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The thermo-solvent-tolerant lipase-producing actinomycete, Streptomyces sp. A3301, was utilized as a biocatalyst for poly (lactic acid) or PLA polymerization. The study aimed to optimize lipase immobilization conditions, characterize the immobilized lipase and apply it for PLA polymerization. The results showed using a sponge as the immobilizing matrix was the most effective method, achieving a maximum activity of 277 U/g of sponge. The optimal sponge size was determined to be 0.125 cm³ and pre-soaking the sponge in 0.1 M phosphate buffer at pH 7.0 for 24 h before use proved advantageous. Immobilization significantly enhanced the thermo-stability of the enzyme, with a relative activity ranging from 140 to 190% within the temperature range of 30 to 60 °C. In contrast, the crude lipase exhibited thermo-stability only within the 30 - 50 °C range. The immobilized lipase demonstrated stability under PLA polymerization conditions, which involved a reaction mixture containing toluene and lactic acid and performed at 60 °C for 8 h. The immobilized lipase maintained its activity under this condition for 5 h, retaining a relative activity of 230%, which was 1.2 times higher than the activity of the crude lipase. When the immobilized lipase was used in PLA polymerization, the resulting PLA product exhibited a molecular weight of 5,333 ± 0.02 Da, and the degree of polymerization was approximately 72. These findings underscore the potential of the immobilization technique to enhance lipase activity for PLA polymerization. [ABSTRACT FROM AUTHOR]

Lead (Pb(II)) ions in water pose a significant threat to both human health and aquatic ecosystems. Various approaches have been employed for wastewater treatment, but adsorption is often preferred due to its effectiveness. However, its practical application is limited by the large quantities of adsorbent required, which consequently increases operational costs. In this study, orange-modified iron-oxide nanoparticles (O-Fe3O4) are synthesized from agro-waste mass (orange peel), and adsorption experiments were conducted for the removal of Pb(II) from aqueous solution. Characterization studies confirm that O-Fe3O4 nanoparticles possess a mesoporous hexagonal nanocrystalline structure, with diameters measuring less than 100 nm. The adsorption process was optimized using a central composite design framework combined with response surface methodology. The analysis of interaction effects demonstrated that they significantly influenced the effectiveness of adsorption removal. The study revealed that an initial concentration of 25 mg/L, a dosage of 0.2 g/L, a contact period of 90 min, and a pH of 5.5 were the optimum conditions to achieve above 95% of Pb(II) removal. The green synthesized O-Fe3O4 nanoparticles, which presented high efficacy, makes it a promising option for implementing the sustainable water purification. [ABSTRACT FROM AUTHOR]

Objective Oil and gas fields brine contains impurities such as petroleum and suspended solids, which have potential impacts on the adsorption and separation of lithium resources. This papper studies the feasibility of lithium adsorption extraction from gas field water and the adaptability of mainstream adsorbents in the market for lithium extraction. Methods The study compared the effects of pH and temperature on the adsorption and desorption efficiency of three types of powder adsorbents: aluminium-based, titanium-based, and manganese-based adsorbents. Aluminium-based adsorbent was selected, and the effects of adsorbent morphology, brine, and brine feed flow rate on adsorption and desorption efficiency were studied, and its cycling stability was evaluated. Results Under the optimal conditions, the saturated adsorption capacities of the three adsorbents are approximately 7.9 mg/g, 12.5 mg/g and 15.3 mg/g, respectively. In this experiment, the ratio of sodium to lithium and potassium to lithium in the desorption solution of aluminum adsorbent is better than that of titanium-based and manganese-based adsorbents, and the dissolution loss rate of titanium and manganese adsorbents is 20 and 70 times that of aluminum-based adsorbent, respectively. The service life during long-term operation is significantly shorter than that of aluminum series adsorbents. The ceramic membrane was used to remove suspended solids and petroleum from brine before the lithium extraction. Under the conditions of 20 BV of brine feed, 12 BV/h of brine feed flow rate, 10 BV of desorption water volume, and 10 BV/h of desorption flow rate, the adsorption capacity of aluminum molding adsorbent, as well as the concentration of lithium in tail brine remain stable in ten consecutive cycles of single-column experiments, with an average lithium adsorption rate of 79.2%. Conclusion It is feasible to use the adsorption method to extract lithium resources from the brine of Longwangmiao gas field. [ABSTRACT FROM AUTHOR]

