Abstract This research demonstrates that modeling approaches can be used to identify priority areas to implement green stormwater infrastructure (GSI) resulting in improved water quality outcomes. The total suspended solids (TSS) washoff loading from watersheds in Lucas County, Ohio due the municipal separate storm sewer system (MS4) was reported based on 2015 rain data. The highest TSS loading was experienced in the winter season in 80% of the watersheds. Subcatchments with the highest predicted TSS washoff loadings were identified as priority areas or hotspots. In subsequent simulations, GSI implementation in hotspots improved water quality by more than twofold as compared to indiscriminate implementation of GSI. These hotspot maps are being used by regional stormwater stakeholders to focus their urban water quality efforts and to identify site characteristics that may be used to inform environmental policy.
Microcystis spp. blooms have occurred annually in western Lake Erie since about 1995. Microcystis produce a group of toxins known as microcystins which can be harmful to livestock and to humans. In this study, surface water samples were collected from six sites during six sampling events from July to October in 2007. In situ environmental data (e.g. pH, temperature) and laboratory analyses (e.g. nutrients) were carried out to characterize the six sites. The Microcystis spp. density ranged from 102 to 107 cells/ml. Microcystin-LR concentration of 20 of all 36 samples were below the detection limit (0.15–5 ppb), while the microcystin-LR concentration in the 16 remaining samples ranged from 0.5 to 3 × 103 μg per gram dry weight. The aim of this research was to investigate the relationships between sampling location, environmental parameters, Microcystis spp. concentration, and microcystin-LR concentration. The results suggest that temperature, nutrient concentration, turbidity, and wind speed and direction (P<0.05) are factors which affected Microcystis spp. density. Sampling site 8M, located 13 m from the Maumee River, provided an advantage for Microcystis spp. growth, presumably due to intermediate water depth (5.5 m) combined with impact from the river. No relationship was found between Microcystis spp. density and microcystin-LR concentration. Temperature, nutrient concentration and DO (P<0.05) were associated with the production of microcystin-LR.
Corrosion inhibitors and surfactants are present in aircraft deicing fluids (ADFs) at significant concentrations (> 1% w/w). The purpose of this research was to study the interactions of a common nonionic surfactant with the commercially significant corrosion inhibitors used in modern ADF (4- and 5-methylbenzotriazole [MeBT]), and to determine the effects of their mixture on the conventional anaerobic digestion process. In mesophilic anaerobic microcosms codigesting wastewater solids, propylene glycol, and MeBT, increasing surfactant levels resulted in enhanced MeBT sorption on digester solids. As judged by anaerobic toxicity assays, responses from digesters containing surfactant concentrations below their critical micelle concentration (CMC) suggested that low nonionic surfactant concentrations could facilitate a reduction in the apparent toxicity of MeBT. In microcosms exposed to surfactant concentrations above their CMC, no increase in MeBT solubility was observed, and the anaerobic toxicity response corresponded to control systems not containing surfactant. Direct microscopic measurements of digesting biomass using fluorescent phylogenetic probes (fluorescent in situ hybridization) revealed that members of the domain Bacteria were more sensitive to MeBT in the presence of surfactant than were members of the domain Archaea.
Many pathogens use mammalian cell surface carbohydrates as anchors for attachments, which subsequently results in infection. The unique combination of magnetic nanoparticles and diverse carbohydrate bioactivities prompts us to develop a magnetic glyco-nanoparticle (MGNP)-based system to rapidly detect Escherichia coli (E. coli) in just 5 min. High capture efficiencies up to 88% were achieved. Moreover, to accurately differentiate three E. coli strains, response patterns of MGNPs were utilized to decipher the pathogen identity. This appealing approach may have clinical applications since the virulence of many pathogens can be correlated with carbohydrate binding specificity. To the best of our knowledge, this is the first time that MGNPs have been used to detect, quantify, and differentiate E. coli cells, which can provide an exciting new avenue for decontamination and diagnostic applications.