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Hydroxyquinone compounds, such as 1,4-dihydroxyanthraquinone and alizarin sulfonate, are widely used in dye manufacturing, pharmaceutical manufacturing, and other industries. However, the treatment of hydroxyquinone-containing wastewater has seldom been examined. This study used a precipitation method with barium salt to treat nano-silver industrial wastewater. The results show that barium chloride was a suitable reagent for significantly degrading COD and color from nano-silver wastewater. When the initial pH value was 10.5, 8 g of BaCl2⋅2H2O were added to 100 mL of wastewater. After reaction at 15°C for 1 h, the removal efficiencies of COD and color in the nano-silver wastewater were 85.6% and 97.1%, respectively. Simulated wastewater containing sodium alizarin-3-sulfonate (ARS) or purpurin was used to further investigate the removal mechanism of hydroxyquinone compounds. Fourier transform infrared spectroscopy, X-ray diffraction, and some related experiments showed that hydroxyquinone compounds can directly react with barium ions in the solution so as to transfer from wastewater to precipitate. In addition, the newly produced barium sulfate particles have positive surface charges, which can improve the removal efficiency of hydroxyquinone compounds due to electrostatic attraction. Keywords: Hydroxyquinone compounds, Wastewater, Barium salt, Precipitation, Electrostatic attraction

Owing to multiple tectonic events after the Late Triassic, the northern segment of the western Sichuan depression (NSWSCD) has a complex geological history of significant uplift and deeply buried. With abundant oil and gas play in the NSWSCD, the study of paleo-oil reservoir systems and early hydrocarbon accumulation in this area is of great significance for deep marine hydrocarbon distribution prediction in complex structural settings. Analysis on the northern section of the Mianyang-Changning Intracratonic Sag (MY-CN IS) and the Tianjingshan Paleouplift (TJS PU), the two Early Paleozoic tectonic units are laterally superimposed. Combined the reservoir bitumen of the Sinian Dengying Fm firstly, the biomarker (TT23/tT24, S21/S22, etc.) and Organic δ13C (lighter than 30‰) characteristics indicate that the Sinian-Jurassic paleo-oil system in the TJS PU area is the main source of Lower Cambrian organic-rich black shale. This is closely related to the superimposition and combination effects of the intracratonic sag and paleouplift. Therefore, this study establishes a geological-geochemical accumulation model through a combination of Ro and fluid inclusion data. The No. 1 fault is an important zoning fault in the NSWSCD, which significantly controls the division of the oil-gas zone. The process of paleo-oil reservoir destroyed directly only exists in the frontal deformation zone. The deep marine strata of the eastern No. 1 fault demonstrate the four-center hydrocarbon accumulation processes, which include oil generation, gas generation, gas storage, and gas preservation. The superdeep Dengying Fm has long-term exploration potential in the NSWSCD.

Abstract The Upper Ordovician–Lower Silurian mudstones (including the Wufeng, Guanyinqiao and Longmaxi Formations) in the Sichuan Basin are some of the most important shale gas plays in China. In order to enhance our understanding of the process of formation of organic carbon up to 10%, optical, microscopy and geochemical methods have been used to investigate the petrographic and geochemical characteristics of the formation. Firstly, three mudstone lithofacies were identified based on a wide variety of mudstone laminations. These are: (a) indistinctly laminated mudstone; (b) parallel-laminated mudstone; and (c) nonparallel-laminated mudstone. Then, combining with the evidence from depocenter migration, Th/U ratios and total organic carbon, the abundant organo-minerallic fabrics suggest that organic carbon was preferentially deposited and preserved in anoxic, low energy and stagnant water conditions during deposition of the Wufeng and Longmaxi Formations. On the contrary, the Guanyinqiao Formation with poor organic carbon was deposited in oxic and high-energy water conditions.

Recent advances in hydrocarbon exploration have been made in the Member Deng-2 marginal microbial mound-bank complex reservoirs of the Dengying Formation in the western Sichuan Basin, SW China, where the depositional process is regarded confusing. The microfacies, construction types, and depositional model of the Member Deng-2 marginal microbial mound-bank complex have been investigated using unmanned aerial vehicle photography, outcrop section investigation, thin section identification, and seismic reflections in the southwestern Sichuan Basin. The microbialite lithologic textures in this region include thrombolite, dendrolite, stromatolite, fenestral stromatolite, spongiostromata stone, oncolite, aggregated grainstone, and botryoidal grapestone. Based on the comprehensive analysis of "depositional fabricselithologyemicrofacies", an association between a fore mound, mound framework, and back mound subfacies has been proposed based on water depth, current direction, energy level and lithologic assemblages. The microfacies of the mound base, mound core, mound flank, mound cap, and mound flat could be recognized among the mound framework subfacies. Two construction types of marginal microbial mound-bank complex have been determined based on deposition location, mound scale, migration direction, and sedimentary facies association. Type Jinkouhe microbial mound constructions (TJMMCs) develop along the windward margin owing to their proximity to the seaward subfacies fore mound, with a northeastwardly migrated microbial mound on top of the mud mound, exhibiting the characteristics of large-sized mounds and small-sized banks in the surrounding area. Type E'bian microbial mound constructions (TEMMCs) primarily occur on the leeward margin, resulting from the presence of onshore back mound subfacies, with the smaller southwestward migrated microbial mounds existing on a thicker microbial flat. The platform margin microbial mound depositional model can be correlated with certain lateral comparison profile and seismic reflection structures in the 2D seismic section, which can provide references for future worldwide exploration. Microbial mounds with larger buildups and thicker vertical reservoirs are typically targeted on the windward margin, while small-sized microbial mounds and flats with better lateral connections are typically focused on the leeward margin. [ABSTRACT FROM AUTHOR]