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1.
This study aims to identify effective antialgal allelochemicals from marine macroalgae that inhibit the growth of red tide microalgae. Practically, new algicidal agents were developed to control red tide. The growth inhibitory effects of 5 marine macroalgae Porphyra tenera, Laminaria japonica, Ulva pertusa, Enteromorpha clathrata, and Undaria pinnatifida on Skeletonema costatum were evaluated by adding crude seawater extracts of macroalgal dry tissue into the culture medium containing S. costatum. The half-effective concentrations at 120 h (EC50, 120 h) of the seawater extracts were 0.6, 0.9, 1.0, 1.0, and 4.7 g/L for the five macroalgae above, respectively. E. clathrata, L. japonica and U. pertusa showed strong allelopathic effect on the growth of S. costatum. There have been no previous reports with regard to the allelopathic effects of the former two macroalgae so far. The possible allelochemicals of 21 compounds of the E. clathrata were detected using Gas chromatography-mass spectrometry (GC-MS) analysis. Unsaturated fatty acids, acrylic acid (C3H4O2), and linolenic acid (C18H30O2) were the most likely allelochemicals in E. clathrata.  相似文献   

2.
Electrochemical conversion of CO2 to hydrocarbons can relieve both environmental and energy stresses. However, electrocatalysts for this reaction usually suffer from a poor product selectivity and a large overpotential. Here we report that tunable catalytic selectivity for hydrocarbon formation could be achieved on Cu nanomaterials with different morphologies. By tuning the electrochemical parameters, either Cu oxide nanowires or nanoneedles were fabricated and then electrochemically reduced to the corresponding Cu nanomaterials. The Cu nanowires preferred the formation of C2H4, while the Cu nanoneedles favored the production of more CH4, rather than C2H4. Our work provides a facile synthetic strategy for preparing Cu-based nanomaterials to achieve selective CO2 reduction.  相似文献   

3.
• Separate reduction and sintering cannot be effective for Cr stabilization. • Combined treatment of reduction and sintering is effective for Cr stabilization. • Almost all the Cr in the reduced soil is residual form after sintering at 1000°C. This study explored the effectiveness and mechanisms of high temperature sintering following pre-reduction with ferric sulfate (FeSO4), sodium sulfide (Na2S), or citric acid (C6H8O7) in stabilizing hexavalent chromium (Cr(VI)) in highly contaminated soil. The soil samples had an initial total Cr leaching of 1768.83 mg/L, and Cr(VI) leaching of 1745.13 mg/L. When FeSO4 or C6H8O7 reduction was followed by sintering at 1000°C, the Cr leaching was reduced enough to meet the Safety Landfill Standards regarding general industrial solid waste. This combined treatment greatly improved the stabilization efficiency of chromium because the reduction of Cr(VI) into Cr(III) decreased the mobility of chromium and made it more easily encapsulated in minerals during sintering. SEM, XRD, TG-DSC, and speciation analysis indicated that when the sintering temperature reached 1000°C, almost all the chromium in soils that had the pre-reduction treatment was transformed into the residual form. At 1000°C, the soil melted and promoted the mineralization of Cr and the formation of new Cr-containing compounds, which significantly decreased subsequent leaching of chromium from the soil. However, without reduction treatment, chromium continued to leach from the soil even after being sintered at 1000°C, possibly because the soil did not fully fuse and because Cr(VI) does not bind with soil as easily as Cr(III).  相似文献   

