Investigation on the pollution release characteristics of subgrade base materials prepared by oil-based cutting thermal desorption residues.

The preparation of oil-based cutting thermal desorption residues into subgrade materials is one of the methods of their resource utilization. While the environmental safety for subgrade materials is lack of discussions. In this study, through the semi-dynamic leaching tests, the leaching characteristics of pollutants from residues subgrade materials under extremely acidic conditions were simulated.

Temporal variation and grade categorization of methane emission from LNG fueling stations.

Natural gas is increasingly seen as the fossil fuel of choice for China as it transitions to renewable sources. The significant development of China's LNG vehicle application and fueling stations and the urgency of climate changes make it particularly important to quantify methane emission from LNG stations, where the data are extremely rare. We carried out a pilot study on direct measurement and quantitative analysis of methane emission from five LNG fueling stations located in Shandong, China following the standard stationary EPA OTM 33A method.

Molecular dynamics simulation study of covalently bound hybrid coagulants (CBHyC): Molecular structure and coagulation mechanisms.

Covalently-bound organic silicate-aluminum hybrid coagulants (CBHyC) have been shown to efficiently remove low molecular weight organic contaminants from wastewater. However, the interaction dynamics and motivations during the coagulation of contaminant molecules by CBHyC are limited. In this study, a molecular dynamics (MD) simulation showed that CBHyC forms core-shell structure with the aliphatic carbon chains gather inside as a core and the hydrophilic quaternary ammonium-Si-Al complexes disperse outside as a shell.

Quantitative assessment of the contribution of soil organic matter functional groups and heteroatoms to PAHs adsorption based on the COSMO-RS model.

Soil organic matter (SOM) is considered as a pivotal factor influencing the adsorption of pollutants. However, few prior quantitative investigations of the SOM functional group distribution to the contaminants' fate have been conducted. In this paper, the SOM cluster method based on COSMO-RS theory has been conducted to illustrate the chemical composition variables of SOM that affect the polycyclic aromatic hydrocarbons (PAHs) fate in quantitative terms.

Tracing sources of oilfield wastewater based on excitation-emission matrix fluorescence spectroscopy coupled with chemical pattern recognition techniques.

In order to prevent the illegal discharge of oilfield wastewater, this work proposed excitation-emission matrix fluorescence (EEMF) spectroscopy coupled with two kinds of chemical pattern recognition methods for tracing the sources of oilfield wastewater. The first pattern recognition method was built from the relative concentrations extracted by alternating trilinear decomposition (ATLD) based on partial least squares-discriminant analysis (PLS-DA) algorithm, and the other one was modeled based on strictly multi-way partial least squares-discriminant analysis (N-PLS-DA). Both methods showed good discrimination abilities for oilfield wastewater samples from three different sources.

Use of Betaine-Based Gel and Its Potential Application in Enhanced Oil Recovery.

In this paper, a betaine-based gel containing 2.0% erucamide propyl betaine (EAPB), 0.5% oleic acid amide propyl betaine (OAPB), and 0.

Assessing the quality of the soil around a shale gas development site in a subtropical karst region in southwest China.

The construction of shale gas facilities disturbs large areas of land and affects soil quality and function. In this study, we investigated the properties (including physical, chemical, and microbiological indicators) of soil at three different distances from a shale gas development site (<30 m, 30-50 m, and 50-100 m) in a karst area in 2017 and 2020. Our results showed that the soil water content; available carbon, nitrogen, and phosphorus concentrations; total nitrogen and total phosphorus concentrations; microbial biomass, and enzyme activities increased (P < 0.

A simple empirical model for phenanthrene adsorption on soil clay minerals.

Soil clay minerals are effective substrate adsorbents of polycyclic aromatic hydrocarbons (PAHs) in natural soil. The adsorbed PAHs result in long-term contamination of soils. In this paper, a typical PAH phenanthrene (Phe) and nine high purity clay minerals are selected as representative PAH pollutants and adsorbents, respectively.

Design of a Microbial Remediation Inoculation Program for Petroleum Hydrocarbon Contaminated Sites Based on Degradation Pathways.

This paper analyzed the degradation pathways of petroleum hydrocarbon degradation bacteria, screened the main degradation pathways, and found the petroleum hydrocarbon degradation enzymes corresponding to each step of the degradation pathway. Through the Copeland method, the best inoculation program of petroleum hydrocarbon degradation bacteria in a polluted site was selected as follows: single oxygenation path was dominated by , hydroxylation path was dominated by OB3b, secondary oxygenation path was dominated by , secondary hydroxylation path was dominated by , double oxygenation path was dominated by ADP1, hydrolysis path was dominated by , and CoA path was dominated by GS-15 to repair petroleum hydrocarbon contaminated sites. The Copeland method score for this solution is 22, which is the highest among the 375 solutions designed in this paper, indicating that it has the best degradation effect.

Comprehensive chemical characterization of dissolved organic matter in typical point-source refinery wastewaters.

In petroleum refineries, the electric desalting, distillation, and stripping processes could generate large amounts of wastewaters that contain toxic substances. In this study, eight wastewater samples were collected from the three typical refining processes for comprehensive chemical characterization of the dissolved organic matter (DOM) using excitation emission matrix fluorescence spectroscopy, gas chromatography-mass spectrometry, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Results showed that protein-like components and benzene were ubiquitous in all these wastewaters.

Electrocoagulation treatment of shale gas drilling wastewater: Performance and statistical optimization.

