Modeling approaches to predict removal of trace organic compounds by ozone oxidation in potable reuse applications

10.1039/c5ew00120jEnvironmental Science: Water Research and Technology15699-70

Effectiveness of a Structured Teaching Program on the Knowledge of Emotional Resilience among Nursing Undergraduates of a Selected Nursing College of Hyderabad

Background: Emotional resilience refers to one's ability to adapt to stressful situations or crises. More resilient people are able to “roll with the punches” and adapt to adversity without lasting difficulties; less resilient people have a harder time with stress and life changes, both major and minor. Objectives: The objectives of the study were to assess the effect of structured training program on knowledge of emotional resilience and to seek association between knowledge scores and selected demographic variables. Material and Methods: The research approach selected for the present study was a quantitative approach. A preexperimental research design was adapted with one-group pretest–posttest design. The study was conducted in a selected nursing college of Hyderabad. The sample size was 32. The sample chosen for the study was B.Sc. Nursing 1st-year students. Convenient sampling technique was used. A questionnaire with multiple-choice questions was prepared. Results: Majority of the students that is 16 (50%) who participated in the study were aged 18 years. Most of them belonged to nuclear family that is 25(78%). The pretest mean scores were 12.4 and the posttest mean scores were 16.5. Paired “t” test value was 18.6 and table value is 2.05 at 0.05 and the df is 31 which indicated that structured teaching was effective in improving knowledge of the students. There was no association between knowledge and selected demographic variables, such as age, religion, and type of family. Conclusion: It is during this novice period that they experience a lot of emotional upheavals and find it difficult to cope with trivial matters. The knowledge about emotional resilience will help them to face the challenges of life with optimism, and it would help them to use their problem-solving skills and to solve complex problems in life

Point-of-use devices for attenuation of trace organic compounds in water

Trace organic compounds (TOrCs) continue to be detected in drinking water, and their recalcitrance makes them difficult to attenuate without installing expensive advanced treatment processes. Because human consumption is a small portion of net household water use, point-of-use (POU) devices may provide additional security against drinking water contaminants. This research evaluated three pitcher and two refrigerator POU devices using two waters. Refrigerator POU devices removed more TOrCs over the manufacturer's expected lifetime in terms of total mass than the pitcher POU devices. Average removal through all filters for nonionic, hydrophobic compounds was higher than for hydrophilic compounds in both waters. Removal of ionic compounds was enhanced by cation/anion exchange resins present in pitcher POU devices. Results indicated that POU devices are capable of removing significant amounts of organic contaminants in water. However, removal of a specific compound depends on its molecular properties, treatment technology implemented, and water quality and lifetime of the cartridge

Investigating landfill leachate as a source of trace organic pollutants

Landfill leachate samples (n = 11) were collected from five USA municipal solid waste (MSW) landfills and analyzed for ten trace organic pollutants that are commonly detected in surface and municipal wastewater effluents (viz., carbamazepine, DEET, fluoxetine, gemfibrozil, PFOA, PFOS, primidone, sucralose, sulfamethoxazole and trimethoprim). Carbamazepine, DEET, PFOA and primidone were detected in all leachate samples analyzed and gemfibrozil was detected in samples from four of the five-landfill sites. The contaminants found in the highest concentrations were DEET (6900-143 000 ng L−1) and sucralose (<10-621 000 ng L−1). Several compounds were not detected (fluoxetine) or detected infrequently (sulfamethoxazole, trimethoprim and PFOS). Using the average mass of DEET in leachate amongst the five landfills and scaling the mass release from the five test landfills to the USA population of landfills, an order of magnitude estimate is that over 10 000 kg DEET yr−1 may be released in leachate. Some pharmaceuticals have similar annual mean discharges to one another, with the estimated annual discharge of carbamazepine, gemfibrozil, primidone equating to 53, 151 and 128 kg year−1. To the authors knowledge, this is the first time that primidone has been included in a landfill leachate study. While the estimates developed in this study are order of magnitude, the values do suggest the need for further research to better quantify the amount of chemicals sent to wastewater treatment facilities with landfill leachate, potential impacts on treatment processes and the significance of landfill leachate as a source of surface water contamination

A simple and rapid direct injection method for the determination of glyphosate and AMPA in environmental water samples

