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[Display omitted] • A magnetic phosphate-functionalized calcium alginate (MPCA) was synthesized. • The mechanical strength improved after in situ magnetization and phosphorylation. • The adsorption process involves multiple adsorption mechanisms. • The excellent magnetic separation of U(VI) from eluent and soil. • An effectiveness in the engineering linked remediation of uranium contaminated soil. The increasingly hazardous and radioactive environmental issues arising from the uranium-contaminated water and soil make it urgent to develop high-yield and efficient adsorbents and the green engineering remediation technology, as well as the engineering remediation evaluation. In this work, we successfully synthesis a phosphate-functionalized magnetic calcium alginate hydrogel (MPCA) in batches by using a simple in-situ coprecipitation method. MPCA keeps maximum adsorption proportion of uranium (≥60.01 %) in the mixed multi-nuclide solution, and high adsorption capacity in different natural simulated uranium-contaminated water systems. In the engineering remediation of natural uranium-contaminated soil, MPCA removes 83.9 % of uranium and 99.8 % of radium in muddy water, even removes 92.9 % of uranium in the soil leaching wastewater. This work also validates a promising green engineering linked soil remediation technology, which combines soil leaching and adsorption separation. The remediated soil meets international emission standards, 92.9 % of uranium in the leachate is removed, 93.2 % of adsorbed uranium is desorbed and enriched. In addition, the reuse of adsorbed leachate and desorbed MPCA also minimize the consumption of engineering water and the derived radioactive water pollution. [ABSTRACT FROM AUTHOR]

[Display omitted] • The preparation process of the CDI electrode is simplified. • Laser-induced graphene (LIG) can be directly used as a CDI electrode. • LIG electrode is modified by one-step electrodeposition of Co 4 S 3. • The LIG6/Co 4 S 3 -15 presents a high adsorption capacity of 2702.79 mg g−1. • UO 2 2+ adsorption is attributed to the synergistic action of EDLs and pseudocapacitance. It has been proved that capacitive deionization (CDI) technology possesses a significant potential for uranium capture. However, the CDI performance has been limited by the complex preparation process of the electrodes and the poor adhesion between electrode materials and collectors. Here we combine the laser-induced graphene (LIG) and the electrodeposition to develop the LIG/cobalt sulfide (LIG/Co 4 S 3) electrodes with good adsorption performance. The obtained LIG6/Co 4 S 3 -15 electrode has both electrical double layers (EDLs) and pseudocapacitance properties, with a specific capacitance of 24.27 F g−1, which is 1.82 times higher than that of LIG6 (13.36 F g−1). The LIG6/Co 4 S 3 -15 electrode exhibited a high adsorption capacity of 2702.79 mg g−1. The advantages of this electrode preparation method are mainly attributed to the synergistic effect of the following aspects: (i) simplified graphene preparation by avoiding wet chemistry and post-treatment steps; (ii) simplified tedious electrode preparation such as electrode slurry distribution and sheet coating; (iii) the three-dimensional structure of LIG provides not only the conductive network but also the site for Co 4 S 3 nanosheet growth, thus avoiding nanosheet aggregation. The abundant pore structure of the conductive graphene substrate and the layered structure of the Co 4 S 3 nanosheets enable the LIG6/Co 4 S 3 -15 electrode with fast charge/ion transport, high hydrophilicity and superior pseudocapacitance, allowing uranyl (UO 2 2+) to be firstly electrosorbed, then physicochemically adsorbed, and finally electrocatalytically reduced/deposited onto the electrode. This study will offer a simple and environmentally friendly method for the synthesis of electrodes and provide a reference for the design of efficient electroadsorption materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel eco-friendly and energy-saving additive, dicyandiamide, was presented. • The action mechanism of dicyandiamide was illustrated. • Dicyandiamide dissolving lignin was discovered for the first time. • Dicyandiamide can better reduce KOH diffusion resistance in lignin than urea. • Dicyandiamide blocked "pseudo-lignin" generation. Alkali pretreatment is one of the most commonly used pretreatment methods in lignocellulose bioprocessing. However, there are still some "pseudo-lignin" that hinder enzymatic hydrolysis and seriously affect the industrialization process of biorefining. Excellent pretreatment additives can effectively cover these shortages. However, most additives have disadvantages like high operating temperature, low effective utilization efficiency, or poor performance. To address this issue, we proposed a novel additive, dicyandiamide (DICY), by means of quantum chemical prediction, and verified its ability on assisting alkali to remove lignin by experiments. The results indicate that the lignin removal by KOH-DICY pretreatment is about 15% higher than KOH pretreatment, thereby increasing the enzymatic efficiency to 97%, while the reaction temperature was lower 20 ℃ than common alkali pretreatment. These are due to the "two birds with one stone" role of DICY on lignocellulose alkali-DICY pretreatment. DICY not only dissolves small amounts of lignin, but also assists alkali to remove lignin by reducing the diffusion resistance of KOH in lignin and blocking the generation of "pseudo-lignin". Thus, DICY effectively improved the lignin removal and enzymatic hydrolysis efficiency of alkali pretreated lignocellulose, and performed better than urea. Moreover, the waste liquid pretreated by DICY combined with KOH has the potential on preparation of agricultural fertilizers. In summary, DICY is a new, environmentally friendly, and energy conservation additive for lign ocellulose alkali pretreatment [ABSTRACT FROM AUTHOR]

