Low Mass Transfer Rates Research Articles

Fabricating Ultrathin Imprinting Layer for Fast Capture of Valsartan via a Metal Affinity-Oriented Surface Imprinting Method.

Rapid separation and enrichment of targets in biological matrixes are of significant interest in multiple life sciences disciplines. Molecularly imprinted polymers (MIPs) have vital applications in extraction and sample cleanup owing to their excellent specificity and selectivity. However, the low mass transfer rate, caused by the heterogeneity of imprinted cavities in polymer networks and strong driving forces, significantly limits its application in high-throughput analysis. Herein, one novel metal affinity-oriented surface imprinting method was proposed to fabricate an MIP with an ultrathin imprinting layer. MIPs were prepared by immobilized template molecules on magnetic nanoparticles (NPs) with metal ions as bridges via coordination, and then polymerization was done. Under the optimized conditions, the thickness of the imprinting layer was merely 1 nm, and the adsorption toward VAL well matched the Langmuir model. Moreover, it took just 5 min to achieve adsorption equilibrium significantly faster than other reported MIPs toward VAL. Adsorption capacity still can reach 25.3 mg/g ascribed to the high imprinting efficiency of the method (the imprinting factor was as high as 5). All evidence proved that recognition sites were all external cavities and were evenly distributed on the surface of the NPs. The obtained MIP NPs exhibited excellent selectivity and specificity toward VAL, with good dispersibility and stability. Coupled with high-performance liquid chromatography, it was successfully used as a dispersed solid phase extraction material to determine VAL in serum. Average recoveries are over 90.0% with relative standard deviations less than 2.14% at three spiked levels (n = 3). All evidence testified that the MIPs fabricated with the proposed method showed a fast trans mass rate and a large rebinding capacity. The method can potentially use high-throughput separation and enrichment of target molecules in batch samples to meet practical applications.

A large population of neutron star low-mass X-ray binaries with long outburst recurrence time?

ABSTRACT Low-mass X-ray binaries (LMXBs) with neutron stars show quite different features that depend on the rate of mass transfer from the donor star. With a high transfer rate, the Z sources are in a persistent soft spectral state, and with a moderate transfer rate the transient Atoll sources have outburst cycles like the black hole X-ray binaries. The observations document very long outburst recurrence times for quite a number of sources. We follow with our computations the evolution of the accretion disc until the onset of the ionization instability. For sources with a low mass transfer rate, the accumulation of matter in the disc is essentially reduced due to the continuous evaporation of matter from the disc to the coronal flow. Different mass transfer rates result in nearly the same amount of matter accumulated for the outburst, which means that the outburst properties are similar for sources with short outburst cycles and sources with long outburst cycles, contrary to some expectations. Then, for systems with long recurrence time, less sources will be detected and the total population of LMXBs could be larger than it appears. This would relieve the apparent problem that the observed number of LMXBs as progenitors of millisecond pulsars (MSPs) is too small compared to the number of MSPs. Concerning the few quasi-persistent sources with year-long soft states, we argue that these states are not outbursts, but quasi-stationary hot states as in Z sources.

Synthesis of zeolite X from fly ash in an impinging stream reactor and its mechanisms

The conventional hydrothermal method with magnetic stirring for the synthesis of zeolite X from fly ash has some problems, such as low micromixing efficiency, low mass transfer rate, and long synthesis time. In this study, impinging stream reactor is used to improve the mass transfer and micromixing and the mechanism how the nucleation and crystallization of zeolite is accelerated is explored. The results show that premixing in the impinging stream reactor can reduce the stirring and aging time from 4 h to 20 min because the hydroxyl free radicals resulting from the cavitation effect can accelerate the crystallization of zeolite. After collision, the viscosity of the system is increased from 0.22 Pa·s to 3 Pa·s, which can increase the residence time of cavitation bubbles in the gel solution and effectively inhibit the aggregation of crystal nuclei. As a result, the crystal nuclei in the system are well dispersed. The impinging stream reactor can also accelerate the mass transfer between liquid and solid phases and improve the micromixing of raw materials, so that the polymerization between Si and Al is increased and the nucleation of zeolite X is accelerated. The degree of order of zeolite X samples obtained by premixing in the impinging stream reactor is much higher than that obtained by magnetic stirring. The relative crystallinity after crystallization for 12 h (100 %) is higher than that obtained by magnetic stirring (94.93 %); and the n(Si/Al) is lower than that obtained by magnetic stirring. It is concluded that premixing in the impinging stream reactor can improve the polymerization of aluminosilicate and accelerate the nucleation and crystallization of zeolite X. Under the same conditions, zeolite X synthesized by premixing in the impinging stream reactor has better CO2 adsorption capacity than those synthesized by magnetic stirring and industrial synthesis.

