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Ozone Formation Potential and Toxicity Potential of VOCs emissions from a Nigerian petroleum products depot Texto completo
2020
Ismail Muhibbu-din
Abstract: Emissions of volatile organic compounds (VOCs) are major causes of tropospheric ozone and aerosol pollutions. This research provided information on ozone formation potential (OFP) and toxicity potential (TP) resulting from VOCs emission from a Nigeria petroleum depot. In this work, speciated VOCs were provided on basis of updated emissions within and around the depot. The observed concentration of individual VOCs and maximum incremental reactivity (MIR) coefficient were applied to assess the OFP of individual VOC in the ambient atmosphere. Major aromatic VOCs species were considered at various locations. The total OFP in the atmosphere of the depot is 1522.42 μg O3/m3. Toluene specie was revealed to be major contributor to OFP with 71.47% while others species were in descending order of benzene (9.16%), m-xylene (8.41%), ethyl benzene (3.98%), p-xylene (3.51%) and o-xylene (3.46%). The TP levels of aerosols pollutions were also reported with respect to locations. The Slop tank area had the highest OFP and TP level. An assessment of TP level and OFP suggests that occupants of some location within the depot are exposed to unhealthy air conditions. The study established that OFP and TP have a relationship within the atmosphere of the depot with respect to location. It is recommended that aggressive controlled measures of VOCs sources should be adopted within the petroleum depot as a way of curtailing the impact of tropospheric ozone and aerosol pollutions.
Mostrar más [+] Menos [-]Investigation of Ambient Aromatic Volatile Organic Compounds in Mosimi Petroleum Products Depot, Sagamu, Nigeria Texto completo
2020
Ismail Muhibbu-din
Among chemical industries, petroleum depots have been identified as large emitters of Volatile Organic Compounds (VOCs).They affect air quality and constitute serious health and environmental problems on the ecosystem. Air samples were collected over activated charcoal, using a low volume air sampler. The sampler was placed at a human breathing height of 1.5 m for a sampling period of 8 hours at seven different sampling locations as follows; Workshop area, Slop Tanks area, Gate 1, Tank Farm area, Gate 2, Otiyelu Village and Marketerâs Block. Desorption process was performed on the adsorbed activated charcoal using a solvent extraction method. The extracted solutions were subjected to Flame Ionization Detection analysis in a Gas Chromatograph using a capillary column HP 5MS with length, inner diameter and particle size set at (30 m à 0.25 mm à 0.25 μm). The Gas Chromatograph was powered with ChemStation RevA09.01 software to determine the concentrations of each of the VOCs species present. The sampling collection and quantitative analysis described above is consistent with ANSI/ASTM D-1605-60 procedure. The identified VOCs species emitted were characterized by toluene (52.84%), benzene (37.61%), xylene (5.67%), and ethyl benzene (3.88%). The observed concentrations uncovered the air tolerance limits set by United States Environmental Protection Agency and the Agency for Toxic Substances and Diseases Registry.
Mostrar más [+] Menos [-]Comparison of the application of Heavy metals adsorption methods from aqueous solutions for development of sustainable environment Texto completo
2020
Hamid Gooran Ourimi | Mehdi Nezhadnaderi
Pollution of water by heavy metals is a major problem such as mercury, lead, cadmium, cobalt, etc. The presence of toxic metals in the environment has detrimental effects on human and animal health and disrupts the balance and order of the ecosystem. Therefore, it is necessary to study the ways to eliminate these pollutants. The aim of this study was to compare nickel metal uptake by biological uptake methods with the help of bacterium and brown algae Sargasom, Focus and Grasilaria red algae and nanotechnology method. Based on the previous interpretations, the processes of removal of nickel from industrial wastewater was compared. Research question is that which method is more effective for removal of heavy metals? Results show that biosorption, as an environmentally friendly method, has a brilliant performance and is a low-cost internal method for wastewater treatment. The biological treatment of effluents is carried out by bacteria, some fungi, algae and protozoa to examine the conversion of effluent into a harmless state. Also results show that Iron-based nanostructured particles are capable of decomposing highly stable contaminants such as perchlorate compounds, air nitrate, heavy metals (nickel and mercury) and radioactive materials such as uranium dioxide. Nanostructured particles are used for immediate treatment of sediments, water treatment and liquid waste.
