Synergistic Process Research Articles

Effective Removal of Methylene Blue on EuVO4/g-C3N4 Mesoporous Nanosheets via Coupling Adsorption and Photocatalysis.

In this study, we first manufactured ultrathin g-C3N4 (CN) nanosheets by thermal etching and ultrasonic techniques. Then, EuVO4 (EV) nanoparticles were loaded onto CN nanosheets to form EuVO4/g-C3N4 heterojunctions (EVCs). The ultrathin and porous structure of the EVCs increased the specific surface area and reaction active sites. The formation of the heterostructure extended visible light absorption and accelerated the separation of charge carriers. These two factors were advantageous to promote the synergistic effect of adsorption and photocatalysis, and ultimately enhanced the adsorption capability and photocatalytic removal efficiency of methylene blue (MB). EVC-2 (2 wt% of EV) exhibited the highest adsorption and photocatalytic performance. Almost 100% of MB was eliminated via the adsorption–photocatalysis synergistic process over EVC-2. The MB adsorption capability of EVC-2 was 6.2 times that of CN, and the zero-orderreaction rate constant was 5 times that of CN. The MB adsorption on EVC-2 followed the pseudo second-order kinetics model and the adsorption isotherm data complied with the Langmuir isotherm model. The photocatalytic degradation data of MB on EVC-2 obeyed the zero-order kinetics equation in 0–10 min and abided by the first-order kinetics equation for10–30 min. This study provided a promising EVC heterojunctions with superior synergetic effect of adsorption and photocatalysis for the potential application in wastewater treatment.

Potential molecular mechanisms of QiZhenYuanDan in treatment of atherosclerosis based on network pharmacology

Objective: By means of network pharmacology, potential targets and molecular pathways of QiZhenYuanDan in the treatment of atherosclerosis (AS) were studied. Methods: TCMSP database was used to obtain the main active components and target information of Astragali Radix, Fructus Ligustri Lucidi, Corydalis Rhizoma and Salvia Miltiorrhiza in QiZhenYuanDan. Disease targets were retrieved by OMIM and other databases. Molecular networks were constructed using Cytoscape. STRING database was searched and PPI network diagram was drawn to obtain the key targets of QiZhenYuanDan in the treatment of AS; and the targets were uploaded to Metascape data platform for GO and KEGG analysis. Results: There were 118 targets of intersection between QiZhenYuanDan and AS, which were used as the predicted targets of QiZhenYuanDan on AS. GO analysis showed that the biological functions of QiZhenYuanDan in the treatment of AS targets mainly involved biological processes, such as the cytokine-mediated signaling pathway, cytokine receptor binding. KEGG pathway was mainly enriched in 155 signaling pathways, including PI3K-Akt, HIF-1, NF-κB signal pathway and inflammatory bowel disease pathway. Conclusion: Based on the result of network pharmacology study, the mechanisms of Qizhenyuandan for AS treatment was preliminarily revealed. The active ingredients such as quercetin and kaempferol act on targets such as IL-6 and PI3K-Akt, and exert anti-AS effects by inhibiting apoptosis, oxidative stress, as well as inflammatory responses. Our result indicates that QiZhenYuanDan exhibits anti-AS effect via a multi-component, multi-target and multi-route synergistic process.

Arsenic Oxidation and Removal from Water via Core-Shell MnO2@La(OH)3 Nanocomposite Adsorption.

