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Litopenaeus vannamei, a highly adaptable shrimp species known for its growth, thrives in environmental conditions with proper water quality. However, salinity stress poses a significant challenge, compromising shrimp survival and growth. To optimize shrimp feed, the inclusion of alginate and Spirulina sp. offers benefits such as enhanced growth and resistance to environmental stress. This research aims to assess the impact of adding Spirulina sp., alginate, and their combination on the survival rate, resistance to the salinity shock test, and growth of L. vannamei. In this study, a completely randomized design (CRD) method with nine different feed doses was used. The treatments included control, supplementation of Alg 1 (alginate 1 g/kg feed), Alg 3 (alginate 3 g/kg feed), Alg 5 (alginate 5 g/kg feed), Sp 3 (spirulina 3 mg/kg feed), Sp 6 (spirulina 6 mg/kg feed), Sp 9 (spirulina 9 mg/kg feed), AS 1+1 (alginate 1 g/kg feed + spirulina 1 mg/kg feed), AS 2+3 (alginate 2 g/kg feed + spirulina 3 mg/kg feed), and AS 3+5 (alginate 3 g/kg feed + spirulina 5 mg/kg feed). The supplementation of feed was given during the fourteen-day rearing period. The results of the study show that the supplementation of Sp 9 (spirulina 9 mg/kg feed) led to a significant growth (α = 0.05). All treatments supplemented with alginate and/or Spirulina sp. water extract had a significant effect (α = 0.05) on the resistance to the salinity shock test. The different treatments in L. vannamei feed supplementation significantly influenced (α = 0.05) shrimp survival. Polysaccharides and antioxidant properties in alginate and Spirulina sp. have an important role in increasing the growth and resistance to salinity shock of L. vannamei. [ABSTRACT FROM AUTHOR]

Geothermal energy has abundant reserves, is clean and environmentally friendly, and is an important alternative energy source for future oil and gas resources. However, during the development of dry hot rock geothermal energy, scaling in hydraulic fractures can easily lead to a decrease in water injection and thermal recovery capacity, affecting the effectiveness of thermal recovery. By comparing the differences in the temperature of the produced liquid in the enhanced dry hot rock geothermal system before and after scaling, the impact of scaling on geothermal development was analyzed, thereby proving the necessity of scale removal in the dry hot rock development process. The influence of different factors on the geochemical response characteristics of dry hot rocks during the descaling process using pH modified fluids was explored. The research results indicate that the generation of precipitates such as calcium carbonate in cracks can lead to a gradual decrease in the temperature of the produced liquid during geothermal development. During the experiment, the temperature of the extracted liquid decreased from the initial 178°C to the final 90°C. In addition, when the pH of the injected liquid is 4.5, the generation of precipitates such as calcium carbonate in hydraulic fractures is minimal, resulting in better geothermal development and the highest temperature of the produced liquid. However, when designing the pH value of the injection solution, it is still necessary to consider the corrosive and destructive effects of the injection solution's acidity and alkalinity on the development system. Finally, due to the sufficient heat exchange between injected water and dry hot rock at lower injection rates, the temperature of produced water will be higher. However, the effectiveness of geothermal development will deteriorate with the increase of injection rate, so it is more reasonable to design the injection rate of injected water at 6 L/min. Research can provide theoretical basis and technical support for the efficient development of dry hot rock geothermal resources. [ABSTRACT FROM AUTHOR]

The potential of B20 cluster decorated with alkali metals (AM = Li, Na, and K) and alkaline earth metals (AEM = Ca, Mg, and Be) to adsorb hydrogen molecules is investigated using density functional theory (DFT). The Bader's topological parameters suggest the presence of non-bonded interaction between the bare structures and H2 molecules. Global reactivity descriptor values confirm that the structures remain stable even after the adsorption of H2 molecules. The results indicate that Na adorned B20 (B20Na2) can store up to 12H2 molecules, with a hydrogen storage capacity of 8.33 wt% and an average adsorption energy is 0.127 eV/H2. The findings suggest that B20 cluster decorated with AM and AEM have the ability to be a promising hydrogen storage material. Additionally, to gain insights into the adsorption and desorption behaviors of H2 molecules, ADMP molecular dynamics simulations methods were performed at room temperatures. [ABSTRACT FROM AUTHOR]

Produced water (PW) presents a significant challenge as a complex wastewater stream, necessitating thorough treatment prior to disposal or further reuse. This study is dedicated to the assessment, reproduction and upgrading of literature‐based preparation protocols for synthetic PW at the tertiary treatment stage; more specifically those methods utilizing high‐pressure homogenizers and ultrasonication. The objective was to produce synthetic model water that can be employed as a standardized controllable medium for optimization experiments of PW treatment techniques. This synthetic medium should facilitate the investigation of specific challenges associated with PW tertiary treatment, independent of the different and often unpredictable composition of real PW. The refined methods were modified for the application in lab‐scale research investigating the use of membrane filtration as tertiary treatment step. [ABSTRACT FROM AUTHOR]

One of the most common problems encountered in the oil industry is the microbiologically induced corrosion (MIC) of steel equipment by the produced water (PW). In this aspect, PW sample, which is known to contain microorganisms, was taken from Adıyaman oil field and used in corrosion tests of N80 tubing steel. Two different laboratory scale systems, test (with non-sterile PW) and control (with sterile PW), were set up and operated at 70°C over 720 h. For corrosion analysis, the coupons were removed from the laboratory-scale systems at certain time intervals and, gravimetric and electrochemical analyses were carried out. The surface of the coupons was examined by scanning electron microscopy (SEM). The corrosion rates of the test coupons obtained from gravimetric analyses were higher than the control ones during the experiment, and the test coupons were 1.46 times more corroded at the end of the experiment. Additionally, it was determined that the current values of the test coupons were significantly higher than those in the control system (p<0.05). The results of corrosion analyses pointed out that N80 steel was corroded microbiologically. SEM analysis showed that microorganisms were present among the corrosion products. The corrosion data obtained from the control system also indicated that the PW was aggressive for N80 steel. [ABSTRACT FROM AUTHOR]