Glyphosate is currently the most widely used herbicide in the world, yet screening of environmental waters for this chemical is limited by the need for specialized derivatization and measurement methods that can be tedious and time-consuming. In this work, we present a novel method for the detection and quantification at trace levels of glyphosate and aminomethylphosphonic acid (AMPA) in environmental water samples. The detection and quantification of the analytes was performed by liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS). Chromatographic separation was achieved with an ion-exchange column and a pH-gradient elution of a solution of ammonium hydroxide and ammonium acetate. The limit of detection for glyphosate and AMPA was 0.25 μg L-1 and the limit of quantification was 0.5 μg L-1with a 20-μL injection. The method was used to investigate the levels of glyphosate and AMPA in surface water samples from the Yarra River catchment area and urban constructed stormwater wetlands. The results indicate that at the time of sampling, no glyphosate or AMPA was present in the samples from the Yarra River catchment area (n = 10). However, glyphosate was detected above the limit of quantification in 33% of the wetland samples (n = 12), with concentrations ranging from 1.95 to 2.96 μg L-1. Similarly, AMPA was quantified in 83% of the wetland samples, with concentrations ranging from 0.55 to 2.42 μg L-1. To our knowledge, this is the first report of a pH-gradient LCMS/MS method for glyphosate and AMPA analysis at ultratrace levels, with minimal sample processing, avoiding costly, time-consuming derivatization and preconcentration steps

A single analytical method for the determination of 53 legacy and emerging per- and polyfluoroalkyl substances (PFAS) in aqueous matrices

A quantitative method for the determination of per- and polyfluoroalkyl substances (PFAS) using liquid chromatography (LC) tandem mass spectrometry (MS/MS) was developed and applied to aqueous wastewater, surface water, and drinking water samples. Fifty-three PFAS from 14 compound classes (including many contaminants of emerging concern) were measured using a single analytical method. After solid-phase extraction using weak anion exchange cartridges, method detection limits in water ranged from 0.28 to 18ng/L and method quantitation limits ranged from 0.35 to 26ng/L. Method accuracy ranged from 70 to 127% for 49 of the 53 extracted PFAS, with the remaining four between 66 and 138%. Method precision ranged from 2 to 28% RSD, with 49 out of the 53 PFAS being below <20%. In addition to quantifying >50 PFAS, many of which are currently unregulated in the environment and not included in typical analytical lists, this method has efficiency advantages over other similar methods as it utilizes a single chromatographic separation with a shorter runtime (14min), while maintaining method accuracy and stability and the separation of branched and linear PFAS isomers. The method was applied to wastewater influent and effluent; surface water from a river, wetland, and lake; and drinking water samples to survey PFAS contamination in Australian aqueous matrices. The compound classes FTCAs, FOSAAs, PFPAs, and diPAPs were detected for the first time in Australian WWTPs and the method was used to quantify PFAS concentrations from 0.60 to 193ng/L. The range of compound classes detected and different PFAS signatures between sample locations demonstrate the need for expanded quantitation lists when investigating PFAS, especially newer classes in aqueous environmental samples

Comparison of high-resolution mass spectrometry acquisition methods for the simultaneous quantification and identification of per- and polyfluoroalkyl substances (PFAS)

Simultaneous identification and quantification of per- and polyfluoroalkyl substances (PFAS) were evaluated for three quadrupole time-of-flight mass spectrometry (QTOF) acquisition methods. The acquisition methods investigated were MS-Only, all ion fragmentation (All-Ions), and automated tandem mass spectrometry (Auto-MS/MS). Target analytes were the 25 PFAS of US EPA Method 533 and the acquisition methods were evaluated by analyte response, limit of quantification (LOQ), accuracy, precision, and target-suspect screening identification limit (IL). PFAS LOQs were consistent across acquisition methods, with individual PFAS LOQs within an order of magnitude. The mean and range for MS-Only, All-Ions, and Auto-MS/MS are 1.3 (0.34-5.1), 2.1 (0.49-5.1), and 1.5 (0.20-5.1) pg on column. For fast data processing and tentative identification with lower confidence, MS-Only is recommended; however, this can lead to false-positives. Where high-confidence identification, structural characterisation, and quantification are desired, Auto-MS/MS is recommended; however, cycle time should be considered where many compounds are anticipated to be present. For comprehensive screening workflows and sample archiving, All-Ions is recommended, facilitating both quantification and retrospective analysis. This study validated HRMS acquisition approaches for quantification (based upon precursor data) and exploration of identification workflows for a range of PFAS compounds

Predicting trace organic compound breakthrough in granular activated carbon using fluorescence and UV absorbance as surrogates

10.1016/j.watres.2015.02.019Water Research7676-8