Arsenic (As(III)), more toxic and with less affinity than arsenate (As(V)), is hard to remove from the aqueous phase due to the lack of efficient adsorbents. In this study, a core–shell structured MnO2@La(OH)3 nanocomposite was synthesized via a facile two-step precipitation method. Its removal performance and mechanisms for As(V) and As(III) were investigated through batch adsorption experiments and a series of analysis methods including the transformation kinetics of arsenic species in As(III) removal, FTIR, XRD and XPS. Solution pH could significantly influence the removal efficiencies of arsenic. The adsorption process of As(V) occurred rapidly in the first 5 h and then gradually decreased, whereas the As(III) removal rate was relatively slower. The maximum adsorption capacities of As(V) and As(III) were up to 138.9 and 139.9 mg/g at pH 4.0, respectively. For As(V) removal, the inner-sphere complexes of lanthanum arsenate were formed through the ligand exchange reactions and coprecipitation. The oxidation of As(III) to the less toxic As(V) by δ-MnO2 and subsequently the synergistic adsorption process by the lanthanum hydroxide on the MnO2@La(OH)3 nanocomposite to form lanthanum arsenate were the dominant mechanisms of As(III) removal. XPS analysis indicated that approximately 20.6% of Mn in the nanocomposite after As(III) removal were Mn(II). Furthermore, a small amount of Mn(II) and La(III) were released into solution during the process of As(III) removal. These results confirm its efficient performance in the arsenic-containing water treatment, such as As(III)-contaminated groundwater used for irrigation and As(V)-contaminated industrial wastewater.

Fabricating S-scheme BiOBr/Zn2In2S5 heterojunction for synergistic adsorption-photocatalytic degradation of tetracycline

Harnessing affordable photocatalysts with high performance for boosting charge separation is an effective strategy to reinforce wastewater contaminant control. Herein, we reported a self-assembled S-scheme heterostructure BiOBr/Zn2In2S5 (BZS) nanoflower with the formation of internal electric field to promote the synergistic effect of adsorption and photocatalysis. The result showed that 7 wt% BiOBr/Zn2In2S5 (BZS-7) has highest tetracycline (TC) adsorption capacity of 34.85 mg g−1, which was fitted well the pseudo-second-order and Langmuir isotherm models. Then the synergistic degradation rate could reach 97.52% after 40 min visible light irradiation, which was 1.34 times higher than that of Zn2In2S5. BZS-7 also performed excellent adsorption-photocatalytic synergy on the removal of TC in simulated seawater and continuous flow reactor, with removal efficiency about 81.11% and 34.35%, respectively. The improved performance could be attributed to unique structures and high exposure surface of reassembled morphologies after the introduction of BiOBr. The antibacterial activity and ecotoxicity evaluation of TC intermediate byproducts indicated that the proposed degradation pathways presented reduced acute and chronic toxicity. The synergistic process of cost-effective S-scheme heterojunction photocatalysts holds the research for practical on-site wastewater remediation.

Hip implant modular junction: The role of CoCrMo alloy microstructure on fretting-corrosion

Cobalt-chromium-molybdenum (CoCrMo) alloy is one of the most used metals in total hip replacement (THR) due to the alloy's superior corrosion qualities and biocompatibility. Over time these prostheses may undergo wear and corrosion processes in a synergistic process known as tribocorrosion. Implant retrieval studies have shown that damage patterns on THR modular junction surfaces indicating specifically in vivo fretting-corrosion to take place. To date, there have been no studies on the fretting-corrosion behaviors of CoCrMo alloy under the consideration of specific microstructural features. A custom-built flat-on-flat fretting-corrosion setup was utilized to test the synergistic tribocorrosion behavior of fretting-corrosion. The difference in microstructure was generated through the cutting orientations of the transverse and the longitudinal direction of the bar stock material, where the longitudinal cut exhibits a characteristic banded microstructure (banded group) and the transverse cut a homogenous microstructure (unbanded group). A three-electrode system was employed to monitor the induced currents. Two different types of electrolytes were used in the current study: 1. Bovine calf serum (BCS-30 g/L protein) (normal conditions) 2. BCS with Lipopolysaccharide (LPS, 0.15 μg/ml) (simulated infectious conditions). In the free potential mode, banded samples showed an increased potential compared to the unbanded samples. In potentiostatic conditions, the banded group also exhibited a higher induced current in both electrolyte environments, indicating more corrosion loss. Both Nyquist and Bode plots showed both orientations of metal becoming more corrosion resistant post-fretting when compared to pre-fretting data. The longitudinal group at OCP demonstrated a unique shape of the fretting-loop, which might be related to tribochemical reactions. Based on the mechanical, electrochemical, and surface characterization data, the transverse group (unbanded) microstructures demonstrates a higher resistance to fretting-corrosion damage.