[Display omitted] • A comprehensive review of g-C 3 N 4 -based membranes for ionic resource recovery. • The design strategies of g-C 3 N 4 nanosheets for membranes are highlighted. • Two types of g-C 3 N 4 -based membranes are reviewed based on their preparation method. • Membranes extract/separate valuable ions, metal ions, radionuclides, and desalinate. Resource recovery from wastewater, seawater and salt lakes has attracted significant attention due to its economic and environmental benefits. Recent achievements in membrane technology have allowed efficient recovery of ionic resources from water, and various membranes have been developed to selectively reject, and recover salts and metals in water steams. With the requirement of high ion selectivity, a wide range of nanomaterials are employed in these membranes. Graphitic carbon nitride (g-C 3 N 4), as two-dimensional nanosheets, with an abundant and intrinsically uniform pore structure network, tunable interlayer spaces, easy and low-cost synthesis, tailored functionality and promising stability, shows high prospects for ion-selective separation. This comprehensive review outlines the development of advanced g-C 3 N 4 -based membranes for ionic resource recovery. First, design strategies of g-C 3 N 4 nanosheets for membranes are highlighted in terms of experimental characteristics and molecular dynamic simulations. Next, g-C 3 N 4 -based membranes made as lamellar membranes and mixed matrix membranes are emphasized, based on their preparation method. Finally, current applications of g-C 3 N 4 -based membranes in ionic resource recovery are presented: valuable ion extraction, metal ion separation, radionuclide capture and desalination. This tutorial review provides insightful guidance on the design strategies, fabrication methods and ionic resource recovery applications of g-C 3 N 4 -based membranes for resource sustainability. [ABSTRACT FROM AUTHOR]

[Display omitted] • A rich-mesoporous biocarbon (CSKN-15) was synthesized and analyzed. • The ultra-high U-selective electrosorption coefficient from the mixed solution. • The diffusion process of U(VI) into the pores is the key in the electrosorption. • Faradaic reactions were first carefully analyzed in the electrosorption of U(VI). • The formation mechanism of uranium peroxide species was revealed. Constructing the excellent rich-mesoporous carbon and exploring its electrosorption process are keys to promote the electrosorption industrialization of uranium. In this work, we develop a rich-mesoporous biocarbon by using alkali-thermal-pyrolysis and ammonia low-temperature plasma, and then systematically investigate its electrosorption kinetics and mechanism of U(VI) considering a series of Faradaic side reactions. After the above treatment, the electrosorption efficiency of U(VI) onto biocarbon improves from 49.75% to 94.45%, and the ultra-high U-selectivity coefficient (S U/M) is higher than 120 from the mixed solution. The kinetic diffusion process of U(VI) into the pores is crucial, even in different water systems. Importantly, Faradaic side reactions are proved to be non-negligible factors in the electrosorption of uranium. Especially, the oxygen reduction at the cathode can convert dissolved oxygen into H 2 O 2 , which oxides the amorphous electro-reduced U(V, IV) to U(VI), and finally forms crystalline uranium peroxide species. To sum up, this work not only offers an excellent uranium-selectivity electroadsorbent, but firstly confirms the influence of Faradaic side reactions that has been ignored in the current electrosorption of uranium. [ABSTRACT FROM AUTHOR]

• Ti 3 C 2 T x -PPy/Bi 2 S 3 enabled the voltage window of AZIC-TPB//ZnSO 4 //Zn to 2.1 V. • Ti 3 C 2 T x served as the expansion joint in voltage-window-expansion engineering. • Bi 2 S 3 and PPy offered pseudocapacitance and widened the voltage window laterally. • The energy density of AZIC-TPB//ZnSO 4 //Zn was elevated to 269.09 Wh Kg−1. • DFT calculations revealed the origins of enhanced electrochemical properties. Although increasing the voltage window should be more effective by square rewarding than the specific capacitance for enhancing the energy density of zinc-ion hybrid capacitors (ZIC), the lack of an ideal cathode has hindered its realization. Herein, Ti 3 C 2 T x -PPy/Bi 2 S 3 composite was fabricated through voltage-window-expansion engineering, where Ti 3 C 2 T x layers were covered by a tremella-like network of PPy through hydrogen bonds (-N H···O- and -N H···F-), and then compounded with pseudocapacitive Bi 2 S 3. Due to the redox reactions of Bi 2 S 3 and PPy at low and high potentials, the working voltage window of AZIC-TPB//ZnSO 4 //Zn was elevated up to 2.1 V with low-cost electrolyte ZnSO 4 , exhibiting a high energy density comparable to that of batteries (269.09 Wh Kg−1 with a power density of 1564.73 W Kg−1). Even at a power density of 12947.15 W Kg−1, the energy density of AZIC kept as high as 107 Wh Kg−1, far exceeding the common level. Density functional theory (DFT) calculation demonstrated the obvious electron transfer between Ti 3 C 2 T x and PPy (or Bi 2 S 3) and advanced conductivity, which promoted the redox reaction and facilitate the charge transfer in the electrochemical process. The strategy of voltage-window-expansion engineering here can be further extended to aqueous energy storage devices, offering a viable path to enhancing energy density. