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1.
Small ; 20(28): e2311713, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38326098

ABSTRACT

The discovery of non-precious catalysts for replacing the precious metal of ruthenium in the oxygen evolution reaction (OER) represents a key step in reducing the cost of green hydrogen production. The 2D d-MHOFs, a new 2D materials with controllable oxygen vacancies formed by controlling the degree of coordination bridging between metal hydroxyl oxide and BDC ligands are synthesized at room temperature, exhibit excellent OER properties with low overpotentials of 207  mV at 10 mA cm-2. High-resolution transmission electron microscopy images and density functional theory calculations demonstrate that the introduction of oxygen vacancy sites leads to a lattice distortion and charge redistribution in the catalysts, enhancing the OER activity of 2D d-MHOFs comprehensively. Synchrotron radiation and in situ Raman/Fourier transform infrared spectroscopy indicate that part of oxygen defect sites on the surface of 2D d-MHOFs are prone to transition to highly active metal hydroxyl oxides during the OER process. This work provides a mild strategy for scalable preparation of 2D d-MHOFs nanosheets with controllable oxygen defects, reveals the relationship between oxygen vacancies and OER performance, and offers a profound insight into the basic process of structural transformation in the OER process.

2.
Molecules ; 29(12)2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38930794

ABSTRACT

This paper investigates the combustion characteristics and pollutant emission patterns of the mixed combustion of lignite (L) and torrefied pine wood (TPW) under different blending ratios. Isothermal combustion experiments were conducted in a fixed bed reaction system at 800 °C, and pollutant emission concentrations were measured using a flue gas analyzer. Using scanning electron microscopy (SEM) and BET (nitrogen adsorption) experiments, it was found that torrefied pine wood (TPW) has a larger specific surface area and a more developed pore structure, which can facilitate more complete combustion of the sample. The results of the non-isothermal thermogravimetric analysis show that with the TPW blending ratio increase, the entire combustion process advances, and the ignition temperature, maximum peak temperature, and burnout temperature all show a decreasing trend. The kinetic equations of the combustion reaction process of mixed gas were calculated by Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) kinetic equations. The results show that the blending of TPW reduces the activation energy of the combustion reaction of the mixed fuel. When the TPW blending ratio is 80%, the activation energy values of the mixed fuel are the lowest at 111.32 kJ/mol and 104.87 kJ/mol. The abundant alkali metal ions and porous structure in TPW reduce the conversion rates of N and S elements in the fuel to NO and SO2, thus reducing the pollutant emissions from the mixed fuel.

3.
J Environ Sci (China) ; 141: 26-39, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38408826

ABSTRACT

Shaerhu (SEH) coal is abundant in Xinjiang, China. The utilization of SEH suffers from severe ash deposition, slagging, and fouling problems due to its high-chlorine-alkaline characteristics. The co-combustion of high-alkaline coal and other type coals containing high Si/Al oxides has been proven to be a simple and effective method that will alleviate ash-related problems, but the risk of heavy metals (HMs) contamination in this process is nonnegligible. Hence, the volatilization rates and chemical speciation of Pb, Cu, and Zn in co-combusting SEH and a high Si/Al oxides coal, i.e., Yuanbaoshan (YBS) coal were investigated in this study. The results showed that the addition of SEH increased the volatilization rates of Pb, Cu, and Zn during the co-combustion at 800°C from 23.70%, 23.97%, and 34.98% to 82.31%, 30.01%, and 44.03%, respectively, and promoted the extractable state of Cu and Zn. In addition, the interaction between SEH and YBS inhibited the formation of the Pb residue state. SEM-EDS mapping results showed that compared to Zn and Cu, the signal intensity of Pb was extremely weak in regions where some of the Si and Al signal distributions overlap. The DFT results indicated that the O atoms of the metakaolin (Al2O3⋅2SiO2) (001) surface were better bound to the Zn and Cu than Pb atoms after adsorption of the chlorinated HMs. These results contribute to a better understanding of the effects of high-alkaline coal blending combustion on Pb, Cu, and Zn migration and transformation.


