查找使用阿拉丁产品的科研文献

On-Line Monitoring of Ultrafiltration Membrane Fouling Based on EIT Sparse Imaging

Qi Wang,Zinan Guo,Jie Wang,Ronghua Zhang,Xiuyan Li,Xiaojie Duan,Yukuan Sun,Wen Sun,Jianming Wang

In-situ catalytic upgrading of Hami coal pyrolysis volatiles over acid-modified kaolin

Yujie Hou,Zongqing Bai,Hao Lu,Zhihao Feng,Tingting Zhang,Yuxing Jia,Zhenxing Guo,Lingxue Kong,Jin Bai,Wen Li

Low-cost kaolin was modified by calcination at different temperatures, followed by HCl leaching, and used as catalyst for in-situ upgrading of Hami coal pyrolysis volatiles in a fixed-bed reactor. The catalyst characteristics, pyrolysis product distributions and tar properties were investigated by multiple methods to understand the relationship between catalyst properties and tar quality. The results indicated that calcination of kaolin promoted the formation of amorphous metakaolin, then the HCl leaching removed most metakaolin framework Al, leading to the production of abundant micro-/mesopores and acid sites. As the rising calcination temperature, the specific surface area and pore volume of acid-modified kaolin (AMK) showed a trend of increasing and then decreasing, and the Brønsted acid sites (BAS) displayed an increasing trend. Compared to non-catalytic pyrolysis, the high specific surface area and certain acid sites of AMKs enhanced the light tar fraction from 37.81 wt% to 43.00–48.45 wt%, and the relative content of aromatics in tar increased from 9.76% to 16.65–22.11%, with monocyclic aromatics, naphthalenes and polycyclic aromatics increasing to 3.5–4.2, 1.2–1.8 and 2.1–3.3 times higher, respectively. AMKs also reduced the content of element O in tar by 17.92–31.54% by promoting the deoxygenation reaction. The tar upgrading performance was determined by the BAS amount and the pore structure of AMKs together. Among all AMKs, AMK800 (calcined at 800 °C and treated by HCl) exhibited the optimum performance for heavy tar conversion, aromatics generation and oxygen removal due to its highest specific surface area and the maximum BAS except AMK900. The acid-modified kaolin has the potential to be an inexpensive and efficient catalyst for future practical applications of upgrading coal pyrolysis tar.

Construction of a novel integrated electrochemical oxidation-coagulation system for simultaneous removal of suspended solids and antibiotics

Changchao Dai,Dahong Chen,Jing Wu,Junfeng Liu,Shuang Shi,Jie Zhang,Yujie Feng

A novel integrated electrochemical oxidation-coagulation system combining boron-doped diamond anode and aluminum cathode was proposed for simultaneous removal of suspended solids and antibiotics. Experiments on simulated wastewater showed that the coupling of boron-doped diamond anode oxidation and aluminum cathode electrochemical coagulation could simultaneously and efficiently remove different forms of pollutants. The integrated system could achieve 67.4% turbidity and 95.48% tetracycline removal in simulated tetracycline wastewater, and 71.25% turbidity and 99.78% sulfamethoxazole removal in simulated sulfamethoxazole wastewater. The oxidation and coagulation functions of the integrated system were verified by in situ particle size analysis and electron spin resonance experiments. Compared with separate electrocoagulation and separate electrooxidation, the integrated system has the advantages of high space utilization, low energy consumption, and wide application range. It is promising to realize the simultaneous and efficient purification of suspended solids and antibiotics in wastewater at low cost.

Experimental and theoretical studies on the adsorption performance of lead by thermal pre-activation and phosphate modified kaolin sorbent