Optimized titania nanotubes photoanode mediated photoelectrochemical oxidation of ammonia in highly chlorinated wastewater via Cl-based radicals

Efficient removal of low-concentration ammonia from chlorinated wastewater is a challenge for decentralized wastewater treatment due to its notorious environmental effect and lethal influence on aquaculture. Photoelectrocatalytic (PEC) oxidation process is considered as an efficient and environment–friendly approach, whereas a low-cost and stable photoanode is crucial. In this study, TiO2 nanotubes (TNTs) photoanode (Ar–TNT–500 °C) with excellent physicochemical and photoelectrochemical properties was prepared by optimizing the parameters of anodization, including the voltage/times of anodization and the atmosphere/temperature of heat treatment. During the synthesis, the electrochemical and heat treatment processes promoted the formation of oxygen vacancies (OV) on the TNTs surface and enhanced its electrocatalytic activity. The optimized Ar–TNT–500 °C photoanode could selectively convert ammonia to N2 (86%) and a small amount of nitrate (14%). Radical quenching and probe experiments confirmed that the ClO produced by rapid quenching of OH and Cl by free chlorine dominated the selective degradation of ammonia in the synergistic process of photocatalysis and electrocatalysis. The cycle of chlorine-based radicals (ClO and Cl) and Cl− provided a continuous and efficient ammonia oxidation system, because chlorine-based radicals could efficiently and selectively oxidize ammonia and reduce the production of toxic (per) chlorate.

Migration mechanism of microcystin-LR synergism with Cu2+ from algal cell to water environment using modified nano system

Effects on various macromolecules in algal cells occurred when heavy metals migrated to algal cells from the water environment. An innovative nanosystem was introduced to explore the synergistic process of MC-LR and Cu2+ in algal cells.In this method, the complex groups of Cu2+ and MC-LR were deeply analyzed by infrared spectroscopy, and the migration process and mechanism of MC-LR in cells were explored. The complexation of MC-LR with Cu2+ changed the exposure of hydrophobic and hydrophilic residues and affected their migration from intracellular to aqueous environment. Cu2+ mainly bound to =N-H in guanidine group of MC-LR, which changed the exposure of hydrophobic and hydrophilic residues of MC-LR and affected its migration from intracellular to water environment. In this paper, the effects of Cu2+ concentration and pH on the optimal coordination of MC-LR were studied. When the concentration of Cu2+ was 0.05 mm-2 mm, the complex of Cu2+ and MC-LR had synergistic amplification effect on the detection signal of the nanosystem, and the relative signal value reached the maximum when the pH value was 7. Part of the free copper ions complexed with MC-LR with changing conformation before migrating to the water environment.

Synergistically Improved Catalytic Ozonation Process Using Iron-Loaded Activated Carbons for the Removal of Arsenic in Drinking Water

This research attempts to find a new approach for the removal of arsenic (As) from drinking water by developing a novel solution. To the author’s knowledge, iron-loaded activated carbons (Fe-AC) have not been previously applied for the removal of As in a synergistic process using ozonation and catalytic ozonation processes. The As was investigated using drinking water samples in different areas of Lahore, Pakistan, and the As removal was compared with and without using catalysts. The results also suggested that the catalytic ozonation process significantly removes As as compared with single ozonation and adsorption processes. Moreover, a feed ozone of 1.0 mg/min and catalyst dose of 10 g was found to maintain a maximum removal efficiency of 98.6% within 30 min. The results of the catalyst dose–effect suggested that the removal of As tends to increase with the increase in catalysts amount. Hence, it is concluded that the Fe-AC/O3 process efficiently removes As in water. Moreover, it was established that the Fe-AC/O3 process might be regarded as an effective method for removing As from drinking water compared to the single ozonation and adsorption processes.