Subject(s)
Chlorine , Metals, Heavy , Chlorine/chemistry , Lead , Incineration , Coal Ash/chemistry , Coal , Metals, Heavy/chemistry , Oxides , Zinc
4.
Langmuir ; 39(22): 7566-7577, 2023 Jun 06.
Article in English | MEDLINE | ID: mdl-37078889

ABSTRACT

This study was to develop a low-cost N-doped porous biocarbon adsorbent that can directly adsorb CO2 in high-temperature flue gas from fossil fuel combustion. The porous biocarbon was prepared by nitrogen doping and nitrogen-oxygen codoping through K2CO3 activation. Results showed that these samples exhibited a high specific surface area of 1209-2307 m2/g with a pore volume of 0.492-0.868 cm3/g and a nitrogen content of 0.41-3.3 wt %. The optimized sample CNNK-1 exhibited a high adsorption capacity of 1.30 and 0.27 mmol/g in the simulated flue gas (14.4 vol % CO2 + 85.6 vol % N2) and a high CO2/N2 selectivity of 80 and 20 at 25 and 100 °C and 1 bar, respectively. Studies revealed that too many microporous pores could hinder CO2 diffusion and adsorption due to the decrease of CO2 partial pressure and thermodynamic driving force in the simulated flue gas. The CO2 adsorption of the samples was mainly chemical adsorption at 100 °C, which depended on the surface nitrogen functional groups. Nitrogen functional groups (pyridinic-N and primary and secondary amines) reacted chemically with CO2 to produce graphitic-N, pyrrolic-like structures, and carboxyl functional groups (-N-COOH). Nitrogen and oxygen codoping increased the amount of nitrogen doping content in the sample, but acidic oxygen functional groups (carboxyl groups, lactones, and phenols) were introduced, which weakened the acid-base interactions between the sample and CO2 molecules. It was demonstrated that SO2 and water vapor had inhibition effects on CO2 adsorption, while NO nearly has no effect on the complex flue gas. Cyclic regenerative adsorption showed that CNNK-1 possessed excellent regeneration and stabilization ability in complex flue gases, indicating that corncob-derived biocarbon had excellent CO2 adsorption in high-temperature flue gas.

5.
J Environ Manage ; 326(Pt B): 116735, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36402021

ABSTRACT

The effect of sediment and residual fish feed on aquaculture water bodies has gained increasing attention to alleviate the eutrophication and heavy metals enrichment induced by aquaculture. Thus, this study intended to reveal the possible interactions among nutrients, heavy metals, and Chlorella vulgaris (C. vulgaris) in aquaculture water bodies containing fish feed and sediment. The analyses showed that consistent with the composition of heavy metals in fish feed, manganese (Mn) and zinc (Zn) accounted for the highest proportions (68-78%) of heavy metals in sediment. Meanwhile, sediment in the centre of aquaculture water bodies (S2) contained more heavy metals than those in the perimeter (S1), but the released concentrations and rates (Rrelease) of heavy metals from S1 were higher than those from S2. Moreover, the biomass, growth rate, specific growth rate, and nitrogen and carbon fixation rate of C. vulgaris increased with adding fish feed, whereas superoxide dismutase (SOD) and malondialdehyde (MDA) decreased. In addition, with C. vulgaris, influenced by the release process from sediment and the uptake by C. vulgaris, the concentration and Rrelease of Mn, Pb, Cu, Mn, Cr and Cd from sediments coexisting with fish feed in water first increased and then decreased in general. The C. vulgaris biomass was significantly negatively related to Mn, Pb, Cu, Ni, Cr, and Cd and PO43-P (P < 0.05), which was caused by the uptake of C. vulgaris and indicated that C. vulgaris biomass is easily affected by these factors. Accordingly, the input of residual fish feed and sediment should be controlled.


Subject(s)
Chlorella vulgaris , Metals, Heavy , Water Pollutants, Chemical , Animals , Geologic Sediments/analysis , Environmental Monitoring , Water Pollutants, Chemical/analysis , Ecosystem , Cadmium/analysis , Lead/analysis , Metals, Heavy/analysis , Aquaculture , Fishes , Water/analysis , Manganese/analysis , Nutrients , Risk Assessment
6.
Molecules ; 28(17)2023 Aug 22.
Article in English | MEDLINE | ID: mdl-37687016

ABSTRACT

To promote the practical application of TiO2 in photocatalytic toluene oxidation, the honeycomb aluminum plates were selected as the metal substrate for the loading of TiO2 powder. Surface-etching treatment was performed and titanium tetrachloride was selected as the binder to strengthen the loading stability. The loading stability and photocatalytic activity of the monolithic catalyst were further investigated, and the optimal surface treatment scheme (acid etching with 15.0 wt.% HNO3 solution for 15 min impregnation) was proposed. Therein, the optimal monolithic catalyst could achieve the loading efficiency of 42.4% and toluene degradation efficiencies of 76.2%. The mechanism for the stable loading of TiO2 was revealed by experiment and DFT calculation. The high surface roughness of metal substrate and the strong chemisorption between TiO2 and TiCl4 accounted for the high loading efficiency and photocatalytic activity. This work provides the pioneering exploration for the practical application of TiO2 catalysts loaded on the surface of metal substrate for VOCs removal, which is of significance for the large-scaled application of photocatalytic technology.