Summary: In order to better preserve phospholipids (PLs)‐type polyunsaturated fatty acids (PUFAs) and astaxanthin (ASTA), Antarctic krill oil (AKO) undergoes only limited refining steps, which results in the presence of metal ions. This study aims to establish a metal ion removal method for AKO by using adsorbents and investigate the effects of the metal ion removal process on nutritional composition, oxidation state and colour of AKO, as well as the effects of metal oil removal of AKO on its nutrition composition, oxidation stability and colour stability upon accelerated storage. Among the three types of adsorbents including silica gel, diatomaceous earth, and attapulgite soil, the last one showed the best comprehensive removal effects. After optimising the removal conditions, attapulgite soil achieved the removal rates of 92.5%, 90.0%, and 86.4%, respectively, for iron ions, magnesium ions and calcium ions. Compared to the fresh AKO, the processed AKO had no significant differences in peroxide value (POV), thiobarbituric acid reactive substances (TBARS), and total oxidation value (TOTOX), as well as PUFA content and lipid class composition, indicating that the metal ion removal process would not cause significant lipid oxidation. Moreover, the processed AKO looks brighter and more transparent, and had higher detection values in L*, a*, and b* but lower UV‐vis absorption at 295 nm (A295) and 420 nm (A420). This indicated that the metal ion removal process improved the colour quality. After accelerated storage at 60 °C for 8 days, the processed AKO sample had significantly lower values in POV, TBARS, and TOTOX, but significant higher PUFA content than the fresh AKO group. Moreover, the processed AKO sample had the higher values of L*, a*, and b*, as well as A470 and A495, but the lower values of A295 and A420. The above results indicate that the removal of metal ions significantly improved the stabilities of oxidation and colour of AKO. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Industry / Hemijska Industrija is the property of Association of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The exceptional photoelectromagnetic characteristics of rare-earth elements contribute significantly to their indispensable position in the high-tech industry. The exponential expansion of the demand for high-purity rare earth and related compounds can be attributed to the swift advancement of contemporary technology. Nevertheless, rare-earth elements are finite and limited resources, and their excessive mining unavoidably results in resource depletion and environmental degradation. Hence, it is crucial to establish a highly effective approach for the extraction and reclamation of rare-earth elements. Adsorption is regarded as a promising technique for the recovery of rare-earth elements owing to its simplicity, environmentally friendly nature, and cost-effectiveness. The efficacy of adsorption is contingent upon the performance characteristics of the adsorbent material. Presently, there is a prevalent utilization of porous adsorbent materials with substantial specific surface areas and plentiful surface functional groups in the realm of selectively separating and recovering rare-earth elements. This paper presents a thorough examination of porous inorganic carbon materials, porous inorganic silicon materials, porous organic polymers, and metal–organic framework materials. The adsorption performance and processes for rare-earth elements are the focal points of discussion about these materials. Furthermore, this work investigates the potential applications of porous materials in the domain of the adsorption of rare-earth elements. [ABSTRACT FROM AUTHOR]

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As the discharge standards for mine water treatment become more stringent, the requirements for effective removal of ammonia nitrogen from mine water are strongly needed. While there are several methods available for treating ammonia nitrogen in wastewater, there is relative scarcity of literature addressing the treatment of mine water specifically containing ammonia nitrogen. To address this issue, this paper conducted a comprehensive analysis of the sources and characteristics of ammonia nitrogen in mine water. It also reviewed various primary technologies used for treating low concentrations of ammonia nitrogen in wastewater, including ion exchange, adsorption, oxidation, membrane separation, and biological methods. The paper aimed to provide technical support for the treatment of ammonia nitrogen-containing mine water in China. The findings of the study reveal that ammonia nitrogen in mine water primarily originates from three sources: Naturally high ammonia nitrogen content in groundwater, the usage of emulsion, dust suppressants, grouting, and gelling materials in the underground coal production process, and the lateral recharge from polluted surface water containing ammonia nitrogen. Ammonia nitrogen-containing mine water is characterized by relatively low ammonia nitrogen content (generally

