A comparison of the sludge conditioning capabilities of Canavalia ensiformis and Brachystegen eurycoma

. The finely ground seeds of Canavalia ensiformis (jack bean) and Brachystegen eurycoma (achi seed) were used in the treatment of sewage sludge. They were found to improve sludge filterability and compare favourably with the traditional, ferric chloride conditioner. The optimum dosage for each sample can be determined by drawing a tangent to the corresponding curve of each sample at the point where there is a sharp break between the straight and curvilinear portion. In this work, the optimum values for C. ensiformis and B. eurycoma are 19.50% (0.39 g/cm³) and 21.5% (0.4 g/cm³) respectively. For ferric chloride, the optimum value is 25% (0.5 g/cm³). These results show that ferric chloride is still a better conditioner than both the other conditioners. However, during sludge filtration, cake and filtrate concentration increased with increasing dosages of both C. ensiformis and B. eurycoma samples. This indicates that they would be useful as conditioners if the primary product of filtration is the procurement of low filtrate concentration or high-quality cake.     

Coal as a source rock for oil: a review

The geological debate about whether, and to what extent, humic coals have sourced oil is likely to continue for some time, despite some important advances in our knowledge of the processes involved. It is clear that not only liptinites, but also perhydrous vitrinites have the potential to generate hydrocarbon liquids in the course of natural coalification. Some liptinites, especially alginite, cutinite, and suberinite, contain a higher proportion of aliphatic moieties in their structure than other liptinites such as sporinite and resinite and are, therefore, more oil-prone. It is of potential value to be able to predict the several environments of deposition in which coals with high liptinite contents or containing perhydrous vitrinites may have been formed. Review of the distribution of oil-prone coals in time and space reveals that most are Jurassic–Tertiary with key examples from Australia, New Zealand, and Indonesia. Methods based both on experimental simulations and the examination of naturally matured samples have been used to determine the order of generation of hydrocarbons from different macerals. Results are not entirely consistent among the different approaches, and there is much overlap in the ranges of degradation, but it seems probable that in the natural environment vitrinites begin to generate early, followed by labile liptinites such as suberinite, then cutinite, sporinite, and, finally, alginite.Petroleum potential may be determined by experimental simulation of natural coalification or inferred through various micro-techniques, especially fluorescence and infrared (IR) spectroscopy, or bulk techniques such as elemental analysis and ¹³C NMR spectroscopy. The latter three techniques enable a measure of the polymethylene component of the coal, which now appears to be one of the best available approaches for determining petroleum potential. No method of experimental simulation of petroleum generation from coals is without criticism, and comparative results are highly variable. However, hydrous pyrolysis, confined pyrolysis, and forms of open-system hydrous pyrolysis approach acceptable simulations.Whether, and to what degree generated liquid hydrocarbons are expelled, has long been the central problem in ‘oil from coal’ studies. The structure of vitrinite was believed until recently to contain an interconnected microporous network in which generated oil would be contained until an expulsion threshold was attained. Recent studies show the pores are not interconnected. Combined with a dynamic model of pore generation, it now seems that expulsion of hydrocarbons is best explained by activated diffusion of molecules to maceral boundaries and ultimately by cleats and fractures to coal seam boundaries. The main reason for poor expulsion is the adsorption of oil on the organic macromolecule, which may be overcome (1) if coals are thin and interbedded with clastic sediments, or (2) if the coals are very hydrogen-rich and generate large quantities of oil.The existence of oil in vitrinite is attested to by solvent extractions, fluorescence properties, and by microscopic observations of oil and bitumen. Experimental simulation of expulsion of oil from coals has only recently been attempted. The relative timing of release of generated CO₂ and CH₄ could have considerable importance in promoting the expulsion of liquid hydrocarbons but the mechanism is unclear. As it is universally agreed that dispersed organic matter (DOM) in some shales readily generates and expels petroleum, it is curious that few consistent geochemical differences have been found between coal macerals and DOM in interbedded shales.Unambiguous evidence of expulsion from coals is limited, and in particular only a few commercial oil discoveries can be confidently correlated to coals. These include Upper Cretaceous Fruitland Formation coals in the USA, from which oil is produced; New Zealand Tertiary coals; and Middle Jurassic coals from the Danish North Sea. It is likely that coals have at least contributed to significant oil discoveries in the Gippsland Basin, Australia; in the Turpan Basin, China; and in the Kutei and Ardjuna basins in Indonesia, but this remains unproven. Early reports that early Jurassic coals in mid-Norway were a major source of the reservoired oils have been shown to be inaccurate.None of the proposed ‘rules of thumb’ for generation or expulsion of petroleum from coals seem particularly robust. Decisions on whether a particular coal is likely to have been an active source for oil should consider all available geological and geochemical information. The assumptions made in computational models should be well understood as it is likely with new understandings of processes involved that some of these assumptions will be difficult to sustain.     

