查看更多>>摘要：? 2022 The Author(s)Offshore natural gas represents a significant portion of global natural gas reserves. Processing of natural gas is essential for gas upgrading before pipeline transportation and utilization. In this work, a phenomena-based approach to propose more sustainable intensified alternatives for separation of sour gases from offshore natural gas is considered. All possible process alternatives are explored systematically using a bottom-up approach. Over six hundred feasible intensified separation alternatives are generated and ranked in terms of enthalpy index. Six intensified separation alternatives are identified as novel and innovative candidates worthy of potential further investigation and possible industrial application. These alternatives are analyzed in terms of performance matrices and LCA indicators and compared against reference cases.
查看更多>>摘要：? 2021Radicals of SO4?-, OH?, non-radical of 1O2 and even direct oxidation all occurred in peroxymonosulfate (PMS) activation process. Hence, to regulate the above radical or non-radical mechanism is of great significance for the treatment of organic pollutants in practical water. In this work, MgAl-minerals exhibited a satisfied performance in controlling the contribution of radicals (SO4?-, OH?) and non-radical (1O2) towards PMS activation based on results of reactive oxygen species scavenger experiments and electron spin resonance spectra. Compared with MgAl-1(61.8%) and MgAl-2 (61.4%) (Al/Mg = 1, 2), MgAl-3 (Al/Mg = 3) exhibited the highest sulfamethoxazole (SMX) removal efficiency (92.5%). Moreover, the contribution of radical and non-radical to SMX degradation were 56.7% and 30.1%, which was different from that of MgAl-1(7.8% and 39.5%) and MgAl-2 (5.2% and 41.6%). The roles of Lewis acid-base site and oxygen vacancies (OVs) in MgAl-minerals on radical and non-radical processes were detailed investigated. Lewis acid sites and OVs can enrich SMX and PMS at the solid-water interface. Simultaneously, OVs promote electron transfer from SMX to PMS acts as electron media, resulting in more SO4?- and OH? generation. While the basic sites favored the generation of 1O2 via PMS self-decomposition mechanism. Therefore, in PMS activation process over MgAl-minerals, the involved reactive oxygen species can be regulated via controlling the amounts of Lewis acid-base sites and oxygen vacancies. This finding provided new insights into PMS oxidation over non-transition metal-based catalysts and water remediation with complex water characteristics.
查看更多>>摘要：? 2021With the assistance of K+, the amount of organic template (TEAOH) in the synthesis was enormously reduced to only 3% of that in the traditional synthesis for the SUZ-4 zeolite. Characterizations such as XRD, SEM, XRF, N2 adsorption/desorption, and 27Al MAS NMR were carried out to determine the physicochemical properties of SUZ-4 zeolites (T1 and T13) synthesized with different TEAOH amount. The specific role of the additional K+ in the synthesis was determined by the combination of experimental data and density functional theory (DFT) calculations. It showed that K+ co-caged with TEA+ preferentially locate in the cages containing 8-MR, and the role of the co-caging K+ ions is to arrange the formed composition building units (CBU) into the SUZ-4 framework. The SUZ-4 zeolite exhibited a fast adsorptive equilibrium of 5 min and high selectivity for Pb2+ in wastewater. The effects of temperature, contact time, adsorbent dosage, pH and initial concentration of Pb2+ solution on adsorption capacity were studied to optimize process conditions. The adsorption kinetics and isotherms suggested that the adsorption rate is determined by the chemical adsorption on the adsorbent surface, and the adsorption ability is related to the physisorption sites in the pores. The adsorption process was composed of two steps and was the comprehensive contribution of ion exchange and chemical adsorption of Pb–O formation. There was no downtrend in the adsorption of SUZ-4 for Pb2+ after ten adsorption-desorption cycles, demonstrating the excellent application prospects of SUZ-4 in removing Pb2+ in wastewater.