This article reviews the mechanism of Li+ de-intercalation and intercalation in manganese-based lithium ion-sieve, titanium-based lithium ion-sieven and aluminum-based adsorbent. The lithium extraction mechanism and the factors affecting the adsorption effect; some problems in lithium ion sieve materials are summarized, and the future research focus and development direction of lithium ion sieves are prospected. [ABSTRACT FROM AUTHOR]

Nickel ferrite nanoparticles (NiFe2O4) have been proposed as a promising candidate for bacterial inactivation. In this study, cotton fabrics were modified by employing a simple adsorption technique to incorporate NiFe2O4. The surface morphology and quantitative analysis of the NiFe2O4-modified cotton fabrics were investigated using field emission scanning electron microscopy (FESEM). The shape and distribution of the NiFe2O4 within the cotton fabrics were examined through high-resolution transmission electron microscopy (HRTEM) analysis of cross-section fabric samples. The synthesized NiFe2O4 exhibited a nanospheric shape with a particle size diameter ranging from 40 to 60 nm. Nitrogen adsorption–desorption analysis confirmed the mesoporous nature of the modified cotton fabric samples. The antibacterial efficacy of the nickel ferrite nanoparticle-modified fabrics was evaluated against Proteus mirabilis, Staphylococcus aureus, Enterococcus aerogenes, Escherichia coli, Klebsiella pneumonia, and Pseudomonas fluorescens bacteria. Furthermore, the durability of the NiFe2O4 nanoparticles on the fabric surface was assessed by subjecting the modified fabrics to 50 cycles of laundering washing, which demonstrated that the nanoparticles did not leach out even after repeated washings. [ABSTRACT FROM AUTHOR]

The ocean covers 70% of the earth’s area, and the seawater uranium is more than 1000 times that of terrestrial uranium ore. In order to increase the power generation and ensure the sustainable operation of nuclear power plants, the development of unconventional uranium resources is of great significance. As an effective means to solve shortage of terrestrial uranium resources, uranium extraction from seawater has received extensive attention in recent years. At present, many methods including membrane separation, chemical deposition, solvent extraction, ion exchange, reduction and adsorption have been applied to uranium extraction from seawater. This paper focuses on the recent research progress of adsorption method used inorganic materials, organic materials, carbon materials as adsorbent, and emerging electroreduction technologies, and further discusses the challenges and opportunities of these two methods.

The development of industry has brought a large amount of CO2 emissions. In the process of achieving the goal of carbon peak and carbon neutralization, carbon dioxide capture, utilization and storage (CCUS) technology is an indispensable key technology. The carbon capture method with high technology maturity at this stage and great development potential in the future is post combustion carbon capture technology, mainly including solvent absorption, adsorption, membrane method and cryogenic distillation. The development and industrial application of the four most commonly used carbon capture methods were briefly introduced, and the industrial applicability of several methods was analyzed, especially the chemical absorption method and physical adsorption method, which are most widely used in large-scale carbon capture projects currently running. Chemical absorption method, adsorption method and membrane carbon capture technology have great development potential in the future, which can quickly promote the achievement of the goal of double carbon and help the near-zero emission of carbon.