Anaerobic digestion of waste activated sludge to produce volatile fatty acids and release nutrients using sodium citrate with sodium hydroxide pretreatment

AbstractThis study investigated the synergistic effect of sodium citrate (SC) and sodium hydroxide (NaOH) on the anaerobic digestion (AD) efficiency of waste activated sludge (WAS). Using the amount of SC as the control variable, changes in sludge cell cracking and AD performance under different pretreatment conditions was investigated. The optimum treatment conditions were a NaOH input of initial pH 10 and an SC concentration of 0.20 g/g total suspended solids. The pretreatment was monitored in 150 min. And the changes in soluble chemical oxygen demand (SCOD), soluble polysaccharide, soluble protein, volatile fatty acids (VFAs), PO43−‐P and NH4+‐N during the pretreatment stage and fermentation process were studied. Results show a significant disintegration effect on WAS under optimal pretreatment conditions, with the peak concentration of SCOD, soluble protein, and soluble polysaccharide being 2059.5, 114.86, and 190.97 mg/L, respectively, which means that large amounts of intracellular carbon sources were released. The production of VFAs included acetic acid, propionic acid, isobutyric acid, n‐butyric acid, isovaleric acid, and n‐valeric acid, with a peak concentration of 9555.89, 1779.12, 608.84, 805.7, 777.91, 184.86 mg·COD/L, respectively. The content of PO43‐P and NH4+‐N were great in fermentation liquid, 71.82 and 320.75 mg/L, respectively. These results indicate that the synergistic process improve VFAs production and contribute to nutrients reuse.

Production of ZnO-CoOx-CeO2 nanocomposites and their dye removal performance from wastewater by adsorption-photocatalysis

In this paper, a new series of ZnO-CoOx-CeO2 nanocomposites were prepared by impregnation method. The composite nano-catalysts were characterized by SEM, TEM, EDS, XRD, FT-IR, XPS, BET and Zeta potential. The removal rate of degraded CR was used to evaluate the adsorption performance and adsorption-photocatalysis synergistic performance of ZnO-CoOx-CeO2 composites. The results show that ZnO-CoOx-CeO2 nanocomposites have the best adsorption activity and photocatalytic oxidation activity than single metal oxide ZnO and binary metal oxide ZnO-Co3O4. In addition, the adsorption-photocatalysis synergistic process showed better activity than the single adsorption process. Then the effects of operation parameters such as catalyst calcination temperature, initial pH and catalyst dosage on the decomposition efficiency of the catalyst were investigated. Under the optimized conditions, when the concentration of catalyst is 1 g L−1, the initial pH is in the range of 6–7, the roasting temperature is 450 °C and the reaction time is 65 min, the removal rate of CR can reach more than 98.8 %. The stability of the prepared catalyst was tested, and it was found that the sample maintained almost the same removal ability after 4 cycles.

Start-up and synergistic nitrogen removal of partial nitrification and anoxic/aerobic denitrification in membrane aerated biofilm reactor

To reduce energy consumption and improve operational stability of traditional biological nitrogen removal (BNR) system, partial nitrification and anoxic/aerobic denitrification were synergistically implemented in membrane aerated biofilm reactor (MABR) by regulating DO and pH. The results indicated that the optimal DO, pH and C/N ratio were 1–2 mg/L, 9.0 and 4–7, respectively. The corresponding average organic removal rate (ORR), total nitrogen removal rate (TNRR) and nitrite accumulation rate (NAR) reached 324 gCOD・m−3・d−1, 48 gN・m−3・d−1 and 77.70%, respectively. Extracellular polymeric substance (EPS) content in biofilm was more abundant than that in inoculated sludge. Multiple aerobic denitrifiers were detected in the biofilm with the relative abundance of 11.19%–22.71%. AQUASIM simulation implied that the distribution and proportion of substrates and bacteria were significantly affected by DO and pH regulation. Overall, this study provided some important insights in the start-up and operation of synergistic nitrogen removal process in BNR system.

Synergistic Nanowire-Enhanced Electroporation and Electrochlorination for Highly Efficient Water Disinfection.

