Review on the Fate of Contaminants in the Niger Delta Environment

Niger Delta environment had suffered from impacts of waste over the years. The significant wastes in the region are crude oil and municipal wastes. Studies have shown the effect and fate of contaminants in the environment and human life. This paper reviews the impact and fate of contaminants in the Niger Delta environment with the focus on crude oil waste and municipal waste. The substantial quantities of waste generated resulted from unreasonable consumption and production, non-compliance to environmental laws and regulations, migration to urban cities, and sporadic expansion of unregulated industrial operations. These contaminants affect various life forms, natural resources, and increase the rate of global warming. It is of urgent importance for concerted efforts from corporate bodies, government, and individuals to ensure proper implementation of effective, safe management of waste. This review used Niger Delta environmental contaminant analysis and remediation case studies to highlight the fate of organic and inorganic contaminants and their associated adverse effects on the environment. This review contains secondary data from online journal articles, radio, symposium, doctoral thesis, organisations, and websites. Keywords: Crude oil, Heavy hydrocarbons, Spills, Dumpsite, Pesticides, Fate, contaminants, Toxic, Degradation. DOI: 10.7176/JEES/10-5-05 Publication date:May 31st 202

Environmental effects of offshore produced water discharges: A review focused on the Norwegian continental shelf

Produced water (PW), a large byproduct of offshore oil and gas extraction, is reinjected to formations or discharged to the sea after treatment. The discharges contain dispersed crude oil, polycyclic aromatic hydrocarbons (PAHs), alkylphenols (APs), metals, and many other constituents of environmental relevance. Risk-based regulation, greener offshore chemicals and improved cleaning systems have reduced environmental risks of PW discharges, but PW is still the largest operational source of oil pollution to the sea from the offshore petroleum industry. Monitoring surveys find detectable exposures in caged mussel and fish several km downstream from PW outfalls, but biomarkers indicate only mild acute effects in these sentinels. On the other hand, increased concentrations of DNA adducts are found repeatedly in benthic fish populations, especially in haddock. It is uncertain whether increased adducts could be a long-term effect of sediment contamination due to ongoing PW discharges, or earlier discharges of oil-containing drilling waste. Another concern is uncertainty regarding the possible effect of PW discharges in the sub-Arctic Southern Barents Sea. So far, research suggests that sub-arctic species are largely comparable to temperate species in their sensitivity to PW exposure. Larval deformities and cardiac toxicity in fish early life stages are among the biomarkers and adverse outcome pathways that currently receive much attention in PW effect research. Herein, we summarize the accumulated ecotoxicological knowledge of offshore PW discharges and highlight some key remaining knowledge needs.publishedVersio

Geophysical Characterization of Oil Spill Sites in Parts of Niger Delta Using Electrical Resistivity Tomography, Southern Nigeria

Geophysical survey using 2D resistivity tomography was acquired to characterize two hydrocarbon impacted sites of Ikarama and Kalaba. In the impacted sites six (6) 2D resistivity imaging profiles were carried out to understand the resistivity distribution as basis for interpreting the depth and lateral extent of contamination. Additionally, two (2) 2D resistivity imaging profiles were also carried out in the un-impacted sites to serve as control.  Surface geophysical survey was acquired using ABEM SAS 1000 terammeter set with electrode constant separation of 6 step array system with a maximum electrode separation of five metres in a traverse of  100 meters.  The 2D resistivity imaging data was interpreted using Res2Div. The results indicated the distribution of electrical resistivity within the subsurface. The resistivity sections were displayed in shades of rainbow colours. The values for the models range from 1.05   the resistivity models show a general increase of resistivity with depth relative to the   control points.  The 2D resistivity models correlate well with the borehole logs as top soil, clay, sandy clay and sand. Also, some of the 2D models indicate increases in resistivity with depth. They also show interaction of water interplaying with the contaminant plume.  The resistivity range of 0.005  to 11.3  which occurred from the surface is interpreted as top soil. Immediately underlying this layer is a region of high resistivity with range of 9.4  to 78.1  which indicate petroleum contamination that may have seeped through the clay horizon to the sandy layer. This may be due to the fact that the invading crude oil may have exceeded the retention capacity of the porous medium hence allowing crude oil to spread to other zones of high hydraulic conductivity materials. In addition, it is also possible that   the clay bodies were not localized.    Superimposition of the  main profile generated to monitor petroleum contaminant and  the control profiles established a remarkably difference showing  the main profiles  increases of resistivity  with depth, while the resistivity of the control profiles decreases with depth and possibly with materials highly resistive at the top. The study established that biodegradation increases as the depth decreases. The characterization of high resistivity with decrease in depth of the impacted sites were due to oil spill contamination whereas, decrease in resistivity with respect to depth is agreeable to non-petroleum site having materials that were restive at the top. The study pointed out hydrocarbon contamination of the both sites between shallow depths of 3m to 7m which may infiltrate to change the composition of near surface aquifers in the locality. Therefore, more geophysical studies is recommended in this area. Keywords: Electrical Resistivity Tomography, Oil spill, Geophysical Characterization DOI: 10.7176/JEES/11-2-08 Publication date: February 28th 202