Aijia Zhang,Jing Liu,Yingju Yang,Yingni Yu,Dawei Wu

Lead removal from flue gas continues to be an important environmental issue. Adding sorbents in the furnace is a reliable method to control lead emission. Modified kaolin sorbent developed by a combined method of thermal pre-activation and phosphate impregnation was first applied to capture lead from flue gas. Modified kaolin exhibited higher PbCl 2 removal performance than raw kaolin at 800–1100 ℃. The best adsorption performance of raw and modified kaolin was obtained at 1000 ℃ with adsorption efficiencies of 76.72 % and 85.87 %, respectively. The adsorption capacity of modified kaolin was about 283.51 mg/g at 1000 ℃. Lead aluminosilicate and lead phosphate were produced in the adsorption reaction. O 2 was conducive to the conversion of PbCl 2 to PbO, and directly participated in the formation of lead aluminosilicate· H 2 O was in favor of the adsorption reaction, and reduced the energy barrier for dechlorination of PbCl 2 , and promoted the eutectic melting process. SO 2 and NO inhibited PbCl 2 removal due to the competitive adsorption between SO 2 /NO and PbCl 2 at the active sites. High concentration of HCl can obviously suppress the reaction of PbCl 2 and modified kaolin. Quantum chemistry calculations were conducted to identify the active sites, and to uncover the molecular-level interaction of PbCl 2 and modified kaolin. Theoretical results manifested that PbCl 2 adsorption was chemisorbed on kaolin (0   0   1) surface. The adsorption energies of PbCl 2 on raw kaolin and modified kaolin were − 124.60 and − 205.90 kJ/mol, respectively. Al, O and P atoms of modified kaolin were identified as the active sites for PbCl 2 adsorption.

Influences of charge properties and hydrophobicity on the coagulation of inorganic and organic matters from water associated with starch-based coagulants

Xinyu Hu,Pan Hu,Hu Yang

In this work, two series of binary graft cationic starch-based coagulants (CS-DMCs and CS-DMLs) with different hydrophobicities and charge densities (CDs) were prepared by graft copolymerization of acrylamide with 2-(methacryloyloxy)-N,N,N- trimethylethanaminium chloride and acryloyloxyethyl dimethyl benzyl ammonium chloride , respectively, on the starch (St) backbone. Kaolin particles, sodium humate (NaHA), and bovine serum albumin (BSA) were used as the simulated sources of inorganic colloidal particles and different organic pollutants in the micropolluted turbid surface water. The influences of the CD and hydrophobicity associated with the St-based coagulants on the removal of kaolin particles, NaHA, and BSA from single, binary, and ternary pollutant aqueous systems were investigated systematically. On the basis of the apparent coagulation performance, the floc characteristics, and the zeta potentials of the supernatants after coagulation, the coagulation mechanisms associated with the structural features of the St-based coagulants and the pollutants treated were explored and discussed in detail. The St-based coagulants with a higher CD and a stronger hydrophobicity showed better coagulation performance due to the synergistic effects of charge neutralization and hydrophobic association. The maximum efficiencies of the optimized St-based coagulant in removal of Kaolin, NaHA and BSA were 93.85%, 100% and 97.52% in their respective single pollutant systems. In addition to these simulated water samples, a real micropolluted turbid surface water tested and compared, further confirming the superiority of the hydrophobically modified cationic St-based coagulants, especially in the purification of organic pollutants in water.

Synergistic treatment of heavy metals in municipal solid waste incineration fly ash with geopolymer and chemical stabilizers

Dongdong Xu,Yun Huang,Xing Jin,Tong Sun

Municipal solid waste incineration fly ash (MSWI-FA) is globally defined as hazardous waste and needs stabilization treatment. In this paper, synergistic treatment by geopolymerization and chemical stabilizers for the heavy metals in MSWI-FA was proposed, and its mechanism was further investigated. The leaching test showed that the concentration of Cu, Cr, Cd, Ni, Zn and Pb could meet the requirement of disposal standard, with more than 99.8% been effectively stabilized while Cr and Ni were below the quantification limits. The MSWI-FA was activated in geological polymerization process and produced Al/Si-based hydration products , while the chemical stabilizers formed chelates with heavy metals, yielding double effects on the geopolymerization. Therefore, with the co-effectiveness of the two processes, most of the heavy metals were firmly stabilized in the compound structure. The developed geopolymerization procedure had potential applications for treating heavy metals in MSWI-FA.

Efficient with low-cost removal and adsorption mechanisms of norfloxacin, ciprofloxacin and ofloxacin on modified thermal kaolin: experimental and theoretical studies

Yuxuan Yang,Zhaoping Zhong,Jiefei Li,Haoran Du,Zhaoying Li

Quinolone antibiotics (QNs) can be potential hazard to environment and human. Combination of experimental and theoretical studies was used to analyze the adsorption properties of norfloxacin, ciprofloxacin and ofloxacin on modified thermally activated kaolin (KL). Main factors (calcination temperature, dose, pH, cations and regeneration) affecting the adsorption were discussed. Adsorption processes fit the pseudo-second order kinetic and Langmuir model well. The adsorption removal of norfloxacin, ciprofloxacin and ofloxacin can reach 88.53%, 89.43% and 91.46%, respectively. Cations inhibited adsorption, and AlS-KLB can maintain 80% efficiency in five cycles under optimal conditions. Simulations showed that the materials had good adsorption capacity for QNs, and the "①" of KL had the best capacity. Simulations explain the adsorption mechanism: F, H, O atoms of QNs are covalently bonded to O atoms from KL, Al 2 O 3 and Al (OH) 3 , C atoms from amorphous carbon and H atoms from C-H and Al (OH) 3 . The Al atoms of Al 2 O 3 and Al, Si atoms of KL are ionically bonded to F, H, O atoms of QNs. This study shed new light on the removal of QNs by providing low-cost and efficient modified KL and elucidating the adsorption mechanism in conjunction with DFT simulations.