Mostrar más [+] Menos [-]Effects of sediment-associated Cu on Tubifex tubifex – Insights gained by standard ecotoxicological and novel, but simple, bioturbation endpoints Texto completo
2020
Thit, Amalie | Banta, Gary T. | Palmqvist, Annemette | Selck, Henriette
Sediments serve as both source and sink of contaminants (e.g., Cu) and biologically important materials (e.g., metals, nutrients). Bioturbation by benthic organisms is ecologically relevant as bioturbation affects the physio-chemical characteristics of sediments, thus altering nutrient and contaminant distribution and bioavailability. We examined the effects of sediment-associated Cu on T. tubifex with conventional toxicity endpoints, such as mortality and growth, and less commonly used non-destructive endpoints, such as bioturbation and feeding. An experimental approach was developed to examine the applicability of simple methods to detect effects on bioturbation and feeding. Two experiments were conducted with 7-day exposures to uncontaminated or Cu-spiked natural sediment at six Cu concentrations to examine Cu bioaccumulation and effects. Endpoints included worm mortality, feeding rate and growth (experiment A) and worm bioturbation (particle diffusion and maximum penetration depth, experiment B). A microparticle tracer was placed on the sediment surface and vertical particle transport was followed over time. Adverse effects were detected for all endpoints (bioturbation, feeding rate, growth and survival): a slight positive effect at the lowest Cu concentrations followed by adverse effects at higher concentrations indicating hormesis. These simple, non-destructive endpoints, provided valuable information and demonstrated that sediment-associated contaminants, such as Cu, can influence bioturbation activity, which in turn may affect the distribution of sediment-bound or particulate pollutants, such as the plastic microparticles studied here. Thus, we suggest to use simple endpoints, such as bioturbation and feeding rate, in ecotoxicity testing since these endpoint account for the influence of interactions between pollutants and benthos and, thus, increase ecological relevance.
Mostrar más [+] Menos [-]Quantification of fluoroquinolones in wastewaters by liquid chromatography-tandem mass spectrometry Texto completo
2020
Maia, Alexandra S. | Paíga, Paula | Delerue-Matos, Cristina | Castro, Paula M.L. | Tiritan, Maria Elizabeth
Antibiotics are the most consumed therapeutic classes worldwide and are released to the environment in their original form as well as potentially active metabolites and/or degradation products. Consequences of the occurrence of these compounds in the environment are primarily related to bacterial resistance development.This work presents a validated analytical method based on solid phase extraction (SPE) using HLB cartridges, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for quantification of seven different fluoroquinolone antibiotics, namely ciprofloxacin (CPF), enrofloxacin (ENR), lomefloxacin (LOM), norfloxacin (NOR), ofloxacin (OFL), prulifloxacin (PLF) and moxifloxacin (MOX) and its application to detect the target compounds in influents and effluents of wastewater treatment plants (WWTP). Linearity was established through calibration curves in solvent and matrix match using internal calibration method in the range of 50–1300 ng L⁻¹ and all the fluoroquinolones showed good linear fit (r² ≥ 0.991). Accuracy ranged between 80.3 and 92.9%, precision was comprised between 7.2 and 14.6%, and 10.7 and 18.1% for intra- and inter-batch determinations, respectively. Method detection and quantification limits ranged from 6.7 to 59.0 ng L⁻¹ and 22.3–196.6 ng L⁻¹, respectively.Influents and effluents of fifteen WWTPs of North of Portugal were analyzed. OFL was the fluoroquinolone found at the highest concentration, up to 4587.0 ng L⁻¹ and 987.9 ng L⁻¹, in influent and effluent, respectively. NOR and PLF were not detected.