Under the background of "carbon peaking and carbon neutrality" policy, the green and efficient wastewater treatment process has become a hotspot and has great significance for achieving carbon emission reduction. Carbonaceous functional materials stand out from all kinds of water treatment materials due to their excellent chemical stability, economic applicability, easy modification and environmental friendliness, which is expected to become a new generation of green environmental protection materials in water treatment. This review focuses on the modification principle, characteristics and application progress of carbon functional materials in the water treatment. Meanwhile, the current challenges and future development of carbonaceous functional materials was prospected, with a view to providing references for further development and application. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rose Bengal, an organic dye is a red or rose color, anionic in nature and important xanthene dyes in textile, dyeing and photochemical industries. where as direct brown 127 belongs to multi-azo class is a black light brown in color and are usually cheap, easily applied for use on cotton and other cellulose fibres such as cotton, rayon and linen. Thence, the present work has fabricated to eliminated the rose Bengal and direct brown 127 dye from waste water where it adsorbed on the surface of the adsorbent i.e. ZnO nanoparticles biologically synthesized by aqueous tuber extract of Arisaema tortuosum. These biologically synthesized ZnO nanoparticles were characterized by UV-Visible, XRD, FTIR SEM and TEM techniques that corroborated the formation of zinc oxide in the nano-range. Certainly the removal of rose Bengal and direct brown 127 dyes by changing their concentration in the aqueous medium using adsorption and degradation method follows centrifugation was estimated by quantitative analysis using UV-Vis spectrophotometer. The results have shown that ZnO NPs were very efficient to remove the rose Bengal and direct brown 127 dye pollutant from aqueous solutions under various conditions (dye concentration, adsorbent dosage, adsorbate dosage, contact time and effect of time on % decolourization of dye with nanoparticle concentration) made it an ideal alternative as compared to other expensive treatment methods and potential toxicity. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fluoride ions are widely distributed in surface rivers and groundwater bodies in China, especially in the mining areas along the Yellow River in the western Yellow River basin that there is a widespread problem of excessive fluoride in the mine water, which poses a potential threat to the local ecological environment and human health. The status quo of fluoride pollution in China is mostly at a low concentration pollution level, which leads to it difficult to remove efficiently through conventional water treatment technologies. The adsorption method is considered to be an effective way to remove low concentration fluoride ions because of its high adsorption efficiency and convenient operation. The research status of fluoride removal by commonly used adsorption materials such as carbon based, minerals, metals and metal organic frameworks (MOFs) was reviewed and summarized before summarizing the influence of different factors on the fluoride removal efficiency and adsorption mechanism of these adsorption materials. Then the application effect and operation cost of adsorption method in mine water treatment were emphatically analyzed, and the development direction of adsorption method in the treatment of low concentration (

Copyright of Power Generation Technology is the property of Power Generation Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the development of global industry, industrial wastewater pollution has caused serious environmental problems, and the demand for green and sustainable adsorbents is increasingly strong in the society. In this article, lignin/cellulose hydrogel materials were prepared using sodium lignosulfonate and cellulose as raw materials and 0.1% acetic acid solution as a solvent. The results showed that the optimal adsorption conditions for Congo red were as follows: an adsorption time of 4 h, a pH value of 6, and an adsorption temperature of 45 °C. The adsorption process was in line with the Langmuir isothermal model and a quasi-second-order kinetic model, which belonged to single molecular layer adsorption, and the maximum adsorption capacity was 294.0 mg/g. The optimal adsorption conditions for Malachite green were as follows: an adsorption time of 4 h, a pH value of 4, and an adsorption temperature of 60 °C. The adsorption process was consistent with the Freundlich isothermal model and a pseudo-second-order kinetic model, which belonged to the chemisorption-dominated multimolecular layer adsorption with the maximum adsorption capacity of 129.8 mg/g. [ABSTRACT FROM AUTHOR]

[Display omitted] Overexploitation of nature by humans has led to an increasingly serious issue of heavy-metal water pollution. To reduce the threat of water pollution to humans and the environment, it is imperative to develop or improve the water treatment technology for heavy-metal-containing wastewater. Functionalized Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 MNPs) have been widely used as effective adsorbents for the removal of heavy-metal ions from water owing to their high efficiency, low cost, selective adsorption ability, and recyclability. In this study, Fe 3 O 4 @DA-DMSA magnetic nanoparticles (FDDMs) were prepared by the functionalization of Fe 3 O 4 MNPs with environmentally friendly dopamine (DA) and a heavy-metal detoxifying agent such as 2,3-dimercaptosuccinic acid (DMSA) for the efficient and rapid adsorption of Pb2+, Cu2+, and Cd2+, with maximum adsorption capacities of 187.62, 63.01, and 49.46 mg/g, respectively. FDDMs exhibited the best ability to remove Pb2+ with a maximum adsorption capacity than that of the most reported Fe 3 O 4 MNP-related adsorbents. In actual wastewater and multi-component simulated water samples contaminated with Pb2+, Cu2+, and Cd2+, the as-prepared adsorbent maintained a good removal ability for Pb2+ with low influence by ionic strength and interfering ions, as well as exhibited an excellent selectivity. According to the results of batch experiments and X-ray photoelectron spectroscopy (XPS) analysis of the adsorbent before and after adsorption, the adsorption mechanism of the adsorbent for the removal of heavy-metal ions mainly involves coordination and ion exchange. In addition, the adsorbent exhibited a good regeneration performance. Therefore, FDDMs can be considered as a promising adsorbent for the treatment of heavy-metal wastewater. [ABSTRACT FROM AUTHOR]

