Microplastics in a freshwater environment receiving treated wastewater effluent.

Small plastic fragments (microplastics or solid particles <5 mm in size or "microbeads" used in personal care products and cosmetics) may ultimately find their way into aquatic environments. We studied the presence of microplastics (particle sizes 53-105 µm and 106-179 µm) spatially and temporally in 3 connected urban lakes being fed by treated wastewater effluent in Lubbock, Texas. These lakes also serve as drainage during storm events. Water samples from drainage playa wetlands within the city were also collected. Our interest was in determining the presence or absence of microplastics in a freshwater environment as well as the source apportionment between personal care products (via wastewater) and discarded plastics (via runoff). Results showed that average concentrations of microplastics in samples collected from lakes ranged from 0.79 ± 0.88 mg/L to 1.56 ± 1.64 mg/L for the 53-105 µm size fraction and from 0.31 ± 0.72 mg/L to 1.25 ± 1.98 mg/L for the 106-179 µm size fraction. For samples collected from playa wetlands, average microplastic concentrations ranged from 0.64 ± 0.92 mg/L to 5.51 ± 9.09 mg/L for the 53-105 µm size fraction and from nondetectable (ND) to 1.79 ± 3.04 mg/L for the 106-179 µm size fraction. Our results (based on comparison of microplastic masses) suggest that urban runoff also contributes microplastics to surface water in addition to the treated wastewater effluent (in this particular case). The present findings may assist in adopting additional monitoring efforts and provide information on the potential contribution of secondary microplastic input into aquatic environments. Integr Environ Assess Manag 2017;13:528-532. © 2017 SETAC.

Biophysical Viscosity: Thermodynamic Principles of Per Capita Chemical Potentials in Human Populations.

Dynamic viscosity has been used to describe molecular resistance to flow under an applied force. This study introduces the theory of biophysical viscosity, the resistance of a region to molecular flow under environmental force to define the rates of per capita anthropogenic chemical efflux into the environment. Biophysical viscosity is an important intermediate quantity, in that it can be used to calculate the chemical potentials of single molecules for individuals in a population. Nonhypothetical emission data was combined with chemical potentials of anthropogenic tracers, to demonstrate that thermodynamic quantities can be used as parameters to directly compare energies associated with individual chemical emissions across geographic regions. These results indicate that population density is not the only factor in the determination of population-level chemical efflux and that biophysical viscosity is a useful tool in determining the per capita chemical potentials of anthropogenic chemicals for environmental risk assessment.

UV filters interaction in the chlorinated swimming pool, a new challenge for urbanization, a need for community scale investigations.

Sunscreen products and some personal care products contain the Ultraviolet (UV) chemical filters, which are entering the surface water. Public concerns about secondary effects of these compounds are growing because of the contamination of the aquatic environment that may reach to potentially toxic concentration levels. This article highlights the reaction of certain UV filters with hypochlorite disinfectant in the presence of sunlight. Due to urbanization and industrialization, use of outdoor plastic swimming pools is increasing. The relatively smaller volume of these pools compared to larger pools may increase the concentration of the UV filters in the pool and their potential interactions with materials of human origin (urine, sweat, cosmetics, skin cells, and hair) to the levels of toxicity concerns for children through the creation of disinfection by products (DBP). Based on our analysis, the minimum concentration levels of 2.85, 1.9, 1.78 and 0.95g/L, respectively, for EHMC, OC, 4-MBC and BP3 UV filters in children pools are predicted. Therefore, this article calls for an urgent investigation of potential toxic effects of the UV filters, the creation of DBPs and their subsequent impacts on human health.

Assessing an intermittently operated household scale slow sand filter paired with household bleach for the removal of endocrine disrupting compounds.

Endocrine disrupting compounds (EDCs) are a contaminant of emerging concern throughout the world, including developing countries where centralized water and wastewater treatment plants are not common. In developing countries, household scale water treatment technologies such as the biosand filter (BSF) are used to improve drinking water quality. No studies currently exist on the ability of the BSF to remove EDCs. In this experiment, the BSF was evaluated for the removal of three EDCs, estrone (E1), estriol (E3), and 17α-ethinyl estradiol (EE2). Removal results were compared to the slow sand filter (SSF) from the literature, which is similar to the BSF in principal but comparisons have revealed differences in removal of other water quality parameters between SSF and BSF. In general, the BSF minimally removed the compounds from spiked lake water as removal was less than 15% for all three compounds, though mass removal much higher than other studies in which the SSF was used. Household bleach was added to the rate was BSF effluent as suggested in order to achieve different Cl- concentrations (0.67, 2.0, 5.0, and 10.0 mg/L) and subsequent removal of EDCs by oxidation was examined. Concentrations were reduced > 98% for all compounds when the Cl- concentration was greater than 5 mg/L. Removal efficiency was > 50% at the 0.67 mg/L Cl- concentration, while almost 70% removal was observed for all compounds at the 2.0 mg/L Cl- concentration.

Occurrence, fate, and persistence of gemfibrozil in water and soil.