Conventional water disinfection methods such as chlorination typically involve the generation of harmful disinfection byproducts and intensive chemical consumption. Emerging electroporation disinfection techniques using nanowire-enhanced local electric fields inactivate microbes by damaging their outer structures without byproduct formation or chemical dosing. However, this physical-based method suffers from a limited inactivation efficiency under high water flux due to an insufficient contact time. Herein, we integrate electrochlorination with nanowire-enhanced electroporation to achieve a synergistic flow-through process for efficient water disinfection targeting bacteria and viruses. Electroporation at the cathode induces sub-lethal damages on the microbial outer structures. Subsequently, electrogenerated active chlorine at the anode aggravates these electroporation-induced injuries to the level of lethal damage. This sequential flow-through disinfection system achieves complete disinfection (>6.0-log) under a very high water flux of 2.4 × 104 L/(m2 h) with an applied voltage of 2.0 V. This disinfection efficiency is 8 times faster than that of electroporation alone. Further, the specific energy consumption for the disinfection by this novel process is extremely low (8 × 10-4 kW h/m3). Our results demonstrate a promising method for rapid and energy-efficient water disinfection by coupling electroporation with electrochlorination to meet vital needs for pathogen elimination.

Electrically supported mediator Co(II)-activated peroxydisulfate synergistic process for organic contaminants elimination

Among homogeneous catalysts, cobalt ions exhibit ultra-high persulfate activation performance. In this work, an electrically supported medium Co(II) activated peroxydisulfate synergistic process was established to eliminate organic contaminants in water. The synergistic catalytic effect was verified by comparing the oxidative degradation performance and reaction rate constant of different coupling systems. The decolorization ability of E-Co(II)-PDS on reactive black 5 (RB5) was explored, and the results showed that the removal rate of RB5 can reach 93.21% under the optimized conditions of current density of 5.71 mA/cm2, initial pH of 4, Co(II) concentration of 0.2 mM and PDS concentration of 5 mM. The effect of water matrix on the removal of RB5 was studied, and it was found that HCO3− and humic acid significantly inhibited the degradation of RB5, while Cl− and H2PO4− could effectively promote it at a certain concentration. Notably, the degradation of RB5 in E-Co(II)-PDS system achieved lower energy consumption, with an energy consumption per unit volume (EE/O) value of 0.4304 kWh·m−3. EPR test, quenching experiments and contribution rate analysis showed that the oxidation active species in E-Co(II)-PDS process were Co(III), sulfate radicals and hydroxyl radicals, and their oxidation contribution rates were 15.72%, 12.69% and 53.25%, respectively. Finally, the decomposition process of RB5 was proposed by the mass spectrometry results. The electric current promotes cobalt ion cycling and PDS activation through electron transfer, and induces Co(II) to promote the activation of PDS, which is the main mechanism of E-Co(II)-PDS system to achieve the robust degradation ability of RB5.

Selective recovery of lithium and efficient leaching of transition metals from spent LiNixCoyMnzO2 batteries based on a synergistic roasting process

A novel process was developed for the selective extraction of Li and efficient leaching of transition metals (TMs) from spent LiNixCoyMnzO2 (NCM) batteries coupled with the synergistic disposal of Na2SO4 byproducts generated from lithium battery industry. The NCM cathode was transformed into water-soluble LiNaSO4 and acid-dissolved divalent oxides of (NiO)m(MnO)n and CoO based on the synergy between self-reduction of graphite anode and Na2SO4 roasting. >85% Li was selectively extracted from the roasted product by water leaching. Subsequently, >95% Ni, >99% Mn and >99% Co were leached by H2SO4 solution without additional reductant. During the self-reduction roasting of graphite anode, the addition of Na2SO4 transformed Li from Li2CO3 to LiNaSO4 with higher solubility and also prevented the overreduction of Ni and Co oxides to the metallic states, which are prone to the deterioration of their acid leaching performance. Through the precise regulation of NCM phases during the synergistic roasting process, the efficient cascade extraction of Li and TMs from spent NCM batteries was realized, and a new way for the comprehensive utilization of the Na2SO4 byproducts was determined. Moreover, the emission of toxic gases SO2 and NOx generated in the acid roasting was avoided. The proposed process obeys the principles of circular economy and green chemistry.