Two-dimensional graphene oxide/MXene lamellar membrane cross-linked by urea with adjustable interlayer spacing for efficient dye rejection and ion sieving

Two-dimensional (2D) membranes demonstrate good performance in molecular and ion separation due to their unique layer structure. However, the sieving performance of 2D membranes is severely limited by drawbacks such as poor stability and low mass transfer rates. Here, we propose a design strategy using urea as a cross-linking agent to construct stable and regular nanochannels inside the graphene oxide/MXene (GO/MXene) composite membranes. More importantly, by changing the composition, the effective interlayer spacing of the membrane can be easily adjusted within 4.47–8.92 Å with angstrom-level precision for tunable ion sieving. The composite membrane exhibits high water permeance (79.58 L m−2 h−1 bar−1) and excellent small molecule dye rejection (>99 %). Moreover, depending on the ionic valence state, the membrane exhibits significant ion sieving. The good Cl−/SO42− selectivity (11.64) makes it a promising alternative to conventional ion exchange membranes. This study demonstrates an innovative and facile way to construct 2D lamellar membranes with stable structures for efficient and precise separation.

Design of nanosheet/nanotube composites of Fe, N-doped carbon for enhanced oxygen reduction in zinc-air batteries

Low-density active sites, low-mass transfer rate, and poor stability of carbon-based catalytic materials from the pyrolysis of conventional metal-nitrogen complexes can hamper the oxygen reduction reaction (ORR). Herein, a composite structure of nitrogen-doped carbon nanosheets grafted with carbon nanotubes are synthesized by Zn-ZIF-L breaking and co-functionalized by coupling Fe2O3 nanoparticles with active Fe-Nx species to form an active ORR catalyst (D-FeNC/MOF). Under the synergetic effect of high-density active sites and multi-size pore distribution, the diffusion resistance of oxygen in the pores can be decreased to facilitate the transfer of reactants and products, and the improvement of ORR efficiency. Comparing to the commercial Pt/C catalyst, the d-FeNC/MOF has exhibited a more positive half-wave potential of 0.875 V (vs. RHE) and a higher catalytic stability. Besides, the zinc-air battery assembled with d-FeNC/MOF as a cathode catalyst can also offer a maximum power density of 170 mW cm−2 and a specific energy density of 842 Wh kg−1. This work can provide a new way for designing non-Pt catalysts for various electrochemical energy devices.

Acetic acid, growth rate, and mass transfer govern shifts in CO metabolism of Clostridium autoethanogenum.

Syngas fermentation is a leading microbial process for the conversion of carbon monoxide, carbon dioxide, and hydrogen to valuable biochemicals. Clostridium autoethanogenum stands as a model organism for this process, showcasing its ability to convert syngas into ethanol industrially with simultaneous fixation of carbon and reduction of greenhouse gas emissions. A deep understanding on the metabolism of this microorganism and the influence of operational conditions on fermentation performance is key to advance the technology and enhancement of production yields. In this work, we studied the individual impact of acetic acid concentration, growth rate, and mass transfer rate on metabolic shifts, product titres, and rates in CO fermentation by C. autoethanogenum. Through continuous fermentations performed at a low mass transfer rate, we measured the production of formate in addition to acetate and ethanol. We hypothesise that low mass transfer results in low CO concentrations, leading to reduced activity of the Wood-Ljungdahl pathway and a bottleneck in formate conversion, thereby resulting in the accumulation of formate. The supplementation of the medium with exogenous acetate revealed that undissociated acetic acid concentration increases and governs ethanol yield and production rates, assumedly to counteract the inhibition by undissociated acetic acid. Since acetic acid concentration is determined by growth rate (via dilution rate), mass transfer rate, and working pH, these variables jointly determine ethanol production rates. These findings have significant implications for process optimisation as targeting an optimal undissociated acetic acid concentration can shift metabolism towards ethanol production. KEY POINTS: • Very low CO mass transfer rate leads to leaking of intermediate metabolite formate. • Undissociated acetic acid concentration governs ethanol yield on CO and productivity. • Impact of growth rate, mass transfer rate, and pH were considered jointly.