Considering that high-purity fresh water is employed in the green production of hydrogen via commercial water electrolyzers and that over 80% of the global population faces significant water safety risks, it is essential to explore alternative water sources. One such alternative is the use of produced water from oil extraction processes. Hence, the main objective of this study is to evaluate the effect of the oil content of oilfield production water on the production of green hydrogen by electrolysis in the presence of carbon quantum dots (CQDs). For this purpose, various electrochemical techniques, such as linear sweep voltammetry (LSV), cyclic voltammetry (CV), and potentiometry, were used to identify the effect of crude oil during hydrogen production. Thermogravimetric analysis (TGA), mass spectrometry (MS), and Fourier-transform infrared spectroscopy (FTIR) were employed to discern the adsorption of crude oil onto the electrodes, quantify the gas fractions generated during the process and identify the functional groups present after the procedure, respectively. Also, optical microscopy was employed to follow the droplet size in the emulsion. The results show that using CQDs affects the Faradaic efficiency, which increases from 77% to 83% with the incorporation of CQDs. In the presence of CQDs, the effects generated by the presence of the oil are inhibited at low oil concentrations. On the contrary, hydrogen production increases by 10.0% (0.1 mL/min) with a faradaic efficiency of 83% and a half-cell efficiency of 41%, compared to the record obtained with the maximum concentration of emulsified crude oil (400 mg/L). The mean size of the initial emulsion droplets was 3.4 μm. At the end of the test, there was evidence of complete breakage of the emulsion due to the effect of the applied electric field. No evidence of adsorption of crude oil on graphite electrodes during electrolysis is observed based on the tests. It has been shown that green hydrogen production from crude oil production water is feasible due to the proposed disruptive electrolytes in the produced water, which inhibit the effect of oil content in the O/W emulsion. This allows the implementation of a new green energy production initiative aligned with the global goal of achieving net zero emissions (NZE) by 2050. The current investigation presents a prospective alternative for harnessing the 18 kW electrical energy potential employed within emulsion-breaking processes within a Colombian field for treatment of around 1000 bpd. This alternative offers a theoretical potential for hydrogen production, approximating 7.36 kW, thus representing a promising opportunity for practical field deployment. • CQDs in electrolysis enhance green hydrogen production efficiency from oilfield-produced water due to their conductive properties. • CQDs significantly increases Faradaic efficiency, inhibiting crude oil's negative effects on hydrogen generation. • Optimized electrolysis with CQDs result in 10% higher hydrogen production at high concentrations of emulsified crude oil. • CQDs mitigate crude oil's negative effects on the system, such as reduced conductivity and electrode degradation. • Gas analysis demonstrates the feasibility of converting oilfield production water into a valuable resource for green energy. [ABSTRACT FROM AUTHOR]

Microbial communities have long been observed in oil reservoirs, where the subsurface conditions are major drivers shaping their structure and functions. Furthermore, anthropogenic activities such as water flooding during oil production can affect microbial activities and community compositions in oil reservoirs through the injection of recycled produced water, often associated with biocides. However, it is still unclear to what extent the introduced chemicals and microbes influence the metabolic potential of the subsurface microbiome. Here we investigated an onshore oilfield in Germany (Field A) that undergoes secondary oil production along with biocide treatment to prevent souring and microbially induced corrosion (MIC). With the integrated approach of 16 S rRNA gene amplicon and shotgun metagenomic sequencing of water-oil samples from 4 production wells and 1 injection well, we found differences in microbial community structure and metabolic functions. In the injection water samples, amplicon sequence variants (ASVs) belonging to families such as Halanaerobiaceae , Ectothiorhodospiraceae, Hydrogenophilaceae, Halobacteroidaceae, Desulfohalobiaceae, and Methanosarcinaceae were dominant, while in the production water samples, ASVs of families such as Thermotogaceae, Nitrospiraceae, Petrotogaceae, Syntrophaceae, Methanobacteriaceae, and Thermoprotei were also dominant. The metagenomic analysis of the injection water sample revealed the presence of C1-metabolism, namely, genes involved in formaldehyde oxidation. Our analysis revealed that the microbial community structure of the production water samples diverged slightly from that of injection water samples. Additionally, a metabolic potential for oxidizing the applied biocide clearly occurred in the injection water samples indicating an adaptation and buildup of degradation capacity or resistance against the added biocide. • Integrated approach of 16S rRNA gene amplicon and shotgun metagenomic sequencing of water-oil samples. • Differences in microbial community structure and metabolic functions between production wells and injection wells. • Metabolic potential for oxidizing the applied biocide in the injection water samples. • Insights of in situ formaldehyde oxidation in oil reservoirs well. [ABSTRACT FROM AUTHOR]

Petroleum-produced water is the primary effluent generated during the oil extraction process, presenting high flow rates, and containing a series of chemical components that are harmful to the environment, such as dissolved manganese. The proof of metrological compatibility between laboratories and different test methods or techniques is an analytical challenge when complying with environmental laws and regulations, which is the aim of this study. The first step of this study was to compare the results of manganese content in real test samples of produced water between some laboratories that used different test methods, that is, flame atomic absorption spectrophotometry, inductively coupled plasma optical emission spectroscopy, and inductively coupled plasma mass spectrometry. Based on one-way analysis of variance, systematic errors were found. The following step was to visit a specific lab, where one could confirm the relevance of the wavelength parameters, operating conditions for the view configuration, and effects of the saline matrices. Finally, a compatibility assessment between the reference laboratory and a new laboratory, which implemented and validated its analytical methodology based on these analytical adjustments, and the experiences and lessons learned in the previous step, was undertaken by a paired t-test. [ABSTRACT FROM AUTHOR]

Long-term biological time series are essential to evaluate previous responses of organisms to alterations in the environment. Biochronological methods based on archival fish otoliths allow setting such time series, but their predictive potential as proxies of past environmental conditions is still underexploited. In this study, we reconstructed growth variation in European sprat (Sprattus sprattus) in the Baltic Sea from 1956 to 2020 based on measurements of the archived otoliths. We used otolith annual increment widths as a proxy of fish somatic growth. We showed significant negative relationships between sprat growth and sprat spawning stock biomass (SSB) associated with strong intraspecific competition for limited food resources. We also identified a link between sprat growth and water salinity—indicator of the ecosystem's hydrological situation. For the first time, we estimated the SSB prior to the period of available historical data based on the otolith-derived information on the past growth variation. This estimation was based on the strong relationships between SSB and fish growth, complemented with temperature and salinity variables as predictors (R2 = 0.62). A model trained on at least 40 years of data from the more recent past allows us to robustly back-estimate SSB. This study provides new multidecadal data, giving insights into environmental factors affecting the growth of Baltic sprat, and demonstrates the potential of otolith-based biochronology for the provisioning of independent indices of the historical fish stock size. The proposed methodological approach broadens the portfolio of possible applications of the biochronology time series to indicate past changes in the aquatic environment. [ABSTRACT FROM AUTHOR]

Produced water is the main waste stream in the oil and gas sector, with significantly greater concentrations of hydrocarbons, heavy metals, and other contaminants. Several works and technologies were developed to reuse the produced water in many applications including drilling and completion fluids. However, in general, a pretreatment is required. According to our knowledge, the reuse of produced water in non-aqueous drilling is still not reported. Therefore, this work proposed the formulation of olefin-based drilling fluids containing between 20-40% of untreated produced water. Through factorial experimental design, the influence of produced water, emulsifier, and viscosifier on the properties of the formulated emulsions was investigated. Our results show that produced water without treatment can be used as an aqueous phase for olefin-based drilling fluids, with the best formulation being the test that has RO/A = 60/40, emulsifier concentration of 14.26 kg/m³ and viscosifier concentration of 2.85 kg/m³. The well-cleaning properties of the proposed formulation were evaluated through numerical simulation in a well with high inclination. The results showed that the hole cleaning was not affected by using untreated produced water in the fluid formulation. The results presented here open a new possibility to reuse produced water in drilling operations without performance loss. [ABSTRACT FROM AUTHOR]