海相碳酸盐岩烃源岩评价的有机碳下限问题

随着勘探程度的提高,深部石油天然气勘探在我国将越来越重要.我国碳酸盐岩地层分布广,埋藏深,其生烃评价是深部石油天然气勘探不可回避的问题.针对我国科学家在这一问题上的争论,提出了海相碳酸盐岩烃源岩评价的三个下限标准,即最低烃源岩的有机碳下限、有效烃源岩有机碳下限和形成大规模油气田的烃源岩有机碳下限.认为以往的争论是最低烃源岩、有效烃源岩下限的争论.通过文献整理、实验研究和计算,认为海相碳酸盐岩普遍存在的Ⅱ型有机质,其最低、有效油源岩的下限值可能在0.1%和0.4%左右,最低、有效气源岩下限可能在0.1%和0.3%左右,大规模油气田形成的TOC应在1%以上.     

Anaerobic digester sludge as nutrient source for culturing of microalgae for economic biodiesel production

After decades of ‘living dangerously’, the human kind has paused to think of Mother Nature. Alternate energy sources are being developed as a part of this realization. The use of indigenous sources of nutrients would considerably bring down the cost of production. A mixed consortium of Chlorella vulgaris, Arthrospira platensis, and tap water-originated Scenedesmus dimorphus was cultured using natural seawater, anaerobic digester sludge, and its growth was compared with synthetic commercial media like Zarrouk’s media, NaNO₃ media, and NH₄Cl media. A spectrophotometric method was standardized for regular biomass estimation. The dry biomass of a 15-day pure, batch culture of Arthrospira was found to yield around 600 mg/L in anaerobic digester sludge, whereas the pure batch culture of chlorella’s growth was hindered mainly due to the presence of bacteria and grazers. Regular microscopic observation and biomass monitoring revealed a drastic reduction in grazing activity, with the use of autoclaved AD sludge, resulting in a strong and stable microalgal mixed consortia. The consortia growth in AD sludge was found to be better than with the synthetic media with no cost of nutrient. The mixed consortia yielded a biomass up to 600 mg/L and lipid of 21.18%. The lipid generated from AD sludge had around 95% unsaturates and contained around 5% omega-3 fatty acids. The use of anaerobic digester sludge in a non-sterile condition reduces the total cost of the biodiesel production process as a whole and introduces a decentralized system for waste water treatment as well.     

Coal and coal macerals as source rocks for oil and gas

The role of coals in the generation and migration of hydrocarbons is discussed from the viewpoints of chemistry and petrology. Extract data and considerations of volatile matter and maturity suggests that under geochemical conditions most coals can give rise to oil, as well as gas. A distinction is drawn between release of absorbed oil and formation of hydrocarbons by thermal breakdown of the coal matrix itself. The generation and preservation of oil require not only that suitable lipidic structures be present but that the product oil can escape before being cracked to gas.Exinite, preferably in large discrete particles, is the most oil-prone maceral. Vitrinite can form oil but subsequent migration depends on the availability of cracks and fissures in the coal matrix. The most highly reflecting forms of inertinite (e.g. fusinite) have no inherent capacity to generate oil. Low reflectance inertinite, such as is common in many Australian coals, may have minor source potential.A speculative attempt is made to quantify the oil-generating capacity of coal macerals and mixtures. As a general broad rule, on a weight basis, exinite can produce ten times more oil than vitrinite and a hundred times more than inertinite. Approximate calculations suggest that thermal maturation of coals can account for all the known oil and gas reserves in the Gippsland and Cooper Basins of Australia, even if only 1% of generated hydrocarbons is trapped.     