查看更多>>摘要：? 2022 Elsevier B.V.Domestic wastewater quality conditions are complex, which will affect the types of flocs in Fe-electrocoagulation (EC). However, the influence of different types of flocs has not been considered for the removal of phosphate in real wastewater. Herein, the removal of phosphate in real domestic wastewater secondary effluent was investigated during Fe-EC process under low and high dissolved oxygen (DO) concentrations. The removal of phosphate was also investigated during Al-EC process for comparison. The results showed that phosphate (1.3 mg/L) could be efficiently removed with an efficiency of 98% ± 2% both during Fe-EC process with low and high DO concentration, as well as during Al-EC process, with a slight lower removal rate during Al-EC (in 5 min) compared with Fe-EC (in 2 min), at 10 mA/cm2. The flocs composition was mainly green rust during Fe-EC with low DO, amorphous trivalent iron oxide/hydroxide during Fe-EC with high DO, and amorphous alum hydroxide during Al-EC. The removal mechanism was also deduced that the removal of phosphate by Fe-EC with high DO and Al-EC was mainly by coagulation, while by Fe-EC with low DO concentration was mainly by ion-exchange adsorption.
查看更多>>摘要：? 2022 Elsevier B.V.The disposal of dyestuff wastewater containing metal ions and dyes is a tough challenge, due to the competition of adsorption sites. Here, aramid nanofiber (ANF) based aerogels are fabricated, which exhibit excellent adsorption performance for sub-nanometric and nanometric adsorbates, such as Cu2+ and Congo red (CR) in this work. Synthesized hierarchical polyhedral oligomeric silsesquioxanes (POSS) cored polyamide amine (PPAMAM) is used to modify ANF aerogels and molecular dynamics simulation results indicate that the POSS core endows synthesized PPAMAM with cavities and mobile terminal groups on ANF surface, compared to normal PAMAM. When prepared aerogels are applied to treat wastewater with co-adsorbate, small metal ions could enter the cavities and coordinate with internal tertiary amines. In contrast, CR molecules are too large to enter cavities and prefer interacting with external primary amines. In addition, blending PPAMAM also increases the specific surface area, which highly enhances the adsorption performance. As a result, simultaneous and effective removal of Cu2+ and CR is achieved, and in binary system, the adsorption capacities are 248.49 and 1502.95 mg/g, respectively. After five cycles, fabricated adsorbents still maintain excellent adsorption performance. Therefore, this work provides a new way to the preparation of effective adsorbents for simultaneous removal of different sized pollutants.
查看更多>>摘要：? 2022Following a circular economy approach, an integrated process is proposed for aroma recovery and fractionation from seafood industry aqueous effluents, combining the advantages of organophilic pervaporation and fractionated condensation. The aim of this work is to recover valuable aromas from aqueous effluents of seafood processing assuring that the aromas recovered are, as much as possible, free from off-flavours in order to be applied as seafood flavouring additives. To reach this objective, an integrated organophilic pervaporation/fractionated condensation process was assessed, with the support of a mathematical model. The mathematical model described and validated in this work allows for simulating the integrated pervaporation - fractionated condensation process and select the optimal operating conditions for a given target separation, performing a minimum experimental work (that comprise only pervaporation with total condensation experiments and inert gas molar flow rate measurements) and using reliable thermodynamic properties (saturation vapour pressures and activity coefficients). The application of this model proves to be a very useful tool for predicting the fractionation of aromas of different chemical families. Which allows to anticipate its wider application, beyond the seafood aroma case-study discussed in this work.
查看更多>>摘要：? 2022Selectively recovery Gallium (Ga) and Indium (In) is significant because of their low reserves and wide range of applications. In this work, tannic acid (TA) functionalized microcrystalline cellulose (MCC-g-GMA-TA) was successfully synthesized by radiation induced grafting polymerization. The selective separation and recovery of Ga(III) and In(III) from potential leaching solution were investigated using batch and fix-bed column experiments. The maximum adsorption capacity reached 26.55 for Ga(III) and 35.63 mg/g for In(III) at pH 3, respectively. Especially, MCC-g-GMA-TA could effectively separate Ga(III) from Ga(III)/As(III) mixing solution, and separate In(III) from In(III)/Zn(II) mixing even at the coexistence ions was 100 times of Ga(III) and In(III). The fixed-bed column experiments revealed that MCC-g-GMA-TA can effectively and selectively recover Ga(III) and In(III) from simulated leaching solution from Zn refinery residue or semiconductor waste. The ionic strength effect, FTIR and XPS analyses revealed that the adsorption of Ga(III) and In(III) by adsorbent was attributed to the formation of chelates between the hydroxyl groups and Ga(III) or In(III). Overall, MCC-g-GMA-TA was demonstrated to be a low cost, pro-environmental and potential adsorbent with excellent selectivity for Ga(III) and In(III) recovery from effluents and prospective sources.
