A water transfer printing method for contact lenses surface 2D MXene modification to resist bacterial infection and inflammation.

Contact lenses (CLs) are prone to adhesion and invasion by pollutants and pathogenic bacteria, leading to infection and inflammatory diseases. However, the functionalization of CL (biological functions such as anti-fouling, antibacterial, and anti-inflammatory) and maintaining its transparency still face great challenges. In this work, as a member of the MXenes family, vanadium carbide (V2C) is modified onto CL via a water transfer printing method after the formation of a tightly arranged uniform film at the water surface under the action of the Marangoni effect. The coating interface is stable owing to the electrostatic forces. The V2C-modified CL (V2C@CL) maintains optical clarity while providing good biocompatibility, strong antioxidant properties, and anti-inflammatory activities. In vitro antibacterial experiments indicate that V2C@CL shows excellent performance in bacterial anti-adhesion, sterilization, and anti-biofilm formation. Last, V2C@CL displays notable advantages of bacteria elimination and inflammation removal in infectious keratitis treatment.

An Antibiotic Nanobomb Constructed from pH-Responsive Chemical Bonds in Metal-Phenolic Network Nanoparticles for Biofilm Eradication and Corneal Ulcer Healing.

In the treatment of refractory corneal ulcers caused by Pseudomonas aeruginosa, antibacterial drugs delivery faces the drawbacks of low permeability and short ocular surface retention time. Hence, novel positively-charged modular nanoparticles (NPs) are developed to load tobramycin (TOB) through a one-step self-assembly method based on metal-phenolic network and Schiff base reaction using 3,4,5-trihydroxybenzaldehyde (THBA), ε-poly-ʟ-lysine (EPL), and Cu2+ as matrix components. In vitro antibacterial test demonstrates that THBA-Cu-TOB NPs exhibit efficient instantaneous sterilization owing to the rapid pH responsiveness to bacterial infections. Notably, only 2.6 µg mL-1 TOP is needed to eradicate P. aeruginosa biofilm in the nano-formed THBA-Cu-TOB owing to the greatly enhanced penetration, which is only 1.6% the concentration of free TOB (160 µg mL-1 ). In animal experiments, THBA-Cu-TOB NPs show significant advantages in ocular surface retention, corneal permeability, rapid sterilization, and inflammation elimination. Based on molecular biology analysis, the toll-like receptor 4 and nuclear factor kappa B signaling pathways are greatly downregulated as well as the reduction of inflammatory cytokines secretions. Such a simple and modular strategy in constructing nano-drug delivery platform offers a new idea for toxicity reduction, physiological barrier penetration, and intelligent drug delivery.

In Situ Construction of NiCoMn-LDH Derived from Zeolitic Imidazolate Framework on Eggshell-Like Carbon Skeleton for High-Performance Flexible Supercapacitors.

Active compounds based on LDH (ternary layered double hydroxide) are considered the perfect supercapacitor electrode materials on account of their superior electrochemical qualities and distinct structural characteristics, and flexible supercapacitors are an ideal option as an energy source for wearable electronics. However, the prevalent aggregation effect of LDH materials results in significantly compromised actual specific capacitance, which limits its broad practical applications. In this research, a 3D eggshell-like interconnected porous carbon (IPC) framework with confinement and isolation capability is designed and synthesized by using glucose as the carbon source to disperse the LDH active material and enhance the conductivity of the composite material. Second, by constructing NiCoMn-LDH nanocage structure based on ZIF-67 (zeolitic imidazolate framework-67) at the nanometer scale the obtained IPC/NiCoMn-LDH electrode material can expose more active sites, which allows to achieve excellent specific capacitance (2236 F g-1 / 310.6 mAh g-1 at 1 A g-1 ), good rate as well as the desired cycle stability (85.9% of the initial capacitance upon 5000 cycles test). The constructed IPC/NiCoMn-LDH//IPC ASC (asymmetric supercapacitor) exhibits superior capacitive property (135 F g-1 /60.1 mAh g-1 at 0.5 A g-1 ) as well as desired energy density (40 Wh kg-1 at 800 W kg-1 ).

A module classification method for light industrial equipment based on improved NSGA2-FCM algorithm.

