Water Liquefaction Research Articles

Importance of Ompw gene to diagnose Vibrio cholerae isolated from stool and water samples

Background. Cholera is a severe acute watery diarrheal disease caused by O1 and O139 serogroup of Vibrio cholerae. The outer-membrane protein W (OmpW) a virulence factor, is involved in inducing protective immunity and triggering the immune response. The aim of this study is to find a rapid and accurate method for diagnosing Vibrio cholerae and investigate the possibility of OmpW gene to achieve this goal, and identify the effective antibiotic against this bacteria. Methods. The current study included 400 stool samples from patients who were suspected of having cholera and 50 samples of water have been collected from various water liquefaction stations in Thi-Qar province. The samples were examined by routine and advanced biochemical, serological methods and molecular method by using PCR to amplify 16S rDNA gene and gene OmpW. Results. Results of stool samples revealed that only 41 (10.25%) of the isolates were identified as Vibrio cholerae by biochemical methods while 38 (92.68%) of the isolates were diagnosed as Ogawa serotype of Vibrio cholerae serogroup O1 by serological and molecular methods. While the water samples did not reveal the appearance of Vibrio cholerae by molecular diagnosis. The study revealed a difference in the resistence rates of isolates to some antibiotics, with the highest percentage rate of resistance (100%) to trimethoprim-sulfamethoxazole while lowest percentage rate of resistance (5.26%) to piperacillin-tazobactam. Also, the study noted 56.58% of isolated V. cholera were resistant for tested antibiotics, 24.73% of isolated V. cholera were gave intermediate response, while 18.69% were sensitive for tested antibiotics. Conclusion. All identified isolates were registered in GenBank, two isolates with number LC793854 and LC793858 were recorded as new isolates. OmpW gene showed great accuracy to diagnose Vibrio cholerae, no less important than the accuracy of 16S rDNA gene to diagnose of these bacteria, and Piperacillin-tazobactam is the best antibiotic to treatment of cholera.

Supercritical Water Liquefaction of Mixed Waste Polystyrene, Polypropylene, and Polyethylene for Production of High Yield Oils.

Supercritical water liquefaction of different plastic wastes has been investigated under high-temperature and high-pressure conditions. The supercritical water liquefaction of commonly used plastic types, comprising polystyrene (PS), polypropylene (PP), and low-density polyethylene (LDPE) as well as their mixtures, is reported. The experiments were carried out at varying feedstock-to-water ratios with a residence time of 60 min under supercritical water reaction conditions. The process produced high oil yields of over 97 wt %, with the highest yields obtained at a plastic:water ratio of 1:3; at higher levels of input water, the yield of oil decreased slightly. The gas phase mainly consisted of light hydrocarbons such as methane, ethane, propane, and butane, with propane found to be the most abundant gas component. Aromatic hydrocarbons and alicyclic hydrocarbons were the major products in the product oil from the supercritical water liquefaction of polystyrene and polypropylene, whereas alkanes were predominant in the oil obtained from LDPE. Analysis of the oil obtained from binary (1:1) and ternary (1:1:1) plastic mixtures showed it exhibited aromatic hydrocarbons as the major constituent, indicating synergistic interaction. It was found that the incorporation of PP in the mixture facilitated the production of cyclic compounds and suppressed the production of alkanes. Supercritical water liquefaction offers an effective solution to plastic pollution, producing valuable products without the need for catalysts.