7.
Molecules ; 28(12)2023 Jun 13.
Article in English | MEDLINE | ID: mdl-37375287

ABSTRACT

Wheat straw, a typical agricultural solid waste, was employed to clarify the effects of torrefaction on the structural features and combustion reactivity of biomass. Two typical torrefaction temperatures (543 K and 573 K), four atmospheres (argon, 6 vol.% O2, dry flue gas and raw flue gas) were selected. The elemental distribution, compositional variation, surface physicochemical structure and combustion reactivity of each sample were identified using elemental analysis, XPS, N2 adsorption, TGA and FOW methods. Oxidative torrefaction tended to optimize the fuel quality of biomass effectively, and the enhancement of torrefaction severity improved the fuel quality of wheat straw. The O2, CO2 and H2O in flue gas could synergistically enhance the desorption of hydrophilic structures during oxidative torrefaction process, especially at high temperatures. Meanwhile, the variations in microstructure of wheat straw promoted the conversion of N-A into edge nitrogen structures (N-5 and N-6), especially N-5, which is a precursor of HCN. Additionally, mild surface oxidation tended to promote the generation of some new oxygen-containing functionalities with high reactivity on the surface of wheat straw particles after undergoing oxidative torrefaction pretreatment. Due to the removal of hemicellulose and cellulose from wheat straw particles and the generation of new functional groups on the particle surfaces, the ignition temperature of each torrefied sample expressed an increasing tendency, while the Ea clearly decreased. According to the results obtained from this research, it could be concluded that torrefaction conducted in a raw flue gas atmosphere at 573 K would improve the fuel quality and reactivity of wheat straw most significantly.

8.
Molecules ; 28(21)2023 Oct 26.
Article in English | MEDLINE | ID: mdl-37959701

ABSTRACT

Pyrolysis and activation processes are important pathways to utilize residues after lipid extraction from microalgae in a high-value way. The obtained microalgae-based nitrogen-doped activated carbon has excellent electrochemical performance. It has the advantage of nitrogen self-doping using high elemental nitrogen in microalgae. In this study, two kinds of microalgae, Nanochloropsis and Chlorella, were used as feedstock for lipid extraction. The microalgae residue was firstly pyrolyzed at 500 °C to obtain biochar. Then, nitrogen-doped activated carbons were synthesized at an activation temperature of 700-900 °C with different ratios of biochar and KOH (1:1, 1:2, and 1:4). The obtained carbon materials presented rich nitrogen functional groups, including quaternary-N, pyridine-N-oxide, pyrrolic-N, and pyridinic-N. The nitrogen content of microalgae-based activated carbon material was up to 2.62%. The obtained materials had a specific surface area of up to 3186 m2/g and a pore volume in the range of 0.78-1.54 cm3/g. The microporous pore sizes of these materials were distributed at around 0.4 nm. Through electrochemical testing such as cyclic voltammetry and galvanostatic charge-discharge of materials, the materials exhibited good reversibility and high charge-discharge efficiency. The sample, sourced from microalgae Chlorella residue at activation conditions of 700 °C and biochar/KOH = 1:4, exhibited excellent endurance of 94.1% over 5000 cycles at 2 A/g. Its high specific capacitance was 432 F/g at 1 A/g.


