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Carbazole compounds are widely used in determining the direction of petroleum migration, but the effect of thermal maturity on carbazoles is still ambiguity. In this paper, using compaction pyrolysis simulation experiments, artificial mature samples with vitrinite reflectance (Ro) range from 0.38 to 3.0% were acquired. And the content and composition change characteristics of carbazole compounds were analyzed in coal source rocks. The experimental results showed that thermal maturity controls the generation of a large amount of carbazole compounds in coal rocks. Compared with the low mature stage, the content of carbazole compounds was about 10–100 times higher in the mature stage. With the increasing maturity, in the coal sample, the content of carbazole compounds showed a trend of first increasing and then decreasing. In derivatives of carbazole, the corresponding maturity for the maximum generation of ethylcarbazole (EC), dimethylcarbazole (DMCA), methylcarbazole (MCA), carbazole (CA) and benzocarbazole (BCA) performed the increasing sequence. With the increasing maturity, the relative abundance of 2-MCA, 1,7-DMCA and benzo[a]carbazole increased with the increasing maturity, while 4-MCA, 1,4-DMCA and benzo[c]carbazole gradually decreased. Benzocarbazole ratio [a]/[a] +[ c] varies only in a narrow range 0.36–0.61 in the entire maturity range, suggesting limited maturity dependence. The experimental conclusion provides more theoretical basis for future geochemical analysis using carbazole compounds. [ABSTRACT FROM AUTHOR]

Numerous research papers on biosorption have been published in the past four decades. This paper reviews and compares heavy metal uptake capacities of various biological and non-biological materials. Adsorption mechanisms and processes of heavy metal ions (HMIs) onto biomasses are summarised and discussed, respectively. In general, all types of adsorbents exhibit certain uptake capacities for HMIs, but the capacity values for different types of biomasses and non-biological materials vary significantly. For HMIs, the reported values for bacterial biomasses typically range from 0.06 mmol·g−1 to 2.84 mmol·g−1; for fungi and yeasts, 0.03 mmol·g−1 to 2.44 mmol·g−1; for fresh water algae, 0.02 mmol·g−1 to 3.15 mmol·g−1; for marine algae, 0.23 mmol·g−1 to 3.77 mmol·g−1; for other biological materials/derivatives, 0.01 mmol·g−1 to 1.78 mmol·g−1 and for non-biological materials, 0.003 mmol·g−1 to 2.40 mmol·g−1. Thereinto, a few macroalgal species exhibit much higher adsorption capacities for HMIs relative to other types of adsorbents. Statistical analysis of heavy metal uptake capacities of various biological and non-biological materials indicates that marine algae are most suitable for the development of industrial biosorbents for the remediation of diluted HMIs-bearing effluents. Biosorption mechanisms of HMIs by biomasses include physical adsorption, ion exchange, electrostatic interaction, surface complexation and inorganic microprecipitation. the physicochemical properties of biosorbents and HMIs as well as external adsorption conditions significantly influence the adsorption process of HMIs onto biomasses. It could be concluded from numerous previous studies that pseudo-first-order and pseudo-second-order models are the most commonly utilised to characterise adsorption process. Up to date biosorption of HMIs remains largely in the laboratory stage. Combining microscopic mechanisms with macroscopic models may be one of the future research directions for removal of HMIs by biomasses. [ABSTRACT FROM AUTHOR]

A natural mud shale (MS) from Yichang Area, China was for the first time experimentally examined for its potential application to oily effluents treatment. The mineralogical compositions, surface structures and pore size distribution of the prepared MS particles were characterised using various advanced analytical technologies, respectively. The performance of the MS particles during the model diesel oil wastewater treatment was examined based on the designed adsorption experiments. Isothermal and kinetic features were investigated according to a variety of adsorption models. The results showed that some pores, cavities and fractures were distributed on the surface of MS particles. The efficiency of MS particles for removing diesel oil from the model oily effluent was associated closely with experimental conditions including the mass of MS particles, initial diesel levels, residence time and pH values. Equilibrium adsorption isotherms conformed to Langmuir model, indicating that the adsorption of diesel oil onto MS particles tended to monolayer adsorption. Kinetics of adsorption of diesel oil on MS complied with the pseudo-second-order model. This suggested that the whole oil removal rate was mainly controlled by chemisorption. Results of our study indicates potential utilisation of unmodified MS particles as an abundant and inexpensive adsorbent for low-concentration diesel oil wastewater. [ABSTRACT FROM AUTHOR]