Conversion of LDPE Plastic Oil to Gasoline by Supercritical Water Liquefaction

LDPE (Low Density Polyethylene) is one of the plastic waste that is often found in the surrounding environment. Based on data from the National Waste Management Information System (SIPSN) in 2022, waste in Indonesia reached 17.834.071 tons/year with 18.5% being plastic waste. Plastic waste management generally uses recycling. However, recycling plastic waste is not efficient enough in tackling plastic waste in Indonesia. Recently, a promising alternative recycling method for the future is pyrolysis, a process to convert plastic into fuel oil. However, the pyrolyzed oil still contains impurities that reduce the quality of the oil. As an effort to improve the quality of pyrolysis oil, the author proposes the addition of zeolite catalyst in the pyrolysis process followed by the Supercritical Water Liquefaction (SWL) method. The zeolite catalyst aids the degradation process thereby accelerating the reaction rate. The SWL method is able to convert plastic waste into low molecular weight chemicals. The results obtained will be analyzed by gas chromatography mass spectroscopy (GC-MS) to determine the length of the carbon chain in the sample. Based on the chromatography data, it is found that the number of peaks and retention times show carbon chains ranging from C8-C12, from these results it can be identified that the sample is included in kerosene or kerosene compounds. After the SWL process, the percentage of kerosene and diesel is reduced to 11% gasoline. So the Supercritical Water Liquefaction process is proven to break down long hydrocarbon chains into lighter ones.

Hydrothermal liquefaction of oil-palm-derived lignin to bio-oils for use as antioxidants in biodiesel

Lignin extracted from oil palm empty fruit bunch (EFB) fibers was used to produce a phenolics-rich bio-oil via hydrothermal liquefaction in pure water, or an ethanol–water (1:1 v v−1) solvent system, in a stirred batch reactor. The effects of liquefaction temperature (200–300 °C), pressure (10–40 bar), reaction time (0.5–3 h), solvent-to-lignin mass ratio (5–20), and the type of gas (N2, H2, CO2) in the reactor headspace were investigated on the yield and antioxidant properties of the bio-oil. The bio-oil and other products were characterized in detail. The conditions for obtaining a high yield of a bio-oil with a maximum phenolics content and the antioxidant activity were the following: ethanol–water solvent system with a solvent-to-lignin mass ratio of 10, 250 °C, 40 bar, H2 in the headspace, and a reaction time of 2 h. The bio-oil product contained multiple phenolics compounds, and proved to be an effective antioxidant additive in biodiesel made from palm oil. The bio-oil produced under the above specified conditions was a superior antioxidant than butylated hydroxytoluene (BHT), an oxidant used commercially. The bio-oil produced using water as the solvent instead of ethanol–water, was a less effective antioxidant.

Some Chemical Properties of Wastewater from the Pharmaceutical Production Processes in the State Company for Drug and Medical Appliances Samarra

The study was conducted during six months, from September 2022 to February 2023, in the General Company for the Industry of Medicines and Medical Supplies in Samarra, one of the companies affiliated to the Ministry of Industry and Minerals. For the purpose of evaluating the efficiency of the biological treatment units for the liquid waste disposed by the company, the water discharged to the treatment units was divided into four sampling stations. : Primary collection basin water or equalization basin (water resulting from industrial processes), aeration basin water (water treated in the treatment unit), sedimentation basin water (water leaving the treatment plant) and liquefaction water (water entering the company). The study includes two aspects: the first is related to the measurement of the chemical properties of the water of the four stations, while the second aspect is that some water determinants were studied and local and international standards and classifications were adopted to compare them. The chemical parameters included pH, dissolved oxygen, biological oxygen requirement, total alkalinity, total hardness, and chloride. The results showed that the pH values tended to be low alkaline with a limited range of variation, as it ranged between 7.1-8.3, while the dissolved oxygen value ranged between 7.0-4.0 mg/l, and the biological oxygen requirement ranged between 1.0-95 mg/l. The results indicate that the values of BOD5 increased in the stations (St.1, St.2, and St.3), in contrast to the station (St.4) for the liquefied water, as it recorded very low values, with significant temporal and spatial differences in most stations within months. the study. As for the total alkalinity, it ranged between 110-200 mg/l in terms of CaCO3 and showed significant temporal and spatial differences in most stations during the months of the study. While the chloride values ranged between 38-255 mg/l. The results of the current study showed a significant variation in the chloride values from one month to the next. The study also confirmed that the chloride values increased during the winter compared to the summer.

