Transport of chemical and microbial compounds from known wastewater discharges: potential for use as indicators of human fecal contamination.
ABSTRACT The quality of drinking and recreational water is currently (2005) determined using indicator bacteria. However, the culture tests used to analyze forthese bacteria require a long time to complete and do not discriminate between human and animal fecal material sources. One complementary approach is to use chemicals found in human wastewater, which would have the advantages of (1) potentially shorter analysis times than the bacterial culture tests and (2) being selected for human-source specificity. At 10 locations, water samples were collected upstream and at two successive points downstream from a wastewaster treatment plant (WWTP); a treated effluent sample was also collected at each WWTP. This sampling plan was used to determine the persistence of a chemically diverse suite of emerging contaminants in streams. Samples were also collected at two reference locations assumed to have minimal human impacts. Of the 110 chemical analytes investigated in this project, 78 were detected at least once. The number of compounds in a given sample ranged from 3 at a reference location to 50 in a WWTP effluent sample. The total analyte load at each location varied from 0.018 microg/L at the reference location to 97.7 microg/L in a separate WWTP effluent sample. Although most of the compound concentrations were in the range of 0.01-1.0 microg/L, in some samples, individual concentrations were in the range of 5-38 microg/L. The concentrations of the majority of the chemicals present in the samples generally followed the expected trend: they were either nonexistent or at trace levels in the upstream samples, had their maximum concentrations in the WWTP effluent samples, and then declined in the two downstream samples. This research suggests that selected chemicals are useful as tracers of human wastewater discharge.
Full-textDOI: · Available from: Edward T Furlong, May 30, 2015
Water Science & Technology Water Supply 02/2012; 12(1):11. DOI:10.2166/ws.2011.068
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ABSTRACT: The removal of flurbiprofen (FLU) by electrosynthesized ferrate(VI) ion and electrocoagulation (EC) process was investigated. The degradation of FLU by ferrate(VI) was affected by pH, applied ferrate(VI) dose and initial drug concentration. Complete removal of FLU was achieved at pH 4 and applied ferrate(VI) dose was 1/1 in volume ratio for its initial concentration of 1 mg/L. Removal decreased with increasing pH. Increasing the ferrate(VI) dose increased the efficiency, but there was no significant difference between 3/1 and 1/1 (v/v) ferrate(VI) doses for FLU removal. The effect of current density and pH for the removal of FLU by EC process were investigated. The optimum conditions were current density of 2.5 mA/cm2 and the solution pH of 6.5. Basic condition (pH 9) showed poor removal efficiency by EC process. Equilibrium concentration was reached within 20 min. TOC removal trends were also investigated for both process. While oxidation was the main mechanism for the removal of FLU by ferrate(VI), charge neutralization was the main removal mechanism by EC process.Chemical Engineering Journal 02/2015; 262:1218-1225. DOI:10.1016/j.cej.2014.10.083 · 4.06 Impact Factor
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ABSTRACT: Millions of tourists visit Kenting National Park (KNP) in southern Taiwan every year, causing great amount of sewage discharges in this area. This study aimed to assess the impact of sewage on KNP surface waters using zebrafish embryo-larval bioassays combined with chemical analyses of pharmaceuticals and personal care products (PPCPs). Surface water samples were collected monthly from May to October in 2010. During the monthly bioassays, zebrafish embryos were exposed to the water samples for 144 h. Hatchability, embryonic heart rate, larval survival rate, and deformities were recorded. Larval swimming behavior was also digitally quantified at the end of exposure. Significant decreases in hatchability and larval survival rate were observed at all sites. Both hatchability and larval survival rate were negatively correlated with nitrite and ammonia concentrations in the water. The field water had little effect on embryonic heart rate and morphology. However, lower swimming speeds and activity levels were observed in the larvae, suggesting neurobehavioral toxicity of the surface waters. The general detection frequency of the 28 target PPCPs was 75 %. High levels of some PPCPs, particularly caffeine, N,N-diethyl-3-methylbenzamide (DEET), and nonylphenol, were measured in the water samples. Our results show that surface waters in KNP have been strongly impacted by human activities, resulting in lethal and behavioral toxicities in developing fish.Environmental Monitoring and Assessment 05/2015; 187(5):4511. DOI:10.1007/s10661-015-4511-9 · 1.68 Impact Factor