Remediation of oily wastewater from an interceptor tank using a novel photocatalytic drum reactor

A novel photocatalytic reactor has been developed to remediate oily wastewaters. In the first instance degradation rates of model organic compounds, methylene blue (MB) and 4-c hlorophenol (4-CP) were determined. The experimental set-up investigated a 1:10 w/v catalyst to organic solution volume, 30 g catalyst, 300 mls MB (10 μM) or 4-CP (100 μM). The catalyst investigated was a pellet catalyst to improve separation of the remediated volume from the catalyst following treatment. MB concentration decreased by 93% after 15 mins irradiation whilst 4-CP concentration decreased by 94% following 90 mins irradiation. Oily waste water (OWW) from an interceptor tank typically containing diesel oils was obtained from Sureclean, an environmental clean-up company. The OWW was treated using the same conditions as MB and 4-CP, the model organic compounds. Levels of total organic carbon (TOC) and total petroleum hydrocarbon (TPH) were used to monitor the efficacy of the photocatalytic reactor. TOC reduced by 45% following two 90 mins treatment cycles. TPH reduced by 45% following 90 mins irradiation and by a further 25% during a second stage of treatment. This reactor can be used as a polishing technique assembled within a wastewater treatment plant. Allowing for more than one pass through the reactor improves its efficiency. 

Novel photocatalytic reactor development for removal of hydrocarbons from water

Hydrocarbons contamination of the marine environment generated by the offshore oil and gas industry is generated from a number of sources including oil contaminated drill cuttings and produced waters. The removal of hydrocarbons from both these sources is one of the most significant challenges facing this sector as it moves towards zero emissions. The application of a number of techniques which have been used to successfully destroy hydrocarbons in produced water and waste water effluents has previously been reported. This paper reports the application of semiconductor photocatalysis as a final polishing step for the removal of hydrocarbons from two waste effluent sources. Two reactor concepts were considered: a simple flat plate immobilised film unit, and a new rotating drum photocatalytic reactor. Both units proved to be effective in removing residual hydrocarbons from the effluent with the drum reactor reducing the hydrocarbon content by 90% under 10 minutes. 

Density Functional Theory Study of Iron and Cobalt Carbides for Fischer-Tropsch Synthesis

Carbides are important phases in heterogeneous catalysis. However, the understanding of carbide phases is inadequate: Fe and Co are the two commercial catalysts for Fischer-Tropsch (FT) synthesis, and experimental work showed that Fe carbide is the active phase in FT synthesis, whereas the appearance of Co carbide is considered as a possible deactivation cause, TO understand very different catalytic roles of carbides, all the key elementary steps in FT synthesis, that is, CO dissociation, C(1) hydrogenation, and C(1)+C(1) coupling, are extensively investigated on both carbide surfaces using first principles calculations. In particular, the most important issues in FT synthesis, the activity and methane selectivity, on the carbide surfaces are quantitatively determined and analyzed. They are also discussed together with metallic Fe and Co surfaces. It is found that (i) Fe carbide is more active than metallic Fe and has similar methane selectivity to Fe, being consistent with the experiments; and (ii) Co carbide is less active than Co and has higher methane selectivity, providing evidence on the molecular level to support the suggestion that the formation of Co carbide is a cause of relatively high methane selectivity and deactivation on Co catalysts.

An Energy Descriptor To Quantify Methane Selectivity in Fischer-Tropsch Synthesis:A Density Functional Theory Study

Selectivity is a fundamental issue in heterogeneous catalysis. In this study, the CH(4) selectivity in Fischer-Tropsch synthesis is chosen to be investigated: CH4 selectivity on Rh, Co, Ru, Fe, and Re surfaces is computed by first-principles methods. In conjunction with kinetic analyses, we are able to derive the effective barrier difference between methane formation and chain growth (Delta E(eff)) to quantify the CH(4) selectivity. By using this energy descriptor, the ranking of methane selectivity predicted from density functional theory (DFT) calculations is consistent with experimental work. Moreover, a linear correlation between Delta E(eff) and the chemisorption energy of C + 4H (Delta H) is found. This fundamental finding possesses the following significance: (i) it shows that the selectivity, which appears to have kinetic characteristics, is largely determined by thermodynamic properties; and (ii) it suggests that an increase of the binding strength of C + 4H will suppress methane selectivity.