Subject(s)
Chlorella , Microalgae , Charcoal , Nitrogen/chemistry , Pyrolysis , Lipids
9.
Langmuir ; 38(32): 9940-9954, 2022 Aug 16.
Article in English | MEDLINE | ID: mdl-35917436

ABSTRACT

The study of the effects of Na and K on the heterogeneous adsorption of hydroxyl-containing char with NO is important for the clean utilization of high alkali coal. In this paper, the effects of Na/K atoms on the adsorption of NO on the char surface were investigated at the GGA-PBE level by choosing zigzag type, armchair type, and saturated hydroxyl-containing char structures based on DFT. It was found that the adsorption stability of NO on structures with active sites was greater for sites close to the hydroxyl group than that for sites far from the hydroxyl group. The stability of char doped by Na/K is related to the char structure and the position of functional groups. The most stable Na/K doped structures are Z-OH-2 (Eads= -350.50 kJ/mol) and A-OH-1-2 (Eads= -339.17 kJ/mol), respectively. The participation of Na/K can increase the adsorption energy of the three structures with NO, and especially the adsorption energy of saturated char with NO is increased by as much as 5 times. The reason for that is the promotion of the hybridization of the C and NO p orbitals. The comprehensive analysis of electrostatic potential, charge transfer, and front orbitals indicates that the effects of decorated sodium and potassium atoms on the char surface are very similar. This study lays a theoretical foundation for the study of the heterogeneous reduction process.

10.
J Phys Chem A ; 126(36): 6148-6159, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-36040916

ABSTRACT

The effect mechanism of Na on reduction of NO with nitrogen-containing char, char(N) still lacks an in-depth study. Based on density functional theory, this study systematically discussed the heterogeneous reaction of NO with four char(N) models, that is, zigzag(N), zigzag(N)@Na, armchair(N), and armchair(N)@Na. Results show that the presence of Na promoted the chemisorption of NO on both zigzag(N) and armchair(N), especially zigzag(N). Mayer bond order analysis revealed that during NO reduction, Na catalyzed the breaking of N-O and C-N bonds in both models as well as dissociation of the N-N structure from the zigzag(N). Dynamics in the 300-1000 K range revealed that the rate constant for the decisive step increased in the order of zigzag(N) < zigzag(N)@Na < armchair(N) < armchair(N)@Na, while the activation energy presented a reverse order. The addition of Na promoted the electron transfer between NO and char(N) and exhibited an obvious catalytic effect on the NO-char(N) reaction by reducing activation energy and increasing the reaction rate constant for the decisive step.

11.
Environ Res ; 212(Pt B): 113300, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35427591

ABSTRACT

The resource utilization of spent alkaline Zn-Mn batteries (S-AZMB) has always been a hot issue in the field of energy regeneration and environmental protection. The cumbersome and complicated purification process is the reason for their limited recycling. Not long ago, we proved that unpurified S-AZMB can be used directly: construct a Z-scheme photocatalytic system by combining with commercial TiO2 through high-temperature calcination. In order for this finding to be truly adopted by the application market, the high energy consumption calcination process needs to be improved urgently. In this work, we explore the temperature dependence of performance for the composite photocatalyst (TiO2@S-AZMB). A series of experimental results confirm that lowering the calcination temperature not only conducive to improving the separation efficiency of photogenerated electron-hole pairs, but also can significantly improve the environmental adaptability of the catalyst. Specifically, the catalyst synthesized by calcination temperature at 200 °C exhibits higher toluene removal efficiency than that at 500 °C under different initial concentration of pollutants, relative humidity, light intensity and oxygen content. This study not only further improves the photocatalytic performance of the composite catalyst, but also accords with the idea of energy saving and emission reduction, which provides more space for the possibility of recycling S-AZMB.

12.
Environ Res ; 206: 112300, 2022 04 15.
Article in English | MEDLINE | ID: mdl-34736638

ABSTRACT

Derived from the biodrying of municipal organic wastes (MOWs), biodried products (BPs) are widely identified as renewable energy sources. In this study, for efficient energy recovery, the pyrolysis characteristics of BPs were investigated by comprehensive kinetic analysis, with special focus on the synergistic effect of bulking agents and the influence of biodegradation. Compared with theoretical raw materials (RMs), it was suggested that the synergistic effect of organics and lignocelluloses in RMs promoted decomposition in Stage 1 (400-570 K), especially for the pyrolysis of RM using sawdust, during which the positive effect achieved decomposition in advance with lower overlap ratio (0.9264) and ΔW (-9.50% at 619.0 K) values. Furthermore, compared with RMs, it was indicated that the kinetic indices (Ea and ln A values) of the BPs were upward in Stage 1 and decreased in Stage 2 due to biodegradation. The results of ΔH, ΔG and ΔS indicated that BP pyrolysis required more heat supply as the reaction progressed but formed a more organized activated complex. In addition, biodegradation observably decreased the generation of gas products and typical functional groups of volatiles during BP pyrolysis, such as CO2 and CO, which presented decreasing ratios of 32.18-42.47% and 30.25-46.47%, respectively. In general, the pyrolysis of BPs was intensified by bulking agents and modified by biodegradation.