In response to the problem that it is easy to fall into local optimum when using the traditional clustering algorithm to divide the modules, this paper improves the initialisation strategy of the NSGA2 algorithm and combines it with the FCM algorithm to propose an improved NSGA2-FCM algorithm for clustering analysis. Firstly, the FBS mapping is used to model the functional structure of the product system and identify the relationship between the product functional structures. Secondly, a correlation synthesis matrix is constructed based on the relationships between the module division drivers. Finally, the improved NSGA2-FCM algorithm is applied to cluster analysis of the product to derive the best module division scheme. The algorithm avoids falling into local optima by optimising the initialisation strategy of the NSGA2 algorithm, while using the FCM algorithm to improve the accuracy of the clustering. This allows the algorithm to explore the solution space more effectively when finding the best module partitioning solution. Finally, the effectiveness of the algorithm for module classification of light industrial equipment is verified using beer fermenters as a case study.

Metal-Organic Frameworks and Their Derivatives-Based Nanostructure with Different Dimensionalities for Supercapacitors.

With the urgent demand for the achievement of carbon neutrality, novel nanomaterials, and environmentally friendly nanotechnologies are constantly being explored and continue to drive the sustainable development of energy storage and conversion installations. Among various candidate materials, metal-organic frameworks (MOFs) and their derivatives with unique nanostructures have attracted increasing attention and intensive investigation for the construction of next generation electrode materials, benefitting from their unique intrinsic characteristics such as large specific surface area, high porosity, and chemical tunability as well as the interconnected channels. Nevertheless, the poor electrochemical conductivity severely limits their application prospects, hence a variety of nanocomposites with multifarious structures have been designed and proposed from different dimensionalities. In this review, recent advances based on MOFs and their derivatives in different dimensionalities ranging from 1D nanopowders to 2D nanofilms and 3D aerogels, as well as 4D self-supporting electrodes for supercapacitors are summarized and highlighted. Furthermore, the key challenges and perspectives of MOFs and their derivatives-based materials for the practical and sustainable electrochemical energy conversion and storage applications are also briefly discussed, which may be served as a guideline for the design of next-generation electrode materials from different dimensionalities.

In Situ Generation of Vertically Crossed P-Cu3Se2 Ultrathin Nanosheets Derived from Cu2S Nanorod Arrays for High-Performance Supercapacitors.

Transition-metal selenides (TMSs) have great potential in the synthesis of supercapacitor electrode materials due to their rich content and high specific capacity. However, the aggregation phenomenon of TMS materials in the process of charging and discharging will cause capacity attenuation, which seriously affects the service life and practical applications. Therefore, it is of great practical significance to design simple and efficient synthesis strategies to overcome these shortcomings. Hence, P-doped Cu3Se2 nanosheets are loaded on vertically aligned Cu2S nanorod arrays to synthesize CF/Cu2S@Cu3Se2/P nanocomposites with a unique core-shell heterostructure. Notably, the Cu2S precursors can be rapidly converted into Cu3Se2 nanorod arrays in situ in just 30 min at room temperature. The unique core-shell heterostructure effectively avoids the aggregation phenomenon, and the doped P elements further enhance the electrochemical properties of the electrode materials. Therefore, the as-prepared CF/Cu2S@Cu3Se2/P electrode exhibits a high areal capacitance of 5054 mF cm-2 (1099 C g-1) at 3 mA cm-2 and still retains 90.2% capacitance after 10 000 galvanostatic charge-discharge (GCD) cycles. The asymmetric supercapacitor (ASC) device assembled from synthetic CF/Cu2S@Cu3Se2/P and activated carbon (AC) possesses an energy density of 41.1 Wh kg-1 at a power density of 480.4 W kg-1. This work shows that the designed CF/Cu2S@Cu3Se2/P electrode has broad application prospects in the field of electrochemical energy storage.

In situ construction of metal-organic frameworks on chitosan-derived nitrogen self-doped porous carbon for high-performance supercapacitors.