A strategy to alleviate membrane fouling by optimizing the structure of the cake layer formed by flocs deposited directly on the membrane in the ultrafiltration process through coagulation and nanoscale Fe3O4/Fe3O4@SiO2 load

Yunxuan Chen,Jun Nan

Membrane fouling has always been a problem hindering the practicability of ultrafiltration . Direct regulation of the structure of the cake layer formed by rapid deposition of flocs as a “secondary barrier” in the in-line coagulation ultrafiltration (C-UF) process has acquired importance as a research topic in comparison to membrane modification and standard coagulation ultrafiltration. In this study, membrane fouling was controlled in the C-UF process via coagulation/nano-scale Fe 3 O 4 load (C/FL-UF) and coagulation/nano-scale Fe 3 O 4 @SiO 2 load (C/FSL-UF). The promotion effects of these two processes (C/FL-UF and C/FSL-UF) on the reduction of membrane fouling and improvement of water quality were systematically studied employing simulated surface water. Floc characteristics, XDLVO theory, and the Hermia model, etc were employed to explain the optimization of cake layer. For coagulation/Fe 3 O 4 load, the floc size was large and loose, whereas, for coagulation/Fe 3 O 4 @SiO 2 load with high recoverability., the floc size was slightly loose. The newly constructed cake layer had improved porosity, structural stability and capacity of water transport. Meanwhile, decrease of unit adhesion free energy and secondary minimum depth along with the substantial increase of energy barrier between the reconstructed cake layers and membranes or colloids explained the mechanism of reduced membrane fouling from the surface energetics. The gradual decrease of water contact angle and the optical images proved that the affinity of the cake layer was significantly reduced. Hermia model further validated the accuracy of this study in controlling membrane fouling by regulating the formation of the cake layer. Finally, the study concluded by analyzing the practicability and efficacy of the procedure to further elucidate the applicability of this research.

Matrix-mediated reversal of Gram-dependent removal in antimicrobial flocculation

Fan Lu,Shengkan Xu,Le Yuan,Jianbo Zhao,Di Cai,Nigel J.D. Graham,Zhen Yang

Renewable starch-based flocculants enable effective bacterial removal. • Matrix-induced reversal of Gram-dependent bacterial removal is revealed. • Matrix effects preferentially enhance E. coli removal over S. aureus . • Inorganic particles cause shear-enabled physical abrasion of bacterial envelopes. • Natural organic matter induces chemical envelope injury via cell-envelope binding. Microbial contamination continues to threaten safe drinking water and sanitation. Antimicrobial flocculation is being increasingly explored as an upstream strategy to reduce disinfection demand and associated risks, yet the impact of environmental matrices on its performance has been overlooked in the past. Here, we report a previously unrecognized, matrix-induced reversal of Gram-dependent bacterial removal during antimicrobial flocculation using cationic flocculants. In matrix-free suspensions, Gram-positive S. aureus is removed more efficiently than Gram-negative E. coli . However, in the presence of representative matrices, involving inorganic suspended particles (ISPs) and natural organic matter (NOM), both bacteria are removed more effectively, but the enhancement is substantially stronger for E. coli , reversing the relative removal ranking. Biomolecular signatures, microscopy and flow cytometry reveal that environmental matrices induce Gram-dependent cell envelope damage, with stronger vulnerability in Gram-negative bacteria: ISPs cause shear-enabled physical abrasion with strong hydrodynamic dependence, whereas NOM induces chemically mediated envelope injury and permeability enhancement through cell-envelope binding. These findings demonstrate that antibacterial flocculation performance is not determined by flocculant properties alone, but by complex interactions among flocculants, bacteria, and co-existing matrices, highlighting the importance of representative water-matrix conditions to microbial control strategies. Download: Download high-res image (174KB) Download: Download full-size image

Innovative Si/DC-HNTs doped phase change microcapsules for enhanced energy storage and fire protection in epoxy coatings