In offshore platforms, elevated costs due to effluent quantity, logistics, space limitation, and availability of solvents hinder produced water treatment, leading petrochemical industries to develop feasible backup strategies to create a sustainable treatment of this byproduct. This context motivates the present study's proposal to use diesel oil in offshore facilities as onboard fuel to remove naphthenic acids (model compound of the dissolved organic fraction) through liquid-liquid extraction. Results achieved out in a separation funnel using synthetic produced water ([cyclohexanecarboxylic naphthenic acid] 0 = 500 mg/L) and diesel as an extracting solvent (10%) present high removal efficiencies of about 60% of the cyclohexanecarboxylic naphthenic acid present in synthetic water produced at pH 2% and 42% at pH 4. The characterization analysis of the diesel oil after the liquid-liquid extraction process indicates that it is suitable for reuse as fuel within the offshore platform dispensing further treatments. [Display omitted] [ABSTRACT FROM AUTHOR]

Wastewater generated as a result of extracting oil and gas from subterranean reservoirs is known as produced water. There are suspended solids, dissolved solids, organic and inorganic compounds, emulsified oil, and other substances. Untreated produced water may have a harmful impact on the ecology. In this study, waste from Coronavirus Face Masks was used as an adsorbent dosage for produced water adsorption discharged from the south Oil Company – Basra. In each trial, a 250 ml beaker held 100 ml of generated water, temperature (25, 35 and 50)°C, adsorbent dosage (2, 5 and 10)g, Investigations were also conducted on contact duration (30, 60, and 90) minutes, pH at (2, 4, 6, and 8), and mixer rotational speed (200 rpm). The ideal parameters for removing 97 percent of the oil were determined to be 25°C, pH 8, 5 g of adsorbent, and 90 min of contact time using a generic model built from the experimental data. Other oil removal equilibrium isotherm models did not adequately account for the experimental results, as did the Langmuir equation. The most common type of adsorption used in kinetics research is pseudo-first-order adsorption. [ABSTRACT FROM AUTHOR]

The corrosion behavior of C20 pipeline steel was studied under Fe oxide and sand deposits in oilfield produced water containing sulfate‐reducing bacteria (SRB) via electrochemical techniques and surface analyses. A galvanic current of about 2 μAcm−2 was detected when the Fe oxide deposited sample and the bare steel were coupled in zero resistance ammeter (ZRA) mode, with the former being the anodic member of the couple. The Fe oxide deposited steel recorded severe localized corrosion after 14 days of testing in the SRB inoculated oilfield produced water. Corrosion severity decreased on the sand‐deposited steel, with general corrosion as the dominant morphology of surface attack. The development of product film was a vital factor in steel corrosion under the Fe oxide deposit. [ABSTRACT FROM AUTHOR]

Membrane distillation integrated with crystallization (MDC) holds promise for sustainable produced water treatment. Addressing challenges like fouling and wetting, common due to high inorganic content and oil-grease presence, requires efficient pretreatment for stable performance. To establish a compact, manageable treatment solution, we examined a pilot-scale integrated electro-coagulation (EC) - microfiltration (MF) system as pretreatment. This step produced 3600 L daily, significantly improving water quality. A remarkable 40% reduction in total organic carbon, 22-fold decrease in total suspended solids, and 600-fold decrease in turbidity underscore its effectiveness. This enhances the suitability for subsequent membrane distillation. In addition, a significant decrease in fouling and scale formation was observed. Long-term batch and continuous MD tests investigated crystallization between MD cycles that prevents significant flux decline. Implementing continuous MDC increased total water recovery six-fold, with stable membrane performance over six cycles, recovering approximately 10% of feed per cycle. These observations highlight the scalable potential of the less-explored integrated treatment (EC-MF-MDC) for effective produced water treatment. This study suggests the viability of the integrated approach for sustainable, larger-scale produced water treatment. [Display omitted] • Membrane distillation integrated with crystallization shows promise technology. • Pilot-scale EC-MF system yields 3600 L daily, boosting water quality. • 40% carbon reduction, 22-fold TSS decrease, enhanced suitability. • Integrated EC-MF-MDC offers sustainable produced water treatment. • Membrane crystallization enhances the MD performance. [ABSTRACT FROM AUTHOR]

Manganese-oxidizing bacteria (MOB) may be found in produced water (PW) due to its manganese (Mn) content and may survive by oxidizing Mn. Additionally, different Mn concentrations can alter the growth of MOB, their growth phases, and their ability to produce MnOx. To investigate these aspects, the presence of MOB was investigated in PW. The MOB isolate was identified by molecular and biochemical methods. Its ability to oxidize Mn was also evaluated using Mn-oxidation agar medium with different Mn concentrations (0.15, 0.5, 1, 2, and 3 g/L). The strain was identified as Bacillus zhangzhouensis. The results showed that the Mn concentrations affected both the strain's growth and its ability to oxidize Mn. Triauxic growth was observed at the concentrations of 0.5 g/L and 1 g/L where the bacterium showed the most intensive growth and Mn-oxidation. In contrast, the concentrations of 2 and 3 g/L inhibited bacterial growth. This is the first study reporting the isolation of Mn-oxidizing B. zhangzhouensis from oil environment. The oil industry should consider the presence of this bacterium as it might be a potential risk for microbiologically influenced corrosion. [ABSTRACT FROM AUTHOR]

This paper reviews the characteristics of membrane distillation technology and the current research progress and hot issues, and compares the latest research progress of membrane distillation technology in terms of membrane material characteristics, membrane wetting and pollution, membrane material modification, research and application in oil and gas field produced water, etc. Membrane distillation technology was found to have great potential for the treatment of oilfield talent effluent, and the energy consumption limitation of membrane distillation technology can be improved by using low-grade thermal energy and coupling other processes. The improvement of membrane materials to obtain high flux and pollution resistant hydrophobic membranes is the key to achieve industrial application of membrane distillation technology. [ABSTRACT FROM AUTHOR]

The identification and assessment of plant stress using wetland satellite images is a major task in remote sensing. In this study, one of the largest constructed wetlands (CWs) in the world, located in the Sultanate of Oman, was examined, assessed, and evaluated using remote sensor data from Sentinel-2. This CW system treats produced water generated during oil exploration activities in a desert environment; thus, CW vegetation is subjected to stress induced by oil hydrocarbons and water salinity. This study examined the plant stress and detected changes between the years of 2017 and 2019. Sentinel satellite images were evaluated for vegetation status extraction. The Normalized Difference Vegetation Index (NDVI), Modified Soil-Adjusted Vegetation Index (MSAVI), and Normalized Difference Salinity Index (NDSI) were used to evaluate the vegetation change. The results showed a comprehensive mapping identification of the plant stress and water flow parameter factors including oil in water contamination (OIW), dissolved oxygen (DO), water temperature (WT), and water conductivity (COND). Among the three indices, it was found that the NDVI showed a very good correlation with all parameters in both years with average R2 = 0.78, 0.67, 0.75, and 0.60 for OIW, DO, WT, and COND, respectively. The same trend was found for MSAVI but with R2 = 0.59, 0.48, 0.55, and 0.56 for OIW, DO, WT, and COND, respectively. This shows that the NDVI performed better than the MSAVI in evaluating the water flow parameters. On the other hand, the NDSI showed a strong correlation with one flow parameter, that is, water conductivity, especially at the outlet cells of the CW with R2 = 0.86 and 0.82 for winter time and summer time, respectively. The synchronization and correlation between the water flow parameters and remote sensing vegetation indices in this study lead to a new approach to large-scale landscape wetland monitoring that improves and helps predict any degradation or stress on vegetation growth. Furthermore, the results of this work can help decision makers potentially modify the wetland design and water flow path to improve future expansion phases. The mapping of such a critical and massive industrial CW should consider the use of high spatial resolution sensors where identifications and classifications are further improved. In summary, this research demonstrates that it is feasible to estimate vegetation stress within the constructed wetland using remote sensing techniques across extensive regions when an ample dataset comprising field data, satellite imagery, and supporting information is accessible. [ABSTRACT FROM AUTHOR]