Ammonia nitrogen pollutant in aqueous media is difficult to treat, which leads to a deterioration of pristine water ecosystems because of eutrophication and poses significant risks to human health. The efficient treatment of low-concentration ammonia nitrogen wastewater remains difficult. Adsorption is a promising remediation strategy, but suitable adsorbent materials that are abundant, low-cost, environmentally friendly, and efficient remain challenging to find. Recent developments in low-cost adsorbent materials for ammonia nitrogen removal from aqueous solution have been summarized. The physicochemical properties; ammonia removal mechanism; and advantages and disadvantages of representative adsorbent materials, including natural mineral materials, industrial byproducts, biochar, biopolymers, and their modified forms, have been compared. Future perspectives and research directions on the use of inexpensive adsorbents for ammonia nitrogen removal have been provided. [ABSTRACT FROM AUTHOR]

In the analysis of the components of gas emissions from metallurgical industries, it is generally accepted that sulphur dioxide is the most harmful to the surrounding ecosystem, and its capture is a pressing problem. The aim of the development is to design a circuit diagram of devices chain for reducing the emissions of toxic gases from metallurgical plants using new technological solutions on the example of purification of roasting gases from sulphur dioxide in the production of molybdenum. The scheme includes an adsorber developed with a vibrating adsorbent layer, which is recommended for ferromanganese nodules (FMN), which have advantages over other adsorbents, including activated carbon. In the case of a spent adsorbent treatment system, elemental sulfur can be produced in the circuit, and FMN should then be considered as manganese concentrates and feedstock for the complex recovery of the associated elements: copper, nickel, cobalt. The line can be used in smelters firing sulphide ores, as in other industries emitting gases with sulphur dioxide as well.

A large amount of fluorine−containing wastewater was produced with the rapid development of the industry. Excessive fluoride content in water will not only endanger ecological security but also pose threat to human health. In this study, common new adsorbents for defluorination, such as metal−based adsorbents, natural adsorbents, and nanomaterial adsorbents were reviewed for its physicochemical properties and fluorine removal efficiency. The fluorine removal mechanism of different adsorbents was introduced in detail, and the future work of the removal of fluorine using novel adsorbents was proposed. This research also introduces the application of the coupling of the adsorption method with the technology of chemical precipitation, filtration, and super−magnetic separation to treat high concentration of fluoride wastewater. A good selection of process combinations according to different needs can achieve high−efficiency defluorination in water. Finally, some existing problems of practical operation of fluorine using removal materials in the environment are summarized, hoping to contribute to the future research of fluorine removal materials. [ABSTRACT FROM AUTHOR]

The two generations of PAMAM-modified magnetic chitosan have been synthesized and are employed as enzyme carriers due to their biocompatibility and high affinity toward the biomolecules. This is the first attempt to use these carriers in the field of enzyme immobilization and is found to be about 93.95% immobilization efficiency by adsorption with second generation of the modified dendritic polymer (CSM-PAMAM G2). Here, α-amylase was also immobilized on CSM-PAMAM G2 by covalent binding method using gluteraldehyde as cross-linking agent in the range of 0.1–1% and found to be optimum immobilized enzyme activity at 0.4% which has been taken for further experimental studies. The immobilized enzymes by both methods have shown wider range of pH stability and exhibited about 60–75% of relative activity at pH 9. They have demonstrated broader temperature stability, and both have shown optimum activity at 60 °C. The effect of polymer concentration on enzyme activity was studied, and the optimum value is found to be at 0.2 g/mL. They have acquired about 85–90% of thermal stability due to their adequate conformational stability that protect from thermal unfolding. The km values 0.53 ± 0.04, 0.85 ± 0.03 and Vmax values 23.25 ± 0.04, 16.67 ± 0.06 for adsorbed and covalently immobilized enzyme confirmed their high affinity and improved activity. They retained 40–60% of relative activities after six months of storage, and the remarkable reuse assay was found to be that the carriers are very easy to handle due to their magnetic separation which will extend their application in many industrial fields. [ABSTRACT FROM AUTHOR]