Detoxification and comprehensive recovery of stainless steel dust and chromium containing slag: Synergistic reduction mechanism and process parameter optimization

Stainless steel dust and chromium containing slag are representative harmful solid wastes produced in modern iron and steel metallurgy industry. Based on the study of stainless steel dust reduction, the direct reduction process with low energy consumption and high efficiency was obtained by changing the addition amount of chromium containing slag and the conditions of reduction process system. The results show that with the addition of chromium containing slag, the basicity of raw materials decreases, the recovery of metal is improved, and the self-pulverization effect of reducing slag is improved. The optimum process conditions are as follows: the mixing ratio of stainless steel dust to chromium containing slag is 94%: 6%, the reduction temperature is 1400 °C, the reduction time is 25 min, the FC/O is 0.9, the recoveries of Fe, Cr and Ni in the reduction products are 90.5%, 90.6% and 91.2%, respectively, the grades of Fe, Cr and Ni in Fe-Cr-Ni-C alloy are 61.3%, 19.9% and 3.7%, respectively, and the contents of harmful components such as S and P are very low. The self-pulverization rate of reduction slag can reach 92.8%, and the residues of metal Fe, Cr and Ni in reduction slag are 134 ppm, 96 ppm and 129 ppm, respectively.

Synergistic enhancement of piezocatalysis and electrochemical oxidation for the degradation of ciprofloxacin by PbO2 intercalation material

In this study, the TiO2 nanotube array intercalated PbO2 (Ti/TiO2-NTA/PbO2-La) material was applied in the piezo-electro-catalytic removal of ciprofloxacin (CIP). The degradation rate of CIP reached up to 91.4% after the mechanical ultrasonic vibration of the Ti/TiO2-NTA/PbO2-La material for 20 min with applied current density of 0.04 mA cm−2. The degradation rate constant (kCIP) of CIP by piezo-electro-catalysis was 8.6 and 17.2 times that of the electrochemical oxidation and piezocatalysis. The degradation of CIP exhibited a rapid nearly-linear increase with increasing applied ultrasonic power (<13.6 W) at a current density of 0.04 mA cm−2 or the current density (<0.11 mA cm−2) at an ultrasonic power of 15.0 W. The enhancement mechanism of the synergistic process was due to that the dynamic piezoelectric field and the applied bias facilitate the carriers transport and accelerate the electric charges carrier separation, hence favouring the generation of homogeneous reactive species. Based on quenching experiments and electron spin resonance (ESR) results, holes (h+) and hydroxyl radical (OH) were found to be the predominant reactive species in CIP removal in the piezo-electro-catalytic process. h+ may be involved in the rate-limiting degradation steps. With the identification of the intermediate byproducts and the theoretical calculations of the frontier electron densities, three possible degradation pathways were proposed in the cleavage of the piperazine and quinolone rings, and substitution of –COOH by –OH group. The findings of this study suggest that the synergistic process of piezocatalysis and electrochemical oxidation is an effective way to promote degradation efficiency of CIP at a ultralow current density and ultrasonic power.

Design of Au Surface‐doped PtFe Catalyst to Modulate Oxygen Binding Energy for Highly Efficient Oxygen Reduction Reaction

AbstractAs ideal cathode catalysts for proton exchange membrane fuel cells (PEMFCs), the oxygen reduction reaction (ORR) activity and durability of Pt‐based alloys can be improved further. This study presents the catalyst with Au doping on the surface of an ordered PtFe alloy (Au‐PtFe/C) utilizing a synergistic process of microwave reduction and chemical replacement, as well as the reorganization of a Pt‐rich surface using acid etching and high temperature annealing. Physical characterization indicated that the oxygen binding energy on the surface of Au‐PtFe/C was more effective at promoting the ORR reaction than commercial Pt/C, which contributes significantly to its enhanced activity. Further electrochemical tests revealed that the Au‐PtFe/C catalyst exposes abundant active sites for ORR, with mass and specific activity up to 12 and 8 times that of commercial Pt/C, respectively. Additionally, the catalyst demonstrated remarkable durability following 10,000 cycles of accelerated durability tests (ADT) in acidic circumstances. In PEMFC test, the single cell with an Au‐PtFe/C cathode also performed admirably when compared with commercial Pt/C. Owing to its facile synthesis, low cost, and exceptional performance, this bimetal‐doped ordered Pt‐based alloy has the capability to be a promising component in fuel cells commercialization.