The existence of fine oil droplets that are difficult to coalesce greatly reduces the oil–water separation efficiency of alkali‒surfactant‒polymer (ASP) flooding-produced water. In order to improve the oil–water separation efficiency and promote the reinjection of ASP-produced water, a novel cationic graft copolymer CDC was obtained by ultrasonically assisted copolymerization of chitosan and dimethyl diallyl ammonium chloride under the initiation of cerium ions. The copolymer CDC was characterized by FT-IR, XRD, TGA and SEM, and it was confirmed that the grafting reaction proceeded successfully. The flocculation effect of copolymer CDC on ASP-produced water (Nan 4–8, pH = 7.83; Sanyuan-6, pH = 9.95) was investigated. Copolymer CDC has better oil removal rate (90.5%) and light transmittance (95.25%) to Nan 4–8 produced water compared with Sanyuan-6-produced water. It has a better oil removal effect when the initial pH of produced water is 6–7 and the temperature is 30 °C. After the addition of CDC, the large-diameter oil droplets in produced water will coalesce and separate. It may be that under weak acid or neutral conditions, the electrostatic attraction of produced water is enhanced, compressing the double electron layer of oil droplets, and destroying the stability of oil droplets. In addition, the hydrophobic effect of –CH=CH2 in CDC molecules increases the hydrophobic association between molecules and increases the probability of oil droplet collision during the flocculation process. [ABSTRACT FROM AUTHOR]

Produced water (PW) is an effluent from the petrochemical industry that has a significant environmental impact due to its high salinity and presence of chemical compounds and heavy metal. Microalgae have been considered promising to phytoremediation of this effluent and producing biomass with high added value. Therefore, this study aimed to stimulate the production of biomass and biomolecules from Chlorella vulgaris by supplementation with PW and evaluate the synergistic effect of sources of physical and chemical stress. C. vulgaris was cultivated in different PW concentations of PW (not autoclaved) and BG11 medium under a 24 h photoperiod, with inoculum pre-adapted the same photoperiod. The culture containing 70% of BG11 and 30% PW (PW 30%) was the most viable, with a biomass production of 1.35 g/L and a higher concentration of carbohydrates (37.46%) and ash (18.21%) than the control culture (100% BG11). Furthermore, PW 30% also resulted in considerable amounts of lipids (9.92%), proteins (21.94%), chlorophyll-a (6.64 μg/mL), chlorophyll-b (10.57 μg/ mL), and carotenoids (21.38 μg/mL). The major fatty acids were C18:3n6 (21.50%), C20:0 (19.96%), C16:0 (17.12%), and C18:0 (12.15%). The PW 30% treatment showed removal efficiencies for iron (61.80%), chlorides (79.64%), phosphates (97.18%), and petroleum hydrocarbons including total petroleum hydrocarbons (TPH; 45.39%) and resolved petroleum hydrocarbons (RPH; 57.57%). The analyzed fuel properties presented an ideal profile for the production of biodiesel and bioethanol, which can be obtained from carbohydrates. Simultaneously, treatment PW 30% resulted in the production of biomolecule-rich in biomass in addition to the bioremediation effect. [ABSTRACT FROM AUTHOR]

Oilfield scaling is a major problem in the oil and gas industry. Scaling issues cost the industry millions of dollars in damage and lost production every year as scaling is one of the main causes of global production decline. In this study, solid scale inhibitors based on silver tungstate loaded KIT-6 were synthesized and evaluated using a static scale inhibition test. The synthesized materials were characterized using wide and low XRD, N2 adsorption–desorption, TGA, and FTIR, SEM, and XPS analyses. Small-angle XRD patterns showed that KIT-6 had 3D-mesopore diffraction peaks with a cubic Ia3d space group. Wide-angle XRD patterns of silver tungstate loaded KIT-6 confirmed the crystallinity. The prepared catalysts are characterized by higher surface areas (394–918 m2 g−1), large pore volumes (0.63–0.98 cm3 g−1), narrow pore size distributions (5.3 nm), and high thermal stability up to 1000 °C. The results of this study demonstrate that the inhibition efficiency of the scale inhibitor increases and that of the calcite scale inhibitor decreases with increasing pH (2 to 8). This proposes that the scale inhibitor is more effective under alkaline conditions. An inhibition efficiency of 99% on calcium carbonate can be achieved at an optimal dosage of 7.5 ppm at 55 °C, indicating that the scale inhibitor exhibits a relatively good inhibition performance on calcium carbonate. The use of these materials can potentially lead to more efficient and cost-effective solutions for scale inhibition in various industrial processes. [ABSTRACT FROM AUTHOR]

The inhibiting efficiency of three newly synthesized organic compounds:5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (HM-1228), 5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (HM-1227) and 5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione (HM-1226) in oilfield produced water on the corrosion of carbon steel has been examined via electrochemical measurements; potentiodynamic polarization (PDP) and electrochemical impedance (EIS) techniques. The adsorption of these compounds on the surface of carbon steel followed Langmuir isotherm. In addition, the surface morphology of uninhibited and inhibited carbon steel was examined by Atomic Force Microscopy (AFM), observing surface improvement when carbon steel samples exposed to the inhibited corrosive solutions. The average surface roughness (Ra) in oilfield produced water solution in the presence of 0.5 mM of HM-1228 inhibitor was 138.28 nm compared to the uninhibited surface 571.62 nm. To explore the corrosion inhibition mechanism, quantum chemical calculations and Monte Carlo simulations were utilized. The HM-1228 inhibitor demonstrated the highest corrosion inhibition efficiency at 94.8% by PDP measurements. The higher corrosion inhibition of compound HM-1228 can be attributed to the presence of di-N-ethyl groups that enhance both electron donating ability and lipophilic properties. [ABSTRACT FROM AUTHOR]

Biofilm formation can help to mitigate the stress placed on organisms during biological treatment of high-salinity wastewaters, such as "produced water" resulting from oil and gas extraction. This study investigated the implementation of two different biofilm-based biological reactors, activated carbon as an adsorptive biofilm surface (Bio-GAC) and aerobic granular sludge (AGS), and a conventional activated sludge (CAS) reactor for the treatment of synthetic produced water (PW) under hypersaline conditions (85,000 mg/L NaCl). A mixture of benzyl alcohol, o-cresol, and phenol were used as a carbon source with concentrations of 100, 100, and 250 mg/L, respectively. The performance of Bio-GAC was higher than AGS, with overall removal efficiencies for aromatic compounds of 100% and 93%. The presence of catechol in all three reactors during the reaction cycle confirmed that biodegradation was occurring. The performance of CAS was significantly lower in terms of removal efficiency for aromatic compounds (73%) and resilience to high salinity. Scanning electron microscopy showed that biofilm-based biosystems establish stronger biofilm texture. Microbial community analysis showed that carbon source and biosystem type played a crucial role in selecting for microbiome structure. These findings show that biofilm reactors can be used to successfully biodegrade toxic organic contaminants in a high-salinity environment, and that the hybrid Bio-GAC process is particularly promising for treating PW. [ABSTRACT FROM AUTHOR]