The intelligent use of regenerable and degradable biomass materials to substitute the synthetic materials can bring huge economic benefits and environmental improvements. In addition, metal-organic framework (MOF) based cathode materials are becoming a research hotspot for supercapacitors. Here, Co nanoparticle-modified nitrogen self-doped porous carbonized chitosan aerogel (CCA-Co) precursors were prepared by sol-gel, freeze-drying technique and carbonization process using biomass chitosan particles and cobalt compounds as raw materials. Then the layered composite (CCA-Co@MOF) was obtained by growing Co-doped Ni MOF (Co-Ni MOF) with CCA-Co precursor as the carrier. Notably, the presence of Co nanoparticles in carbonized chitosan aerogel (CCA) not only promotes the self-assembly of CCA and MOF, but also etched Co ions can participate in the growth of MOF, resulting in excellent electrochemical performance. Specifically, the specific capacitance of CCA-Co@MOF reaches 1877.2 F g-1, which is much superior to CCA-M@MOFs (M = Ni, Zn and Cu) and other contrast materials. Furthermore, the asymmetric supercapacitor (CCA-Co@MOF//AC ASC) assembled using CCA-Co@MOF and activated carbon (AC) electrodes, exhibits a high energy density (45.9 Wh kg-1 at 431.7 W kg-1). This work highlights the advantages of metal nanoparticle-modified and carbonized chitosan aerogels for MOF growth, demonstrating its great value in the field of electrochemical energy storage.

Embedding of conductive Ag nanoparticles among honeycomb-like NiMn layered double hydroxide nanosheet arrays for ultra-high performance flexible supercapacitors.

Layered double hydroxides are considered promising electrode materials for the preparation of high-energy-density supercapacitors owing to their suitable microstructure and significant electrochemical properties. In this study, honeycomb-like NiMn-layered double-hydroxide (NiMn-LDH) nanosheet arrays with numerous electron/ion channels, a large number of active sites, considerable redox reversibility, and significant electrical conductivity were synthesized by combining Co2(OH)2CO3 nanoneedle arrays with NiMn-LDH nanosheet arrays and Ag nanoparticles on a carbon cloth (CC) substrate through a hydrothermal strategy (CC@Co2CH/NM-LDH-Ag). The fabricated CC@Co2CH/NM-LDH-Ag binder-free electrode exhibited a high specific capacitance of 10,976 mF cm-2 (3092F/g, 1391.4C g-1) at 2 mA cm-2 (1 A/g), and a high capacitance retention of 93.2 % after 10,000 cycles at a current density of 20 mA cm-2. In addition, a solid-state asymmetric supercapacitor (ASC) device assembled using CC@Co2CH/NM-LDH-Ag as the cathode possessed an ultrahigh energy density of 68.85 Wh kg-1 at a power density of 722.6 W kg-1, and two fabricated ASC units in series were able to power a multifunctional display for more than 30 min. Therefore, this study provides a new approach for the design and synthesis of high-performance flexible electrodes.

pH-Activatable Organic Nanoparticles for Efficient Low-Temperature Photothermal Therapy of Ocular Bacterial Infection.

Low-temperature photothermal therapy (PTT) systems constructed by integrating organic photothermal agents with other bactericidal components that initiate bacterial apoptosis at low hyperthermia possess a promising prospect. However, these multicomponent low-temperature PTT nanoplatforms have drawbacks in terms of the tedious construction process, suboptimal synergy effect of diverse antibacterial therapies, and high laser dose needed, compromising their biosafety in ocular bacterial infection treatment. Herein, a mild PTT nanotherapeutic platform is formulated via the self-assembly of a pH-responsive phenothiazinium dye. These organic nanoparticles with photothermal conversion efficiency up to 84.5% necessitate only an ultralow light dose of 36 J/cm2 to achieve efficient low-temperature photothermal bacterial inhibition at pH 5.5 under 650 nm laser irradiation. In addition, this intelligent mild photothermal nanoplatform undergoes negative to positive charge reversion in acid biofilms, exhibiting good penetration and highly efficient elimination of drug-resistant E. coli biofilms under photoirradiation. Further in vivo animal tests demonstrated efficient bacterial elimination and inflammatory mitigation as well as superior biocompatibility and biosafety of the photothermal nanoparticles in ocular bacterial infection treatment. Overall, this efficient single-component mild PTT system featuring simple construction processes holds great potential for wide application and clinical transformation.

Ternary NiCeCo-Layered Double Hydroxides Grown on CuBr2@ZIF-67 Nanowire Arrays for High-Performance Supercapacitors.