Yuxin Zhang,Jiayi Han,Yutong Yang,Yapeng Wang,Shaoxiang Li,Jiaji Cheng

HNTs are modified with DA, C and KH-560 as a flame-retardant filler. • The SDHs are first incorporated into MPCMs to build extra heat transfer channels. • SDH-MPCM/EP coatings significantly reduce indoor temperature fluctuation. • The composite coating reduces HRR and THR, showing excellent flame retardancy. Phase change material microcapsules (MPCMs) effectively address the leakage issue inherent in conventional phase change materials, while enabling efficient thermal energy storage and controlled heat release, thus providing an ideal material foundation for energy-saving building coatings. However, the defects of MPCMs—namely low thermal conductivity and flammability—seriously restrict their widespread application in practical engineering. To overcome these challenges, this study fabricated a novel modified phase change microcapsule (SDH-MPCMs) via in situ polymerization, using capric acid (CA) as the core and polymethyl methacrylate (PMMA) as the shell. Flame-retardant filler Si/DC-HNTs (SDHs) is incorporated into the system to endow the material with triple functionality: thermal energy storage, flame retardancy, and temperature regulation. The microcapsules are subsequently dispersed into epoxy resin (EP) to fabricate SDH-MPCM/EP composite coatings. Characterization techniques including TEM, XPS, and FTIR confirmed the successful synthesis of SDHs and SDH-MPCMs. When SDH-MPCMs dispersed in the EP, the composite coatings exhibit a 23.57% reduction in peak heat release rate (HRR), a 20.89% decrease in total heat release (THR). Small-scale room model test reveals that the coating reduces indoor temperature fluctuation effectively, enhancing thermal regulation capability. This research advances the development of multifunctional building coating materials by demonstrating a viable approach to simultaneously achieve efficient heat storage, enhanced flame safety, and improved temperature regulation.

Mechanism analysis of a novel natural cationic modified dextran flocculant and its application in the treatment of blue algal blooms

Lei Wang,Xinyu Zhang,Xin Zhang,Xueqin Hu,Jingwen Yang,Hongbin Zhang

Blue algae, a type of harmful microalgae, are responsible for causing harmful algal blooms that result in severe environmental issues. To address this problem, a biopolysaccharide-based flocculant was developed for treating blue algae blooms. This flocculant was created by modifying high molecular weight dextran using the natural cationic monomer betaine (Dex-Bet), making it environmentally friendly. Various techniques were used to characterize the prepared Dex-Bet flocculant, including infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy ( 1 H NMR), X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The effectiveness of the Dex-Bet flocculant was evaluated using kaolin-simulated wastewater. The results showed that the treated supernatant had a transmittance of up to 98.25 %. Zeta potential analysis revealed that the main mechanisms of flocculation were charge neutralization, charge patching, and adsorption bridging. The application of Dex-Bet in treating blue-green algae resulted in a maximum removal rate of 98.2 %. This study provides a potential flocculant for blue algae bloom treatment.

High-performance intercalated composite solid electrolytes for lithium metal battery

Yutong Jing,Qiang Lv,Bo Wang,Bochen Wu,Cheng Li,Shengbo Yang,Dianlong Wang,Huakun Liu,Shixue Dou

Composite solid electrolytes (CSEs) combining the advantages of both inorganic and organic solid-state electrolytes, are expected to become the most promising solid electrolyte owning to their favorable interfaces with electrodes. However, low room-temperature ionic conductivity restricts the application of CSEs in lithium metal batteries. Herein, we design an intercalated CSE based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Kaolin (2SiO 2 -Al 2 O 3 -2H 2 O), employed as an oxidative flame retardant, imparts nonflammability to the material. The polar molecule dimethyl sulfoxide (DMSO) is inserted between the kaolin layers as the pre-intercalation treatment, serving as an organic additive within the PVDF-HFP based SPE. The intercalated structure of CSE provides rapid Li + transport channels, resulting in a high ionic conductivity (8.58 × 10 −4  S cm −1 ) and large Li + transference number at room temperature. The Li||Li symmetrical cell with prepared CSE exhibits outstanding cyclic stability of over 1400 h at a current density of 0.2 mA cm −2 for the capacity of 0.2 mAh cm −2 . Moreover, the assembled Li||LiFePO 4 cell delivers a high initial capacity of 140.5 mAh g −1 with a capacity retention of 81.2 % after 800 cycles at 0.5 C. In this paper, we present a novel approach for constructing high-performance solid-state lithium metal batteries.