To reduce the environmental impact of offshore oil and gas, the hydrocarbon discharge regulations tend to become more stringent. One way to reduce the oil discharge is to improve the control systems by introducing new oil-in-water (OiW) sensing technologies and advanced control. De-oiling hydrocyclones are commonly used in offshore facilities for produced water treatment (PWT), but obtaining valid control-oriented models of hydrocyclones has proven challenging. Existing control-oriented models are often based on droplet trajectory analysis. While it has been demonstrated that these models can fit steady-state separation efficiency data, the dynamics of these models have either not been validated experimentally or only describe part of the dynamics. In addition to the inlet OiW concentration, they require the droplet size distribution to be measured, which complicates model validation as well as implementation. This work presents an approach to obtain validated nonlinear models of the discharge concentration, separation efficiency, and discharge rate, which do not require the droplet size distribution to be measured. An exhaustive search approach is used to identify control-oriented polynomial-type Hammerstein–Wiener (HW) models of de-oiling hydrocyclones based on concentration measurements from online OiW monitors. To demonstrate the effectiveness of this modeling approach, a PI controller is designed using the Skogestad internal model control (SIMC) tuning rules to control the discharge OiW concentration directly. The identification experiment emulates an offshore PWT system with installed OiW monitors, which is realistic with the legislative incentive to include online OiW discharge measurements. The proposed approach could enable the application of OiW-based control on existing offshore PWT facilities, resulting in improved de-oiling performance and reduced oil discharge. [ABSTRACT FROM AUTHOR]

Objective The study is aiming to explore the key corrosion bacteria in the production process of shale gas, and analyze the potential succession law of bacteria. Methods The 16S rRNA high-throughput sequencing analysis technology was used to sequence the bacterial flora in the fracturing fluid preparation water and produced water of a shale gas platform in Weiyuan area. Results The bacterial structure of fresh water is completely different from that of produced water and recycled flowback fluid, the richness and diversity of bacteria decreased after fracturing. The key corrosive bacteria include Arcobacter, Marinobacterium and Pseudomonas, etc. The bacterial community in the freash water is mainly composed of mesophilic, aerobic bacteria with weak functions such as sulfate reduction and acid production. While in the recycled flowback fluid, there are a large number of bacteria with functions of sulfur metabolism, acid production and biofilm production. After fracturing, in the produced water there are mainly facultative anaerobic, anaerobic or strictly anaerobic bacteria with functions such as sulfate reduction, sulfur reduction, sulfur oxidation, acid production, biofilm production, iron reduction, and some thermophilic bacteria were identified. Conclusion This provides theoretical and technical support for further research on bacterial corrosion of gathering and transportation pipelines and pipeline protection. [ABSTRACT FROM AUTHOR]

Removal of organic pollutants and metal ions from produced water by adsorption, using prepared activated carbon (AC) from sewage sludge, with chemical activations using NaOH, KOH and ZnCl2 separately and pyrolysis at different temperatures (500, 600 and 700 °C). Pure sludge and prepared ACs were analyzed using FTIR and XRD. The results showed 18% crystallinity compared to that of commercial AC, which has 44% crystallinity. The results of FTIR demonstrate that the properties of the post-treated affect the final products depending on the method used and that it contains similar functional groups to those present in the commercial AC, but at a higher peak intensity. Adsorption treatments were carried out at 25, 35 and 45 °C solution temperatures. The results showed that the removal of pollutants from produced water using prepared AC with all types of chemical activations reached 99.5%, such as commercial AC with 0.06 g dosage of adsorbent at pyrolysis temperatures of 500 and 600 °C and a solution temperature of 25 °C. The obtained results refer to the mechanism of exothermic reaction and physical adsorption. It was observed that despite the lower dosage of adsorbent of 0.01 g, a sufficient treatment of pollutants was achieved. This reveals the effectiveness of using sewage sludge as a cheap adsorbent. Also, using pure sewage sludge, the adsorption data showed a 95.2% removal of the pollutants. This result indicated that pure sludge has an efficient adsorption capacity and can be utilized as a cheap and environmentally friendly material. For the removal of manganese and cadmium metal ions from the produced water, the resultant data showed that more than 90% of manganese was adsorbed and more than 97% of cadmium was adsorbed, especially when using pure sewage sludge and prepared activated carbon with NaOH chemical activation at pyrolysis temperatures of 500 °C and 600 °C. [ABSTRACT FROM AUTHOR]

A capillary electrophoresis‐mass spectrometry method was used to analyze naphthenic acids in produced water samples. It was possible to detect cyclopentanecarboxylic, benzoic, cyclohexanebutyric, 1‐naphthoic, decanoic, 3,5‐dimethyladamantane‐1‐carboxylic, 9‐anthracenecarboxylic, and pentadecanoic acids within ca. 13 min using a buffer composed of 40 mmol/L ammonium hydroxide, 32 mmol/L acetic acid and 20% v/v isopropyl alcohol, pH 8.6. The proposed method showed good repeatability, with relative standard deviation (RSD) values of 6.6% for the sum of the peak areas and less than 2% for the analysis time. In the interday analysis, the RSD values for the sum of the peak areas and migration time were 10.3% and 10%, respectively. The developed method demonstrated linear behavior in the concentration range between 5 and 50 mg/L for benzoic, decanoic, 3,5‐dimethyladamantane‐1‐carboxylic and 9‐anthracenecarboxylic acids, and between 10 and 50 mg/L for cyclopentanecarboxylic, cyclohexanebutyric, 1‐ naphthoic, and pentadecanoic acids. The detection limits values ranged from 0.31 to 1.64 mg/L. Six produced water samples were analyzed and it was possible to identify and quantify cyclopentanecarboxylic, benzoic, cyclohexanebutyric, and decanoic acids. The concentrations varied between 4.8 and 98.9 mg/L, proving effective in the application of complex samples. [ABSTRACT FROM AUTHOR]

We studied the dissociation of water (H2O*, with * denoting adspecies) on atomic oxygen (O*)-covered Rh nanoclusters (RhO*) supported on a graphene film grown on a Ru(0001) surface [G/Ru(0001)] under ultrahigh-vacuum conditions and with varied surface-probe techniques and calculations based on density-functional theory. The graphene had a single rotational domain; its lattice expanded by about 5.7% to match the Ru substrate structurally better. The Rh clusters were grown by depositing Rh vapors onto G/Ru(0001); they had an fcc phase and grew in (111) orientation. Water adsorbed on the Rh clusters was dissociated exclusively in the presence of O*, like that on a Rh(111) single-crystal surface. Contrary to the case on Rh(111)O*, excess O* (even at a saturation level) on small RhO* clusters (diameter of 30–34 Å) continued to promote, instead of inhibiting, the dissociation of water; the produced hydroxyl (OH*) increased generally with the concentration of O* on the clusters. The difference results from more reactive O* on the RhO* clusters. O* on RhO* clusters activated the dissociation via both the formation of hydrogen bonds with H2O* and abstraction of H directly from H2O*, whereas O* on Rh(111)O* assisted the dissociation largely via the formation of hydrogen bonds, which was readily obstructed with an increased O* coverage. As the disproportionation (2 OH* → H2O* + O*) is endothermic on the RhO* clusters but exothermic on Rh(111)O*, OH* produced on RhO* clusters showed a thermal stability superior to that on the Rh(111)O* surface—thermally stable up to 400 K. [ABSTRACT FROM AUTHOR]