Nitration of o-xylene in the microreactor: Reaction kinetics and process intensification

Nitration reactions are extensively studied in organic synthesis despite their notorious dangers, high reaction rates, and heterogeneous reaction systems. To date, most industrial nitration reactions rely on conventional batch reactors characterized by low mass transfer rates and limited reaction conditions. In contrast, microreactors represent a valuable technology for intensifying such nitration reactions. In this work, we established a continuous flow system of o-xylene nitration and determined the kinetics and mass transfer. The effects of mixing performance, nitric acid concentration, molar ratio, reaction temperature, and residence time on the process safety were investigated separately. The experimental data is supported by dimensionless number calculations, providing a more comprehensive understanding of the nitration reaction's transport and reaction performance in a heart-shaped microreactor. Remarkably, the residence time of the heart-shaped microreactor was reduced by an order of magnitude, while the volumetric mass transfer coefficient was improved by several orders of magnitude compared to conventional stirred tank reactors. Moreover, the spent nitric acid could be efficiently recovered and reused after concentration, further enhancing the sustainability and cost-effectiveness of the process. Our findings demonstrate the significant potential of microreactors for intensifying nitration reactions and paving the way for the design and optimization of more efficient and safer synthetic processes.

Developing an ecofriendly UCST-type enzymatic cascade system for efficient and cost-effective starch solid wastes treatment

Enzymatic utilization of starch solid wastes is promising but hindered by its high cost. Enzymes immobilization is one solution; however, the key challenge remains the low mass transfer rate between the solid immobilization system and the solid wastes. Herein, an enzymatic modification strategy was applied instead of the traditional immobilization method. A novel system composed of poly(methacrylic acid), polyacrylic acid, and gelatin was firstly prepared and then used to modify α-amylase and glucoamylase to endow them with upper critical solution temperature (UCST) characteristic. As a result, we found that the wastes can be hydrolyzed efficiently with the modified co-enzymes above UCST and can be easily recovered and separated below UCST, thus the cost of starch wastes treatment can be largely reduced. Besides, the proposed method exhibited excellent environmental-friendly and bio-safety properties. Therefore, this method laid a solid foundation for efficient and cost-effective enzymatic conversion of starch solid wastes.

Constructing reduced porous graphene oxide for tailoring mass-transfer channels in ultrathin MXene (Ti3C2Tx) membranes for efficient dye/salt separation

Two-dimensional (2D) membranes such as graphene oxide (GO) and MXene have attracted increasing interest in water purification. Critical challenges that impede their performance in separation applications include poor stability (swelling), low mass-transfer rate (high tortuosity), and an unavoidable trade-off between permeability and selectivity. Herein, we propose an effective multidimensional channel design strategy for preparing high-performance 2D composite membranes, featuring robust and abundant mass transfer channels. Specifically, reduced porous GO (rPGO) with high-density nanopores (size: ca. 14.7 nm, density: ca. 2.2 × 1014 m−2) and a few oxygen-containing functional groups were rationally designed and then deployed as multifunctional intercalators in MXene interlayers (rPGO-MXene, rPGM) to construct highly permeable, in-plane nanochannels and stable and tunable interlayer sieve channels. The intercalation of tailorable rPGO provides additional transport channels and weakens the interlayer repulsive hydration force, yielding composite membranes with remarkably enhanced water permeability and anti-swelling properties. As a result, the optimized membrane (10 % rPGM) exhibited an outstanding water permeability of 198.8 L m−2h−1 bar−1, 100 % rejection of Congo red, 5.3 % rejection of NaCl, and satisfactory stability (30 h) under cross-flow separation conditions. This study provides an innovative and facile approach for designing robust 2D membranes with abundant permeable nanochannels for highly efficient and precise molecular separation.

A promising formation channel for symbiotic X-ray binaries: cases of IGR J17329−2731 and 4U 1700+24

ABSTRACT Recent observations demonstrate that the symbiotic X-ray binary (SyXB) IGR J17329−2731 contains a highly magnetized neutron star (NS), which accretes matter through the wind from its giant star companion, and suggest that 4U 1700+24 may also have a highly magnetized NS. Accretion-induced collapse (AIC) from oxygen–neon–magnesium white dwarf (ONeMg WD) + red giant (RG) star binaries is one promising channel to form these SyXBs, while other long standing formation channels have difficulties to produce these SyXBs. By considering non-magnetic and magnetic ONeMg WDs, I investigate the evolution of ONeMg WD + RG binaries with the mesa stellar evolution code for producing SyXBs with non-magnetic or magnetized NSs. In the pre-AIC evolution with magnetic confinement, the mass accumulation efficiency of the accreting WD is increased at low-mass transfer rate compared with the non-magnetic case. The newborn NSs formed via AIC of highly magnetized WDs could inherit the large magnetic field through conservation of magnetic flux, and the systems could have a long age compatible with that of the red giant companions. These young and highly magnetized NSs could accrete matters from the stellar wind of the giant companions to that shine as those observed SyXBs, and could preserve their high magnetic field during this time. The mesa calculation results show that the initial parameter (initial RG mass and orbital period) space for the AIC with magnetic confinement to form SyXBs with highly magnetized NSs shifts to be lower and narrower compared with that of the no magnetic confinement case.