4.
以硝普钠(Sodium nitroprusside,SNP)为一氧化氮(Nitric oxide,NO)供体研究了NO对海洋微藻生长的影响.对不同浓度SNP在海水介质中释放NO的过程进行了监测;对所培养的亚心形扁藻(Platymonas subcordiformis)和中肋骨条藻(Skeletonema costatum)进行藻密度测定,观测NO对微藻生长的影响.结果表明:5、10和100μmol·L-1的SNP释放NO浓度大约分别为6×10-9、9×10-9和2×10-7mol·L-1左右,而释放时间分别为4、5.5和7.5h.研究表明,NO对不同微藻有明显不同的作用规律:NO持续作用下,对亚心形扁藻的最佳作用浓度在10-8mol·L-1数量级;对赤潮藻中肋骨条藻的最佳作用浓度在10-9mol·L-1数量级;赤潮藻对NO的响应比非赤潮藻更灵敏,NO可能是海洋生态系中微藻生长重要的调节因子.  相似文献   

5.
以萝卜为受体,采用培养皿法比较研究了几种菊科入侵种和非入侵种的化感潜力。结果表明:入侵种和非入侵种都具有化感作用,且入侵种在高浓度下的化感抑制作用强度不一定都大于非入侵种。在0.2 g.mL-1浓度时,艾蒿和黄鹌菜的综合化感作用强度分别是小飞蓬的2.5和3.1倍;而紫茎泽兰和银胶菊则是小飞蓬的3.8和3.5倍。而不同植物浸提液对萝卜的不同检测指标影响不同。其中,紫茎泽兰对萝卜种子发芽和幼苗生长的影响主要表现为化感抑制作用。银胶菊和除0.025 g.mL-1外的黄鹌菜各浸提液都使萝卜种子萌发受较强的抑制,且抑制强度随浸提液浓度的升高而增大,而对幼苗生长则表现为"低促高抑"的规律。小飞蓬和苦荬菜对萝卜种子萌发和幼苗根长为抑制作用,但对其苗高和鲜质量为促进作用。除0.025 g.mL-1外,艾蒿对萝卜种子萌发和幼苗根长有较强的抵制,对其苗高和鲜质量则呈"低促高抑"的规律。  相似文献   

6.
● Fe3O4 NPs increased the biomass and chlorophyll content of hemp clones. ● Fe3O4 NPs penetrated and were internalized by root cells. ● Fe3O4 NPs induced the alteration of metabolite profiles in hemp leaves. ● The psychoactive compound THC in hemp leaves was significantly down-regulated. We investigated the effect of iron oxide nanoparticles (Fe3O4 NPs, ~17 nm in size) on the phenotype and metabolite changes in hemp (Cannabis sativa L.), an annual crop distributed worldwide. Hemp clones were grown in hydroponic cultures with Fe3O4 NPs (50, 100, 200, or 500 mg/L) for four weeks. TEM and ICP-MS were used to determine Fe3O4 NPs uptake and translocation. LC-MS-based metabolomics was employed to explore the deep insight into the effect of Fe3O4 NPs on hemp plants. The results revealed that plant growth enhanced gradually with increasing concentrations of given NPs up to 200 mg/L, which improved the fresh weight and dry weight by 36.13% and 74.68%, respectively, compared to the control. Even at a high dose (500 mg/L), Fe3O4 NPs promoted plant growth, including increased biomass and tissue length. NPs significantly increased the iron and chlorophyll content in plant tissues Increased catalase activity and reduced hydrogen peroxide content in hemp leaves suggested that the Fe3O4 NPs activated the defense system. TEM showed that NPs were abundantly attached to the cell wall and dispersed throughout the root cells. Metabolomics revealed that Fe3O4 NPs induced metabolic reprogramming in hemp leaves, including the up-regulation of carbohydrates and organic acids, and down-regulation of antioxidants, especially tetrahydrocannabinol (THC). The significantly up-regulated metabolites, including peonidin and 2-hydroxycinnamic acid, could be involved in photosynthesis in hemp plants. These results demonstrate the potential of Fe3O4 NPs for promoting hemp growth and decreasing the THC content at low doses.  相似文献   