The patriarchal clan system is an important prerequisite for the formation and development of Chinese traditional culture. The spatial layout and space usage of traditional buildings are intimately related to patriarchal culture. Thus, analyzing the spatial layout and usage is an effective way to trace the culture of traditional buildings. In this study, a typical traditional building named Huzhai in eastern Zhejiang was examined as an example. The spatial layout characteristics of Huzhai and different space usage relations corresponding to different users under the influence of the patriarchal clan system were investigated through "all lines" analysis in space syntax. In this process, traditional ritual activities were considered crucial for tracing the culture of traditional buildings in the eastern Zhejiang province. The results demonstrate that spatial layout and the usage of traditional buildings in the eastern Zhejiang province have led to "class" distinctions under the influence of patriarchal culture. The sacrificial activities of families further emphasize the class distinctions of building space. The differences in building space usage among different classes reflect the unequal distribution of social resources in China's traditional feudal society. These differences reflect the inequality of space mastership and control among different classes that are a result of the unequal distribution of social resources in China. [ABSTRACT FROM AUTHOR]

Sulfate reduction by activated carbon (AC), a model compound for solid bitumen (pyrobitumen) without gas generative potential, was studied experimentally for the first time. The simulation experiments show that hydrogen sulfide (H2S) is produced from hydrothermal reduction of calcium sulfate (CaSO4) by AC at elevated temperatures. This result demonstrates that water can also act as a hydrogen source for H2S generation in addition to hydrocarbons. The formation mechanism of H2S may undergo a three-stage sequential process with calcium sulfide (CaS) as the unstable intermediate. The reactivity of carbon is thermodynamically higher than that of methane at ≥ 150 oC but lower than that of ethane or propane in sedimentary basins. Carbon-initiated sulfate reduction follows a zero–order reaction with an apparent activation energy Ea of 172.36 kJ/mol. When extrapolated to the temperature range of typical oil and gas reservoirs (100–200 oC), the order of the rate constant is determined as propane > ethane > solid bitumen > methane in the TSR of CaSO4. Although solid bitumen contributes little to hydrocarbon gas generation, H2S derived from carbon-initiated sulfate reduction may act as an indispensable catalyst for the consequent alteration of methane by TSR in deep buried gas reservoirs with high dryness coefficient. [ABSTRACT FROM AUTHOR]

Sulfate rocks and organic sulfur from sedimentary organic matter are conventionally assumed as the original sulfur sources for hydrogen sulfide (H2S) in oil and gas reservoirs. However, a few recent experiments preliminarily indicate that the association of pyrite and hydrocarbons may also have implications for H2S generation, in which water effects and natural controls on the evolution of pyrite sulfur into OSCs and H2S have not been evaluated. In this study, laboratory experiments were conducted from 200 to 450°C to investigate chemical interactions between pyrite and hydrocarbons under hydrothermal conditions. Based on the experimental results, preliminary mechanism and geochemical implications were tentatively discussed. Results of the experiments showed that decomposition of pyrite produced H2S and thiophenes at as low as 330°C in the presence of water and n-pentane. High concentrations of H2S were generated above 450°C under closed pyrolysis conditions no matter whether there is water in the designed experiments. However, much more organic sulfur compounds (OSCs) were formed in the hydrous pyrolysis than in anhydrous pyrolysis. Generally, most of sulfur liberated from pyrite at elevated temperatures was converted to H2S. Water was beneficial to breakdown of pyrite and to decomposition of alkanes into olefins but not essential to formation of large amounts of H2S, given the main hydrogen source derived from hydrocarbons. In addition, cracking of pyrite in the presence of 1-octene under hydrous conditions was found to proceed at 200°C, producing thiols and alkyl sulfides. Unsaturated hydrocarbons would be more reactive intermediates involved in the breakdown of pyrite than alkanes. The geochemistry of OSCs is actually controlled by various geochemical factors such as thermal maturity and the carbon chain length of the alkanes. This study indicates that the scale of H2S gas generated in deep buried carbonate reservoirs via interactions between pyrite and natural gas should be much smaller than that of thermochemical sulfate reduction (TSR) due to the scarcity of pyrite in carbonate reservoirs and the limited amount of long-chained hydrocarbons in natural gas. Nevertheless, in some cases, OSCs and/or low contents of H2S found in deep buried reservoirs may be associated with the deposited pyrite-bearing rock and organic matters (hydrocarbons), which still needs further investigation. [ABSTRACT FROM AUTHOR]