Environmental importance of rhamnolipid production from molasses as a carbon source

Rhamnolipid has been known as biosurfactant which is produced by Pseudomonas aeruginosa in fermentation process. Several carbon sources such as ethanol, glucose, vegetable oil and hydrocarbon have been used to produce rhamnolipid. In this study, we are trying to use molasses which is a waste product from sugar industry as carbon source to produce rhamnolipid. The bacterium which was previously isolated from Iranian oil over years Glycolipid production by isolated bacterium using sugar beet molasses as a carbon and energy source was investigated. Result from the study showed that the growth of the bacteria using molasses as carbon sources is growth-associated. The specific production rate of rhamnolipid with 2%, 4%, 6%, 8% and 10% of molasses are 0.00065, 4.556, 8.94, 8.85, and 9.09 respectively. The yield of rhamnolipid per biomass with 2%, 4%, 6%, 8% and 10% molasses are 0.003, 0.009, 0.053, 0.041 and 0.213 respectively. The production of rhamnolipid (0.0531 g. rhamnolipid/g biomass) is higher compare to the culture grown in aerobic condition (0.04 g. rhamnolipid/g biomass). These studies indicate that renewable, relatively inexpensive and easily available resources can be used for important biotechnological processes.     

Anaerobic digested sludge: a new supplementary nutrient source for ethanol production

Effluent sludge from an anaerobic digester was used as a source of nitrogen, phosphate, sulfur, and other nutrients in the culture medium of ethanol production by the yeast Saccharomyces cerevisiae. Several pretreatments (mechanical, chemical, thermal, and thermo-chemical) were performed on the anaerobic digested sludge (ADS) to make the nutrients accessible to the yeast cells. Preliminary experiments revealed that S. cerevisiae is not able to assimilate the carbon content of the ADS. However, when glucose was added to the medium, ethanol production was observed. The yield of ethanol using untreated ADS was only 10 % of the theoretical yield, but alkaline pretreatment improved it up to 43 %. By separating the hydrolysate of alkaline-treated ADS from the suspended solids, the ethanol yield from the supernatant was further improved up to 65 % of theoretical yield. Alkaline-treated ADS exhibited competitive performance with the mixture of yeast extract and mineral salts in ethanol fermentation.     

Compacted sewage sludge as a barrier for tailing impoundment

The feasibility of compacted sewage sludge serving as a barrier for tailing impoundment was evaluated by the batch test and hydraulic conductivity test with respect to heavy metal retardation and impermeability. The batch test results showed that the effective removal of heavy metals approached 97.8 and 93.4% for Zn and Cd, respectively. Formation of precipitation of oxy(hydroxide) and carbonate minerals was mainly responsible for the attenuation of heavy metals in the early period of the test. Nevertheless, the further removal of heavy metals can be attributed to the sulfate reduction. The hydraulic conductivity test indicated that almost all of the heavy metals contained in simulated acid pore water were retarded by compacted sewage sludge. The hydraulic conductivity of the compacted sewage sludge ranged from 3.0 × 10⁻⁸ to 8.0 × 10⁻⁸ cm s⁻¹, lower than 1.0 × 10⁻⁷ cm s⁻¹, which is required by regulations for the hydraulic barrier in landfill sites. Thus, this study suggested that compacted sewage sludge could be used as a bottom barrier for tailing impoundment.     

Treatment of synthetic acid mine drainage using rice wine waste as a carbon source

Spent mushroom compost (SMC) is commonly used as a carbon source for passive treatment systems in South Korea; however, it has some drawbacks, such as sulfate release from itself. Consequently, investigations to identify effective substitutes for SMC are necessary. In this study, batch experiments were conducted for 27 days to evaluate the efficiency of rice wine waste (RWW) for reducing sulfate and removing dissolved metals within synthetic acid mine drainage (AMD). The results showed that RWW could be more suitable than SMC, which even released sulfate in the early stage of the experiment, for sulfate reduction by sulfate-reducing bacteria. Both materials produced similar results with respect to the removal of dissolved metals, such as Fe and Al. Furthermore, a mixture of SMC and RWW showed the greatest efficiency in sulfate removal. Overall, both RWW and the mixed carbon source showed comparable performance to SMC, which indicated that RWW had a great potential for use as a carbon source for AMD treatment.     