Mostrar más [+] Menos [-]Contrasting effects of iron plaque on the bioavailability of metallic and sulfidized silver nanoparticles to rice Texto completo
2020
Wu, Yun | Yang, Lei | Gong, Hua | Dang, Fei | Zhou, Dong-Mei
Interaction between silver nanoparticles (AgNPs) and iron plaque, which forms at the root surface of wetland plants under waterlogging conditions, is a critical process that controls the bioavailability of AgNPs. In this study, we comparatively evaluated how and to what extent iron plaque affected silver uptake sourced from metallic (Ag⁰NPs) and sulfidized (Ag₂S-NPs) silver nanoparticles under hydroponic conditions. After the formation of iron plaque at the root surface upon exposure to Fe²⁺ at 0–100 μg mL⁻¹, rice (Oryza sativa L.) seedlings were transferred to AgNP suspensions. Silver uptake depended on the amount of iron plaque and AgNP species (Ag⁰NPs vs. Ag₂S-NPs): Ag₂S-NP exposure had lower or comparable Ag uptake to that of Ag⁰NP exposure at low levels of Fe²⁺ (0–80 μg mL⁻¹), but significantly higher Ag uptake at 100 μg Fe²⁺ mL⁻¹. Such contrasting effects of iron plaque on the bioavailability of Ag⁰NPs and Ag₂S-NPs were attributed to their influences on AgNP dissolution. However, the translocation factors (TFs) and particle size distribution of NPs in planta (as determined by single-particle inductively coupled plasma-mass spectrometry analysis) were not affected by the amount of iron plaque. These results reveal contrasting effects of iron plaque on the bioavailability of Ag⁰NPs and Ag₂S-NPs, and raise concerns about the exposure of wetland plants to Ag₂S-NPs in Fe-rich environments, where high Fe levels may facilitate Ag₂S-NP bioavailability.
Mostrar más [+] Menos [-]Phosphorus-rich biochar produced through bean-worm skin waste pyrolysis enhances the adsorption of aqueous lead Texto completo
2020
Yan, Yubo | Sarkar, Binoy | Zhou, Lei | Zhang, Ling | Li, Qiao | Yang, Jianjun | Bolan, Nanthi
In China, more than 10,000 tons of bean-worm, which is rich in protein (68.5%) and essential amino acids (52.8%), is consumed annually. Thus, a large amount of bean-worm skin waste is generated, and is often indiscriminately disposed of, potentially causing environment problems. In this study, bean-worm skin (BWS) waste was pyrolyzed at 500 °C to produce biochar (BWS-BC), and the surface properties of BWS and BWS-BC were characterized using various spectroscopic techniques. Pb(II) adsorption properties of BWS and the corresponding biochar as a function of solution pH, contact time, and equilibrium concentration of Pb(II) were examined using adsorption isotherm, kinetics and thermodynamics studies. The maximum Pb(II) adsorption capacities based on the Langmuir isotherm model were calculated as 45 and 62 mg g⁻¹ for BWS and BWS-BC, respectively, which were comparable to the values obtained for biochars derived from other agro-wastes. The adsorption feasibility, favorability and spontaneity of Pb(II), as derived from the thermodynamic parameters, indicated that chemisorption and precipitation (e.g., hydroxypyromorphite) were the main adsorption mechanism in case of BWS and BWS-BC, respectively. Thus, conversion of BWS to biochar for Pb(II) adsorption can be considered as a feasible, promising and high value-added approach for BWS recycling.
Mostrar más [+] Menos [-]Arsenic speciation in sea cucumbers: Identification and quantitation of water-extractable species Texto completo
2020
Gajdosechova, Zuzana | Palmer, Calvin H. | Dave, Deepika | Jiao, Guangling | Zhao, Yanfang | Tan, Zhijun | Chisholm, Jeffrey | Zhang, Junzeng | Stefanova, Roumiana | Hosena, Ābula | Mester, Zoltan
With the constant quest for new sources of superfoods to supplement the largely nutrient deficient diet of the modern society, sea cucumbers are gaining increasing popularity. Three species of sea cucumbers, Cucumaria frondosa, Apostichopus californicus and Apostichopusjaponicus were collected from three geographical regions, Atlantic and Pacific coast of Canada and Yellow sea/ East China sea in China, respectively. These organisms were sectioned into parts (body wall, tentacles, internal organ, skin and muscle) and analysed for total arsenic (As) by inductively coupled plasma mass spectrometry (ICP-MS) and As species by high-performance liquid chromatography (HPLC) coupled to ICP-MS. Normal and reversed sequential extractions were optimised to address As distribution between lipids (polar and non-polar) and water-extractable fractions. Two extraction methods for water-extractable As were compared in terms of the number and the amount of extracted species. The results revealed that total As concentration and As species distribution varies significantly between sea cucumbers species. Total As in studied body parts ranged between 2.8 ± 0.52 and 7.9 ± 1.2 mg kg⁻¹, with an exception of the muscle tissue of A. californicus, where it reached to 36 ± 3.5 mg kg⁻¹. Arsenobetaine (AsB) was the most abundant As species in A. californicus and A.japonicus, however, inorganic As represented over 70% of total recovered As in the body parts of C. frondosa. Arsenosugars-328 and 482 were found in all studied body parts whereas arsenosugar-408 was only found in the skin of A. californicus. This is the first time that such a variation in As species distribution between sea cucumber species has been shown.