The inhibiting efficiency of three newly synthesized organic compounds:5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (HM-1228), 5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (HM-1227) and 5-((4'-(dimethylamino)-[1,1'-biphenyl]-4-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione (HM-1226) in oilfield produced water on the corrosion of carbon steel has been examined via electrochemical measurements; potentiodynamic polarization (PDP) and electrochemical impedance (EIS) techniques. The adsorption of these compounds on the surface of carbon steel followed Langmuir isotherm. In addition, the surface morphology of uninhibited and inhibited carbon steel was examined by Atomic Force Microscopy (AFM), observing surface improvement when carbon steel samples exposed to the inhibited corrosive solutions. The average surface roughness (Ra) in oilfield produced water solution in the presence of 0.5 mM of HM-1228 inhibitor was 138.28 nm compared to the uninhibited surface 571.62 nm. To explore the corrosion inhibition mechanism, quantum chemical calculations and Monte Carlo simulations were utilized. The HM-1228 inhibitor demonstrated the highest corrosion inhibition efficiency at 94.8% by PDP measurements. The higher corrosion inhibition of compound HM-1228 can be attributed to the presence of di-N-ethyl groups that enhance both electron donating ability and lipophilic properties. [ABSTRACT FROM AUTHOR]

With the large-scale application of polymer flooding technology, the polymer concentration in produced water is increasing, which leads to incomplete regeneration of filter media by gravity field hydraulic backwashing technology only. In this study, the high-gravity backwashing technology is constructed by coupling gravity field and swirl field, which promotes the development of the oilfield. Based on the cascade theory, this paper establishes a mathematical expression of radial collision force in the high-gravity backwashing process in the vortex tube and solves a mathematical equation of high-gravity backwashing velocity gradient G based on the efficient zone of collision force action. Meanwhile, based on the discrete element method and computational fluid dynamics theory, the inter-particle collision regulation of the high-gravity backwashing process is simulated by the coupled FLUENT-EDEM method, and the high-efficiency zone of the backwashing process is verified. In this high-efficiency zone, the theoretical and simulated values of velocity gradient G for different high-gravity values match well, with differences ranging from –5.8 % to +7.1 %, indicating that the theoretical model of high-gravity backwashing is correct. When the high-gravity value is 210–240 g, the total impulse of the filter bed per unit time reaches a great value, and the backwashing velocity gradient G is 3047.1 s−1, which is much larger than the G value of combined air-water backwashing. The high-gravity backwashing technology breaks through the technical bottleneck of low efficiency in the action of the gravity field. It enriches and develops the gravity field hydraulic backwashing technology of the filter bed. • A new method of high-gravity backwashing is proposed, and a theoretical model of high-gravity backwashing is constructed. • The mathematical equations particle impact force and velocity gradient in high efficiency area of high-gravity backwashing are established. • The coupling method of FLUENT-EDEM is used to study the backwashing process, which provides a new idea for the backwashing of traditional water treatment filter bed. [ABSTRACT FROM AUTHOR]

Hyper-saline water streams, such as the produced water from the oil industry, cannot be treated via the conventional desalination method, such as reverse osmosis (RO), due to the extreme required pressure to overcome the osmotic pressure. This research investigates the effect of oil fouling and cleaning behaviors when the forward osmosis (FO) process is applied to treat hyper-saline-produced water. Synthetic produced water with total dissolved solids (TDS) concentration of 240 g/l (contained Na, Ca, Mg, Fe, Cl, SO4, and CO3 ions) and oil content of 100 ppm was used as a feed solution. Also, two draw solutions, namely: ammonium bicarbonate (NH4HCO3) and magnesium chloride (MgCl2) of concentrations 6 M and 4.8 M, respectively, were utilized for the FO operation. Results showed that the MgCl2 draw solution provided significantly higher water flux than NH4HCO3 due to MgCl2's high osmotic pressure and low scaling influence. Furthermore, the individual impact of oil was found to be low on the FO's water flux. However, a synergistic effect between the oil and inorganic scaling was noticed. SEM technique was used to comprehend the observation and analyze the fouling content. Although the feed was a highly polluted stream, it was found that osmotic backwashing can recover more than 90% of the initial flux. [ABSTRACT FROM AUTHOR]

The versatility of metal coordination geometry and organic linkers is used to derive metal–organic frameworks (MOFs) with an intriguing network structure in the solid-state, exerting significant control over its functional application. In this study, we prepared Co-benzene dicarboxylic acid based MOFs with 1D and 2D network structures with similar coordination environment and studied their electrocatalytic OER activity in alkaline medium. The use of bidentate amines (2,2′-bipyridine and DABCO) controlled the dimensionality and produced water coordinated 1D (Co-MOF-1D) and 2D (Co-MOF-2D) network structures. Although both Co-MOFs showed strong electrocatalytic OER activity, Co-MOF-2D exhibited relatively strong OER activity (required overpotential (η) of 211 mV to produce 10 mA cm−2 current density) compared to Co-MOF-1D (η10 = 237 mV). Co-MOF-2D exhibited excellent stability with a low Tafel slope, charge transfer resistance, and high electrochemical surface area that further supported the enhanced OER activity. [ABSTRACT FROM AUTHOR]

The deposition of inorganic scale in pipelines used in the exploration of oil on marine platforms caused by the precipitation of metal ions is one of the main causes for reduction in the production process of the oil industry. Therefore, a simple and efficient method for the determination of scaling ions in oilfield produced water using laser-induced breakdown spectroscopy (LIBS) was developed. Filter paper was used as a cellulosic solid substrate for phase conversion of Mg(II), Ca(II), Sr(II) and Ba(II) ions in saline medium. Instrumental parameters such as laser pulse energy, gate delay and gate width were evaluated along with sample preparation parameters, such as the type of cellulosic, polymeric or glass substrate, sample volume deposited on the substrate and the time required for drying, use of internal standards and effect of salinity. Energy-dispersive X-ray spectroscopy (EDS) analysis showed a homogeneous distribution of the analytes on the microfibers of the filter paper. The results indicated that salinity significantly affects the emission intensities of the analytes as well as the relative standard deviations, which ranged from 5.2 to 8.1% and 9.2 to 12.9% for samples prepared in water and in a solution with a salinity of 30‰, respectively. The spectral data were normalized using the C emission line (C I 247.88 nm) to minimize the matrix effect of the highly saline waters. Under optimized conditions and considering data without and with normalization, it was possible to obtain limits of detection ranging from 1.0 to 11.4 mg L−1, with a linear response range from 20 to 60 mg L−1 for Mg(II), Ca(II) and Sr(II) ions and from 40 to 80 mg L−1 for Ba(II) ions in aqueous solutions. The determination of scaling ions in produced water by LIBS showed that data normalization provides results that do not significantly differ from those obtained by inductively coupled plasma atomic emission spectroscopy (ICP OES) at a confidence level of 95%, demonstrating that the developed method has potential application to monitor the concentration of scaling ions in produced water, helping prevent scaling in the pipelines of oil platforms. [ABSTRACT FROM AUTHOR]