Determination of carbon dioxide solubility in oil during interaction with a compound gaseous phase

A thermodynamic method for the determination of the solubility of a mixture of carbon dioxide and hydrocarbon gases in oil is elaborated on the basis of stage-oil separation. A method for the calculation of Henry’s constants for gases that are dissolved in oil and their temperature extrapolation are shown. Effective thermodynamic properties are estimated for carbon dioxide and C₁–C₈ hydrocarbon gases dissolved in oil. A thermodynamic model that satisfactorily describes the separation of gas from oil is created and may be included in a more complex calculation model of carbonate scaling during the exploitation of oil deposits.     

The continental mantle as a source for hotspot volcanism

The source of hotspot volcanism lies in metasomatized regions of the continental mantle proximal to ancient sutures and failed rifts. Such regions are prone to melting under hotcell conditions on continental rifting, and to erosion into the deeper mantle by asthenospheric flow. In opening basins, rifting parallel to such sutures or failed rifts delaminates and cycles continental mantle into the MORB source. Rifting at some angle to a suture or failed rift generates a hotspot track by preferential melting of the metasomatized mantle as it is cycled toward the rift axis. Continental mantle eroded into the asthenosphere becomes displaced from the continent by net westward drift of the lithosphere relative to the deep mantle to give rise to hotspot volcanism in long-lived ocean basins.     

Pump-and-treat method to remove nitrate from groundwater with liquor as the carbon source

As a common pollutant in groundwater, nitrate poses a significant threat to drinking water safety, especially in rural areas. A feasible solution to this problem must be established. In this study, a simple sand bucket was designed to investigate the capability of denitrification with liquor as the carbon source to remove nitrate from pumped groundwater, and the feasibility of the pump-and-treat method. Results showed that addition of a proper amount of liquor enhanced the growth and metabolism of denitrifying bacteria, efficiently reduced the nitrate content in pumped groundwater, and restricted the accumulation of intermediate products. The removal rate of nitrate exceeded 99% and reached about 16.0 mg/L/day when the carbon-to-nitrogen (C/N) ratio was higher than 0.8. The accumulated concentration of nitrite as an intermediate was less than 1.0 mg/L when the C/N ratio was higher than 1.5. However, acetate accumulation was significant. Considering the accumulation of intermediates, the appropriate range of the C/N ratio should be 1.5–1.8. In addition, onset and maintenance of denitrification were not significantly influenced by dissolved oxygen and pH. The pump-and-treat method can provide a convenient and practical channel for household or collective removal of nitrate from pumped groundwater in rural areas because liquor as a household drink is frequently accessible and inexpensive in many areas.     

Denitrification of nitrate-contaminated groundwater using biodegradable snack ware as carbon source under low-temperature condition

A considerable increase in nitrate concentration in groundwater has been observed in many countries. This research focuses on nitrate removal using biodegradable snack ware (BSW) as both carbon source and biofilm support for denitrifiers. The denitrification efficiency of a laboratory-scale denitrification reactor packed with BSW was examined in a low-temperature condition. The nitrate removal efficiency supported by BSW decreased to approximately 40% at 12°C from nearly 100% at 25°C with 50?mg/L of nitrate-nitrogen in the influent and 2?h of hydraulic retention time (HRT). The complete nitrate removal was obtained when nitrate-nitrogen concentration was no more than 15?mg/L at 2?h of HRT and at 12°C. If the initial concentration of nitrate-nitrogen was 50?mg/L, 5?h of HRT was needed for the complete nitrate removal. Nitrite concentration in the treated water decreased evidently as HRT was increased from 2 to 5?h, or as nitrate-nitrogen concentration in the influent decreased to 15?mg/L from 50?mg/L. It was observed that varying HRT and nitrate concentration in the influent had no noticeable effect on dissolved organic carbon content in the effluent under the experimental conditions. This study indicated that the complete nitrate removal could be achieved readily even at 12°C using BSW as carbon source by changing HRT or the initial concentration of nitrate in the influent, which has some useful implications in environmental engineering practice.     

Stable isotopes and cellulase activity as evidence for detritus as a food source for juvenile Gulf menhaden

Menhaden are one of the most abundant components of fish communities in Gulf and Atlantic estuaries. Juvenile menhaden have been reported to have zooplankton, phytoplankton, andSpartina-derived detritus in their guts. However, there has been disagreement over the importance of the detritus as a food source. We show, using physiological and stable isotope evidence, that detritus can be used by juvenile Gulf menhaden. Their diet is very roughly 30% detritus- and 70% plankton-based.     