Mostrar más [+] Menos [-]Fine sediment particle microscopic characteristics, bioavailable phosphorus and environmental effects in the world largest reservoir Texto completo
2020
Wang, Xiaoxiao | Zhou, Jun | Wu, Yanhong | Bol, Roland | Wu, Yong | Sun, Hongyang | Bing, Haijian
The transport and retention of sediments in fine grain sizes plays an important role in the cycles of phosphorus (P), and is closely related to the extent and potential for eutrophication in water reservoirs. In order to highlight the environmental indications for the transport of fine sediment particles and the associated bioavailable phosphorus (Bio-P) in the world largest reservoir, the Three Gorges Reservoir (TGR), the suspended and bed sediments were collected at 13 sections in 2016. The sediment physicochemical properties, micromorphology of sediment particles, distribution of elements on particle surface, P adsorption parameters, and P fractions in different grain sized sediments were analyzed. The results showed that the fine sediment particles had a strong P adsorption ability due to their micromorphology, mineral compositions, and the high contents of Fe/Al/Mn (hydr)oxides, which contributed a higher concentration of Bio-P in <16 μm sediment particles. The adsorption of P on the sediment particles occurred longitudinally along the TGR, and the fine sediment particles (<16 μm) dominated the transport and distribution of Bio-P in the TGR sediments. The reduced inflow and retention of fine sediment particles, caused by the construction of cascade reservoirs along the Jinsha River (upper reach of the Yangtze River), has resulted in the decrease in the retention of Bio-P in the TGR. Therefore, we conclude that the continuously decrease of inflow and retention of the fine sediment particles in the TGR, and with it a reduced sediment P buffer capacity, may enhance algal blooms occurrence also in view of the increased P discharge from the overall TGR catchment. The study results can contribute to improved management guidance on fine sediment particles and associated phosphorus for the operation and environmental protection of other large reservoirs in the world.
Mostrar más [+] Menos [-]An integrated offshore oil spill response decision making approach by human factor analysis and fuzzy preference evaluation Texto completo
2020
Ye, Xudong | Chen, Bing | Lee, Kenneth | Storesund, Rune | Zhang, Baiyu
Human factors/errors (such as inappropriate actions by operators and unsafe supervision by organizations) are a primary cause of oil spill incidents. To investigate the influences of active operational failures and unsafe latent factors in offshore oil spill accidents, an integrated human factor analysis and decision support process has been developed. The system is comprised of a Human Factors Analysis and Classification System (HFACS) framework to qualitatively evaluate the influence of various factors and errors associated with the multiple operational stages considered for oil spill preparedness and response (e.g., oil spill occurrence, spill monitoring, decision making/contingency planning, and spill response); coupled with quantitative data analysis by Fuzzy Set Theory and the Technique for Order Preference by Similarity to Ideal Solution (Fuzzy-TOPSIS) to enhance decision making during response operations. The efficiency of the integrated human factor analysis and decision support system is tested with data from a case study to generate a comprehensive priority rank, a robust sensitivity analysis, and other theoretical/practical insights. The proposed approach improves our knowledge on the significance of human factors/errors on oil spill accidents and response operations; and provides an improved support tool for decision making.
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