Orbital Decay in M82 X-2

M82 X-2 is the first pulsating ultraluminous X-ray source discovered. The luminosity of these extreme pulsars, if isotropic, implies an extreme mass transfer rate. An alternative is to assume a much lower mass transfer rate, but with an apparent luminosity boosted by geometrical beaming. Only an independent measurement of the mass transfer rate can help discriminate between these two scenarios. In this paper, we follow the orbit of the neutron star for 7 yr, measure the decay of the orbit (), and argue that this orbital decay is driven by extreme mass transfer of more than 150 times the mass transfer limit set by the Eddington luminosity. If this is true, the mass available to the accretor is more than enough to justify its luminosity, with no need for beaming. This also strongly favors models where the accretor is a highly magnetized neutron star.

Energy-Efficient H2O2 Electro-production Based on an Integrated Natural Air-Diffusion Cathode and Its Application

Given the low oxygen mass transfer rate and high aeration energy consumption, the traditional two-electron oxygen reduction reaction (ORR) is restricted. In this study, the integrated natural air diffusion cathode (INAC) and a reactor configuration with the horizontal scale facing to air (FTA) demonstrated highly selective H2O2 production for the removal of organic contaminants. Simply synthesized by shaping the mixture of carbon black and polytetrafluoroethylene, the INAC exhibited not only massive pores in all directions for sufficient mass transfer but also the integrated configuration for low charge transfer resistance. Based on the oxygen mass transfer models, for the ORR reaction kinetics, the interface oxygen concentration index was higher than 40, contributing to the high current efficiency of H2O2 production (>90%). The oxygen diffusion model can provide the quantitative description of H2O2 synthesis for porous electrode optimized design. Combining the INAC with the reactor configuration with the FTA mode for free additional O2/air source supply, the electrical efficiency per order was lower than 0.14 kWh m–3, and the removal rate of sulfonamides per unit current could reach 11 mg min–1 A–1, reaching the best reports. This ultraefficient process equipped with the INAC and the FTA mode provides a meaningful practical application prospect for wastewater treatment.

Design and development of a new static mixing bioreactor for enzymatic bioprocess: Application in biodiesel production

Mass transfer efficiency plays an important role in enzymatic biological processes, especially for non-aqueous biocatalytic processes. In these processes, low interphase mass transfer rates result in relatively long reaction residence time in traditional batch reactors. Therefore, the design and development of new bioreactors is crucial. In this study, a novel static mixing bioreactor was designed and applied to enzymatically catalyzed biodiesel production, which is a typical interfacial reaction system. In order to achieve good mixing effect and low pressure drop, the structure of bioreactor, including unit configuration, aspect ratio and rotation angle was designed and optimized by computational fluid dynamics. The realizable k-epsilon model was used, it was proved to be grid independent with 833678 hexahedral unstructured grids that were adopted to improve the structure for material mixing. After modification of the reactor, the final optimized structure is an R-R configuration with an aspect ratio of 1.5 and a rotation angle of 150°. Based on the above improved bioreactor, the process conditions for enzymatic production of biodiesel were optimized. The optimized reaction conditions were as follows: the length of the static mixer was 30 cm, the material flow rate was 1.77 m/s, the reaction temperature was 40 °C, the amount of methanol added was 3 times, and molar ratio of 3.4 alcohol to oil and 10% lipase dose were used. Under the optimal conditions, the yield of biodiesel in 1.5 h could reach 81.28%, and it could still be above 70% after 12 times of repeated use of lipase. Under the same reaction conditions, the reaction time for the static mixer to reach the same conversion rate (81.28%) was 1/3 of that of the stirred reactor, confirming the excellent mass transfer performance of the static mixer bioreactor.

