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This study investigated the use of eggshell membrane (ESM) as a bio-sorbent and the effect of temperature, pH, and initial concentration on its efficiency. Furthermore, by altering the chemical composition, modified eggshell membrane (MESM) was prepared, and its efficiency was compared with the ESM. Results showed that the adsorption of boron preferred an acidic condition; pH 6 at 35 °C. In addition, the positive value of ΔH° suggested that the reaction favored endothermic pathway, while the negative value for ΔG° further suggested that the adsorption process was spontaneous. Furthermore, the ESM could adsorb 97% of boron, while MESM was able to adsorb 95%. From the Fourier transform infrared (FTIR), different functional groups were recorded on the surface of the ESM and MESM, and they played key role in the boron adsorption mechanisms. Linear Freundlich model was suggested to best describe the experimental data with 99.4% correlation coefficient. [ABSTRACT FROM AUTHOR]

Abstract: Application of microemulsion modified raw date pits as an inexpensive solid extractant for removing methylene blue (MB), copper ion (Cu2+) and cadmium ion (Cd2+) has been presented. The results summarised herein are also part of an investigation conducted to evaluate the adsorption capacity by taking into consideration the experimental parameters such as pH, particle size and initial solute concentration. The experimental data obtained from the adsorption isotherms studies were used to find pollutants distribution factors and modelled using both Langmuir and Freundlich equations. The modified adsorbent was more effective toward all pollutants with high removal capacities (50–350 mg/g) and with very large distribution values (9–235 L/g) which indicates the suitability of this new material for extraction organic and inorganic pollutants. After microemulsion modification, the FTIR scans of the samples show clear differences in the position and intensity the characteristics bands of the raw date pits (RDP). Three mechanisms of the MB, Cu2+ and Cd2+ adsorption onto μE-MDP are possible: (i) adsorption by an electrostatic force of the anionic head group of the surfactant and the positive charge of the dye (MB+) or the metal ions (Cu2+ or Cd2+), (ii) adsorption by tail groups of the surfactant and the hydrophobic character of the MB molecules. The MB is a basic dye and has basic characteristics and therefore is expected to interact strongly with the anionic head groups of the surfactants (RCOO–). In the contrary, the Cu2+ and Cd2+ ions are not expected to interact by the tail groups of the surfactant where the ionic radii of these ions may explain the differences between Cu2+ (0.72 Å) and Cd2+ (0.99 Å) adsorption capacities and (iii) filling the channel (pores) of the RDP by dissolving in the microemulsion micelles. [Copyright &y& Elsevier]

The investigations into structural changes which occur during adsorbent modification and the adsorption mechanisms are essential for an effective design of adsorption systems. Manganese oxides were impregnated onto diatomite to form the type known as δ-birnessite. Initial investigations established the effectiveness of manganese oxides-modified diatomite (MOMD) to remove basic and reactive dyes from aqueous solution. The adsorption capacity of MOMD for methylene blue (MB), hydrolysed reactive black (RB) and hydrolysed reactive yellow (RY) was 320, 419, and 204mg/g, respectively. Various analytical techniques were used to characterise the structure and the mechanisms of the dye adsorption process onto MOMD such as Fourier transform infrared (FTIR), X-ray diffraction (XRD) and atomic absorption spectrometry (A.A.). A small shift to higher values of the d-spacing of dye/MOMD was observed indicating that a small amount of the dye molecules were intercalated in the MOMD structure and other molecules were adsorbed on the external surface of MOMD. Two mechanisms of dye adsorption onto MOMD were proposed; intercalation of the dye in the octahedral layers and adsorption of the dye on the MOMD external surface. Moreover, the results demonstrated that the MOMD structure was changed upon insertion of MB and RY with an obvious decrease in the intensity of the second main peak of the MOMD X-ray pattern. [Copyright &y& Elsevier]