7.
Toxic antifouling chemicals released into the seawaters leads to marine environmental degradation. In order to identify a nontoxic antifoulant, an assessment of antifouling (AF) efficacy of some AF candidates was made at Ayagin harbor, east coast of South Korea. In this static panel study conducted during October 2000-March 2001, some commercial antifoulants, seaweed and seagrass extracts were screened. On panel surfaces coated with a seaweed extract, Ishige okamurae exhibited effective AF activity. Ulva pertusa was encountered as a 'monospecific' fouler with fairly high fouling coverage on many of the test panel surfaces. In recent years the increased influx of inorganic pollutants in the coastal waters causes exorbitant growth of fouling marine algae found all along the Korean peninsula. Especially, a cosmopolitan ship fouling alga U. pertusa occur with high abundance. It was largely suggested that the proposed international ban on the toxic antifoulant tributyltin (TBT) had significant effect on the 'green tide' phenomenon occurring in different parts of the world. However, it appears that Korean scenario of 'green tide' is a localized. Antifouling efficacy of some AF coatings and fouling coverage of a green tide alga, U. pertusa are discussed.  相似文献   

8.
• BiVO4/Fe3O4/rGO has excellent photocatalytic activity under solar light radiation. • It can be easily separated and collected from water in an external magnetic field. • BiVO4/Fe3O4/0.5% rGO exhibited the highest RhB removal efficiency of over 99%. • Hole (h+) and superoxide radical (O2) dominate RhB photo-decomposition process. • The reusability of this composite was confirmed by five successive recycling runs. Fabrication of easily recyclable photocatalyst with excellent photocatalytic activity for degradation of organic pollutants in wastewater is highly desirable for practical application. In this study, a novel ternary magnetic photocatalyst BiVO4/Fe3O4/reduced graphene oxide (BiVO4/Fe3O4/rGO) was synthesized via a facile hydrothermal strategy. The BiVO4/Fe3O4 with 0.5 wt% of rGO (BiVO4/Fe3O4/0.5% rGO) exhibited superior activity, degrading greater than 99% Rhodamine B (RhB) after 120 min solar light radiation. The surface morphology and chemical composition of BiVO4/Fe3O4/rGO were studied by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV–visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. The free radicals scavenging experiments demonstrated that hole (h+) and superoxide radical (O2) were the dominant species for RhB degradation over BiVO4/Fe3O4/rGO under solar light. The reusability of this composite catalyst was also investigated after five successive runs under an external magnetic field. The BiVO4/Fe3O4/rGO composite was easily separated, and the recycled catalyst retained high photocatalytic activity. This study demonstrates that catalyst BiVO4/Fe3O4/rGO possessed high dye removal efficiency in water treatment with excellent recyclability from water after use. The current study provides a possibility for more practical and sustainable photocatalytic process.  相似文献   

9.
利用开放式空气CO2浓度升高(free air carbon-dioxide enrichment,FACE)平台中的水培试验,研究了低氮(LN:10 mg·L-1)和高氮(HN:30 mg·L-1)水平下,大气CO2浓度升高对化感与非化感水稻(Oryza sativa L.)品种的生长、碳氮比(C/N)和化感物质含量的影响,并分析了CO2浓度升高条件下水稻C/N和化感物质含量间的相互关系.结果表明:CO2浓度升高对化感(PI)与非化感水稻品种(秀水)的生长均有极显著促进作用.CO2浓度升高后,LN条件下水稻C/N显著增加,HN条件下则无显著变化.CO2浓度升高后化感水稻品种次生代谢物质含量增加,特征化感物质含量增加,非化感品种的这种变化不显著.化感水稻品种C/N分别与次生代谢物质含量和特征化感物质含量之间呈显著正相关关系.  相似文献   

10.
In recent years, industrial pollutants and the mountain forest fire ashes released into seawater cause damage to the marine environment, mainly it reduces the algal productivity in the inter tidal region. To get recover from the stress due to pollutants and to increase the growth and development of biofouling algae (benthic organisms), Ecklonia cava extract was investigated for its biofouling attracting efficiency. Bioactive guided fractions of E. cava extract derived from column chromatography were tested against spore attachment of a fouling alga, Ulva pertusa. Fraction B showed increased spore attachment rate with a maximum of 92 +/- 5%. This fraction was further analysed on HPLC, GC-Mass and NMR, deduced as pentadecanoic acid.  相似文献   

