细化搜索
结果 1821-1830 的 4,935
Physical-chemical characterization of microplastics present in some exfoliating products from Spain 全文
2019
Godoy, V. | Martín-Lara, M.A. | Calero, M. | Blázquez, G.
Plastic pollution in oceans is a global problem, with growing research efforts focusing on the threat of microplastics (<5 mm fractions). A source of microplastics pollution is derived from personal care products that contain polyethylene micro-spheres which are not captured by wastewater plants. In this work, ten personal care products (mainly scrubs) containing microplastics and marketed in Spain, were physico-chemically characterized. The obtained results proved that those microplastics had different particle size and are presented in high percentages in some cases, between 6 and 7% of the total product. Products with smaller particles usually showed higher concentrations than products with larger particles. Although all the microplastics were shown to be polyethylene, some impurities were observed that demonstrated the presence of silicates and oxides in the microplastics. Regards to morphology, the shape of the particles was irregular in general, although some completely spherical particles can be observed.
显示更多 [+] 显示较少 [-]Evaluation of water quality and heavy metal concentrations in the RAMSAR Wetland El Yali (Central Chile, 33°45′S) 全文
2019
Rivera, Cecilia | Quiroga, Eduardo | Meza, Verónica | Pastene, Marion
The EYNR is the most important wetland in central Chile because it is protected as a RAMSAR site. It includes coastal lagoons, estuaries and saltmarshes, sustaining an important biodiversity. The chemical complexity was described using water and soil samples, which are characterized by high levels of alkalinity and soil cations. In addition, high concentrations of Cu (0.01–0.080 mg L⁻¹) and Pb (0.120–0.566 mg L⁻¹) in water were measured. Using a simplified index of water quality for oxygen demand, the ecological status of the wetland was classified as bad quality due to the existing use of land. Multivariable analyses and heavy metal index classified this wetland as having low to intermediate deterioration due to the combination of heavy metals. If this trend is allowed to continue unabated, the food web complexes in this wetland are likely to be at the highest risk of induced heavy metal contamination.
显示更多 [+] 显示较少 [-]Footprints in the sand – Assessing the seasonal trends of volatile methylsiloxanes and UV-filters 全文
2019
Capela, Daniela | Vila, Marlene | Llompart, Maria | Dagnac, Thierry | Garcia-Jares, Carmen | Alves, Arminda | Homem, Vera
This study focused on the determination of seven volatile methylsiloxanes (VMSs) and eleven UV-filters (UVFs) in beach sand from the Oporto's region (Portugal). A QuEChERS methodology (“Quick, Easy, Cheap, Effective, Rugged, and Safe”) was used to extract VMSs from the sand, which has never been employed before. To extract the UVFs, a solid-phase microextraction (SPME) was used. The analyses were performed by gas chromatography–mass spectrometry (GC–MS). Twenty-three beach sand samples were analysed, from two campaigns – summer/winter. VMSs were found in all the samples with concentrations ranging from 0.007 ± 0.001 to 17.8 ± 0.9 ng g−1dw, while UVFs in summer samples from 0.030 ± 0.001 to 373 ± 17 ng g−1dw. Cyclic VMSs and octocrylene (OC) were detected in higher concentrations. In general, higher levels were detected in summer than winter. Hazard quotients were determined and 3-(4′-methylbenzylidene) camphor (4-MBC), 2-ethylhexyl 4-methoxycinnamate (EMC) and benzophenone-3 (BP3) presented values >1, which may indicate that they may pose an ecotoxicological risk.
显示更多 [+] 显示较少 [-]Baseline assessment of contaminants in marine biota prior to remediation of industrial effluent impacted sediments in a former tidal estuary in Nova Scotia, Canada 全文
2019
Romo, Jessica | Chaudhary, Meenakshi | Walker, Tony R.
Contaminated sediments at a pulp mill and former chor-alkali effluent treatment facility in Nova Scotia, Canada will undergo remediation. However, baseline studies assessing contaminants in marine biota in the marine receiving environment are lacking. Historical qualitative and quantitative contaminant data in biota from Boat Harbour (a former tidal lagoon which was used to treat industrial effluent since 1967), and surrounding marine environment were reviewed to establish baseline pollution from industrial effluent and contaminated sediments. Elevated metal, dioxins and furan concentrations previously measured in marine biota needs updating to help inform pre-remediation monitoring. Selection of species, contaminants of concern and sampling locations were ad hoc and often inconsistent with environmental effects monitoring requirements under Canadian federal Pulp and Paper Effluent Regulations. These consolidated baseline data are required to determine historical impacts and to assist future monitoring during Boat Harbour sediment remediation to compare against.