Abstract: As a result of the changes that occur during their use, used engine oils tend to differ in chemical and physical composition from a virgin oil. In general recycled oils have: much higher water and sediment levels than virgin oil; relatively higher concentrations of organic compounds (oxidation products); and relatively higher levels of metals such as Fe, Cd, Cr, Pb, etc. Therefore, the aim of this work was to investigate, assess and to observe, by means of the physical and the chemical properties of the oils, atomic absorption (AA), inductive couple plasma (ICP) and Fourier transform infrared (FTIR) analyses the extent of the differences occurring between the virgin and recycled oil. In important part of this work was also the development of analytical techniques based on the use of FTIR spectroscopy; in relation to the rapid analysis of lubricants; in particular for the differentiation of virgin and recycled oil. The results obtained were expected to be useful for differentiation purposes, providing information on whether the metal concentrations and oxidation products could be an appropriate feature for differentiating a particular oil sample from the others. This work is categorized into a two-step procedure. Firstly, an evaluation of a typical FTIR spectrum of an engine oil sample (mono- and multigrade) is presented. The broad feature centered at 1716cm−1 is due to the presence of carbonyl containing degradation products of oil. A band observed at 1732, 1169, 1154 and 1270cm−1 assigned to the polymethacrylate stretching vibrations, allows the determination of viscosity modifier and pour point depressant additives. The observed differences in the specific spectral bands (1732, 1169, 1154 and 1270 and 1716cm−1) are investigated and discussed. Secondly, an analytical technique for the measurement of the levels of the wear metals is also applied. [Copyright &y& Elsevier]

Abstract In this study, ten bacterial strains were found to be mercury resistant after their isolation from Qatari coastal sediments. Tolerance was found to be up to 100–150 ppm for five strains. Those strains had optimum growth conditions at salinity level of 10 ppm NaCl and pH 7–8. Starting from a concentration 7.9 ppm of mercury extracted from fluorescent lamps and after 6 days of incubation at 37 °C, two isolated strains HA6 (Bacillus spp.) and HA9 (Acinetobacter sp.) showed 96.7% and 98.9% of mercury bio-uptake efficiency, respectively. Other strains were capable of removing more than 60% of extracted mercury. Highlights • Bacillus spp. and Acinetobacter sp. showed 96.7% and 98.9% Hg removal. • Other strains were capable of removing more than 60% of extracted mercury. • Almost all strain exhibited the highest growth density at pH level between 7 and 8. • Acinetobacter sp. was able to be tolerant up to 200 ppm of mercury. • Such strains can be applied in bioremediation of highly mercury-polluted areas. [ABSTRACT FROM AUTHOR]

Bacteria play a variety of roles in the environment. They maintain the balance in the ecosystem and provide different ecosystem services such as in biogeochemical cycling of nutrients, biodegradation of toxic pollutants, and others. Therefore, isolation and identification of different environmental bacteria are important to most environmental research. Due to the high cost and time associated with the conventional molecular techniques, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has gained considerable attention for routine identification of bacteria. This review aims to provide an overview of the application of MALDI-TOF MS in various environmental studies through bibliometric analysis and literature review. The bibliometric analysis helped to understand the time-variable application of MALDI-TOF MS in various environmental studies. The categorical literature review covers various environmental studies comprising areas like ecology, food microbiology, environmental biotechnology, agriculture, and plant sciences, which show the application of the technique for identification and characterization of pollutant-degrading, plant-associated, disease-causing, soil-beneficial, and other environmental bacteria. Further research should focus on bridging the gap between the phylogenetic identity of bacteria and their specific environmental functions or metabolic traits that can help in rapid advancements in environmental research, thereby, improving time and cost savings. • It provides an overview of MALDI-TOF MS applications in environmental studies. • Isolation and identification of environmental bacteria are important to environmental research. • MALDI-TOF MS has high accuracy and precision for the identification of various types of bacteria. • It is used for rapid identification of bacteria present in water, air, and different surfaces. [ABSTRACT FROM AUTHOR]

