Assessment of phthalic acid esters plasticizers in sediments of coastal Alabama, USA: Occurrence, source, and ecological risk.

Considering the ubiquitous occurrences and ecotoxicity of phthalates (PAEs), it is essential to understand their sources, distribution, and associated ecological risks of PAEs in sediments to assess the environmental health of estuaries and support effective management practices. This study provides the first comprehensive dataset on the occurrence, spatial variation, inventory, and potential ecological risk assessment of PAEs in surface sediments of commercially and ecologically significant estuaries in the southeastern United States, Mobile Bay and adjoining eastern Mississippi Sound. Fifteen PAEs were widely detected in the sediments of the study region, with total concentrations varying between 0.

Sources and composition of natural and anthropogenic hydrocarbons in sediments from an impacted estuary.

Hydrocarbons in estuarine sediments provide information on sources of sedimentary organic matter (OM), and they are thus useful for tracing natural and anthropogenic OM inputs to the estuary. Here, we assessed the amounts, compositions and sources of natural and anthropogenic hydrocarbons from the sediments of a large, ecologically important estuary, Mobile Bay in Southeast USA. TOC/TN ratios and δC of organic carbon suggest that the bulk natural OM was sourced from marine phytoplankton and bacteria mixed with marsh and terrigenous C3 plants.

Quantifying colloid fate and transport through dense vegetation and soil systems using a particle-plugging tempered fractional-derivative model.

Colloid contaminants are widely distributed in surface runoff from crop land and can be effectively removed by vegetative filter strips (VFS), whose quantification however proves difficult. Standard mechanism-based models contain many unknown parameters with intrinsic uncertainty, limiting their applicability and potential extension for other environmental conditions and colloid contaminant types. To remedy this limitation and capture the complex dynamics of colloids through the soil-vegetation system, this study proposes a parsimonious, particle-plugging tempered fractional advection-dispersion eq.

Bacterial community shift in the coastal Gulf of Mexico salt-marsh sediment microcosm in vitro following exposure to the Mississippi Canyon Block 252 oil (MC252).

In this study, we examined the responses by the indigenous bacterial communities in salt-marsh sediment microcosms in vitro following treatment with Mississippi Canyon Block 252 oil (MC252). Microcosms were constructed of sediment and seawater collected from Bayou La Batre located in coastal Alabama on the Gulf of Mexico. We used an amplicon pyrosequencing approach on microcosm sediment metagenome targeting the V3-V5 region of the 16S rRNA gene.

Attenuation of trace elements in coal fly ash leachates by surfactant-modified zeolite.

Potential leaching of trace elements from older, unlined fly ash disposal facilities is a serious threat to groundwater and surface water contamination. Therefore, effective methods for containing the pollutant elements within the unlined coal combustion products (CCPs) disposal facilities are required to minimize any potential impact of leachate emanating from such facilities into the nearby environment. Because surfactant-modified zeolite (SMZ) has the potential to sequester both cationic and anionic trace elements from aqueous solutions, bench-scale batch and column experiments were performed to test its ability to remediate trace elements in leachates generated from both alkaline and acidic fly ash samples.