Synergistic effect of discrete ultrasonic and H2O2 on physicochemical properties of chitosan

Synergistic degradation of chitosan by discrete ultrasonic and H2O2 was investigated. The effects of ultrasonic time, ultrasonic power, chitosan concentration, and H2O2 concentration were evaluated. The results revealed that ultrasonic power, H2O2 concentration and ultrasonic time were positively correlated with degradation rate, while chitosan concentration was negative. The results of degradation kinetics revealed that the synergistic degradation process was consistent with the first-order reaction. Changes of characterization of chitosan were analyzed by FTIR, 13C NMR, XRD, SEM, and AFM analysis. The results indicated that the synergistic degradation did not destroy the pyranose ring. The crystal structure of degraded chitosan was destroyed, and the molecular conformation changed significantly. The antioxidant activity of the original and degraded chitosan was determined by DPPH and reducing power assays. The degraded chitosan had higher antioxidant activity. All results showed that the synergistic degradation of discrete ultrasound and H2O2 was a feasible method for large-scale low molecular weight chitosan production.

Glucose-Responsive ZIF-8 Nanocomposites for Targeted Cancer Therapy through Combining Starvation with Stimulus-Responsive Nitric Oxide Synergistic Treatment.

With the rapid development of nanomedicine, low side effects and high-efficiency green antitumor approaches have attracted great attention. Herein, we report a strategy for the in situ synthesis of graphene oxide@zeolitic imidazolate framework-8 (GOx@ZIF-8) composite nanoparticles with high catalytic efficiency, under mild conditions by adding GOx molecules to the precursor of ZIF-8, and use them as a carrier to achieve efficient loading of l-Arg. In addition. folic-acid-conjugated bovine serum albumin (FA-BSA) has been used to engineer the surface of GOx@ZIF-8-l-Arg composite nanoparticles to enhance their specific recognition of tumor cells. With the high glucose level and low pH in the tumor intracellular environment, FA-BSA/GOx@ZIF-8-l-Arg rapidly consumed the intracellular glucose and produced H2O2, which profusely deteriorated the intracellular environment. Subsequently, a large amount of l-Arg was continuously released from the nanoparticles, reacting with H2O2 to continuously produce a high concentration of nitric oxide (NO), which further damaged the tumor cells. The FA-BSA/GOx@ZIF-8-l-Arg composite nanoparticles were cleverly designed to kill cancer cells efficiently through a starvation-NO synergistic process. This emerging green antitumor method has a promising application prospect in targeted therapy for the efficient clearance of cancers.

The drinking water disinfection performances and mechanisms of UVA-LEDs promoted by electrolysis

In this study, the UVA (Ultraviolet A) drinking water disinfection was promoted by electrolysis. The influences of the UVA, electrolysis current, bubbling and temperature were investigated. The disinfection mechanisms and bacterial reactivation had been studied. The results revealed that the treatment time needed to reach the DL (detection limit, about 5.4 log removal) was shortened from 180 to 80 min by the electrolysis. The total electricity consumption decreased from about 126–57.0 kJ/L. Compared with increasing the UVA irradiation, increasing the electrolysis current in a certain range was more preferred to improve the disinfection rate. Oxygen bubbling or higher temperature could enhance the E. coli inactivation. The quenching experiment and EPR (Electron paramagnetic resonance) detection confirmed that ROSs (1O2, ·O2- and ·OH) played important roles for the disinfection. Compared with the treatment with UVA alone, the cell membrane damage was more severe by the promoting method. In addition to the dramatically reduced enzyme activity, the synergistic process degraded most of the bacterial genomic DNA, and the bacteria were completely killed. Therefore, hybrid with electrolysis is a better way for the application of the UVA-LED disinfection.