Adsorption is one of the best methods for removing metals from aqueous medium. In the present study, bentonite clay was used as an adsorbent for heavy metal Cr+6 removal from the synthetic solution as well as actual waste water collected from local tanneries. Bentonite was used with and without chemical modification to improve removal efficiency. The adsorbent was modified with HCl, H2SO4 and NaOH. The batch adsorption technique was applied to study the effect of pH, initial concentration of metal ions, adsorbent dose and shaking time on the adsorption process. The chemical oxygen demand and biological oxygen demand of tannery effluents were significantly reduced upto 77.6% and 81.2%, respectively. The original bentonite clay removed upto 59%, while 98% removal was achieved with H2SO4 modified bentonite clay, 68% with HCl modified clay and 89% by NaOH-modified clay. Furthermore, the percentage removal efficiency was reduced by increasing the initial concentration of metal ions. The current study concluded that bentonite clay is a good adsorbent and modifications to bentonite clay can effectively improve the physical characteristics of the clay to adsorb Cr+6 ions. Moreover, bentonite clay is inexpensive and readily available in our country. [ABSTRACT FROM AUTHOR]

The production process of mineral resources generates a large amount of acid mine drainage, which is highly acidic, has a high sulfate content, and contains multiple heavy metal ions, easily leading to environmental pollution. In this experiment, biochar adsorption - precipitation method was used to remove heavy metal ions from acid mine drainage. The biochar was produced from corn stalk through pyrolysis at 600 °C. The study investigated its effect on copper removal from acid mine drainage and the adsorption capacity of the regenerated biochar adsorbent. Subsequently, the precipitation method was used to remove other heavy metals, and the treated wastewater met the Class I discharge standard requirements of GB 8978 - 1996 "Comprehensive Wastewater Discharge Standard". [ABSTRACT FROM AUTHOR]

Objective Under the background of global energy conservation and emission reduction and the guidance of China’s dual-carbon strategic objectives of "carbon dioxide peaking and carbon neutrality", targeted research on CO2 capture technology suitable for various working conditions has become an extremely important research trend. Methods Combining the latest developments in the field of carbon capture, in view of the CO2 emission in the combustion process, the advantages, disadvantages and application trends of absorption method, adsorption method, cryogenic separation, membrane absorption method, and hyper gravity method were compared. Meanwhile, the development trend of CO2 capture technology was analyzed and summarized. Results The technical characteristics of several post-combustion capture technologies for CO2 were clarified. It is elucidated that the selection of absorbent is the key to the current absorption methods, and the optimization of reactor and operating conditions are also extremely crucial. In view of adsorption methods, the development of adsorbents with high selectivity, high adsorption capacity, good desorption capacity, and low cost are the top priority for large-scale industrial applications. As for membrane technology, the advantage is easy and flexible operation, but improving the performance of membranes still requires continuous research. Overall, the characteristics, application potential and research directions of several capture technologies were clarified. Conclusions Although many CO2 absorption and separation technologies have been widely studied and applied, there are still many problems in the specific applications. In the field of carbon capture, the research on new materials and new solvents for CO2 absorption and separation is still a frontier and hot topic. From the perspective of carbon capture technology, the future development trend is likely to be the use of two or more technologies in series to meet the decarbonization demand under more complex conditions. [ABSTRACT FROM AUTHOR]

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chromium tanned leather wastes (CTLW) and vegetable tanned leather wastes (VTLW) were used as adsorbent materials to remove the Biebrich scarlet dye (BS), as an anionic dye from wastewater, using an adsorption method. The effects of various factors, such as weight of leather waste, time of shaking, and the starting concentration of Biebrich scarlet dye, temperature and pH were studied. It described the adsorption process using Langmuir and Freundlich isotherm models. The obtained results agreed well with the Langmuir model, and the maximum adsorption capacities of CTLW and VTLW were 73.5294 and 78.1250 mg.g-1, respectively, suggesting a monolayer adsorption process. The adsorption kinetic was found to follow a pseudo-second-order kinetic model with correlation coefficients R² > 0.9982 and 0.9900 for CTLW and VTLW, respectively. The results predicted that chromium leather wastes were more suitable adsorbents for the removal of BS dye from wastewater than vegetable tanned leather wastes, and the adsorption process is endothermic, according to the study of the effect of temperature. [ABSTRACT FROM AUTHOR]

