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Serum biomarkers of polyfluoroalkyl compound exposure in young girls in Greater Cincinnati and the San Francisco Bay Area, USA
2014
Pinney, Susan M. | Biro, Frank M. | Windham, Gayle C. | Herrick, Robert L. | Yaghjyan, Lusine | Calafat, Antonia M. | Succop, Paul | Sucharew, Heidi | Ball, Kathleen M. | Kato, Kayoko | Kushi, Lawrence H. | Bornschein, Robert
PFC serum concentrations were measured in 6–8 year-old girls in Greater Cincinnati (GC) (N = 353) and the San Francisco Bay Area (SFBA) (N = 351). PFOA median concentration was lower in the SFBA than GC (5.8 vs. 7.3 ng/mL). In GC, 48/51 girls living in one area had PFOA concentrations above the NHANES 95th percentile for children 12–19 years (8.4 ng/mL), median 22.0 ng/mL. The duration of being breast fed was associated with higher serum PFOA at both sites and with higher PFOS, PFHxS and Me-PFOSA-AcOH concentrations in GC. Correlations of the PFC analytes with each other suggest that a source upriver from GC may have contributed to exposures through drinking water, and water treatment with granular activated carbon filtration resulted in less exposure for SWO girls compared to those in NKY. PFOA has been characterized as a drinking water contaminant, and water treatment systems effective in removing PFCs will reduce body burdens.
显示更多 [+] 显示较少 [-]From a millennium base line to 2012: Beach litter changes in Wales
2014
Williams, A.T. | Randerson, P. | Alharbi, O.A.
Forty-five beaches at 41 bathing area locations in Wales were analysed for litter in 2000 and 2012, via a standard seven category checklist. Fourteen resorts, 2 urban, 11 village, 15 rural 3 remote, were graded, A to D. A grade beach numbers changed from 5 to19; B, 27 to 24; C, 9 to 2; D, 4 to 0, many beaches maintaining their current status. Assuming trend continuance within the next 12years, the A:B grade ratio would approach equilibrium of 44:56, with no grade C or D beaches. Recreational litter was ubiquitous; fishing materials prevalent along Cardigan Bay. New water treatment plant investment reduced sewage related debris. Despite apparent increased awareness of beach litter, improving visitor behaviour through information/education should be a future priority. Removing a few gross items could improve beach grades at little cost to local authorities and benefits to the Welsh economy.
显示更多 [+] 显示较少 [-]Removal of Plant Pathogen Propagules from Irrigation Runoff using Slow Filtration Systems: Quantifying Physical and Biological Components
2014
Nyberg, Elizabeth T. | White, Sarah A. | Jeffers, Steven N. | Bridges, William C.
Recycling irrigation water is a common practice at ornamental plant nurseries for conserving water; however, it poses the risk of sourcing and dispersing waterborne plant pathogens, especially species of Phytophthora. Slow sand filtration is a water treatment process that can remove pathogens from water, but the slow rate of water treatment may limit its application at nursery operations. In this study, four novel substrates (crushed brick, calcined clay, polyethylene beads, and Kaldnes® medium) in addition to sand were examined to determine how effective each substrate was at removing zoospores of Phytophthora nicotianae from water. The effects of substrate physical parameters, substrate depths (0, 5, 10, 20, 40, and 60 cm), and microbe density (after nursery effluent was recirculated through each substrate for 21 days) on zoospore removal by each substrate were quantified. Sand was the most effective physical filter and supported development of the best biological filter for removing zoospores. Sand columns 40 and 60 cm deep removed zoospores completely using physical filtration alone, and zoospore removal by sand at 10- and 20-cm depths was increased with the addition of biological filtration. Kaldnes® medium and polyethylene beads were the least effective filtration substrates under all conditions tested. After 21 days of recirculating nursery effluent through substrate columns, microbe density in and zoospore removal by all substrates increased. With further optimization, crushed brick may have potential to be utilized as a recycled material for a slow filtration system focused on removing plant pathogens from irrigation water.
显示更多 [+] 显示较少 [-]Influence of Biofilm on Activated Carbon on the Adsorption and Biodegradation of Salicylic Acid in Wastewater
2014
Combarros, R. G. | Rosas, I. | Lavín, A. G. | Rendueles, M. | Díaz, M.
This paper presents a study of the combined process of adsorption and biodegradation in solid biologically activated carbon (AC) for the removal of salicylic acid aimed at determining the influence of the presence of biofilm on the process. Adsorption on AC and biodegradation of free cell cultures were studied separately so as to compare their performance with that of the combined biosorption system. The formation of bacterial biofilm on the surface of the carbon was investigated. The study was carried out using a range of synthetic solutions containing between 15 and 500 mg/L salicylic acid simulating an industrial effluent from the pharmaceutical industry. An individual bacterium, Pseudomonas putida (DSM 4478), was used to study the differentiated effects. Filtrasorb 400 and GAC 830 ACs were used in the adsorption processes and Filtrasorb 400 in the biofilm formation and combined biosorption processes. As regards, combined adsorption/biodegradation results indicated that the bioactivated carbon system outperformed the combination of conventional AC and biological water treatment processes when working with high pollutant concentrations.