Low-Pressure Hydrothermal Processing of Disposable Face Masks into Oils

A total of 5.4 million tons of face masks were generated worldwide annually in 2021. Most of these used masks went to landfills or entered the environment, posing serious risks to wildlife, humans, and ecosystems. In this study, batch low-pressure hydrothermal processing (LP-HTP) methods are developed to convert disposable face masks into oils. Three different materials from face masks were studied to find optimal processing conditions for converting full face masks into oil. The oil and gas yields, as well as oil compositions, depend on the feedstock composition, particle size, and reaction conditions. Yields of 82 wt.% oil, 17 wt.% gas, and minimal char (~1 wt.%) were obtained from full masks. LP-HTP methods for converting face masks have higher oil yields than pyrolysis methods in the literature and have lower operating pressures than supercritical water liquefaction. LP-HTP methods for face masks can increase net energy returns by 3.4 times and reduce GHG emissions by 95% compared to incineration. LP-HTP has the potential to divert 5.4 million tons of waste masks annually from landfills and the environment, producing approximately 4.4 million tons of oil.

Evaluation of the Performance of the Makhmuor Villages Water Filtration Plant in Nineveh Governorate / Iraq

The current study was conducted to evaluate the performance of the Makhmuor villages water filtration plant and to ensure the validity of the water produced and delivered to the consumer. The physical, chemical and biological properties of the Tigris River water at the intake of the plant and at different stages of the plant and the water reaching the residential areas benefiting from the plant were studied. The studied samples were collected for a period of five months, monthly from July to November 2022. Temperature, electrical conductivity, total dissolved solids, turbidity, dissolved oxygen, biological oxygen demand, total alkalinity, total hardness, calcium, magnesium, chloride, sulfates, phosphates, nitrates, pH, residual chlorine, and the total number of bacteria. And the total number of coli bacteria and the number of plankton. The results of the study showed that many samples conformed to the Iraqi and international specifications for drinking water, except for turbidity, as it exceeded the permissible limit in most samples, which is less than 5 (Nephelometric Turbidity Unit) NTU, and dissolved oxygen reached 4.4 and 4.8 mg / liter in the Tigris River for the month of August and water Liquefaction in the villages for the months of July and September, respectively, as well as 4.4 mg/L in the automated sedimentation and filtration ponds and the village 2 for the month of November. The biological requirement for oxygen in seven samples in different locations for the months of October, August and November was 0.1 mg/L and the highest value was 6.4 mg/L in basin 2 in October. And nitrates were in low concentrations. As for residual chlorine, all tests were free of any percentage of it, except for the month of November, when it was in the plant tank 2 mg / liter and in the two villages 0.3 mg / liter. Thus, the number of bacteria increased and appeared in all samples throughout the study period.

Isolation and molecular identification of Cryptosporidum spp. from watar samples in Al-Diwaniyah province

This study was conducted to isolate Cryptosporidium from water sources in Al-Diwaniyah Governorate Where water samples were collected during the period extending from September 2021 to February 2022, with a total of 500 water samples distributed among three water sources, namely, The total percentage of contamination of the three water sources (rivers, purification plants and liquefaction water) with the Cryptosporidium parasite was 16%. The results of using the interlaced polymerase chain reaction technique for examining 40 water samples from two different sources (rivers and purification stations) showed the presence of the hsp70 gene with a molecular weight of 370 pb of C. parvum, reaching 40%. C. Parvum recording in water samples by molecular methods is the first in Iraq.

Hydrothermal liquefaction of Spirulina platensis in post-carbonization wastewater from sewage sludge