Some modified kaolin materials have the potential as adsorbents for the removal of numerous pollutants. In view of this, we developed two modified kaolin named Fe–kaolin and Co/Mn–kaolin, respectively, and studied the adsorption properties and mechanism of two materials for micro-plastics. The results showed that the adsorption of micro-plastics on these two modified kaolin materials reached equilibrium basically after 72 h. The adsorption capacity of Co/Mn–kaolin for micro-plastics was about 22.00 mg·g−1 while the adsorption capacity of Fe–kaolin for micro-plastics was about 13.68 mg·g−1. The adsorption of micro-plastics by these two adsorbents may follow the pseudo-first-order kinetic model and the Freundlich isotherm model. The adsorption behavior of micro-plastics on Co/Mn–kaolin was an exothermic adsorption process while the adsorption behavior of micro-plastics on Fe–kaolin was an endothermic adsorption process. This work provides two low-cost, environmentally friendly and reusable adsorbents for the extraction of multiple micro-plastics in water simultaneously, which means that these two modified kaolin materials have the application chance of the lab-scale experiments. Besides, this work provides another new idea for the recycling and reuse of kaolin tailings and some heavy metal ions in the environment, which is very beneficial to the comprehensive treatment of the environment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Tiangong University is the property of Journal of Tianjin Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Adsorption method is one of the most important methods for the treatment of organic dye wastewater. Since the actual industrial wastewater generally contains multiple organic dyes, it is necessary to develop adsorbents that can remove multiple organic dyes simultaneously and efficiently. Some modified kaolin materials have the potential as adsorbents for the removal of numerous pollutants. In view of this, we prepared the aqueous solution containing methylene blue, rhodamine B and orange II and developed two modified kaolin materials called Fe-kaolin and kaolin, respectively. Then we studied the adsorption properties of the two materials in the solution containing three organic dyes. The results showed that among three organic dyes, both Fe-kaolin and kaolin had the largest adsorption capacity for methylene blue, followed by orange II, and finally rhodamine B. In addition, the quality of adsorbents, time, the concentration of Cl–, pH and temperature had great impact on the adsorption effect of organic dyes on these two materials. Among these factors, the quality of adsorbents had the greatest influence on the adsorption. Therefore, the regeneration or the best adsorption effect of the two modified kaolin materials on multiple organic dyes can be realized by adjusting these factors. For example, the activation and regeneration of adsorbents was achieved by adjusting pH. This technology had the advantages of simple operation and low cost. Furthermore, the mechanism of the three organic dyes by the modified kaolin materials was studied. The results showed the adsorption of these three organic dyes by the modified kaolin materials was a chemical adsorption process and an endothermic adsorption process. The adsorption of methylene blue by the two modified kaolin materials was monolayer adsorption. But it was difficult to judge whether the other two organic dyes adsorbed by the two modified kaolin materials was monolayer adsorption or multilayer adsorption. Last but not least, the adsorption of methylene blue by these two modified kaolin materials can usually proceed spontaneously while the adsorption of the other two organic dyes by these two modified kaolin materials usually cannot proceed spontaneously. In short, these two modified kaolin materials had the potential in the treatment of wastewater containing multiple organic dyes. This work has certain significance for the recycling applications of kaolin tailings and the development of novel modified kaolin materials that can remove multiple organic dyes in wastewater efficiently. [ABSTRACT FROM AUTHOR]