Modeling comprehensive chemical composition of weathered oil following a marine spill to predict ozone and potential secondary aerosol formation and constrain transport pathways

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 120 (2015): 7300–7315, doi:10.1002/2015JC011093.Releases of hydrocarbons from oil spills have large environmental impacts in both the ocean and atmosphere. Oil evaporation is not simply a mechanism of mass loss from the ocean, as it also causes production of atmospheric pollutants. Monitoring atmospheric emissions from oil spills must include a broad range of volatile organic compounds (VOC), including intermediate-volatile and semivolatile compounds (IVOC, SVOC), which cause secondary organic aerosol (SOA) and ozone production. The Deepwater Horizon (DWH) disaster in the northern Gulf of Mexico during Spring/Summer of 2010 presented a unique opportunity to observe SOA production due to an oil spill. To better understand these observations, we conducted measurements and modeled oil evaporation utilizing unprecedented comprehensive composition measurements, achieved by gas chromatography with vacuum ultraviolet time of flight mass spectrometry (GC-VUV-HR-ToFMS). All hydrocarbons with 10–30 carbons were classified by degree of branching, number of cyclic rings, aromaticity, and molecular weight; these hydrocarbons comprise ∼70% of total oil mass. Such detailed and comprehensive characterization of DWH oil allowed bottom-up estimates of oil evaporation kinetics. We developed an evaporative model, using solely our composition measurements and thermodynamic data, that is in excellent agreement with published mass evaporation rates and our wind-tunnel measurements. Using this model, we determine surface slick samples are composed of oil with a distribution of evaporative ages and identify and characterize probable subsurface transport of oil.Funded by Gulf of Mexico Research Initiative2016-05-0

微生物機能測定手法を利用した熱帯および温帯沿岸生態系管理に関する研究

この博士論文は内容の要約のみの公開（または一部非公開）になっています筑波大学 (University of Tsukuba)201

The English Channel: Contamination status of its transitional and coastal waters.

The chemical contamination (organic compounds, metals, radionuclides, microplastics, nutrients) of English Channel waters has been reviewed, focussing on the sources, concentrations and impacts. River loads were only reliable for Pb, whereas atmospheric loads appeared robust for Cd, Pb, Hg, PCB-153 and γ-HCH. Temporal trends in atmospheric inputs were decreasing. Contaminant concentrations in biota were relatively constant or decreasing, but not for Cd, Hg and HBCDD, and deleterious impacts on fish and copepods were reported. However, data on ecotoxicological effects were generally sparse for legacy and emerging contaminants. Intercomparison of activity concentrations of artificial radionuclides in sediments and biota on both Channel coasts was hindered by differences in methodological approaches. Riverine phosphate loads decreased with time, while nitrate loads remained uniform. Increased biomass of algae, attributable to terrestrial inputs of nutrients, has affected benthic production and shellfisheries. A strategic approach to the identification of contaminant impacts on marine biota is recommended

On the Production of High-Purity Docosahexaenoic Acid from Heterotrophic Microalgae

Omega-3 fatty acids provide significant health benefits and are a popular nutritional supplement in the nutraceuticals industry. Omega-3 fatty acids such as docosahexaenoic Acid (DHA) and eicosapentaenoic Acid (EPA) have been reported to improve heart health and mental health. In addition, DHA consumption has been tied to improvements in infant cognitive development. Therefore, high-purity DHA is a desired ingredient in the production of infant formula. The omega-3 oils originating from fish tend to have carcinogenic risks in addition to a bad odor. In recent years, the industry trend has shifted to producing these omega-3 fatty acids via microalgae species– making it a profitable time to enter the DHA production market. The proposed design is for a plant to cultivate the Schizochytrium cells in the upstream process, and then extract and purify the desired omega-3 fatty acid oils in the downstream process. The project proposal called for production of 881,800 lb DHA per year, but our plant has the capacity to produce 1,148,000 lb DHA per year at a competitive price of $362.90 per lb of DHA. Clinton, Iowa was chosen as the plant location due to its proximity to the Mississippi River and the Archer Daniels Midland (ADM) plant, allowing for direct access to water and waste disposal. Our process is estimated to have an IRR of 153.8$775,600,000 and a ROI of 206.5%. The process itself begins with fermentation of the microalgae cells, starting with lab-scale fermentors, increasing in size to seed fermentors, and finally scaling up to production fermentor size. Schizochytrium sp. is the strain of heterotrophic microalgae, chosen for its ability to accumulate lipids in high concentration, and its ability to produce DHA triglyceride in high selectivity with respect to other omega-3 fatty acids. Following fermentation, extraction operations are carried out with a hexane solvent and bead mill to extract the crude oils. The hexane is then evaporated and recycled back to the bead mill. The purification process of the crude oil involves saponification of the triglycerides into fatty acid salts. Acetic acid is then added to convert the salts into the final docosahexaenoic acid product. The saponification and protonation reactions take place in Scheibel columns. The final DHA product is 98% pure by mass, and will be sent to a pack out station to be packaged into pharmaceutical grade drums for customers