1RXH J082623.6–505741: A New Long-period Cataclysmic Variable with an Evolved Donor and a Low Mass-transfer Rate

We report the discovery of 1RXH J082623.6−505741, a 10.4 hr orbital period compact binary. Modeling extensive optical photometry and spectroscopy reveals a ∼0.4 M ⊙ K-type secondary transferring mass through a low-state accretion disk to a nonmagnetic ∼0.8 M ⊙ white dwarf. The secondary is overluminous for its mass and dominates the optical spectra at all epochs and must be evolved to fill its Roche Lobe at this orbital period. The X-ray luminosity L X ∼ 1–2 × 1032 erg s−1 derived from both new XMM-Newton and archival observations, although high compared to most CVs, still only requires a modest accretion rate onto the white dwarf of ∼ 3 × 10−11 to 3 × 10−10 M ⊙ yr−1, lower than expected for a cataclysmic variable with an evolved secondary. No dwarf nova outbursts have yet been observed from the system, consistent with the low derived mass-transfer rate. Several other cataclysmic variables with similar orbital periods also show unexpectedly low mass-transfer rates, even though selection effects disfavor the discovery of binaries with these properties. This suggests the abundance and evolutionary state of long-period, low mass-transfer rate cataclysmic variables are worthy of additional attention.

A Long-period Pre-ELM System Discovered from the LAMOST Medium-resolution Survey

We present LAMOST J041920.07+072545.4 (hereafter J0419), a close binary consisting of a bloated, extremely low mass pre-white dwarf (pre-ELM WD) and a compact object with an orbital period of 0.607189 days. The large-amplitude ellipsoidal variations and the evident Balmer and He i emission lines suggest a filled Roche lobe and ongoing mass transfer. No outburst events were detected in the 15 years of monitoring of J0419, indicating a very low mass transfer rate. The temperature of the pre-ELM, , makes it cooler than the known ELMs, but hotter than most cataclysmic variable donors. Combining the mean density within the Roche lobe and the radius constrained from our spectral energy distribution fitting, we obtain the mass of the pre-ELM, M 1 = 0.176 ± 0.014 M ⊙. The joint fitting of light and radial velocity curves yields an inclination angle of degrees, corresponding to a mass of the compact object of M 2 = 1.09 ± 0.05 M ⊙. The very bloated pre-ELM has a smaller surface gravity (, R 1 = 0.78 ± 0.02 R ⊙) than the known ELMs or pre-ELMs. The temperature and the luminosity () of J0419 are close to those of the main sequence, which makes the selection of such systems through the H-R diagram inefficient. Based on the evolutionary model, the relatively long period and small indicate that J0419 could be close to the “bifurcation period” in the orbital evolution, which makes J0419 a unique source to connect ELM/pre-ELM WD systems, wide binaries, and cataclysmic variables.

A correlation for average droplet diameter in rotating packed beds

AbstractA rotating packed bed (RPB) is a novel process intensification technology that increases mass transfer rate using a strong centrifugal acceleration. Inside an RPB, the inlet jet of the liquid absorbent is broken into tiny droplets. It is reported that RPBs provide 11 times larger mass transfer area compared to equal‐sized packed beds and two to three orders of magnitude higher mass transfer compared to equal‐sized stirred tanks. The novelty of the technology and lack of research, however, undermines the adoption of RPBs where a low mass transfer rate is the main bottleneck. In this work, we study the effect of bed size on the average droplet diameter in RPBs and investigate scale‐up criteria to preserve the average droplet diameter at a large scale. Furthermore, we develop a correlation for the average droplet diameter using the experimental data and simulation results obtained using a volume of fluid (VOF) method. This correlation is obtained from dimensional analysis. The effects of rotating speed, absorbent flow rate, wire mesh packing diameter, bed diameter, absorbent viscosity, density, and surface tension are included in the dataset. Among these parameters, rotating speed, centrifugal force, and surface tension have the highest correlation coefficients (R2 = 0.88, 0.83, and 0.42, respectively) with the average droplet diameter.

Образование сварных твердофазных соединений проволок при изготовлении пористых сетчатых материалов из стали 12Х18Н10Т

The experience of using turbine blade shells based on porous mesh materials in aerospace products and high-temperature gas turbines has shown that they are subject to destruction when under the influence of pressure fluctuations. So, first of all, fatigue failure occurs, in those permeable shells where there are no high-quality connections of structure-forming elements. It has been established that in diffusion welding and rolling welding, the strength of welded bonds increases with an increase in the process temperature, as well as in the vacuum depth and deformation time in diffusion welding. Research findings show that at strain rates of 10–2…1.0 s–1, the low quality of welded joints is explained by the high deformation resistance of microroughnesses on the contact surfaces of the wires and the low rate of diffusion mass transfer in the connection zone. The study establishes that under the conditions of diffusion and impact welding in vacuum, the formation of a solid-phase joint is possible on the entire surface of the macrocontact. At the same time, in percussion welding, the influence of the temperature value in the investigated interval on the quality of welded bonds is much lower than that for processes with lower loading rates. Practical recommendations are given for determining the optimal modes of wire mesh welding in the manufacture of porous mesh materials made of 12Kh18N10T steel.