Subject(s)
Pyrolysis , Sewage , Biodegradation, Environmental , Hot Temperature , Kinetics
13.
J Environ Manage ; 317: 115457, 2022 Sep 01.
Article in English | MEDLINE | ID: mdl-35751261

ABSTRACT

Selective catalytic reduction (SCR) technology is currently the most effective deNOx technology and has broad application prospects. Moreover, there is a large NOx content in marine engine exhaust. However, the marine engine SCR catalyst will be affected by heavy metals, SO2, H2O(g), hydrocarbons (HC) and particulate matter (PM) in the exhaust, which will hinder the removal of NOx via SCR. Furthermore, due to the high loading operation of the marine engine and the regeneration of the diesel particulate filter (DPF), the exhaust temperature of the engine may exceed 600 °C, which leads to sintering of the SCR catalysts. Therefore, the development of new catalysts with good tolerances to the above emissions and process parameters is of great significance for further reducing NOx from marine engines. In this work, we first elaborate on the mechanism of the SCR catalyst poisoning caused by marine engine emissions, as well as the working mechanism of SCR catalysts affected by the engine exhaust temperature. Second, we also summarize the current technologies for improving the properties of SCR catalysts with the aim of enhancing the resistance and stability under complex working conditions. Finally, the challenges and perspectives associated with the performance optimization and technology popularization of marine SCR systems are discussed and proposed further. Consequently, this review may provide a valuable reference and inspiration for the development of catalysts and improvement in the denitration ability of SCR systems matched with marine engines.


Subject(s)
Particulate Matter , Vehicle Emissions , Catalysis , Hydrocarbons , Vehicle Emissions/analysis
14.
J Environ Manage ; 316: 115211, 2022 Aug 15.
Article in English | MEDLINE | ID: mdl-35561491

ABSTRACT

Over the past decade, biochar-supported nZVI composites (nZVI/biochar) have been developed and applied to treat various pollutants due to their excellent physical and chemical properties, especially in the field of chromium (VI) removal. This paper reviewed the factors influencing the preparation and experiments of nZVI/biochar composites, optimization methods, column experimental studies and the mechanism of Cr(VI) removal. The results showed that the difference in raw materials and preparation temperature led to the difference in functional groups and electron transfer capabilities of nZVI/biochar materials. In the experimental process, pH and test temperature can affect the surface chemical properties of materials and involve the electron transfer efficiency. Elemental doping and microbial coupling can effectively improve the performance of nZVI/biochar composites. In conclusion, biochar can stabilize nZVI and enhance electron transfer in nZVI/biochar materials, enabling the composite materials to remove Cr(VI) efficiently. The study of column experiments provides a theoretical basis for applying nZVI/biochar composites in engineering. Finally, the future work prospects of nZVI/biochar composites for heavy metal removal are introduced, and the main challenges and further research directions are proposed.


Subject(s)
Soil , Water Pollutants, Chemical , Adsorption , Charcoal/chemistry , Chromium/chemistry , Iron/chemistry , Water/chemistry , Water Pollutants, Chemical/chemistry
15.
J Environ Manage ; 289: 112535, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-33895580

ABSTRACT

In comparison with various restaurant cuisines, common cooking methods are more represented in residential cooking. Rather than the exhaust pipe or the ambient environment in the cooking room, the respiration zone better reflects the health risks for operators. In this study, the concentrations of total volatile organic compound (TVOC) released from six typical cooking methods were monitored online in the respiratory zone, and the VOCs were analysed by GC-MS. The results demonstrated that the intensities of exposure to TVOC for the different cooking methods decreased as follows: stir-frying (3.809 mg/m3) > quick-frying (2.724 mg/m3) > deep-frying (2.465 mg/m3) > boiling (1.161 mg/m3)≈stewing (1.149 mg/m3) > limit in China (0.600 mg/m3) > steaming (0.440 mg/m3). The intense ventilation mode of the ventilator reduced exposure to TVOC by 45-63% relative to the medium mode. Eleven types of VOCs (approximately 200 compounds) were found in Chinese residential cooking fumes, and the predominant contaminants were aldehydes, followed by alkanes, unsaturated aldehydes, alcohols and alkenes. The mass percentage of aromatic hydrocarbons in all VOCs emitted from Chinese residential cooking was only 1%, while the value was 17-48% for commercial restaurants. The results of a health risk assessment revealed that the total potential carcinogenic risk level for VOCs released by six residential cooking methods decreased as follows: deep-frying (5.75) > stir-frying (3.95) > quick-frying (2.94) > stewing (1.99) > boiling (1.73) > steaming (1.48). Chinese residential cooking, and especially deep frying, has potential health impacts for the operator.