Wet solid waste can achieve good dewaterability through hydrothermal carbonization. However, massive wastewater rich in organics is also generated during the process. Previous studies reported the anaerobic digestion potential of organic wastewater, but its inhibitors cause challenges. In our early work, the aqueous by-product from hydrothermal liquefaction of microalgae has been successfully recycled back into the liquefaction process, leading to an enhanced oil yield. Herein, this study addresses the possibility of wastewater from sewage sludge dewatering as a solvent to convert microalgae for biocrude production under temperature of 260-320 ° C . Results show that the wastewater owned a chemical oxygen demand value of 14 g/L and a total organic carbon value of 5.89 g/L with a nitrogen content of 10.34%. The biocrude yield in this wastewater was 31.3–38.7 wt%, higher than liquefaction in pure water (27–33 wt%). Over 10% increment was reached, demonstrating the potential of organic wastewater as a solvent for biocrude production. Following a slight decrease of the nitrogen content, the higher heating value of the biocrude from the wastewater solvent was close to that formed in pure water, suggesting a non-significant influence on fuel quality. Besides, the enhancing mechanism of wastewater stream on liquefaction was discussed based on various analytical approaches. Compound analysis indicates a reduction of nitrogenous chemicals in the wastewater during liquefaction, which are more likely to be transformed to oil phase forming amides. Therefore, this recycling strategy would help develop novel routes for utilization of organic wastewater, significant for sewage sludge treatment.

Influence of extraction solvents on the recovery yields and properties of bio-oils from woody biomass liquefaction in sub-critical water, ethanol or water–ethanol mixed solvent

In this work, the effects of extraction solvents: acetone, ethanol, dichloromethane (DCM) and ethyl acetate (EA), on the yields and characteristics of bio-oil products obtained from liquefaction of rubberwood sawdust (RS) at 300 ℃ for 30 min in water, ethanol or water–ethanol mixed solvent (50/50, v/v) were comparatively studied. When pure water or ethanol was used as the reaction medium, the highest bio-oil yield was obtained by acetone (30.41 wt%) or EA (31.69 wt%), respectively. Besides, significantly higher bio-oil yields were observed in RS liquefaction in water–ethanol mixed solvent with the maximum bio-oil yield of 56.67 wt% obtained by acetone. But ethanol was always the least efficient in recovering bio-oil in all cases. Besides, the elemental analysis showed that DCM was conducive to recover the bio-oil products with lower oxygen contents and the higher HHVs, while the acetone-extracted bio-oils were worse in quality. However, the highest carbon recovery (CR) and energy recovery (ER) were obtained by acetone due to its higher bio-oil yield produced in water–ethanol mixed solvent. As suggested by GC–MS, GPC and TGA analysis, the extraction solvents and reaction mediums both greatly affected the chemical compositions of the bio-oil products. Phenols were dominant in bio-oil products, followed by hydrocarbons, ketones, esters, etc. Acetone tended to extract the bio-oil with larger carbon numbers and molecular weights, which might explain its higher bio-oil recovery yield in water or water–ethanol mixed solvent. DCM was beneficial to recover the bio-oil was more light compounds with smaller molecular weights and lower boiling point distribution. But for the liquefaction in pure ethanol, more similar chemical compositions were observed among different samples when compared to the cases in other reaction mediums.

Wave-induced seabed momentary liquefaction in shallow water

To realize seabed behaviours under extreme waves in coastal regions, a wave-induced seabed response subjected to high-order cnoidal wave theory is studied via Biot’s consolidation theory. An analytical model is proposed for a dynamic response comprising pore pressure and effective stresses in a permeable layer of the seafloor. The seabed pressure solutions yielded by cnoidal waves up to the third order are derived as an input loading under boundary conditions, and high-power Jacobian elliptic cosine functions involved in cnoidal wave theory are approximated in terms of a Fourier series to construct the seabed response via the superposition of harmonic solutions. For the present Fourier series approximation of Jacobian elliptic cosine functions, a convergence analysis is performed, and a verification of seabed pressure compared with experimental data shows good agreement. The characteristics of the present solution are investigated, and the discrepancies among the solutions for each order and a harmonic solution for linear waves are demonstrated on the profiles of effective stresses and excess pore pressure. Compared with the third-order solution, the harmonic solution provides a better prediction at the wave peak than the other solutions, but the prediction of excess pore pressure around the wave trough shows a remarkable overestimation for every solution except the second-order solution. The impact of seabed momentary liquefaction induced by shallow water waves is evaluated, and the influence of wave parameters, including wave height and wavelength, is determined. This study reveals the significance of the nonlinear effect on seabed response under high-order cnoidal waves and provides the underlying implication to liquefaction assessment.