Carbon Capture and Storage Toward Industrialization: A Novel Continuous Process for the Production of Carbon Dioxide Clathrates

Gas hydrates have been potentially recognized for developing new technologies for CO2 capture and storage; however, the respective industrialization faces difficulties. Hydrate's crystallization is highly exothermic, 1.3 kJ tonne−1 of captured CO2, and it only occurs in a narrow window of temperatures, typically 1–5 °C. Previous works have systematically reported low space–time yields (STY) due to low specific heat and mass transfer rates of the technologies tested. Herein, NetMIX, a novel mixing technology, is used for the continuous production of CO2 hydrates. NetMIX is a structured mixer consisting of a network of unit cells comprising mixing chambers interconnected by channels. The device used here has specific heat transfer rates ranging from 107 to 108 . The setup proves to be capable of producing hydrates at a STY of 200 , two orders of magnitude larger than other technologies, resulting in a slurry with more than 20 wt% of CO2 inside the hydrates lattice. The solid is characterized, and a cubic structure I (sI) hydrate structure is detected, with no ice traces. Moreover, results indicate that the process is stable, and no plugging occurs, crucial for industrialization.

Analysis of Ozonation Processes Using Coupled Modeling of Fluid Dynamics, Mass Transfer, and Chemical Reaction Kinetics.

The efficacy of oxidation of recalcitrant organic contaminants in municipal and industrial wastewaters by ozonation is influenced by chemical reaction kinetics and hydrodynamics within a reactor. A 3D computational fluid dynamics (CFD) model incorporating both multiphase flow and reaction kinetics describing ozone decay, hydroxyl radical (•OH) generation, and organic oxidation was developed to simulate the performance of continuous flow ozonation reactors. Formate was selected as the target organic in this study due to its well-understood oxidation pathway. Simulation results revealed that the dissolved ozone concentration in the reactor is controlled by rates of O3(g) interphase transfer and ozone self-decay. Simulations of the effect of various operating conditions showed that the reaction stoichiometric constraints between formate and ozone were reached; however, complete utilization of gas phase ozone was hard to achieve due to the low ozone interphase mass transfer rate. Increasing the O3(g) concentration leads to an increase in the formate removal rate by ∼5% due to an enhancement in the rate of O3(g) interphase mass transfer. The CFD model adequately describes the mass transfer occurring in the two-phase flow system and confirms that O3(g) interphase mass transfer is the rate-limiting step in contaminant degradation. The model can be used to optimize the ozone reactor design for improved contaminant degradation and ozonation efficiency.

A homogeneous reagent for Ni2+ capture from wastewater: The phase transition mechanism and impact evaluation for aerobic sludge

Heterogeneous process with low mass transfer rate is limited in the treatment of large-volume Ni-containing wastewater. The homogeneous reaction provides a promising strategy to solve this problem, but phase transition process of Ni2+ removal and its potential impact on activated sludge system are rarely explored. Herein, the Ni2+ removal efficiency and process were firstly investigated in detail by using S-containing reagent with dithioamino groups. When the dosage of reagent concentration was controlled at 5–10:1(Ni), Ni2+ can be rapidly and completely removed within 1 min. Additionally, other coexisting Cu2+, Co2+, Cd2+, and Pb2+ could be synchronously removed with more reagent adding, while the typical organics (e.g., humic/citric acid) in water and high concentration of chemical oxygen demand (3800 mg L−1) in actual wastewater, exhibited negligible inhibition for Ni2+ capture. The phase transition was visually investigated by charge coupled device camera and paticle size change. Experimental characterizations demonstrate that the dithioamino groups in capture reagent could efficiently chelate with Ni2+, which can be validated by the theoretical calculations. Vitally, the utilization of reagent cannot affect the nitrification activity of aerobic sludge system through short-term experiment and 29 months of operation while ensuring total Ni removal efficiency. These findings highlight an opportunity for using S-containing organic reagents to remove heavy metal ions from actual wastewater, especially in the application of the sewage treatment plant with bulky water.