Subject(s)
Air Pollutants , Air Pollutants/analysis , China , Cooking , Environmental Monitoring , Risk Assessment
16.
J Environ Manage ; 284: 112070, 2021 Apr 15.
Article in English | MEDLINE | ID: mdl-33561760

ABSTRACT

Chlorella vulgaris (C. vulgaris) was promising microalgae to simultaneously achieve biomass production, carbon dioxide (CO2) fixation, nutrients removal and proteins production especially under different conditions of CO2 gas and wastewaters. Results presented that maximal specific growth rate of C. vulgaris was 0.21-0.35 d-1 and 0.33-0.43 d-1 at 0.038% and 10% CO2 respectively, and corresponding maximal CO2 fixation rate was attended with 4.51-14.26 and 56.26-85.72 mg CO2·L-1·d-1. C. vulgaris showed good wastewater removal efficiency of nitrogen and phosphorus at 10% CO2 with 96.12%-99.61% removal rates. Nitrogen fixation amount achieved 41.86 mg L-1 when the initial NH4Cl concentration was set at 60 mg L-1 at 10% CO2. Improved total protein (25.01-365.49 mg) and amino acids (24.56-196.44 mg) contents of C. vulgaris biomass was observed with the increasing of added CO2 and ammonium concentrations. Moreover, the developed kinetic function of C. vulgaris growth depends on both phosphorus quota and nitrogen quota with correlation coefficient (R2) ranged from 0.68 to 0.97. Computed maximal consumed nutrients concentrations (ΔCmax) based on Logistic function are positively related to initial NH4+-N concentrations, which indicated that adding ammonium could stimulate the utilization of both phosphorus and nitrogen.


Subject(s)
Chlorella vulgaris , Microalgae , Biomass , Carbon Dioxide , Nitrogen/analysis , Nutrients , Phosphorus , Wastewater
17.
J Environ Sci (China) ; 101: 49-71, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33334538

ABSTRACT

Due to the increasingly strict emission standards of NOx on various industries, many traditional flue gas treatment methods have been gradually improved. Except for selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) methods to remove NOx from flue gas, theoxidation method is paying more attention to NOx removal now because of the potential to simultaneously remove multiple pollutants from flue gas. This paper summarizes the efficiency, reaction conditions, effect factors, and reaction mechanism of NO oxidation from the aspects of liquid-phase oxidation, gas-phase oxidation, plasma technology, and catalytic oxidation. The effects of free radicals and active components of catalysts on NO oxidation and the combination of various oxidation methods are discussed in detail. The advantages and disadvantages of different oxidation methods are summarized, and the suggestions for future research on NO oxidation are put forward at the end. The review on the NO removal by oxidation methods can provide new ideas for future studies on the NO removal from flue gas.


Subject(s)
Air Pollutants , Mercury , Catalysis , Coal , Oxidation-Reduction
18.
J Environ Sci (China) ; 93: 66-90, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32446461

ABSTRACT

China's energy dependents on coal due to the abundance and low cost of coal. Coal provides a secure and stable energy source in China. Over-dependence on coal results in the emission of Hazardous Trace Elements (HTEs) including selenium (Se), mercury (Hg), lead (Pb), arsenic (As), etc., from Coal-Fired Power Plants (CFPPs), which are the major toxic air pollutants causing widespread concern. For this reason, it is essential to provide a succinct analysis of the main HTEs emission control techniques while concurrently identifying the research prospects framework and specifying future research directions. The study herein reviews various techniques applied in China for the selected HTEs emission control, including the technical, institutional, policy, and regulatory aspects. The specific areas covered in this study include health effects, future coal production and consumption, the current situation of HTEs in Chinese coal, the chemistry of selected HTEs, control techniques, policies, and action plans safeguarding the emission control. The review emphasizes the fact that China must establish and promote efficient and clean ways to utilize coal in order to realize sustainable development. The principal conclusion is that cleaning coal technologies and fuel substitution should be great potential HTEs control technologies in China. Future research should focus on the simultaneous removal of HTEs, PM, SOx, and NOx in the complex flue gas.