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel KOH-UHP-Si pretreatment strategy of Lignocellulose was proposed. • The mechanism of KOH-UHP-Si pretreatment was illustrated. • The mechanism of urea promoting KOH pretreatment effectiveness was illustrated. • The removal rate of lignin and cellulose content were over 97% and 81%. • Glucose yield was 0.77 g/g, which was 9 times of untreated corn stover. Alkali pretreatments are considered as one of the most popular strategies to pretreat lignocellulose due to its high-efficiency, low-cost, high lignine removing and cellulose content. Nevertheless, glucose concentration obtained from lignocellulose by alkali pretrements still can't meet biorefinery requirements. Thus, a novel strategy to pretreat lignocellulose by combining KOH, UHP (urea peroxide) and organosilane (KOH-UHP-Si pretreatment) was proposed. This novel strategy solved two difficult problems that seriously affected the combined pretreatment of alkali and advanced oxidant, and then the cellulose relative content and glucose yield were increased by about 2.4 times and 9 times compared with the original straw, about 19% and 20% compared with the alkali (KOH) pretreatment, and about 2.2 times and 3.3 times compared with the advanced oxidation (UHP) pretreatment. After optimizing the pretreatment process, cellulose relative content in corn straw reached 81.4%, and the removal rates of lignin and hemicellulose were increased to 97.3% and 88.13%, respectively. In addition, we illustrated the mechanism of KOH-UHP-Si pretreatment, in which KOH plays the major role, the organosilane suspension and UHP play the auxiliary role. When the organosilane reduced mass transfer resistance in the reaction system, KOH and UHP assisted and promote each other mutually. Besides, we also illustrated the mechanism of urea assisting KOH removal of lignin through quantum chemical calculations. Moreover, the substances contained in wastewater produced by the novel technique could be turned into agricultural fertilizers after being processed simply, and there will be zero emission in the whole process. Our results indicate that KOH-UHP-Si pretreatment was a high efficiency low cost and eco-friendly strategy for lignocellulose pretreatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Modified carbon black (CB) by O 2 plasma technology for improving CDI capacity. • The effect and mechanism of plasma modified CB (PCB) to improve CDI were explored. • PCB improved the salt removal performance 6.9 times that of the original CB (OCB) • PCB can be applied to improve CDI of various active materials. • PCB has universal applicability in purifying brine, heavy metals and radionuclides. Previous research on capacitive deionization (CDI) mainly focuses on electrode active materials, while the research on conductive additive and their modification for improving CDI performance are rarely reported. In this work, we mainly investigate the effect and mechanism of oxygen (O 2) plasma-modified carbon black (PCB) to enhance CDI performance. The CB treated with O 2 plasma at 100 W for 10 min (CB-100 W-10 min) was assembled with activated carbon (AC) to form a CB-100 W-10 min/AC electrode with excellent desalination performance (32.54 mg g−1), 6.9 times that of the original CB/AC electrode (OCB/AC, 4.91 mg g−1). The roles of the specific surface area, hydrophilicity, electrical conductivity, and specific capacitance of CB in enhancing the performance of CDI were explored, and the interaction mechanism between H 2 O molecules and CB was investigated using molecular dynamics (MD) simulations. The advantages of PCB are mainly attributed to the synergy of the following aspects: (i) The excellent three-dimensional network structure acts as a "bridge" between activated carbon and increases the contact sites for allowing more PCB and AC to participate in the electrosorption process; (ii) Shorter electron transmission paths and more electron transmission channels between PCB and AC promote the electrosorption rate; (iii) High surface roughness and oxygen-containing functional groups of PCB boost hydrophilicity and dispersibility. Interestingly, we found that PCB possesses universal applicability in the enhancement of deionization performance of various active materials for purification of brine, heavy metals and radionuclides. This work unprecedentedly applies plasma technology to the modification of conductive additive, providing new ideas for material modification and improvement of CDI technology. [ABSTRACT FROM AUTHOR]