Gas-to-liquid (GTL) sludge is a specific wastewater treatment by-product, which is generated during the industrial process of natural gas conversion to transportation fuels. This least studied sludge is pathogen-free and rich in organic carbon and plant nutrients. Therefore, it can be reused for soil enhancement as a sustainable management strategy to mitigate landfill gas emissions. In this field study, we compared the performance of soil treatments with GTL sludge to the more conventional chemical fertilizers and cow manure compost for the cultivation of cotton under hyperarid conditions. After a complete growing season, GTL sludge application resulted in the enhancement of soil properties and plant growth compared to conventional inputs. As such, there was a significant dose-dependent increase of soil organic matter (4.01% and 4.54%), phosphorus (534 and 1090 mg kg−1), and cumulative lint yield (4.68 and 5.67 t ha−1) for GTL sludge application rates of 1.5% and 3%, respectively. The produced fiber quality was adequate for an upland cotton variety (Gossypium hirsutum var. MAY 344) and appeared more dependent on the prevailing climate conditions than soil treatments. On the other hand, the adverse effects generally related to industrial sludge reuse were not significant and did not affect the designed agro-environmental system. Accordingly, plants grown on GTL sludge-amended soils showed lower antioxidant activity despite significant salinity increase. In addition, the concentrations of detected heavy metals in soil were within the standards' limits, which did not pose environmental issues under the described experimental conditions. Leachate analysis revealed no risks for groundwater contamination with phytotoxic metals, which were mostly retained by the soil matrix. Therefore, recycling GTL sludge as an organic amendment can be a sustainable solution to improve soil quality and lower carbon footprint. To reduce any environmental concerns, an application rate of 1.5% could be provisionally recommended since a two-fold increase in sludge dose did not result in a significant yield improvement. [Display omitted] • Gas-to-liquid sludge is a carbon-rich by-product of GTL wastewater treatment. • GTL sludge land application mitigates the risks of landfill gas emissions. • GTL sludge improves soil and plant properties under hyperarid conditions. [ABSTRACT FROM AUTHOR]

Because of the high production of oil and gas in Qatar, the likelihood of oil spill occurrence is most probably susceptible to happen. Contaminated soil treatment is very expensive. Cost effective mechanisms are investigated to treat this threatening issue. For that reason, bioremediation and biotechnology tools are introduced to help accelerate and remove the pollution caused by the contamination process. This paper demonstrated the importance of optimising the treatment conditions to the indigenous bacterial strain to obtain the highest biodegradation efficiency rates. The usage of biopile system technology was used with biostimulation and bioaugmentation processes. The indigenous Bacillus sonorensis (B. sonorensis) D1 bacterium played a crucial role in the biodegradation process when introduced to optimized conditions; carbon/nitrogen/phosphorus (C/N/P) (100/10/1), temperature (37 °C), surfactant tween 80 (0.12% (v/w)), and moisture (10%). Gas chromatography (mass spectrometry/flame ionization detector) (GC- (MS/FID)), Fourier transform infrared (FTIR), and colony-forming unit (CFU) analyses were performed. The diesel range organics (DRO) and polycyclic aromatic hydrocarbons (PAH) removal (%) of the weathered oil contaminated soil reached, after 160 days, 39.2% and 32.4% simultaneously when ammonium nitrate was used as a nitrogen source. Whereas urea inhibited the oil degradation process and caused the pH to rise to 9.55. Image 1040 • Urea inhibited oil degradation process and caused pH to rise to 9.55 • Adding the surfactant tween 80 to urea enhanced bacterial growth with urea. • The bioavailability of the hydrocarbons is not always related to bacterial growth. • B. sonorensis D1 was able to biodegrade weathered oil at optimized conditions. • Using ammonium nitrate as a nitrogen source improved the biodegradation process. [ABSTRACT FROM AUTHOR]