显示更多 [+] 显示较少 [-]Comparison of persistent organic pollutants (POPs) between small cetaceans in coastal and estuarine waters of the northern Gulf of Mexico 全文
2019
Balmer, Brian | Ylitalo, Gina | Watwood, Stephanie | Quigley, Brian | Bolton, Jennie | Mullin, Keith | Rosel, Patricia | Rowles, Teri | Speakman, Todd | Wilcox, Lynsey | Zolman, Eric | Schwacke, Lorelei H.
Small cetaceans continue to be exposed to elevated levels of persistent organic pollutants (POPs). The goals of this study were to use data from remote biopsy sampling and photographic-identification to compare POP concentrations between small cetacean stocks in the northern Gulf of Mexico. During 2015–2017, 74 remote biopsies were collected in St. Andrew Bay and adjacent coastal waters from two species: common bottlenose dolphin (Tursiops truncatus) (N = 28, ♀; N = 42, ♂) and Atlantic spotted dolphin (Stenella frontalis) (N = 2, ♀; N = 2, ♂). Common bottlenose dolphin POP concentrations were significantly higher in St. Andrew Bay than coastal waters. Male St. Andrew Bay dolphins had the highest Σ DDT (dichlorodiphenyl-dichloroethane) levels measured in the southeastern U.S. (67 μg/g, 50–89 μg/g; geometric mean and 95% CI) and showed a significant negative relationship between Σ DDT and sighting distance from a St. Andrew Bay point source.
显示更多 [+] 显示较少 [-]Decision analysis to support wastewater management in coral reef priority area 全文
2019
Barnes, Megan D. | Goodell, Whitney | Whittier, Robert | Falinski, Kim A. | Callender, Tova | Htun, Hla | LeViol, Cecilia | Slay, Hudson | Oleson, Kirsten L.L.
A cocktail of land-based sources of pollution threatens coral reef ecosystems, and addressing these has become a key management and policy challenge in the State of Hawaiʻi, other US territories, and globally. In West Maui, Hawaiʻi, nearly one quarter of all living corals were lost between 1995 and 2008. Onsite disposal systems (OSDS) for sewage leak contaminants into drinking water sources and nearshore waters. In recognition of this risk, the Hawaiʻi State Department of Health (DOH) is prioritizing areas for cesspool upgrades. Independently, we applied a decision analysis process to identify priority areas to address sewage pollution from OSDS in West Maui, with the objective of reducing nearshore coral reef exposure to pollution. The decision science approach is relevant to a broader context of coastal areas both statewide and worldwide which are struggling with identifying pollution mitigation actions on limited budgets.
显示更多 [+] 显示较少 [-]Effects of Surface Active Additives on the Enzymatic Treatment of Phenol and Its Derivatives: a Mini Review 全文
2019
Alshabib, Muntathir | Onaizi, Sagheer A.
PURPOSE OF REVIEW: Phenolic wastewaters represent a serious health and environmental problem. The remediation of phenolic wastewaters using oxidoreductase enzymes has emerged as an attractive environmentally friendly treatment method. However, the loss of enzyme activity during the treatment remains a key limitation. Thus, the aim of this article is to review and assess the recent progress in utilizing surface active additives (i.e., polymers, biopolymers, surfactants, and biosurfactants) for the reduction of enzyme inhibition and, thus, the enhancement of enzymatic remediation of phenolic wastewaters. RECENT FINDINGS: The reported effect of polymeric and surfactant additives on the enzymatic remediation of phenolic pollutants is mixed. Some studies reported significant enhancements while others demonstrated minimal or no gains. More seriously, it has been reported that these fossil-based additives might lead to a higher toxicity of the treated wastewaters. Bio-based (biopolymers and biosurfactants) additives might address this toxicity issue; however, the bio-based additives are not always as effective as the fossil-based ones. Despite the beneficial effect, with some exceptions, of additives, the enhancement level varies widely, probably due to the variations in the reaction environment. Thus, to draw meaningful and reliable conclusions on which additive(s) is more promising, thorough studies under unified conditions are needed. Additionally, generation of secondary pollutions associated with the fossil-based additives urges the replacement of such additives with bio-based ones. However, the effectiveness of the bio-based additives is still not sufficiently documented, stressing the need for more in-depth studies.