11.
• UV/O3 process had higher TAIC mineralization rate than O3 process. • Four possible degradation pathways were proposed during TAIC degradation. • pH impacted oxidation processes with pH of 9 achieving maximum efficiency. • CO32– negatively impacted TAIC degradation while HCO3 not. • Cl can be radicals scavenger only at high concentration (over 500 mg/L Cl). Triallyl isocyanurate (TAIC, C12H15N3O3) has featured in wastewater treatment as a refractory organic compound due to the significant production capability and negative environmental impact. TAIC degradation was enhanced when an ozone(O3)/ultraviolet(UV) process was applied compared with the application of an independent O3 process. Although 99% of TAIC could be degraded in 5 min during both processes, the O3/UV process had a 70%mineralization rate that was much higher than that of the independent O3 process (9%) in 30 min. Four possible degradation pathways were proposed based on the organic compounds of intermediate products identified during TAIC degradation through the application of independent O3 and O3/UV processes. pH impacted both the direct and indirect oxidation processes. Acidic and alkaline conditions preferred direct and indirect reactions respectively, with a pH of 9 achieving maximum Total Organic Carbon (TOC) removal. Both CO32– and HCO3 decreased TOC removal, however only CO32– negatively impacted TAIC degradation. Effects of Cl as a radical scavenger became more marked only at high concentrations (over 500 mg/L Cl). Particulate and suspended matter could hinder the transmission of ultraviolet light and reduce the production of HO· accordingly.  相似文献   

12.
Chemical looping combustion is a promising technology for energy conversion due to its low-carbon, high-efficiency, and environmental-friendly feature. A vital issue for CLC process is the development of oxygen carrier, since it must have sufficient reactivity. The mechanism and kinetics of CO reduction on iron-based oxygen carriers namely pure Fe2O3 and Fe2O3 supported by alumina (Fe2O3/Al2O3) were investigated using thermo-gravimetric analysis. Fe2O3/Al2O3 showed better reactivity over bare Fe2O3 toward CO reduction. This was well supported by the observed higher rate constant for Fe2O3/Al2O3 over pure Fe2O3 with respective activation energy of 41.1±2.0 and 33.3±0.8 kJ·mol−1. The proposed models were compared via statistical approach comprising Akaike information criterion with correction coupled with F-test. The phase-boundary reaction and diffusion control models approximated to 95% confidence level along with scanning electron microscopy results; revealed the promising reduction reactions of pure Fe2O3 and Fe2O3/Al2O3. The boosting recital of iron-based oxygen carrier support toward efficient chemical looping combustion could be explained accurately through the present study.  相似文献   

13.
● N2H4 addition enhanced and recovered anammox performance under Cr(VI) stress. ● N2H4 accelerated electron transfer of Cr(VI) reduction for detoxification. ● N2H4 enhanced anammox metabolism for activity recovery from Cr(VI) inhibition. ● Extracellular Cr(VI) reduction to less toxic Cr(III) was the dominant mechanism. The hexavalent chromium (Cr(VI)) would frequently impose inhibition to anaerobic ammonium oxidation (anammox) process, hindering the efficiency of nitrogen removal in wastewater treatment. Hydrazine (N2H4), which is an intermediate product of anammox, participates in intracellular metabolism and extracellular Cr(VI) reduction. However, the roles of N2H4-induced intracellular metabolism and extracellular reduction in nitrogen removal under Cr(VI) stress remain unclear. The addition of 3.67 mg/L of N2H4 increased the anammox activity by 17%. As an intermediate, N2H4 enhanced anammox metabolism by increasing the heme c content and electron transfer system activity. As a reductant, N2H4 accelerated the reduction of c-Cyts-mediated extracellular Cr(VI) to the less toxic Cr(III). Extracellular Cr(III) accounts for 74% of the total Cr in a Cr(VI)-stressed anammox consortia. These findings highlight that N2H4-induced extracellular Cr(VI) reduction is the dominant mechanism for the survival of anammox consortia. We also found that N2H4 increased the production of extracellular polymeric substances to sequester excessive Cr(VI) and produced Cr(III). Taken together, the study findings suggest a potential strategy for enhancing nitrogen removal from ammonium-rich wastewater contaminated with Cr(VI).  相似文献   

