This study employed lignin-sulfonated (LS) to develop biobased carbon materials (LS-Cs) through a sulfur-doping approach to enhance their physicochemical properties, adsorption capabilities, and energy storage potentials. Various characterization techniques, including BET surface area analysis, SEM imaging, XPS, Raman spectroscopy, and elemental composition (CHNS), were employed to assess the quality of the LS-Cs adsorbent and electrode samples. Response Surface Methodology (RSM) was utilized for optimizing the two main properties (specific surface area, A
Abstract Naturally occurring layered double hydroxide mineral, brucite (BRU), was compared with hydromagnesite (HYD) and a commercial Mg-rich mineral adsorbent (trade name AQM PalPower M10) to remove antimony (Sb) from synthetic and real wastewaters. The BRU and HYD samples were calcined prior to the experiments. The adsorbents were characterized using X-ray diffraction, X-ray fluorescence, and Fourier transform infrared spectroscopy. Batch adsorption experiments were performed to evaluate the effect of initial pH, Sb concentration, adsorbent dosage, and contact time on Sb removal from synthetic wastewater, mine effluent, and textile industry wastewater. Several isotherm models were applied to describe the experimental results. The Sips model provided the best correlation for the BRU and M10. As for the HYD, three models (Langmuir, Sips, and Redlich–Peterson) fit well to the experimental results. The results showed that the adsorption process in all cases followed the pseudo-second-order kinetics. Overall, the most efficient adsorbent was the BRU, which demonstrated slightly higher experimental maximum adsorption capacity (27.6 mg g -1 ) than the HYD (27.0 mg g -1 ) or M10 (21.3 mg g -1 ) in the batch experiments. Furthermore, the BRU demonstrated also an efficient performance in the continuous removal of Sb from mine effluent in the column mode. Regeneration of adsorbents was found to be more effective under acidic conditions than under alkaline conditions.
Natural gas hydrate (NGH) has attracted much attention as a new alternative energy globally. However, evaluations of global NGH resources in the past few decades have casted a decreasing trend, where the estimate as of today is less than one ten-thousandth of the estimate forty years ago. The NGH researches in China started relatively late, but achievements have been made in the South China Sea (SCS) in the past two decades. Thirty-five studies had been carried out to evaluate NGH resource, and results showed a flat trend, ranging from 60 to 90 billion tons of oil equivalent, which was 2–3 times of the evaluation results of technical recoverable oil and gas resources in the SCS. The big difference is that the previous 35 group of NGH resource evaluations for the SCS only refers to the prospective gas resource with low grade level and high uncertainty, which cannot be used to guide exploration or researches on development strategies. Based on the analogy with the genetic mechanism of conventional oil and gas resources, this study adopts the newly proposed genetic method and geological analogy method to evaluate the NGH resource. Results show that the conventional oil and gas resources are 346.29 × 108 t, the volume of NGH and free dynamic field are 25.19 × 104 km3 and (2.05–2.48) × 106 km3, and the total amount of in-situ NGH resources in the SCS is about (4.47–6.02) × 1012 m3. It is considered that the resource of hydrate should not exceed that of conventional oil and gas, so it is 30 times lower than the previous estimate. This study provides a more reliable geological basis for further NGH exploration and development.
The majority of oil and gas resources in the world are related to saline sediments, which mainly occur in sedimentary strata in the form of cap rocks or salt-associated shales. A large number of shale oil resources have been discovered in the saline shale sediments of the Cenozoic terrestrial lake basin in China. The hydrocarbon generation ability and the reservoir capacity of shale control the oil and gas generation. The reservoir capacity is mainly characterized by pore type, structure and porosity. Most of China's shale oil and gas resources belong to salt-bearing formations. The role of gypsum-salt rocks in the formation and evolution of organic matter (OM) in such formations has received extensive attention. However, systematic understanding is lacking. Research on the pore formation and evolution in shale under the action of gypsum-salt rock sediments is especially weak. Taking the shales in the third member of the Shahejie Formation (Es3) of the Bohai Bay Basin as an example, the influence of halite on the formation and evolution process of pores was studied in this paper. The results show that halite and gypsum minerals were associated with OM, which made them more likely to develop OM pores. The samples with a high halite mineral content (HC) are more developed regarding the pore volume and specific surface area than those with a low HC. The formation of thick salt rocks is influenced by factors of deep thermal brine upwelling, sea erosion and arid environments. The frequent alternation between humid and arid environments led to the outbreak and death of organisms and the precipitation of gypsum-salt rock, which formed the simultaneous deposition of OM and halite minerals. Finally, we have established a model of shale pore evolution under the participation of the gypsum-salt rock, and halite minerals contribute to pore development in both Stage II and Stage IV. This study provides strong microscopic evidence for the pore system formation and evolution in salt-bearing reservoirs.
Precipitation as ettringite (Ca 6 Al 2 (SO 4 ) 3 (OH) 12 •26H 2 O) is an effective method for sulphate removal from mine water.The addition of calcium hydroxide and aluminium to sulphate-containing mine water in stoichiometric amounts induces an increase in pH to approximately 12.5, leading to the precipitation of ettringite.Typically, aluminium salts are used as the source of aluminium; however, in this research, an electrochemical dosage of aluminium was used, and the results were compared with the results of chemical ettringite precipitation as well as the results of computational simulations of sulphate removal.The mine water sulphate concentration was reduced 99.0% and 98.6% from the initial 1,060 ± 20 mg L -1 using a current density of 28 mA cm -2 in electrochemical aluminium dosing and chemical aluminium dosing, respectively, which was close to the theoretical 100% sulphate removal.When using the current density of 28 mA cm -2 in the electrochemical aluminium dosing, the recovered ettringite purity was 92.5%, which was almost the same as the 92.6% purity in the chemical aluminium dosing characterised with X-ray diffraction and Rietveld analysis.The results indicate that the electrochemical dosing of aluminium could be an alternative to aluminium salt application in ettringite precipitation.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