Pharmaceuticals and personal care products (PPCPs) have emerged as a group of potential environmental contaminants of concern. The occurrence of gemfibrozil, a lipid-regulating drug, was studied in the influent and effluent at a wastewater treatment plant (WWTP) and groundwater below a land application site receiving treated effluent from the WWTP. In addition, the sorption of gemfibrozil in two loam soils and sand was assessed, and biological degradation rates in two soil types under aerobic conditions were also determined. Results showed that concentrations of gemfibrozil in wastewater influent, effluent, and groundwater were in the range of 3.47 to 63.8 µg/L, 0.08 to 19.4 µg/L, and undetectable to 6.86 µg/L, respectively. Data also indicated that gemfibrozil in the wastewater could reach groundwater following land application of the treated effluent. Soil-water distribution coefficients for gemfibrozil, determined by the batch equilibrium method, varied with organic carbon content in the soils. The sorption capacity was silt loam > sandy loam > sand. Under aerobic conditions, dissipation half-lives for gemfibrozil in sandy loam and silt loam soils were 17.8 and 20.6 days, respectively; 25.4 and 11.3% of gemfibrozil was lost through biodegradation from the two soils over 14 days.

Occurrence of synthetic musk fragrances in effluent and non-effluent impacted environments.

Synthetic musk fragrances (SMFs) are considered micropollutants and can be found in various environmental matrices near wastewater discharge areas. These emerging contaminants are often detected in wastewater at low concentrations; they are continuously present and constitute a constant exposure source. Objectives of this study were to investigate the environmental fate, transport, and transformation of SMFs. Occurrence of six polycyclic musk compounds (galaxolide, tonalide, celestolide, phantolide, traseolide, cashmeran) and two nitro musk compounds (musk xylene and musk ketone) was monitored in wastewater, various surface waters and their sediments, as well as groundwater, soil cores, and plants from a treated wastewater land application site. Specifically, samples were collected quarterly from (1) a wastewater treatment plant to determine initial concentrations in wastewater effluent, (2) a storage reservoir at a land application site to determine possible photolysis before land application, (3) soil cores to determine the amount of sorption after land application and groundwater recharge to assess lack thereof, (4) a lake system and its sediment to assess degradation, and (5) non-effluent impacted local playa lakes and sediments to assess potential sources of these compounds. All samples were analyzed using gas chromatography coupled with mass spectrometry (GC-MS). Data indicated that occurrence of SMFs in effluent-impacted environments was detectable at ng/L and ng/g concentrations, which decreased during transport throughout wastewater treatment and land application. However, unexpected concentrations, ng/L and ng/g, were also detected in playa lakes not receiving treated effluent. Additionally, soil cores from land application sites had ng/g concentrations, and SMFs were detected in plant samples at trace levels. Galaxolide and tonalide were consistently found in all environments. Information on occurrence is critical to assessing exposure to these potential endocrine disrupting compounds. Such information could provide a scientific framework for establishing the need for environmental regulations.

Limitations encountered for the treatment of a low C:N waste using a modified membrane-aerated biofilm reactor.

A modified membrane-aerated biofilm reactor (mMABR) that combined oxygen permeable membranes and inert attachment media to support both nitrification and denitrification was used to treat a carbon-limited (COD:N = 1.8) and ammonium-rich (NH4+ = 650 g-N/m3) space habitation waste stream. An eight-fold increase in intramembrane air pressure did not affect process performance; however, for an air pressure of 11 kPa (gauge), lower and upper hydraulic loading limits for the mMABR were identified at 30 g-N/m3 x d and 123 g-N/m3 x d, respectively. Oxygen limitation occurred at the highest loading rate and alkalinity limitation occurred at the lowest loading rate. Partial nitrification was noted at both limitations. Additionally, increased recirculation ratios were shown to decrease denitrification efficiency. Mean carbon and nitrogen removal rates were as high as 75.3 g-C/m3 x d (0.26 g-C/m2d) and 63.8 g-N/m3 x d (0.22 g-N/m2 x d), respectively. The mMABR achieved maximal nitrification and denitrification performance given the stoichiometric nature of the waste.

Uptake of 17α-ethynylestradiol and triclosan in pinto bean, Phaseolus vulgaris.

Pharmaceuticals and personal care products (PPCPs) have emerged as a group of potential environmental contaminants of concern. PPCPs in soil may enter terrestrial food webs via plant uptake. We evaluated uptake of 17α-ethynylestradiol (EE2) and triclosan in bean plants (Phaseolus vulgaris) grown in sand and soil. The extent of uptake and accumulation of EE2 and triclosan in plants grown in sand was higher than in plants grown in soil. In sand (conditions of maximum contaminant bioavailability), bioconcentration factors (BCFs) of EE2 and triclosan in roots (based on dry weights) were 1424 and 16,364, respectively, whereas BCFs in leaves were 55 for EE2 and 85 for triclosan. In soil, the BCF of EE2 decreased from 154 in the first week to 32 in the fourth week while it fluctuated in leaves from 18 to 20. The BCF for triclosan in plants grown in soil increased over time to 12 in roots and 8 in leaves. These results indicate that the potential for uptake and accumulation of PPCPs in plants exists. This trophic transfer pathway should be considered when assessing exposure to certain PPCPs, particularly with the use of recycled wastewater for irrigation.