查看更多>>摘要：? 2022 Elsevier B.V.Understanding of synergistic mechanisms on bimetal single atom catalysts is a vital basis to design and synthesize effective catalytic materials. A bimetal of Fe and Ni anchored carbon nitride (CN-FeNi-P) is prepared by PH3-induced annealing method using soft-template precursors. Experimental results show that the coordination sites of Fe/Ni-N4P2 are uniformly distributed on the carbon nitride, and a structure of Fe-P-Ni is formed at the second shell via P bridging. Herein, Fe-dominated active sites are formed by the interaction between Fe and Ni single atoms in CN-FeNi-P. Benefitting from the synergistic effects, the CN-FeNi-P exhibits a high efficiency electron utilization, achieving 100% of enoxacin degradation under visible light irradiation within 40 min. In addition, it achieves 58% of defluorination rate which is rarely mentioned in others. The facile method expands to other single atom catalysts in photocatalysis and electrolysis, and this work provides a new insight into understanding synergistic mechanisms of bimetal single atom catalysts.
查看更多>>摘要：? 2022 Elsevier B.V.Highly efficient Bi0.5Fe0.5VO4/honeycomb ceramic plate (Bi0.5Fe0.5VO4/HCP) was successfully prepared and placed in the discharge zone of the dielectric barrier discharge (DBD) to construct a DBD plasma-catalyst system. Doxycycline Hyclate (DH), an antibiotic widely used in aquaculture was selected to estimate the catalytic activity. The synergistic effect makes the system exhibit excellent catalytic activity and mineralization ability. A series of characterization technologies were employed to systematically investigate the as-prepared photocatalysts. Additionally, the effect of different initial conditions (pH, power, water matrices, etc.) on DH removal was evaluated. The 3D EEMs results distinctly present the process of DH being mineralized, and the significantly enhanced TOC removal rate indicates that Bi0.5Fe0.5VO4 can promote the increase of mineralization rate. The formation and role of active specials ([rad]OH, O3, and H2O2, etc.) were also deeply investigated. Furthermore, possible DH degradation pathways were proposed based on LC-MS analysis and theoretical calculations. Comprehensive toxicity analysis revealed that a decreasing trend in the toxicity of the intermediates. Eventually, the DBD plasma-catalyst reaction mechanism was investigated in detail. This study provides an effective and simple technical route to combine different advanced oxidation processes in a synergistic way to treat wastewater.
查看更多>>摘要：? 2022 Elsevier B.V.Viral vectors have attracted attention as a potential new therapeutic modality for gene therapy. In this study, we developed a temperature-modulated viral vector purification column using a mixed polymer brush composed of thermoresponsive and anionic polymers as packing material ligands. The mixed polymer brushes were modified on silica beads using a combination of reversible addition ? fragmentation chain transfer (RAFT) polymerization of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and subsequent atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAAm). The temperature-modulated zeta potential change in the prepared mixed polymer brush was attributed to the PNIPAAm shrinking and exposing of PAMPS. The prepared mixed polymer brush modified beads were used as packing materials, and the elution behavior of the adeno associated virus type 2 (AAV2) vector was observed. The AAV2 vector was adsorbed on the mixed polymer brush by electrostatic and hydrophobic interactions at 40 °C. By reducing the temperature to 5 °C, adsorbed AAV2 vector on the mixed polymer brush was desorbed and eluted from the column due to lowering the electrostatic and hydrophobic interactions between the AAV2 vector and mixed polymer brush. The AAV2 vector was separated from bovine serum proteins as a contaminant using the column. The ability to infect cells was maintained by the recovered AAV2 vectors from the column. Thus, the developed column would be beneficial for the simple purification of viral vectors.
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