Selective deuterium ion acceleration using the Vulcan petawatt laser

We report on the successful demonstration of selective acceleration of deuterium ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison et al. [Phys. Plasmas 19, 030707 (2012)], an ion beam with >99% deuterium ions and peak energy 14 MeV/nucleon is produced with a 200 J, 700 fs, > 10 20 W/cm 2 laser pulse by cryogenically freezing heavy water (D<inf>2</inf>O) vapor onto the rear surface of the target prior to the shot. Within the range of our detectors (0°-8.5°), we find laser-to-deuterium-ion energy conversion efficiency of 4.3% above 0.7 MeV/nucleon while a conservative estimate of the total beam gives a conversion efficiency of 9.4%.

Quality Assurance for GCxGC-FID, Accreditation for TPH CWG Protocol

A new technological approach in the analysis and forensic interpretation of Total Hydrocarbons in soils and waters using 2D Gas Chromatography method (GC-GC) was developed alongside environmental forensic and the assessment models to provide better customer products for the environmental industry.
The objective was to develop an analytical methodology for TPH CWG. Raw data from this method is then to be evaluated for forensic interpretation and risk assessment modelling. Access will be made available to the expertise in methods of forensic tracing contaminant sources, transport modelling, human health risk modelling and detailed quantitative risk assessment.
The quantification of internal standards was key to the development of this method. As the laboratory does not test for TPH in 1D, it was requested during INAB ISO 17025 audit to individually map out where each compound falls chromatographically in the 2D. This was done through comparing carbon equivalent numbers to the n-alkane carbons. This proved e.g. 2-methylnaphthalene has 11 carbons in its structure; its carbon equivalent is 12.84 , the result of which falls within the band of Aromatic eC12-eC16 as opposed to expected eC10-eC12. This was carried out for all 16 PAH (polyaromatic hydrocarbons) and BTEX (benzene, toluene, ethylbenzene and o, m and p-xylenes). The n-alkanes were also assigned to their corresponding aliphatic bands e.g. nC8 would be expected to be in nC8-nC10.
The method was validated through a designated systematic experimental protocol and was challenged with spikes of known concentration of hydrocarbon parameters such as recoveries, precision, bias and linearity. The method was verified by testing a certified reference material which was used as a proficiency round of testing for numerous laboratories.
It is hoped that the method will be used in conjunction with the analysis through Bonn Agreement with their OSINet group. This is a panel of experts and laboratories (including CLS) who forensically identify oil spill contamination from a water source.
This method can prove itself to be a robust method and benefit the industry for contaminated land and water but the method needs to be seen as separate from the regular 1D chromatography. It will help identify contaminants and assist consultants, regulators, clients and scientists valuable information not seen in 1D

Ionic liquid solvents of perhalide type for metals for extraction radioactive metals from mineral ores.

The invention relates to a process for dissolving metals (e.g., Al, Cu, Fe, Cr, Sb, Ti, and W) in perhalide contg. ionic liqs. having the formula (I), and to the extn. of metals from mineral ores; the remediation of materials contaminated with heavy, toxic, or radioactive metals; and to the removal of heavy and toxic metals from hydrocarbon streams. In the formula (I), [X] comprises at least one perhalide anion selected from [I3]-, [BrI2]-, [Br2I]-, [ClI2]-, [ClBr2]-, [BrCl2]-, or [ICl2]-, [ClI3]-. The (Cat+) is a cationic species selected from: ammonium, azaannulenium, azathiazolium, benzimidazolium, benzofuranium, benzotriazolium, borolium, cinnolinium, diazabicyclodecenium, diazabicyclononenium, diazabicyclo- undecenium, dithiazolium, furanium, guanidinium, imidazolium, indazolium, indolinium, indolium, morpholinium, oxaborolium, oxaphospholium, oxazinium, oxazolium, iso-oxazolium, oxathiazolium, pentazolium, phospholium, phosphonium, phthalazinium, piperazinium, piperidinium, pyranium, pyrazinium, pyrazolium, pyridazinium, pyridinium, pyrimidinium, pyrrolidinium, pyrrolium, quinazolinium, quinolinium, isoquinolinium, quinoxalinium, selenozolium, sulfonium, tetrazolium, iso-thiadiazolium, thiazinium, thiazolium, thiophenium, thiuronium, triazadecenium, triazinium, triazolium, iso-triazolium, and uronium. [on SciFinder(R)]

Process for removing metals from hydrocarbons.

