has not comparatively evaluated the impacts of these processes on the photoproduction of reactive intermediates (RIs) from freshly sourced terrestrial DOM. We performed controlled irradiation and incubation experiments with leaf and soil samples collected from an acid-impacted lake watershed in the Adirondack Mountain region of New York to examine the effects of DOM processing on the apparent quantum yields of RIs (Φ), including excited triplet states of DOM (DOM*), singlet oxygen (O), and hydroxyl radicals (OH). Photodegradation led to net reductions in Φ, Φ, and Φ, whereas (photo-)biodegradation resulted in increases in Φ and Φ.

Photochemical Characterization of Surface Waters from Lakes in the Adirondack Region of New York.

The Adirondack Mountain region of New York, a historical hotspot for atmospheric sulfur and nitrogen deposition, features abundant lakes that are experiencing browning associated with recovery from acidification. Yet, much remains unknown about the photoreactivity of Adirondack lake waters. We quantified the apparent quantum yields (Φ) of photochemically produced reactive intermediates (RIs), such as excited triplet states of dissolved organic matter (DOM*), singlet oxygen (O), and hydroxyl radicals (OH), for surface waters collected from 16 representative Adirondack lakes.

A facile polymerisation of magnetic coal to enhanced phosphate removal from solution.

Globally, there are increased threats to available freshwater resources due to pollution, climate change, and increased demand from population growth. Phosphorus is one of the essential nutrients required for animal and plant growth. However, when it is released into freshwater resources in excess amounts, it can become a pollutant through eutrophication.

Water soluble organic aerosols in the Colorado Rocky Mountains, USA: composition, sources and optical properties.

Atmospheric aerosols have been shown to be an important input of organic carbon and nutrients to alpine watersheds and influence biogeochemical processes in these remote settings. For many remote, high elevation watersheds, direct evidence of the sources of water soluble organic aerosols and their chemical and optical characteristics is lacking. Here, we show that the concentration of water soluble organic carbon (WSOC) in the total suspended particulate (TSP) load at a high elevation site in the Colorado Rocky Mountains was strongly correlated with UV absorbance at 254 nm (Abs254, r = 0.