Behavior of braced wall embedded in saturated liquefiable sand under seismic loading

It is well known that the generation of excess pore water pressure and/or liquefaction in foundation soils during an earthquake often cause structural failures. This paper describes the behavior of a small-scale braced wall embedded in saturated liquefiable sand under dynamic condition. Shake table tests are performed in the laboratory on embedded retaining walls with single bracing. The tests are conducted for different excavation depths and base motions. The influences of the peak magnitude of the ground motions and the excavation depth on the axial forces in the bracing, the lateral displacement and the bending moments in the braced walls are studied. The shake table tests are simulated numerically using FLAC 2D and the results are compared with the corresponding experimental results. The pore water pressures developed in the soil are found to influence the behavior of the braced wall structures during a dynamic event. It is found that the excess pore water pressure development in the soil below the excavation is higher compared to the soil beside the walls. Thus, the soil below the excavation level is more susceptible to the liquefaction compared to the soil beside the walls.

Low-pressure hydrothermal processing of mixed polyolefin wastes into clean fuels

The amount of polyolefin waste, which is 63% of the total plastic waste, has grown exponentially over the past six decades. Its degradation products pose a serious threat to ecosystems and human health. Polyolefins can be converted to clean oils or fuels by using the supercritical water liquefaction (SWL) method at high pressures (≥23 MPa), which require high capital and energy costs. A new low-pressure (~2 MPa) hydrothermal processing (LP-HTP) method is developed to convert polyolefin waste with 50% or more polypropylene into oils with 87% yield at 450 °C and 45 min. The oils, which are C4 to C25 hydrocarbons, can be distilled into clean gasoline and ultra-low sulfur diesel. With this method, up to 190 million tons of fuels can be produced annually from polyolefin waste, resulting in savings of 92% of the energy and 71% of the GHG emissions compared to conventional methods for producing fuels.

Using Isopropanol as a Capping Agent in the Hydrothermal Liquefaction of Kraft Lignin in Near-Critical Water

In this study, Kraft lignin was depolymerised by hydrothermal liquefaction in near-critical water (290–335 °C, 250 bar) using Na2CO3 as an alkaline catalyst. Isopropanol was used as a co-solvent with the objective of investigating its capping effect and capability of reducing char formation. The resulting product, which was a mixture of an aqueous liquid, containing water-soluble organic compounds, and char, had a lower sulphur content than the Kraft lignin. Two-dimensional nuclear magnetic resonance studies of the organic precipitates of the aqueous phase and the char indicated that the major lignin bonds were broken. The high molar masses of the char and the water-soluble organics, nevertheless, indicate extensive repolymerisation of the organic constituents once they have been depolymerised from the lignin. With increasing temperature, the yield of char increased, although its molar mass decreased. The addition of isopropanol increased the yield of the water-soluble organic products and decreased the yield of the char as well as the molar masses of the products, which is indicative of a capping effect.

Supercritical water co-liquefaction of LLDPE and PP into oil: properties and synergy

The supercritical water liquefaction of PE/PP mixtures yields around 86.84–90.70% oil without catalyst or H2.

Measurement of Radon Concentration in Random Samples from Liquefaction Water Network in Al-Kifl District of Babylon / Iraq

Measurement of Radon Concentration in Random Samples from Liquefaction Water Network in Al-Kifl District of Babylon / Iraq

Sub- and Supercritical Water Liquefaction of Kraft Lignin and Black Liquor Derived Lignin

To mitigate global warming, humankind has been forced to develop new efficient energy solutions based on renewable energy sources. Hydrothermal liquefaction (HTL) is a promising technology that can efficiently produce bio-oil from several biomass sources. The HTL process uses sub- or supercritical water for producing bio-oil, water-soluble organics, gaseous products and char. Black liquor mainly contains cooking chemicals (mainly alkali salts) lignin and the hemicellulose parts of the wood chips used for cellulose digestion. This review explores the effects of different process parameters, solvents and catalysts for the HTL of black liquor or black liquor-derived lignin. Using short residence times under near- or supercritical water conditions may improve both the quality and the quantity of the bio-oil yield. The quality and yield of bio-oil can be further improved by using solvents (e.g., phenol) and catalysts (e.g., alkali salts, zirconia). However, the solubility of alkali salts present in black liquor can lead to clogging problem in the HTL reactor and process tubes when approaching supercritical water conditions.