Fjords play an important role in biological productivity worldwide but are vulnerable to climate/anthropogenic effects. Chilean Patagonia (41°S–55°S) is one of the largest fjord ecosystems in the world, characterized by a complex geography with highly heterogeneous hydrographic conditions and a permanent input from oceanic water mass, both of which influence the ichthyoplankton distributional patterns. In this study, we analysed the distributional patterns of ichthyoplankton and its diversity during austral spring from 1996, 2009 and 2019 in the southern Chilean fjords (47°S–54°S). The area shows important latitudinal gradients of sea surface temperature (from 15°C to 5°C), fjord‐ocean variability in salinity (from 23 to 33) and water column temperature (3°C to 9°C). Spatial (but not temporal) variations in the composition and abundance of ichthyoplankton were recorded, caused mainly by differences in the abundance of larval Sprattus fuegensis, Maurolicus australis and Sebastes oculatus. Richness was higher on continental shelf and the lowest nearby fjord's head and ice fields. At the spatial scale, β‐diversity showed an increased species replacement (turnover) across areas, suggesting an important role of environmental conditions (e.g., salinity and water stratification) on the larval fish structure in this region. Ordination analysis indicates that changes in salinity and temperature, caused by ice melting, is the main environmental factor influencing the abundance of larval Thysanopsetta naresi (1996), Cataetyx messieri (2009) and Bathylagichthys parini (2019). Finally, this study highlights the importance of the conservation and protection of the Chilean Patagonia and monitoring ichthyoplankton communities, which are vital biomarkers of ecosystem health. [ABSTRACT FROM AUTHOR]

This article reviews the application o£ pervaporation technology in high salinity wastewater treatment. The effects of wastewater composition, feed water temperature, osmotic vacuum, wastewater flow state and membrane materials, are mainly discussed・ Based on the previous work, the feasibility of applying pervaporation technology to the treatment of high salinity wastewater is discussed・ The pervaporation technology is expected to become one of the important technology choices in the zero discharge of wastewater. [ABSTRACT FROM AUTHOR]

In view of the common problems of conventional water shutoff agent, such as "Either not injected or not plugged, can not deep profile control and flooding, and poor effect of increasing oil and dewatering", a novel terpolymer was prepared from acrylamide（AM）,2-acrylamide-2-methylpropanesulfonic acid（AMPS） and N-（3-dimethylaminopropyl） methacrylamide（DMAPMA）, at the same time, multiple emulsions were prepared to encapsulate the crosslinking agent. The results showed that the cross-linking time of the multi-emulsion system could be delayed more than 1 times to 5～15 d, and the optimal gel system had good temperature and salt resistance, it is suitable for reservoirs with salinity less than 100 000 mg/L and temperature between 70 ℃ and 90 ℃. The gel system has the advantages of low initial viscosity, easy injection into low permeability formation, controllable cross-linking time and high gelling strength, and the hypertonic channel is effectively blocked. [ABSTRACT FROM AUTHOR]

The produced water of oilfield binary flooding contains a large number of residual oil displacement agents such as polymers and surfactants. The interaction between oil displacement agents and water results in the enhanced stability of oil droplets and colloidal particles in the produced water. The treatment cost of traditional coagulation technology is high, the amount of sludge is large, and the quality of treated water is difficult to meet the requirements of reinjection indicators. This paper studies the influence of the process of sedimentation-aeration-biological contact oxidation-filtration on the turbidity, particle electronegativity and particle size distribution of the produced water from binary flooding. The result showed that the best process: gravity sedimentation for 12 h, aeration for 12 h under the condition of aerated water ratio of 30∶1, biological contact oxidation for 7 d, using fiber ball as filter material to filter the produced water from binary flooding. The field test has achieved good treatment effect, and the treated water quality meets the requirements of reinjection with oil content less than 5 mg/L, solid suspended solids less than 10 mg/L, and the median particle size of suspended solids less than 2 μm. [ABSTRACT FROM AUTHOR]

Effective pre-dehydration is achieved to stabilize and improve oil production in high water cut oil fields. In order to reduce the pressure loss during the pre-dewatering process, a low-pressure-loss dynamic hydrocyclone (LPDH) was developed. And its swirler vane was designed which can not only drive liquid into circumferential rotational flow but also produce axial pressure. The axial pressure will compensate for the separation process pressure loss. The key parameters that affected the axial pressure were studied, the relative motion between the fluid and the vane was analyzed, and a pre-dehydration LPDH was designed (processing capacity is 1.0 m3/h). The changes in the separation efficiency and axial pressure of the LPDH with the operational and physical parameters were studied by the computational fluid dynamics (CFD) numerical simulation method. The results revealed that the pressure is increased during rotation-starting, and the pressure loss of LPDH was lower than the dynamic and compound hydrocyclones. Notably, low shear stress was generated using the designed vane when the fluid started rotating, and the separation efficiency increased under these conditions. When the speed of rotation of the swirler is 167.5 rad/s, the separation efficiency of the LPDH is greater than 99.8%. [ABSTRACT FROM AUTHOR]

Borophene is emerging as a promising electrode material for Li, Na, Mg, and Ca ion batteries due to its anisotropic Dirac properties, high charge capacity, and low energy barrier for ion diffusion. However, practical synthesis of active and stable borophene remains challenging in producing electrochemical devices. Here, we introduce a method for borophene aerogels (BoAs), utilizing hexagonal boron nitride aerogels. Borophene grows between h-BN layers utilizing boron-boron bridges, as a nucleation site, where borophene forms monolayers mixed with sp2-sp3 hybridization. This versatile method produces stable BoAs and is compatible with various battery chemistries. With these BoAs, we accomplish an important milestone to successfully fabricate high-performance next-generation batteries, including Na-ion (478 mAh g-1, at 0.5C, >300 cycles), Mg-ion (297 mAh g-1, at 0.5C, >300 cycles), and Ca-ion (332 mAh g-1, at 0.5C, >400 cycles), and Li-S batteries, with one of the highest capacities to date (1,559 mAh g-1, at 0.3C, >1,000 cycles). [ABSTRACT FROM AUTHOR]