14.
MC-LR removal performances under different AOPs were compared systematically. Higher removal efficiency and synergistic effects were obtained by combined process. The acute biotoxicity raised in different degrees after oxidation. Microcystin-LR attracts attention due to its high toxicity, high concentration and high frequency. The removal characteristics of UV/H2O2 and O3/H2O2 advanced oxidation processes and their individual process for MC-LR were investigated and compared in this study. Both the removal efficiencies and rates of MC-LR as well as the biotoxicity of degradation products was analyzed. Results showed that the UV/H2O2 process and O3/H2O2 were effective methods to remove MC-LR from water, and they two performed better than UV-, O3-, H2O2-alone processes under the same conditions. The effects of UV intensity, H2O2 concentration and O3 concentration on the removal performance were explored. The synergistic effects between UV and H2O2, O3 and H2O2 were observed. UV dosage of 1800 mJ·cm2 was required to remove 90% of 100 mg·L1 MC-LR, which amount significantly decreased to 500 mJ·cm2 when 1.7 mg·L1 H2O2 was added. 0.25 mg·L1 O3, or 0.125 mg·L1 O3 with 1.7 mg·L1 H2O2 was needed to reach 90% removal efficiency. Furthermore, the biotoxicity results about these UV/H2O2, O3/H2O2 and O3-alone processes all present rising trends with oxidation degree of MC-LR. Biotoxicity of solution, equivalent to 0.01 mg·L1 Zn2+, raised to 0.05 mg·L1 Zn2+ after UV/H2O2 or O3/H2O2 reaction. This phenomenon may be attributed to the aldehydes and ketones with small molecular weight generated during reaction. Advice about the selection of MC-LR removal methods in real cases was provided.  相似文献   

15.
采用过硫酸钠(PDS)直接氧化和催化活化氧化脱色罗丹明B(RhB),分别考察了PDS剂量、pH、催化剂、Cl-浓度对RhB脱色的影响.结果表明,PDS在无外加催化剂下能够有效脱色RhB,pH越低,脱色率越高;当pH 2.4,PDS用量为3.5 g·L-1,在120 min内RhB的脱色率可达92%;自由基淬灭实验表明,酸性条件下主要为PDS直接氧化脱色RhB,并存在小部分硫酸根自由基(SO44·-)作用.在pH 5.6、pH 8.0条件下,外加活性炭纤维(ACF)、四氧化三铁(Fe3O44)、Fe3O44负载型催化剂(ACF/Fe3O44)可促进PDS对RhB脱色;在pH 2.4条件下,外加ACF对RhB脱色的促进作用较小,Fe3O44、ACF/Fe3O44对RhB脱色有一定抑制作用.不同pH和催化剂处理下,低浓度Cl-(0.01、0.04 mO4l·L-1)对RhB脱色速率都呈现抑制作用,高浓度Cl-(0.08 mO4l·L-1)相对于低浓度Cl-处理都呈促进作用.不同浓度Cl-处理在反应前60 min RhB脱色速率差异较大,而反应120 min后脱色率差异较小.提出Cl-通过调控SO44·-脱色RhB途径来影响RhB脱色速率的机理,Cl-竞争消耗SO44·-降低RhB脱色速率,但经一系列反应生成的Cl2·-能与RhB快速反应而提高RhB脱色速率;Cl-对RhB的脱色反应速率的影响存在抑制-促进双重机制,且与Cl-浓度相关.研究结果为基于PDS直接氧化和催化氧化处理含盐染料废水的研究和应用提供了一定的理论依据.  相似文献   