Produced water is responsible for the largest contribution in terms of waste stream volume associated with the production of oil and gas. Characterization of produced water is very crucial for the determination of its main components and constituents for optimal selection of the treatment method. This review aims to review and critically discuss various treatment options that can be considered cost-efficient and environmentally friendly for the removal of different pollutants from produced water. Great efforts and progresses were made in various treatment options, including batch adsorption processes, membrane filtration, advanced oxidation, biological systems, adsorption, coagulation, and combined processes. Chemical precipitation, membrane filtration, and adsorption have high removal efficiencies that can reach more than 90% for different produced water components. The most effective method among these methods is adsorption using different adsorbents media. In this review, date-pits activated carbons, microemulsions-modified date pits, and cellulose nanocrystals as low-cost adsorbents were thoroughly reviewed and discussed. Moreover, the potential of using biological treatments in the removal of various pollutants from produced water such as conventional activated sludge, sequential batch reactor, and fixed-film biological aerated filter reactors were systematically discussed. Generally, produced water can be utilized in various fields including habitat and wildlife, agricultural and irrigation sector, energy sector, fire control, industrial use also power regeneration. The degree of treatment will depend on the application that produced water is being reused in. For instance, to use produced water in oil and gas industries, water will require minimal treatment while for agricultural and drinking purposes high treatment level will be required. It can also be concluded that one specific technique cannot be recommended that will meet all requirements including environmental, reuse, and recycling for sustainable energy. This is because of various dominant factors including the type of field, platform type, chemical composition, geological location, and chemical composition of the production chemicals. [Display omitted] • Adsorptive batch and biological treatments of produced water (PW) were discussed. • PW responsible for the largest contribution of waste stream volume. • PW characterizations are crucial for the optimal selection of treatment methods. • The development of treatment options for produced water was reviewed. • The degree of PW treatment depends on the application that PW is being reused in. [ABSTRACT FROM AUTHOR]

This study examines which management methods are the most recent and advanced in managing rejected brine generated from desalination plants. It also provides up-to-date information regarding the most adequate technologies that generate a minimum quantity of rejected brine via the use of minimization techniques and analyzes the method of direct disposal that has lately received noticeable improvements. It further discusses the reuse of discarded brine to recover valuable goods and sequestration of carbon dioxide. Sustainability is an important parameter that needs consideration to achieve uninterrupted operation of the discarded brine management to achieve the least environmental, social, and economic aftermath. To properly deal with any environmental issues related to brine disposal, different methods are implemented so that, in the end, higher water recovery is achievable from the desalination processes, namely brine minimization and rejection technologies (pressure retarded osmosis, microbial desalination cell technology), membrane-based technologies (vibratory shear enhanced processing, forward osmosis, electrodialysis, electrodialysis reverse, and electrodialysis metathesis, pervaporation method, thermal-based technologies (wind-aided intensified evaporation, brine concentrators, ohmic evaporator, membrane distillation, multi-stage flash distillation. This review also critically examined the two conventional approaches commonly used in life cycle assessment (LCA), when evaluating the ecotoxic effect of discarded brine. It intends to discuss the currently available methods and propose an improved method for evaluating the toxicity potential of brine on the aquatic ecosystem originated from seawater desalination plants. The Group-by-Group method takes into consideration the demerits of the two methods of the traditional method of LCA or chemical-specific approach as it provides a more holistic coverage for complicated brine to be disposed of. Recently, attention has been focused on recovering valuable metals from the discharged concentrated brine waste. Certainly, attaining marketable products from the discharged concentrated brine would offer an economic benefit and reducing the whole desalination costs. Ion imprinting polymers have potential applications in metal recovery from brine. Finding selective, more efficient, and less expensive imprinted polymers for extraction/pre-concentration of valuable ions is a vital and challenging task. Lastly, the brine should be seen as a resource and not as a waste to attain sustainability in its management approaches. Hybrid processes would be highly recommended to get the absolute transformation of the discarded brine from desalination processes to more valuable constituents. [Display omitted] • Brine is best managed when reducing its volume to the bare and accepted levels. • Brine is considered as a resource to achieve sustainability in water management. • All the emerging technologies are suitable for minimizing the brine volume. • The "group-by-group" approach can evaluate the ecotoxic effect of discarded brine. • Ion imprinting polymers have potential applications in metal recovery from brine. [ABSTRACT FROM AUTHOR]