显示更多 [+] 显示较少 [-]Degradation of the potential rodent contraceptive quinestrol and elimination of its estrogenic activity in soil and water
2014
Zhang, Quan | Wang, Cui | Liu, Wanpeng | Qu, Jiapeng | Liu, Ming | Zhang, Yanming | Zhao, Meirong
Quinestrol has shown potential for use in the fertility control of the plateau pika population of the Qinghai–Tibet Plateau. However, the environmental safety and fate of this compound are still obscure. Our study investigated degradation of quinestrol in a local soil and aquatic system for the first time. The results indicate that the degradation of quinestrol follows first-order kinetics in both soil and water, with a dissipation half-life of approximately 16.0 days in local soil. Microbial activity heavily influenced the degradation of quinestrol, with 41.2 % removal in non-sterile soil comparing to 4.8 % removal in sterile soil after incubation of 10 days. The half-lives in neutral water (pH 7.4) were 0.75 h when exposed to UV light (λ = 365 nm) whereas they became 2.63 h when exposed to visible light (λ > 400 nm). Acidic conditions facilitated quinestrol degradation in water with shorter half-lives of 1.04 and 1.47 h in pH 4.0 and pH 5.0 solutions, respectively. Moreover, both the soil and water treatment systems efficiently eliminated the estrogenic activity of quinestrol. Results presented herein clarify the complete degradation of quinestrol in a relatively short time. The ecological and environmental safety of this compound needs further investigation.
显示更多 [+] 显示较少 [-]Enhancing soluble phosphorus removal within buffer strips using industrial by-products
2014
Habibiandehkordi, Reza | Quinton, John N. | Surridge, Ben W. J.
Using industrial by-products (IBPs) in conjunction with buffer strips provides a potentially new strategy for enhancing soluble phosphorus (P) removal from agricultural runoff. Here, we investigate the feasibility of this approach by assessing the P sorption properties of IBPs at different solution-IBPs contact time (1–120 min) and solution pH (3, 5.5, 7.5), as well as possible adverse environmental effects including P desorption or heavy metal mobilisation from IBPs. Batch experiments were carried out on two widely available IBPs in the UK that demonstrated high P sorption capacity but different physicochemical characteristics, specifically ochre and Aluminium (Al) based water treatment residuals (Al-WTR). A series of kinetic sorption–desorption experiments alongside kinetic modelling were used to understand the rate and the mechanisms of P removal across a range of reaction times. The results of the kinetic experiments indicated that P was initially sorbed rapidly to both ochre and Al-WTR, followed by a second phase characterised by a slower sorption rate. The excellent fits of kinetic sorption data to a pseudo-second order model for both materials suggested surface chemisorption as the rate-controlling mechanism. Neither ochre nor Al-WTR released substantial quantities of either P or heavy metals into solution, suggesting that they could be applied to buffer strip soils at recommended rates (≤30 g kg⁻¹ soil) without adverse environmental impact. Although the rate of P sorption by freshly-generated Al-WTR applied to buffer strips reduced following air-drying, this would not limit its practical application to buffer strips in the field if adequate contact time with runoff was provided.
显示更多 [+] 显示较少 [-]Comparison of metals extractability from Al/Fe-based drinking water treatment residuals
2014
Wang, Changhui | Bai, Leilei | Pei, Yuansheng | Wendling, Laura A.
Recycling of drinking water treatment residuals (WTRs) as environment amendments has attracted substantial interest due to their productive reuse concomitant with waste minimization. In the present study, the extractability of metals within six Al/Fe-hydroxide-comprised WTRs collected throughout China was investigated using fractionation, in vitro digestion and the toxicity characteristic leaching procedure (TCLP). The results suggested that the major components and structure of the WTRs investigated were similar. The WTRs were enriched in Al, Fe, Ca, and Mg, also contained varying quantities of As, Ba, Be, Cd, Co, Cr, Cu, K, Mn, Mo, Na, Ni, Pb, Sr, V, and Zn, but Ag, Hg, Sb, and Se were not detected. Most of the metals within the WTRs were largely non-extractable using the European Community Bureau of Reference (BCR) procedure, but many metals exhibited high bioaccessibility based on in vitro digestion. However, the WTRs could be classified as non-hazardous according to the TCLP assessment method used by the US Environmental Protection Agency (USEPA). Further analysis showed the communication factor, which is calculated as the ratio of total extractable metal by BCR procedure to the total metal, for most metals in the six WTRs, was similar, whereas the factor for Ba, Mn, Sr, and Zn varied substantially. Moreover, metals in the WTRs investigated had different risk assessment code. In summary, recycling of WTRs is subject to regulation based on assessment of risk due to metals prior to practical application.