Subject(s)
Air Pollutants/analysis , Air Pollution , Trace Elements/analysis , China , Coal/analysis , Environmental Monitoring , Power Plants
19.
Med Sci Monit ; 23: 2189-2197, 2017 May 08.
Article in English | MEDLINE | ID: mdl-28481865

ABSTRACT

BACKGROUND Hydroxyethyl starch (HES) solutions are used for volume expansion during surgery. We aimed to investigate how 6%HES 130/0.4 affects hemostasis. MATERIAL AND METHODS Blood samples were collected from 12 healthy adult volunteers, diluting with 6%HES 130/0.4 (HES group) or Ringer lactate solution (RL control group). The hemodilution ratio (HR) of citrated blood volume to plasma substitute volume was 10: 0 (undiluted), 10: 2, 10: 4, and 10: 6. Clotting factors activity was measured. Thrombin generation was monitored. Platelet function was analyzed. RESULTS 1) Activity of coagulation factor was decreased with increasing HR compared to undiluted baseline, and the activity of FVIII was significantly decreased in HES vs. RL. 2) Calibrated automated thrombography (CAT) results showed HES extended lag time, time to peak (ttpeak), start tail, and decreased peak of thrombin generation. Although lag time and ttpeak were significantly prolonged in HES vs. RL, endogenous thrombin potential (ETP) did not change. 3) Flow cytometric (FCM) analysis showed that HES reduced platelet phospholipids serine (PS) vs. baseline and RL. 4) HES significantly decreased antithrombin activity (AT: A) of the anticoagulant system with increasing HR vs. baseline and RL. 5) For fibrinolytic system, HES did not affect fibrinogen degradation products (FDP) and D-dimers (D-D) vs. baseline, or α2-antiplasmin (α2-AP) vs. RL. CONCLUSIONS By reducing FVIII activity and platelet PS expression, HES interfered with PS combining to FXIa, FVIIIa, and FVa, which affected the acceleration and explosion stage of thrombin. The decreased velocity and peak of thrombin generation delays and reduces clot formation. Combined 6%HES 130/0.4 decreased anticoagulant activity and may have clinical utility.


Subject(s)
Hemodilution , Hemostasis/drug effects , Hydroxyethyl Starch Derivatives/pharmacology , Adult , Blood Coagulation/drug effects , Blood Platelets/metabolism , Calibration , Fibrinolysis/drug effects , Flow Cytometry , Humans , Isotonic Solutions/pharmacology , Middle Aged , Ringer's Lactate , Thrombin/pharmacology
20.
Water Sci Technol ; 73(8): 1848-54, 2016.
Article in English | MEDLINE | ID: mdl-27120639

ABSTRACT

Novel honeycomb-like carriers, made of polypropylene, were applied to enhance biomass retention capacity so as to improve Anammox start-up performance in a fixed bed reactor (FBR). The reactor was operated for 3 months. On day 45, Anammox activity appeared. After 61 days' operation, the removal efficiencies of ammonium and nitrite were both over 91% based on 70 mg N L(-1) of the influent ammonium and influent nitrite, indicating that a remarkable Anammox activity was attained. A final specific Anammox activity of 0.12 g NH4(+)-N gVSS(-1) d(-1) was reached (VSS: volatile suspended solids). The FBR showed a good capacity for resisting shock loading and was more able to resist shock loading of nitrogen concentration than resist hydraulic shock loading. Phylogenetic analysis showed that Candidatus Brocadia anammoxidans' and Candidatus Kuenenia stuttgartiensis' were detected in the mature biofilm, and Candidatus Brocadia anammoxidans' was the dominant Anammox strain. Candidatus Kuenenia stuttgartiensis' played a positive role in the reactor performance, as it could consumed nitrite quickly and efficiently so as to avoid an adverse effect of temporary nitrite accumulation. The results showed that the honeycomb-like carriers were suitable for start-up of Anammox.


Subject(s)
Ammonium Compounds/metabolism , Bacteria/metabolism , Bioreactors , Polypropylenes , Ammonium Compounds/chemistry , Anaerobiosis , Animals , Bacteria/classification , Biofilms , Biomass , Nitrites , Oxidation-Reduction , Waste Disposal, Fluid , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/metabolism
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