In this study, thermal reduction of MgSO by NHCl was operated in the presence of water at 350 °C for 168 h. It was found that NHCl reacted with MgSO to produce HS, N and MgCl as the main products. Based on the experimental results and the assumption that the MgSO-NHCl reaction could approach a state of chemical equilibrium in natural environments over geological time scales, thermochemical program HSC 6.0 was utilized to model this geochemical process occurring in sedimentary basins. The results indicate that NH thermodynamically more easily participates in the reduction of SO than C-C normal alkanes of oil and gas at reservoir temperatures. The heat liberated from the reaction of MgSO-NHCl was estimated as 200.40-270.50 J/mol MgSO in typical oil and gas reservoirs (100-200 °C), which is much smaller than previous studies. In comparison with the minimum temperature range (100-140 °C) for conventional thermochemical sulfate reduction (TSR) using hydrocarbons, the inferred threshold temperature for initiating reduction of SOby NH in geological settings is only about 50-60 °C. The present study shows NH may play an additional role in TSR process by serving as an inorganic reductant, which has substantial implications for the formation of HS and N in sedimentary basins. [ABSTRACT FROM AUTHOR]

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H2-rich gas in carbonate reservoirs is usually attributed to thermochemical sulfate reduction (TSR). In this paper, thermal simulation experiments on the reaction system of CH4-MgSO4-H2O were carried out using autoclave at 425°C-525°C. The threshold temperature for initiating TSR is much lower than our previous studies (550°C). Properties of the reaction products were analyzed by microcoulometry, gas-chromatography (GC), Fourier transform-infrared spectrometry (FT-IR) and X-ray diffraction (XRD) methods. Thermodynamics and reaction kinetics of TSR processes were investigated on the basis of the experimental data. The results show that thermochemical reduction of magnesium sulfate with methane can proceed spontaneously to produce magnesium oxide, hydrogen sulfur, and carbon dioxide as the main products, and high temperature is thermodynamically favorable to the reaction. According to the reaction model, the calculated activation energy of TSR is 101.894 kJ/mol, which is lower than that by most previous studies. Mg2+ may have played a role of catalytic action in the process of TSR. The elementary steps of TSR and reaction mechanism were discussed tentatively. The study can provide important information on the explanation of geochemical depth limit for natural gas and on the generation of high H2S gas in deep carbonates reservoirs. [ABSTRACT FROM AUTHOR]

The TSR process may be one of the reasons to result in the natural gas destruction in deep carbonate reservoirs. The work on this field has been the subject of much research in recent years. In this paper, thermal simulation experiments on the reaction of CH4-CaSO4 were carried out using autoclave at high temperature and high pressure. The products were characterized by some advanced analytical methods. The thermodynamics and kinetics were discussed and the reaction mechanism was investigated tentatively. It is found that the reaction can proceed spontaneously to produce H2S, H2O and CaCO3 as the main products at the temperature range of 550–700°C. The activation energy and geological reaction ? action rate calculated from the kinetic model can be compared with those from previous work. The results obtained in this paper can provide important information on the explanation of geochemical depth limit for natural gas and on the exploration of gas reservoirs. [ABSTRACT FROM AUTHOR]

The traditional residence with protogenetic spatial arrangement is regarded as a critical carrier of social logic of space, which makes it an ideal object for studying the relationship between the spatial form and social context. To this end, a comparative analysis is conducted using Depthmap Software. This study is based on space syntax theory between two groups of proxies of sharp differences in spatial organization in one geomorphic unit where the natural factors show little variations, while the human factors present a bifurcating distribution. Furthermore, the study clarifies the differences among genotypes of the domestic space system. Finally, combined with historical material, it proves the dual division of regional sociocultural factors as decisive forces shaping the traditional living space and its constructed manifestations. [ABSTRACT FROM AUTHOR]

After more than 40 years' opening-up and reform, China's urbanization has entered a new type of urbanization. In order to reveal the rule of different infrastructure investments and urbanization relationships, this paper uses Shanghai as a case by applying econometric methods to study the detailed relationship between different indicators from 1990 to 2019. Firstly, we quantify that each variable has a long-term co-integration relationship with urbanization by co-integration test. And we found that the real estate is a main driving force of urbanization while the construction project investment plays an important role in promoting the urbanization rate in the studied period. Secondly, according to the Granger test, our study illustrates that each variable has a bilateral Granger relationship with urbanization while the urbanization rate has more Granger causality impact on the studied variables. Thirdly, based on impulse response test and variance decomposition analysis, we found that urbanization rate with other variables accounts for the majority of the percentage of impacts while the total investment in fixed assets and its three categories contribute a small amount to the urbanization rate. Finally, we propose policy suggestions to strengthen healthy urbanization development in Shanghai. [ABSTRACT FROM AUTHOR]