Audra Morse

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.

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.

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.

Nitrification-denitrification biological treatment of a high-nitrogen waste stream for water-reuse applications.

This research was conducted to evaluate the use of biological nitrification-denitrification systems as pre-processors for recycling wastewater to potable water in support of space exploration. A packed-bed bioreactor and membrane-aerated nitrification reactor were operated in series with a 10:1 recycle ratio over varying loading rates. The dissolved organic carbon (DOC) removal exceeded 80% for all loading rates (theta = 1 to 6.8 days), while total nitrogen removal generally increased with decreasing retention time, with a maximum removal of 55%. The degree of nitrification generally declined with decreasing retention time from a high of 80% to a low of 60%. Maximum DOC and total nitrogen volumetric removal rates exceeded 1000 and 800 g/m3 x d, respectively, and maximum nitrification volumetric conversion rates exceeded 300 g/m3 x d. At low hydraulic loading rates, the system was stoichiometrically limited, while kinetic limitations dominated at high hydraulic loading rates. Incomplete nitrification occurred at high loading rates, likely as a result of the high pH and large concentrations of ammonia.

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.

Development and Testing of a TRL 5 Bioreactor for Pretreatment of a Lunar Surface Wastestream

Water is the most critical life support element, representing 65% of the daily mass input for crew members even under the most stringent water use approaches. A reliable water source is therefore a critical concern for long term space habitation, whether in orbit (e.g. ISS), on the moon, Mars, or beyond. Water recovery systems currently under development for space missions are intensive users of resources including power for processes such as distillation and consumables for post-treatment based on adsorption and chemical oxidation of contaminants. As such, current designs exchange one cost (stored water) for others (power generation, stored consumables). Logistic savings characteristic of water recycling would be better reduced by implementing alternative, low-input systems. A pre-distillation bioreactor would require few resources while substantially improving system performance: >90% removal of wastewater organics including surfactants, pH stabilization, oxidation of NH 4 + to NO 3 - , (up to 80%), and improved distillation brine properties. We report on the design, construction, and testing of a TRL 5 biological membrane aerated reactor for pre-treatment (carbon and ammonia oxidation) of an early planetary base (e.g. Lunar) wastewater capable of integration with physio-chemical systems.

Optimization of a Membrane-Aerated Biological Reactor in Preparation for a Full Scale Integrated Water Recovery Test

Water recycling is a fundamental component of life support systems due to the substantial contribution of water to the total equivalent system mass. Optimizing the integrated water recycling systems is essential in any efforts to enable long term space habitation. Membrane aerated biological reactors (MABRs) have proven to be an efficient and sustainable pretreatment process for extra terrestrial wastewater recycling applications in closed loop life support systems. The CoMANDR (Counter-diffusion Membrane Aerated Nitrifying Denitrifying Reactor) system can be used to treat unstabilized wastewater composed of urine, hygiene water, humidity condensate, and laundry water. The operation and assessment of the CoMANDR is in support of the integrated systems test to be implemented by Johnson Space Center pairing a biological reactor with a forward/reverse osmosis unit to treat the aforementioned waste stream. After a two month start up period we have systematically evaluated the CoMANDR performance for a variety of loading rates and verified the operation of the system under pressurized conditions. Results support the ability of the system to effectively reduce organic carbon by over 90% and convert up to 70% of the total influent N to non-organic forms (e.g. NOx or N2). Operation has been demonstrated using both air and pure O2, although in each case further control refinements are required to help maximize the denitrification potential of the reactor. We have also demonstrated that for at least up to 3 weeks, CoMANDR can be put into recycle and brought back on line with no start up required supporting the ability to intermittently operate the system.

Performance of a TRL 5 Bioreactor for Pretreatment of an Extended Habitation Wastestream

Water is one of the most critical and costly life support elements, even under the most stringent water use approaches. Technologies that can increase the sustainability of water processing by reducing expendables and helping to close the water loop can have large impacts on mission costs. Current technologies for water processing are intensive users of resources, including power for processes such as distillation, and consumables for preand post-treatment. In particular, urine pre-processing requires the continuous consumption of hazardous and corrosive chemicals. Further, current recovery rates are limited partly by the chemical pre-processing, and the brine produced from this pre-treated chemical is challenging to process. Biological pre-treatment may offer substantial efficiencies over traditional technologies, and offer secondary benefits with only minor costs. For the past 9 months, we have operated a TRL 5 membrane aerated bioreactor processing an extended habitation waste stream (urine/hygiene/humidity condensate). The reactor has successfully processed the wastewater at loading rates of 20 L/d and 30 L/d and is currently being challenged at 40 L/d. The reactor has exceeded 70% NH4 + conversion, 86% DOC conversion, 55% TN reduction, and maintained a pH < 7. Conversion rates for NH4 + and DOC are approaching 1 g/m 2 -d. Finally, preliminary gas phase measurements reveal that the total O2 consumption is ~100 g/d, while CO2 production was ~ 4g/d and N2 production was estimated at 20 g/d (~13 L/d).

Providing an engineering design model for secondary teachers

The Texas Tech University (Texas-Science, Technology, Engineering and Math) T-STEM Center develops and offers professional development workshops for K-12 teachers in the engineering design process. Although, for many years we have offered workshops in varied areas such as LEGO Robotics, rocketry, GLOBE, FOSS and PASCO, our aim is to provide teachers exciting and innovative ways to teach science, math and technology so teachers and students might see a direct correlation between the subject and engineering disciplines. By developing an engineering design model that is accessible to secondary teachers who have little or no background in engineering, teachers see how engineering crosses disciplines and can be addressed in any discipline. The Texas Tech Engineering Design Model uses project- based and problem-based learning as the underpinnings for introducing teachers to the design process in an approachable model that becomes more elegant in application as the model is used to solve problems.

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.