One-step transformation of biomass to fuel precursors using a bi-functional combination of Pd/C and water tolerant Lewis acid

Direct one-pot transformation of lignocellulosic biomass has been developed as an effective and sustainable strategy to produce fuel blend stocks and high value chemical building blocks. In this wok, a bi-functional catalyst system consisting of palladium supported on carbon (Pd/C) and metal triflates (i.e., Sm(OTf)3, La(OTf)3, and Cu(OTf)2) were shown to promote the biomass liquefaction in both hot-compressed water and supercritical ethanol medium, converting fir wood into oxygenated compounds. The highest bio-oil yield from hydrothermal liquefaction (HTL) was 10.47 wt% over Pd/C whereas the highest bio-oil yield of 49.71 wt% was achieved from supercritical ethanol liquefaction (SCEL) over the bi-functional catalyst system of Pd/C and La(OTf)3. Higher heating values, carbon recovered values and boiling point distributions were further determined for elucidating the physical properties of the bio-oils. Gas chromatography mass spectrometry (GC–MS) analysis of the bio-oils revealed the chemical composition of the bio-oils. Substituted phenols and cyclopentenone/cyclopentanone type compounds consisted of more than 60 area% of the total products from HTL, whereas phenol and esters represented the major products from SCEL. The major reaction pathways are proposed based on the GC–MS results, which include depolymerizaton, isomerization, dehydration, condensation, and hydrogenation.

Liquefaction of water on the surface of anisotropic two-dimensional atomic layered black phosphorus

The growth and wetting of water on two-dimensional(2D) materials are important to understand the development of 2D material based electronic, optoelectronic, and nanomechanical devices. Here, we visualize the liquefaction processes of water on the surface of graphene, MoS2 and black phosphorus (BP) via optical microscopy. We show that the shape of the water droplets forming on the surface of BP, which is anisotropic, is elliptical. In contrast, droplets are rounded when they form on the surface of graphene or MoS2, which do not possess orthometric anisotropy. Molecular simulations show that the anisotropic liquefaction process of water on the surface of BP is attributed to the different binding energies of H2O molecules on BP along the armchair and zigzag directions. The results not only reveal the anisotropic nature of water liquefaction on the BP surface but also provide a way for fast and nondestructive determination of the crystalline orientation of BP.

Comparative investigation on bio-oil production from eucalyptus via liquefaction in subcritical water and supercritical ethanol

The present work addresses the liquefaction of eucalyptus for the production of bio-oil, examining the effects of solvent on the conversion process. The liquefaction was conducted at 260–320 °C in subcritical water and supercritical ethanol, and the bio-oil produced was analyzed by elemental components, higher heating value, GC–MS, and FTIR. Results showed that reaction medium and temperature exhibited notable influence on the process. The optimum condition for the preparation of bio-oil from eucalyptus should be conducted under water at 300 °C for 30 min, which can produce a high bio-oil yield of 30.1%. As the hydrothermal liquefaction temperature increased, the contents of aldehydes, phenols, and alkanes in the heavy oil decreased, while those of esters and ketones increased. After liquefaction in ethanol, the main substances in the heavy oil were esters, phenols, ketones, alcohols, alkanes and olefins. In light oil, esters, alcohols, phenols and ketones were the main substances. The properties of the bio-oil produced made it suitable to be applied as a promising precursor of bio-based aromatics and/or phenolic-rich antioxidant.