Induced-Polarization Measurements on Unconsolidated Sediments from a Site of Active Hydrocarbon Biodegradation

To investigate the potential role that indigenous microorganisms and microbial processes may play in altering low frequency electrical properties, induced-polarization (IP) measurements in the frequency range of 0.1 to 1000 Hz were acquired from sediment samples retrieved from a site contaminated by hydrocarbon undergoing intrinsic biodegradation. Increased imaginary conductivity and phase were observed for samples from the smear zone (contaminated with residual-phase hydrocarbon), exceeding values obtained for samples contaminated with dissolved-phase hydrocarbons, and in turn, exceeding values obtained for uncontaminated samples. Real conductivity, although generally elevated for samples from the smear zone, did not show a strong correlation with contamination. Controlled experiments on uncontaminated samples from the field site indicate that variations in surface area, electrolytic conductivity, and water content across the site cannot account for the high imaginary conductivity observed within the smear zone. We suggest that microbial processes may be responsible for the enhanced IP response observed at contaminated locations. Scanning electron microscopy and IP measurements during acid leaching indicate that etched pits on mineral surfaces -- caused by the production of organic acids or formed during microbial colonization of these surfaces -- are not the cause of the IP enhancement. Rather, we postulate that the accumulation of microbial cells (biofilms) with high surface area at the mineral-electrolyte interface generates the IP response. These findings illustrate the potential use of electrical measurements to noninvasively monitor microbial activity at sites undergoing natural hydrocarbon degradation

POLLUTION MITIGATION FOR HYDROCARBONS OF PETROLEUM THROUGH THE BIOREMEDIATION

Environmental contamination by hydrocarbons resulting from activities related to the oil sector is one of the great problems of our time and with the growth of production, distribution and consumption in recent years accidents involving oil or its derivatives have been increasingly steady. This environmental problems and frequent have become increasingly critical, since as can reach the soil, air and bodies of surface and underground water. Besides that, contain compounds with high level of toxicity, mobility and persistence in the environment, and generate a major ecological impact, these pollutants hinder the treatment of contaminated areas. The objective this work is to analyze from the law involved in the prevention of environmental damage this work also sought to introduce control measures and repair of the impacts caused by the oil industry, with emphasis on bioremediation technology as a mitigation measure, working in the recovery of degraded areas. Several studies developed in Brazil and the world has shown good results in restoring environments that have been polluted by hydrocarbons. It was also demonstrated the importance of the choice of technique bioremediation that followed the most used techniques for the biodegradation of hydrocarbons, both in situ and ex situ, as well as the processes involved for the bioremediation occurs effectively and safely. The development of studies like this can help generate new technologies or improve those that already exist, which is fundamental for the enrichment of new environmental decontamination projects.Environmental contamination by hydrocarbons resulting from activities related to the oil sector is one of the great problems of our time and with the growth of production, distribution and consumption in recent years accidents involving oil or its derivatives have been increasingly steady. This environmental problems and frequent have become increasingly critical, since as can reach the soil, air and bodies of surface and underground water. Besides that, contain compounds with high level of toxicity, mobility and persistence in the environment, and generate a major ecological impact, these pollutants hinder the treatment of contaminated areas. The objective this work is to analyze from the law involved in the prevention of environmental damage this work also sought to introduce control measures and repair of the impacts caused by the oil industry, with emphasis on bioremediation technology as a mitigation measure, working in the recovery of degraded areas. Several studies developed in Brazil and the world has shown good results in restoring environments that have been polluted by hydrocarbons. It was also demonstrated the importance of the choice of technique bioremediation that followed the most used techniques for the biodegradation of hydrocarbons, both in situ and ex situ, as well as the processes involved for the bioremediation occurs effectively and safely. The development of studies like this can help generate new technologies or improve those that already exist, which is fundamental for the enrichment of new environmental decontamination projects