With the continuous increase of shale gas production in China, the associated water production is also increasing, which is the mixture of the water used for hydraulic fracturing and the brine retained in shale formation. During the treatment of produced water, valuable elements such as lithium, potassium and bromine are further enriched and concentrated. especially lithium. resources, which has broad prospects for development and utilization, and can alleviate the contradiction between supply and demand of strategic resource lithium in China. In this paper, the shale gas resources in Sichuan are introduced and summarized mainly. And the ion content in the produced water of shale gas in Weiyuan and Changning areas in southern Sichuan is listed respectively. At present, the produced water volume of each well in Weiyuan and Changning is 19 800 m³ and 15 293 m³ respectively, and the lithium content in most of the produced water is 10, 62-58, 96 mg/L, which has high economic utilization value. The reserves and prospects of lithium resources in the produced water of shale gas are predicted. The applicability of extraction method, membrane separation method and adsorption method to the extraction of lithium in shale gas produced water are summarized, which provides the reference for the comprehensive utilization of lithium resources from shale gas formation in southern Sichuan. [ABSTRACT FROM AUTHOR]

Portable FADs are operated to collect fish using sound where fish can detect sound using the inner ear, swim bladder, and lateral line. Fish that are close to the sound source are categorized as positive acoustic-taxi fish, while fish that are away from the sound source are called negative acoustic- taxi. In portable FADs, the sound emitted can propagate in the waters. Temperature and salinity affect the sound waves that propagate the water column. The purpose of this study was to measure the frequency of portable FADs with a frequency of 1.000-5.000, 6.000-10,000, 11.000-15.000 Hz on a laboratory scale, to measure the frequency of portable FADs with a frequency of 11.000-15.000 Hz on a field scale in Palabuhanratu. This research was conducted by direct measurement in the field with 3 repetitions for each frequency. The results from the laboratory show that the frequency of 11.000- 15.000 Hz has little noise. The results of measurements in the field show that there are differences in amplitude at each time and distance due to temperature, salinity and other environmental factors such as currents and wind. Sound waves that can be detected at a depth of 2 meters and 6 meters horizontally. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two novel triazine derivatives (BTT-1 and BTT-2) were synthesized as corrosion inhibitors by a facile one-step method. • BTT-1 and BTT-2 exhibit high inhibitive performance with the inhibition efficiency of 97.9 % and 98.4 %. • The adsorption mechanism of BTT-1 and BTT-2 was explored by theoretical calculations in the aqueous environment. • The effect of substituents on the inhibitive performance of BTT-1 and BTT-2 was unveiled. In this work, two triazine derivatives (BTT-1 and BTT-2) were synthesized by the simple one-step condensation of three components and used as high-efficient corrosion inhibitors to deal with the corrosion issue of carbon steel (CS) in petroleum industry. Electrochemical tests indicate that both BTT-1 and BTT-2 present superior inhibition performance with the inhibition efficiency of 97.9 % and 98.4 % at a low concentration of 0.18 mM, respectively. Quantum chemical calculations reveal that compared to BTT-1 molecule with a butyl chain, the introduction of benzyl group endows BTT-2 molecule with more adsorption sites, which favors the adsorption of BTT-2 molecule on CS surface. Furthermore, the GFN-xTB calculations demonstrate that BTT-1 and BTT-2 could adsorb on CS surface through the formation of Fe−N and Fe−S bonds. Compared to BTT-1, BTT-2 exhibits stronger adsorption on CS surface by forming more and shorter bonds with a more negative adsorption energy, which accounts for the better inhibitive performance of BTT-2. [ABSTRACT FROM AUTHOR]

Even with the development of alternative fuels and energy sources, the world is still highly dependent to the petroleum production and extraction. Align to this, the treatment of oilfield produced water (OPW) is a global challenge, since for each barrel of extracted oil it is produced 3 barrels of OPW in average. OPW contains numerous organic compounds, including naphthenic acids (NAs), which are considered recalcitrant compounds and are not efficiently removed by conventional OPW treatment. Advanced oxidation processes (AOPs) produce highly reactive hydroxyl radicals (•OH) and are considered a promising alternative for the degradation of resistant organic compounds. This review focuses on the treatment of OPW and degradation of pollutants present in its composition through different AOPs (ozonation, photocatalysis, photochemical oxidation and Fenton-based processes). The factors affecting the processes and strategies to improve AOPs efficiency for OPW treatment are discussed. The background information regarding each process, their main operational parameters and recent publications were addressed aiming to present viable technologies for the complete treatment of OPW. The main finds indicate that individual processes may present some limitations, and much of the emerging research in this field is directed towards the use of combined processes. [Display omitted] [ABSTRACT FROM AUTHOR]

Produced water (PW) has been generated in a huge amount representing the largest volume waste stream. Membrane technology has found a leading ability in treating PW due to its significant advantages, such as lower cost, easy installation, and being environmentally friendly. Mixed matrix membranes (MMMs) have received significant research interest due to their flexibility, multifunctionality enhances the membrane performance with increasing selectivity, permeability, robustness, mechanical strength, and resistance to fouling. This mini‐review paper identifies the utilization of different membranes for treating PW. It also gives a review of different types of MMMs with specific fillers for the application of PW treatment. Lastly, some methods to enhance the performance of mixed matrix membranes have been highlighted. The issues and challenges in membranes are also discussed. Practitioner Points: Mixed matrix membranes (MMMs) are a potential membrane type for PW treatment.This mini‐review paper identifies the use of several membranes to treat PW. It also examined various types of MMMs containing specific fillers for the application of PW treatment.Methods for improving the performance of mixed matrix membranes have been highlighted, including the use of novel materials, surface modification, and cross‐linking.The issues and challenges in membranes are also discussed. [ABSTRACT FROM AUTHOR]

• Freeze-melt is an efficient way for removing contaminants from compressed leachate. • COD, TOC, NH 3 -N and TP are effectively removed by freeze-melt treatment. • Ice formation rate was a very important factor for removal rate of contaminants. • Contaminants in ice with small size are easier to melt-out of the ice. A small amount of leachate with complex composition will be produced during the compressing of municipal solid waste in refuse transfer stations. In this study, the freeze-melt method, a green and efficient wastewater treatment technology, was used to treat the compressed leachate. The effects of freezing temperature, freezing duration, and ice melting method on the removal rates of contaminants were investigated. The results showed that the freeze-melt method was not selective for the removal of chemical oxygen demand (COD), total organic carbon (TOC), ammonia-nitrogen (NH 3 -N) and total phosphorus (TP). The removal rate of contaminants was positively correlated with freezing temperature and negatively correlated with freezing duration, and the slower the growth rate of ice, the higher the purity of ice. When the compressed leachate was frozen at −15 °C for 42 h, the removal rates of COD, TOC, NH 3 -N and TP were 60.00%, 58.40%, 56.89% and 55.34%, respectively. Contaminants trapped in ice were removed during the melting process, especially in the early stages of melting. The divided melting method was more beneficial than the natural melting method in removing contaminants during the initial stage of melting, which contributes to the reduction of produced water losses. This study provides a new idea for the treatment of small amounts of highly concentrated leachate generated by compression facilities distributed in various corners of the city. [ABSTRACT FROM AUTHOR]

This paper summarizes the advantages and disadvantages of the existing treatment technology in oilfield oil production sewage, introduces the main components and characteristics of oilfield wastewater treatment, summarizes and summarizes the latest research achievements and existing problems of filtration technology, air flotation technology, membrane separation technology, advanced oxidation technology, biofilm technology, biological demulsification technology・ The development and innovation directions of physical, chemical and biological technologies for oilfield wastewater treatment are prospected through the problems of oilfield sewage treatment technology. [ABSTRACT FROM AUTHOR]