With the intensification of industrial and agricultural wastewater pollution, biotoxin heavy metals remain in the natural hydrosphere, posing a great threat to the ecological environment. In the ten methods for heavy metal removal in aqueous environments discussed in this paper, the adsorption method demonstrates greater flexibility and superior cost and environmental benefits. Phytate, with its abundant phosphate groups and good conductivity, is widely used in the modification process of various adsorbents. The report in this study shows that phytate-modified adsorbents generally improve the adsorption of heavy metals, such as the adsorption rate of cadmium and copper on nanofiltration membranes reaching nearly 100%, the adsorption capacity of magnetic particles increasing by 11.480 times, and even up to 17.233 times for biochar. In addition, a large number of adsorbents modified with phytate can maintain good adsorption performance after 2–5 cycles and are easy to regenerate. In this paper, we compare a wide range of remediation techniques for heavy metal pollution and the advantages and disadvantages of adsorbents, and analyze the structure and adsorption mechanism of phytate. The synthetic process and adsorption capability of the composite products regarding the application of phytate modification are highlighted. This paper focuses on several effective adsorbents for phytate modification, reflecting the benefits and potentials of phytate as a modifier, with the goal of enhancing the adsorption performance of raw materials and remediating heavy metal pollution in water environments. [Display omitted] • Comparison of performance between phytate and commonly used adsorbents. • Elaboration on the adsorption mechanism and influencing factors of phytate. • The adsorption performance of typical phytate modified composite agents was compared. • Existing problems and development directions of phytate modification are analyzed. • Phytate modification has the feasibility of controlling heavy metal pollution in water environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • FLAM as a metal organic aerogel exhibits an ultrahigh adsorption capacity for oxytetracycline. • FLAM is prepared by rapid microwave-assisted synthesis. • The FLAM demonstrates satisfactory adsorption capacity in the co-existing experiment. • l -aspartic acid is used as a bio-ligand for fabricating FLAM. Developing advanced adsorption materials is of great significance for removing antibiotics from wastewater owing to the increasingly severe issue of antibiotic contamination. Herein, a novel bio-based metal organic aerogel (FLAM) adsorbent with macroscopic shapeability, formed through the coordination of l -aspartic acid (L-AA) and Fe salt, was fabricated for the first time via the microwave-assisted synthesis method. Subsequently, the FLAM was used to remove oxytetracycline (OTC) from aqueous solution, and the result indicated FLAM exhibited ultrahigh adsorption capacity for OTC with a record-high value of 1566 mg·g−1, which greatly outperformed the reported adsorbents. The adsorption equilibrium curve and adsorption thermodynamics followed the pseudo-second-order kinetics model and the Freundlich model respectively, which indicated multilayer adsorption and chemisorption dominated the adsorption process. Significantly, the adsorbent also enabled efficient decontamination of tetracycline (TC) and chlortetracycline hydrochloride (CTC). Such an excellent adsorption capability of FLAM can be attributed to multiple factors, i.e., electrostatic interaction, surface complexation and hydrogen bonding. Coexisting experiments demonstrated that the FLAM possessed excellent application ability in treating practical antibiotic wastewater. Ultrahigh adsorption capacity and fast-synthesis method prefigured its broad prospect for OTC-related wastewater remediation. [ABSTRACT FROM AUTHOR]

With the continuous improvement of technological level, the potential of rare earth elements (REEs) called "industrial gold" in various fields has been continuously explored, and some rare earth elements are regarded as very valuable additives in the high-tech field. With the rapid development of the rare earth industry in recent years, the demand for REEs has continued to rise. Because neighboring rare earth elements have extremely similar physical and chemical properties, in industrial applications, the purity of rare earth elements has high requirements, so the separation between rare earth elements is particularly important. Over time, people have developed a variety of techniques for the separation and recovery of rare earth elements, commonly used including chemical precipitation, ion exchange, solvent extraction, membrane separation, and adsorption, etc. At present, there are few reports on the comprehensive progress of all separation and purification technologies for a single rare earth element. This article mainly summarizes the latest developments in the separation of rare earth elements, evaluates the advantages and disadvantages of various process technologies, and prospects the development prospects of rare earth element separation technologies. [Display omitted] • Latest developments in separation technologies of single rare earth elements were reviewed. • Different technologies commonly used in rare earth separation at present were briefly evaluated. • Adsorption method in the separation of rare earth elements was mainly introduced. • Challenges faced by the current rare earth separation technologies were also put forwarded. [ABSTRACT FROM AUTHOR]