16.
Aqueous solutions of phenol were oxidized by hydrogen peroxide assisted by microwave (MW) irradiation. A simple kinetic model for the overall degradation of phenol in the presence of excess H2O2 is proposed in which the degradation rate of phenol is expressed as a linear function of the concentrations of phenol and H2O2. A detailed parametric study showed that the degradation rate of phenol increased with increasing [H2O2] until saturation was observed. Phenol degradation followed apparent zero-order kinetics under MW radiation or H2O2 oxidation. However, after 90 min of irradiation, the observed kinetics shifted to pseudo first order. The overall reaction rates were significantly enhanced in the combined MW/H2O2 system, mainly because microwave could accelerate H2O2 to generate hydroxyl radical (·OH) and other reactive oxygen intermediates. The observed synergetic effects of the MW/H2O2 process resulted in an increased in the net reaction rate by a factor of 5.75. When hydrogen peroxide is present in a large stoichiometric excess, the time required to achieve complete mineralization is reduced significantly.  相似文献   

17.
• Size and shape-dependent MnFe2O4 NPs were prepared via a facile method. • Ligand-exchange chemistry was used to prepare the hydrophilic MnFe2O4 NPs. • The catalytic properties of MnFe2O4 NPs toward dye degradation were fully studied. • The catalytic activities of MnFe2O4 NPs followed Michaelis–Menten behavior. • All the MnFe2O4 NPs exhibit selective degradation to different dyes. The magnetic nanoparticles that are easy to recycle have tremendous potential as a suitable catalyst for environmental toxic dye pollutant degradation. Rationally engineering shapes and tailoring the size of nanocatalysts are regarded as an effective manner for enhancing performances. Herein, we successfully synthesized three kinds of MnFe2O4 NPs with distinctive sizes and shapes as catalysts for reductive degradation of methylene blue, rhodamine 6G, rhodamine B, and methylene orange. It was found that the catalytic activities were dependent on the size and shape of the MnFe2O4 NPs and highly related to the surface-to-volume ratio and atom arrangements. Besides, all these nanocatalysts exhibit selectivity to different organic dyes, which is beneficial for their practical application in dye pollutant treatment. Furthermore, the MnFe2O4 NPs could be readily recovered by a magnet and reused more than ten times without appreciable loss of activity. The size and shape effects of MnFe2O4 nanoparticles demonstrated in this work not only accelerate further understanding the nature of nanocatalysts but also contribute to the precise design of nanoparticles catalyst for pollutant degradation.  相似文献   

18.
• Strong metal-support interaction exists on Pt/Fe3O4 catalysts. • Pt metal particles facilitate the formation of oxygen vacancies on Fe3O4. • Fe3O4 supports enhance the strength of CO adsorption on Pt metal particles. The self-inhibition behavior due to CO poisoning on Pt metal particles strongly impairs the performance of CO oxidation. It is an effective method to use reducible metal oxides for supporting Pt metal particles to avoid self-inhibition and to improve catalytic performance. In this work, we used in situ reductions of chloroplatinic acid on commercial Fe3O4 powder to prepare heterogeneous-structured Pt/Fe3O4 catalysts in the solution of ethylene glycol. The heterogeneous Pt/Fe3O4 catalysts achieved a better catalytic performance of CO oxidation compared with the Fe3O4 powder. The temperatures of 50% and 90% CO conversion were achieved above 260°C and 290°C at Pt/Fe3O4, respectively. However, they are accomplished on Fe3O4 at temperatures higher than 310°C. XRD, XPS, and H2-TPR results confirmed that the metallic Pt atoms have a strong synergistic interaction with the Fe3O4 supports. TGA results and transient DRIFTS results proved that the Pt metal particles facilitate the release of lattice oxygen and the formation of oxygen vacancies on Fe3O4. The combined results of O2-TPD and DRIFTS indicated that the activation step of oxygen molecules at surface oxygen vacancies could potentially be the rate-determining step of the catalytic CO oxidation at Pt/Fe3O4 catalysts. The reaction pathway involves a Pt-assisted Mars-van Krevelen (MvK) mechanism.  相似文献   