甲基二苯并噻吩分布指数（MDBI）作为烃源岩成熟度标尺的探讨

选择库车坳陷和雅布赖盆地两个烃源岩热演化系列,在GC/MS分析的基础上探讨了二苯并噻吩类成熟度参数,如MDR4、MDR23、MDR、MDR’等的热演化特征,首次提出利用甲基二苯并噻吩分布指数(MDBI)作为研究区有效的新型成熟度标尺。结果表明,在成熟至高成熟阶段MDR4和MDR23主要受热力作用控制,在研究区应用效果良好;MDR在较高热演化阶段变化速率显著增加,而且适合于Ⅱ2和Ⅲ型有机质。甲基二苯并噻吩分布指数与其他有效参数,如Ro、tmax和MPI等之间的相关系数矩阵进一步证实,在Ro=0.67%～1.22%范围内,MDBI能够准确提供烃源岩热演化历史方面的信息。该指数的提出还有望为原油热成熟度的判识提供一个新的途径。     

Gravitational potential as a source of earthquake energy

Some degree of tectonic stress within the earth originates from gravity acting upon density structures. The work performed by this “gravitational tectonics stress” must have formerly existed as gravitational potential energy contained in the stress-causing density structure.According to the elastic rebound theory (Reid, 1910), the energy of earthquakes comes from an elastic strain field built up by fairly continuous elastic deformation in the period between events. For earthquakes resulting from gravitational tectonic stress, the elastic rebound theory requires the transfer of energy from the gravitational potential of the density structures into an elastic strain field prior to the event.An alternate theory involves partial gravitational collapse of the stress-causing density structures. The earthquake energy comes directly from a net decrease in gravitational potential energy. The gravitational potential energy released at the time of the earthquake is split between the energy released by the earthquake, including work done in the fault zone and an increase in stored elastic strain energy. The stress associated with this elastic strain field should oppose further fault slip.     

The university as a local source of expertise

The relationship between the university and the city is expressed, amongst others, by the transfer of knowledge from the university to local actors. The universitys role as a local source of knowledge is studied by analyzing the outflow of the two main knowledge assets to the local area: graduates and research results. By comparing the results from universities in the Netherlands and the United Kingdom comparative evidence is discussed.     

The Strecker synthesis as a source of amino acids in carbonaceous chondrites: deuterium retention during synthesis

Deuterium-enriched amino acids occur in the Murchison carbonaceous chondrite. Synthesis from D-enriched interstellar precursors by Strecker reactions during aqueous alteration of the parent body has been proposed. To test this hypothesis, we have measured the retention of deuterium in amino acids produced from HCN, NH3, and formaldehyde-D2, acetaldehyde-D4, and acetone-D6 in H2O. The isotopic label is 50% to 98% retained, with variations in retentivity depending on the amino acid and the reaction conditions. If amino acids, once formed on the parent body by the Strecker synthesis, lose no deuterium by subsequent exchange with water or H-bearing minerals, then the observed deuterium isotopic composition of Murchison amino acids represents as much as 50% or more of the enrichments inherited from their interstellar precursors. Imino diacids are prominent side products of the Strecker synthesis which have not been reported in carbonaceous chondrites. Under the conditions of the Strecker reaction using deuterium labeled aldehydes and ketones, unlabeled amino acids are also formed by an HCN polymerization route indicating multiple pathways for the synthesis of amino acids in meteorites.     

PAH refractory index as a source discriminant of hydrocarbon input from crude oil and coal in Prince William Sound,Alaska

Geochemical correlation and differentiation of hydrocarbons from crude oils and coals is difficult. The complex mixture of the hydrocarbon constituents and the dynamic nature of these constituents in the environment as they weather contribute to this difficulty. A new parameter, the polycyclic aromatic hydrocarbon (PAH) refractory index, is defined here to help in this correlation. The PAH refractory index is a ratio of two of the most refractory constituents of most crude oils, namely triaromatic steranes and monomethylchrysenes. These are among the most persistent compounds in oil after deposition in the environment and thus retain reliably the signature of the original petroleum input. This index is utilized in Prince William Sound (PWS) to differentiate three different oils, as well as to provide evidence that coal, not oil, is the dominant source of the PAHs which are prominent constituents of marine sediments from PWS and the Gulf of Alaska.