Shale gas drilling wastewater is a challenging waste stream generated in gas industries. It is a mixture of different organic and inorganic compounds. Treatment of this complex wastewater relies on a suitable technology for the removal of small suspended particles and dissolved elements.

A rapid change in microbial communities of the shale gas drilling fluid from 3548 m depth to the above-ground storage tank.

Despite the growing body of studies on the various fracturing phrases, the research on the differences between subterranean and surface microorganisms at shale gas drilling sites is still limited. Generally, shale gas development and the production process are divided into drilling and fracturing. The distribution of microbial communities in the latter has been paid some attention, but a deficit remains in terms of our understanding of the microbial community in the former, especially for the phase of drilling flowback and drilling flowback surface.

Facile Approach to Fabricate a High-Performance Superhydrophobic Mesh.

When superhydrophobic meshes are used for oil/water separation, high flux and high intrusion pressure are usually compromised. Herein, a high-performance superhydrophobic stainless steel mesh membrane with a hairy-like poly(divinylbenzene) (PDVB) coating is fabricated by precipitated cationic polymerization. The synthesis is facile, which is completed in one step at ambient temperature within a short time, i.

A study on the reaction mechanism of microwave pyrolysis of oily sludge by products analysis and ReaxFF MD simulation.

The products distributions of oily sludge (OS) pyrolysis was fully explored by combining the pyrolysis experiments and molecular simulation, to help to deeply understand this complicated reaction process. The results of products analysis indicated that the main reactions include chain-breaking reactions, dehydrogenation reactions, aromatization reactions, alkylation reactions, and dehydrogenation condensation reactions. Microwave pyrolysis of model OS comprised of n-dodecane and OS sediment were conducted to further explore the specific reaction during the pyrolysis process, and the results showed that the pyrolysis of saturated alkanes begins at 350℃, and dehydrogenation condensation begins at 500℃.

Emission characteristics of nitrogen and sulfur containing pollutants during the pyrolysis of oily sludge with and without catalysis.

The oily sludge is a category of hazardous solid waste generated in petrochemical industries. Pyrolysis is an efficient approach for sustainable treating the oily sludge with limited environmental impacts, but the pollutant emission during the pyrolysis process is still a big challenge. Herein, the emission characteristics of nitrogen (N) and sulfur (S) containing pollutants during the oily sludge pyrolysis with and without catalysis was illuminated via a TG-FTIR-MS system (ThermoGravimetric-Fourier Transform InfaRed-Mass Spectroscopy).

Degradation of hydroxypropyl guar gum at wide pH range by a heterogeneous Fenton-like process using bentonite-supported Cu(0).

To seek for efficient Fenton-like oxidation processing for treatment of waste fracturing fluid containing hydroxypropyl guar gum (HPGG), in heterogeneous reaction, five bentonite-supported zero-valent metal catalysts were prepared by liquid-phase reduction. The results showed that the bentonite-supported zero-valent copper exhibited best catalytic performance, attributed to the high dispersion of active sites of zero-valent copper. The effects of the most relevant operating factors (HO concentration, catalyst dosage, temperature and pH) were evaluated in detail.

Molecular transformation of dissolved organic matter in refinery wastewater.

Dissolved organic matter (DOM) has an important impact on the water treatment and reuse of petroleum refinery wastewater. In order to improve the treatment efficiency, it is necessary to understand the chemical composition of the DOM in the treatment processes. In this paper, the molecular composition of DOM in wastewater samples from a representative refinery were characterized.

Roles of Oxygen Vacancies in the Bulk and Surface of CeO for Toluene Catalytic Combustion.

Catalytic combustion technology is one of the effective methods to remove VOCs such as toluene from industrial emissions. The decomposition of an aromatic ring via catalyst oxygen vacancies is usually the rate-determining step of toluene oxidation into CO. Series of CeO probe models were synthesized with different ratios of surface-to-bulk oxygen vacancies.

Bioelectrochemical remediation of Cr(VI)/Cd(II)-contaminated soil in bipolar membrane microbial fuel cells.

Heavy-metal contaminated soils post great environmental and health concerns. In this study, Cr and Cd which are frequently observed in contaminated soils, were selected as representatives of hazardous heavy metals because of their different redox potentials and electric charges. Cr(VI)-, Cd(II)-, Cr(VI)/Cd(II)-contaminated soils were remediated in two-chamber air-cathode MFCs, in order to investigate the remediation of soil contaminated by single heavy metal and mixed heavy metals.

A comparative study among machine learning and numerical models for simulating groundwater dynamics in the Heihe River Basin, northwestern China.

Groundwater is unique resource for agriculture, domestic use, industry and environment in the Heihe River Basin, northwestern China. Numerical models are effective approaches to simulate and analyze the groundwater dynamics under changeable conditions and have been widely used all over the world. In this paper, the groundwater dynamics of the middle reaches of the Heihe River Basin was simulated using one numerical model and three machine learning algorithms (multi-layer perceptron (MLP); radial basis function network (RBF); support vector machine (SVM)).

The Effect of the Hydrate Antiagglomerant on Hydrate Crystallization at the Oil-Water Interface.

Clathrate hydrates are ice-like compounds consisting of small gas molecules enclosed in water molecule cages. The formation of gas hydrate in oil and gas pipelines may result in flow assurance failure and serious safety and environmental concerns. Antiagglomeration is a promising method to mitigate gas hydrate risks in hydrocarbon flowlines.