This invention relates to a process for removing metals, particularly mercury, from hydrocarbon streams by use of an ionic liq., where in the metal-contg. hydrocarbon stream is contacted with an ionic liq. to produce a product hydrocarbon stream having reduced mercury content. [on SciFinder(R)]

Ionic liquids and their use in extraction processes.

There is provided a process for the extn. of at least one arom. compd. from a mixt. with at least one aliph. hydrocarbon, which process comprises contacting said mixt. with a salt that is in a liq. state at a temp. below 150°C, said salt having a cation which comprises an arom. nitrogen-contg. heterocyclic ring system, in which a nitrogen atom forming part of said ring system is quaternized and in which said ring system is substituted by at least one electron-withdrawing substituent. Some of said salts are novel. [on SciFinder(R)]

Development and testing of an intermediate temperature glass sealant for use in mixed ionic and electronic conducting membrane reactors

High temperature ceramic membranes have interesting possibilities for application in areas of new and developing technologies such as hydrocarbon combustion with carbon dioxide capture and electrochemical promotion of catalysis (EPOC). However, membrane module sealing remains a significant technical challenge. In this work a borosilicate glass sealant (50SiO₂·25B₂O₃·25Na₂O, mol%) was developed to fit the requirements of sealing an air separation membrane system at intermediate temperatures (300-600 °C). The seal was assessed by testing the leak rates under a range of conditions. The parameters tested included the effect of flowrate on the leak rate, the heating and cooling rates of the reactor and the range of temperatures under which the system could operate. Tests for durability and reliability were also performed. It was found that the most favourable reactor configuration employed a reactor with the ceramic pellet placed underneath the inner chamber alumina tube (inverted configuration), using a quartz wool support to keep the membrane in place prior to sealing. Using this configuration the new glass-based seal was found to be a more suitable sealant than traditional alternatives; it produced lower leak rates at all desirable flowrates, with the potential for rapid heating and cooling and multiple cycling, allowing for prolonged usage. © 2010 Elsevier B.V. All rights reserved.

Protective role of glycerol against benzene stress: insights from the Pseudomonas putida proteome

Chemical activities of hydrophobic substances can determine the windows of environmental conditions over which microbial systems function and the metabolic inhibition of microorganisms by benzene and other hydrophobes can, paradoxically, be reduced by compounds that protect against cellular water stress (Bhaganna et al. in Microb Biotechnol 3:701-716, 2010; Cray et al. in Curr Opin Biotechnol 33:228-259, 2015a). We hypothesized that this protective effect operates at the macromolecule structure-function level and is facilitated, in part at least, by genome-mediated adaptations. Based on proteome profiling of the soil bacterium Pseudomonas putida, we present evidence that (1) benzene induces a chaotrope-stress response, whereas (2) cells cultured in media supplemented with benzene plus glycerol were protected against chaotrope stress. Chaotrope-stress response proteins, such as those involved in lipid and compatible-solute metabolism and removal of reactive oxygen species, were increased by up to 15-fold in benzene-stressed cells relative to those of control cultures (no benzene added). By contrast, cells grown in the presence of benzene + glycerol, even though the latter grew more slowly, exhibited only a weak chaotrope-stress response. These findings provide evidence to support the hypothesis that hydrophobic substances induce a chaotropicity-mediated water stress, that cells respond via genome-mediated adaptations, and that glycerol protects the cell's macromolecular systems. We discuss the possibility of using compatible solutes to mitigate hydrocarbon-induced stresses in lignocellulosic biofuel fermentations and for industrial and environmental applications.