显示更多 [+] 显示较少 [-]Tracing underground sources of pollution to coastal waters off Map Ta Phut, Rayong, Thailand 全文
2019
Burnett, William C. | Sola, Phachirarat | Chanyotha, Supitcha | Bidorn, Butsawan | Kritsananuwat, Rawiwan | Chinfak, Narainrit
We explored the possibility that an underground pathway, “submarine groundwater discharge” (SGD), may contribute to the observed coastal contamination from a large industrial complex on the Gulf of Thailand. Three surveys were performed to map the area for the natural groundwater tracers radon, thoron and salinity. The results from all three surveys were internally consistent showing a point source adjacent to a large pier that serves the complex. It may be that a piling, driven into the ground to support the pier, intercepted a shallow aquifer and this resulted in an underground pathway between land and sea. Some low-density sediments are enriched in radium, we suspect from fly ash from a nearby power plant. Water quality parameters showed that total petroleum hydrocarbons (TPHs) correlated strongly to nitrite, dissolved inorganic phosphate and silica, indicating a common source. Data analysis shows that diffuse seepage accounts for more discharge than the point source.
显示更多 [+] 显示较少 [-]Impact of emission control areas on atmospheric pollutant emissions from major ocean-going ships entering the Shanghai Port, China 全文
2019
Wan, Zheng | Zhang, Qiang | Xu, Zhipeng | Chen, Jihong | Wang, Qin
Ocean-going ships are mostly driven by high‑sulfur heavy fuel oil, which poses public health and environmental concerns. Emission control areas (ECA) have been developed for the regulatory control of the sulfur content in fuel. We tracked 28 sample vessels that entered and exited Shanghai Port, to understand how air pollutants, including oxysulfides (SOx), nitric oxide (NOx), and particulate matter smaller than 10 μm (PM₁₀), would change under the ECA regulations. Emission reductions vary with the types and sizes of the ships. In our sample pool, oil/chemical tankers and container ships have the highest decline rates of SOx emissions at 26.8%–56.4% and 17.4%–56.6%, respectively. Cruise ships, container ships, and liquefied gas carriers occupy the highest share ratios of pollutant emissions in the sample pool because of the higher average gross tonnage and correspondingly higher-rated power of the ships' main engines. As expected, SOx and PM₁₀ emissions under hoteling conditions (operations while stationary at dock) can be considerably reduced by switching to low-sulfur fuel. Using fuel with the much lower sulfur content of 0.1% m/m in the ECA, the SOx and PM₁₀ emissions of our sample pool could be reduced considerably by up to 94.4% and 78.3%, respectively, compared to the 0.5% m/m sulfur content used during ship hoteling.
显示更多 [+] 显示较少 [-]Aliphatic and polycyclic aromatic hydrocarbons in surface seawater of the GULF of Trieste (northern ADRIATIC) 全文
2019
Penko, Ludvik | Bajt, Oliver
Concentrations, spatial distribution and sources of aliphatic hydrocarbons (AH) and polycyclic aromatic hydrocarbons (PAH) were determined in surface seawater of the Gulf of Trieste, northern Adriatic. This area is one of the most industrialized and urbanized areas in the northern Adriatic with intense maritime traffic. The surface seawater samples were collected at 31 sites and total hydrocarbon concentrations were determined. In general, concentrations (0.1 to 43.2 μg l⁻¹, mean 4.8 μg l⁻¹, Chrysene equivalents) were higher in summer. Concentrations of total aliphatic hydrocarbons were from 17.2 to 2326.5 μg l⁻¹ (mean 543.3 μg l⁻¹). The major component was the unresolved complex mixture (UCM), comprising from 78% to 97% of the total aliphatic hydrocarbons. Total PAH concentrations varied from 89 ng l⁻¹ to 294 ng l⁻¹ (mean 179 ng l⁻¹). The most contaminated sites were the marina of San Giusto and the municipal harbor of Piran.Different evaluation indeces were applied to determine the origin of hydrocarbons. The prevailing origin of aliphatic hydrocarbons is petrogenic, with the significant contribution of the biogenic at some sites. The results presented indicate the fresh inputs of hydrocarbons, which are subject to intense degradation processes. The PAH group profile showed the predominance of 2–3 ring PAHs. PAHs were of mixed origin with more pronounced petrogenic origin, presumably due to oil spills from ships and boats. The presence of a relatively high content of perylene in seawater is an indication of its terrestrial input.According to the presented results and compared to results from different areas worldwide, the seawater in the Gulf of Trieste can still be considered slightly to moderately polluted with PAHs.
显示更多 [+] 显示较少 [-]