显示更多 [+] 显示较少 [-]Risk assessment of heavy metals and their source distribution in waters of a contaminated industrial site
2014
Krishna, A Keshav | Mohan, K Rama
Industrially contaminated sites with hazardous materials are a priority and urgent problem all over the world. Appropriate risk assessment is required to determine health risks associated with contaminated sites. The present study was conducted to investigate distribution of potentially hazardous, heavy metal (As, Cd, Cr, Cu, Ni, Pb and Zn) concentrations in surface and groundwater samples collected during summer (pre-monsoon) and winter (post-monsoon) seasons from an industrially contaminated site, Hyderabad, India, with potential source of metal contamination because of industrial effluents and usage of pesticides in agriculture. Heavy metal (HM) concentrations were analysed by using inductively coupled plasma-mass spectrometer and were compared with permissible limits set by the World Health Organisation. Data obtained was treated using multivariate statistical approaches like R-mode factor analysis (FA), principal component analysis, cluster analysis, geoaccumulation index, enrichment factor, contamination factor and the degree of contamination. Health risk assessment like chronic daily intake (CDI) and hazard quotient (HQ) were also calculated. Relatively high levels were noted in surface water with average concentrations during summer and winter seasons showing 16.13 and 11.83 for As, 7.91 and 1.64 for Cd, 88.33 and 32.90 for Cr, 58.11 and 28.26 for Cu, 53.62 and 69.96 for Ni, 173.8 and 118.6 for Pb, and 2,943 and 1,889 μg/L for Zn. While in groundwater, the mean metal levels during two seasons were 18.18 and 3.76 for As, 1.67 and 0.40 for Cd, 29.40 and 5.15 for Cr, 17.03 and 4.19 for Cu, 25.4 and 6.09 for Ni, 81.7 and 2.87 for Pb and 953 and 989 μg/L for Zn, respectively. FA identified two factors with cumulative loadings of F1—60.82 % and F2—76.55 % for pre-monsoon surface water and F1—48.75 % and F2—67.55 % for groundwater. Whereas, three factors with cumulative loadings of F1—39.13 %, F2—66.60 % and F3—81.01 % for post-monsoon surface water and F1—50.31 %, F2—66.18 % and F3—81.54 % for groundwater. The health risk assessment like CDI and HQ indices with increased levels of hazardous elements in the surface and groundwater were safe for drinking purposes provided some water treatment methodologies are adopted.
显示更多 [+] 显示较少 [-]The relevance of physicochemical and biological parameters for setting emission limit values for plants treating complex industrial wastewaters
2014
Huybrechts, Diane | Weltens, Reinhilde | Jacobs, Griet | Borburgh, Ab | Smets, Toon | Hoebeke, Lut | Polders, Caroline
The influents of plants treating complex industrial wastewaters from third parties may contain a large variety of often unknown or unidentified potentially harmful substances. The conventional approach of assessing and regulating the effluents of these plants is to set emission limit values for a limited set of physicochemical parameters, such as heavy metals, biological oxygen demand, chemical oxygen demand and adsorbable organic halogen compounds. The objective of this study was to evaluate the relevance of physicochemical parameters for setting emission limit values for such plants based on a comparison of effluent analyses by physicochemical and biological assessment tools. The results show that physicochemical parameters alone are not sufficient to evaluate the effectiveness of the water treatment plants for removing hazardous compounds and to protect the environment. The introduction of toxicity limits and limits for the total bioaccumulation potential should be considered to supplement generic parameters such as chemical oxygen demand and adsorbable organic halogens. A recommendation is made to include toxicity screening as a technique to consider in the determination of best available techniques (BAT) during the upcoming revision of the BAT reference document for the waste treatment industries to provide a more rational basis in decisions on additional treatment steps.
显示更多 [+] 显示较少 [-]Formation potentials of bromate and brominated disinfection by-products in bromide-containing water by ozonation
2014
Lin, Tao | Wu, Shouke | Chen, Wei
The ozonation involved in drinking water treatment raises issues of water quality security when the raw water contains bromide (Br⁻). Br⁻ions may be converted to bromate (BrO₃⁻) during ozonation and some brominated disinfection by-products (Br-DBPs) in the following chlorination. In this study, the effects of ozone (O₃) dosage, contact time, pH, and Br⁻and ammonia (NH₃-N) concentrations on the formation of BrO₃⁻and Br-DBPs have been investigated. The results show that decreasing the initial Br⁻concentration is an effective means of controlling the formation of BrO₃⁻. When the concentration of Br⁻was lower than 100 μg/L, by keeping the ratio of O₃dosage to dissolved organic carbon (DOC) concentration at less than 1, BrO₃⁻production was effectively suppressed. The concentration of BrO₃⁻steadily increased with increasing O₃dosage at high Br⁻concentration (>900 μg/L). Additionally, a longer ozonation time increased the concentrations of BrO₃⁻and total organic bromine (TOBr), while it had less impact on the formation potentials of brominated trihalomethanes (Br-THMFP) and haloacetic acids (Br-HAAFP). Higher pH value and the presence of ammonia may lead to an increase in the formation potential of BrO₃⁻and Br-DBPs.
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