19.
● Appreciable H2O2 production rate was achieved in MRCs utilizing NH4HCO3 solutions. ● Carbon black outperformed activated carbon as the catalyst for H2O2 production. ● The optimum carbon black loading for H2O2 production on air-cathode was 10 mg/cm2. ● The optimum number of cell pairs was determined to be three. ● A maximum power density of 980 mW/m2 was produced by MRCs with 5 cell pairs. H2O2 was produced at an appreciable rate in microbial reverse-electrodialysis cells (MRCs) coupled with thermolytic solutions, which can simultaneously capture waste heat as electrical energy. To determine the optimal cathode and membrane stack configurations for H2O2 production, different catalysts, catalyst loadings and numbers of membrane cell pairs were tested. Carbon black (CB) outperformed activated carbon (AC) for H2O2 production, although AC showed higher catalytic activity for oxygen reduction. The optimum CB loading was 10 mg/cm2 in terms of both the H2O2 production rate and power production. The optimum number of cell pairs was determined to be three based on a tradeoff between H2O2 production and capital costs. A H2O2 production rate as high as 0.99 ± 0.10 mmol/(L·h) was achieved with 10 mg/cm2 CB loading and 3 cell pairs, where the H2O2 recovery efficiency was 52 ± 2% and the maximum power density was 780 ± 37 mW/m2. Increasing the number of cell pairs to five resulted in an increase in maximum power density (980 ± 21 mW/m2) but showed limited effects on H2O2 production. These results indicated that MRCs can be an efficient method for sustainable H2O2 production.  相似文献   

20.
• Gas diffusion electrode (GDE) is a suitable setup for practical water treatment. • Electrochemical H2O2 production is an economically competitive technology. • High current efficiency of H2O2 production was obtained with GDE at 5–400 mA/cm2. • GDE maintained high stability for H2O2 production for ~1000 h. • Electro-generation of H2O2 enhances ibuprofen removal in an E-peroxone process. This study evaluated the feasibility of electrochemical hydrogen peroxide (H2O2) production with gas diffusion electrode (GDE) for decentralized water treatment. Carbon black-polytetrafluoroethylene GDEs were prepared and tested in a continuous flow electrochemical cell for H2O2 production from oxygen reduction. Results showed that because of the effective oxygen transfer in GDEs, the electrode maintained high apparent current efficiencies (ACEs,>80%) for H2O2 production over a wide current density range of 5–400 mA/cm2, and H2O2 production rates as high as ~202 mg/h/cm2 could be obtained. Long-term stability test showed that the GDE maintained high ACEs (>85%) and low energy consumption (<10 kWh/kg H2O2) for H2O2 production for 42 d (~1000 h). However, the ACEs then decreased to ~70% in the following 4 days because water flooding of GDE pores considerably impeded oxygen transport at the late stage of the trial. Based on an electrode lifetime of 46 days, the overall cost for H2O2 production was estimated to be ~0.88 $/kg H2O2, including an electricity cost of 0.61 $/kg and an electrode capital cost of 0.27 $/kg. With a 9 cm2 GDE and 40 mA/cm2 current density, ~2–4 mg/L of H2O2 could be produced on site for the electro-peroxone treatment of a 1.2 m3/d groundwater flow, which considerably enhanced ibuprofen abatement compared with ozonation alone (~43%–59% vs. 7%). These findings suggest that electrochemical H2O2 production with GDEs holds great promise for the development of compact treatment technologies for decentralized water treatment at a household and community level.  相似文献   

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