Ternary layered double-hydroxide-based active compounds are regarded as ideal electrode materials for supercapacitors because of their unique structural characteristics and excellent electrochemical properties. Herein, an NiCeCo-layered double hydroxide with a core-shell structure grown on copper bromide nanowire arrays (CuBr2@NCC-LDH/CF) has been synthesized through a hydrothermal strategy and calcination process and utilized to fabricate a binder-free electrode. Due to the unique top-tangled structure and the complex assembly of different active components, the prepared hierarchical CuBr2@NCC-LDH/CF binder-free electrode exhibits an outstanding electrochemical performance, including a remarkable areal capacitance of 5460 mF cm-2 at 2 mA cm-2 and a capacitance retention of 88% at 50 mA cm-2 as well as a low internal resistance of 0.163 Ω. Moreover, an all-solid-state asymmetric supercapacitor (ASC) installed with CuBr2@NCC-LDH/CF and activated carbon electrodes shows a high energy density of 118 Wh kg-1 at a power density of 1013 W kg-1. Three assembled ASCs connected in series can operate a multifunctional display for over three and a half hours. Therefore, this innovative work provides new inspiration for the preparation of electrode materials for supercapacitors.

Drug-free contact lens based on quaternized chitosan and tannic acid for bacterial keratitis therapy and corneal repair.

Bacterial keratitis (BK) and related inflammatory diseases causes irreversible damage to the corneal tissue. In this study, a novel polyacrylamide semi-interpenetrating network hydrogel including quaternized chitosan and tannic acid (PAM-QCS-TA) were used to construct a novel antibacterial and antioxidant contact lens. The obtained hydrogels showed high water content (>85%), swelling resistance, light transmittance (>90%) and adjustable mechanical property. Both quantitative and qualitative antibacterial experiments against Staphylococcus aureus and Escherichia coli (E. coli) indicated excellent sterilization function especially against E. coli (almost 100%). Due to the presence of tannin acid, it showed obvious antioxidant properties, which relieved oxidative stress and protect cells from reactive oxygen species-induced cytotoxicity. Animal experiments also indicated the shortened treatment time of BK (only 3 days) as well as the protection of eye tissue structure. Therefore, such drug-free antibacterial and antioxidant contact lens avoiding the development of drug resistance is a potential candidate in ocular infectious and inflammatory diseases treatment.

Cyanobacteria-based self-oxygenated photodynamic therapy for anaerobic infection treatment and tissue repair.

Photodynamic therapy (PDT) is an important technique to deal with drug-resistant bacterial infections in the post-antibiotic era. However, the hypoxic environment in intractable infections such as refractory keratitis and periodontitis, makes PDT more difficult. In this work, spontaneous oxygen-producing cyanobacteria were used as the carrier of photosensitizer (Ce6), and ultrasmall Cu5.4O nanoparticles (Cu5.4O USNPs) with catalase activity for infection and inflammation elimination and rapid tissue repair (CeCycn-Cu5.4O). The loading of Ce6 and Cu5.4O USNPs onto cyanobacteria surface were confirmed by transmission electron microscopy, nano particle size analyzer, scanning electron microscopy. In vitro sterilization and biofilm removal experiments demonstrated that the restriction of hypoxic environment to PDT was significantly alleviated due to the oxygen production of cyanobacteria. Under laser irradiation, the close transfer of energy photons to oxygen produced by cyanobacteria reduced more than 90% of Ce6 dosages (660 nm, 200 mW/cm2, 2 min). It is worth mentioning that both rapid sterilization through PDT and long-term oxidized free radicals elimination were achieved by adjusting the ratio of Ce6 and Cu5.4O USNPs. Both periodontitis and refractory keratitis animal models proved the excellent self-oxygenation enhanced antibacterial property and promotion of tissue repair.

Origami and layered-shaped ZnNiFe-LDH synthesized on Cu(OH)2 nanorods array to enhance the energy storage capability.

The combination of layered nanorod arrays with unique core-shell structure and transition metal layered double hydroxide (LDH) is considered as a feasible solution to improve the electrochemical performances of capacitor electrode. In this study, layered ZnNiFe-LDH@Cu(OH)2/CF core-shell nanorod arrays, which consist of ultrathin ZnNiFe-LDHs nanosheet shells and ordered Cu(OH)2 nanorod inner cores, are successfully designed and fabricated by a typical hydrothermal way and a simple in situ oxidation reaction. The electrode prepared using ZnNiFe-LDH@Cu(OH)2/CF nanomaterial reveals an remarkable area capacitance of 6100 mF cm-2 at 3 mA cm-2 current density, which is excellently superior than those of ZnFe-LDH@Cu(OH)2/CF, NiFe-LDH@Cu(OH)2/CF, Cu(OH)2/CF and CF. Additionally, the capacitance retention remains as high as 83.4% after 5000 cycles and a very small Rs (0.567 Ω) can be observed. In addition, an asymmetric supercapacitor device is successfully fabricated employing ZnNiFe-LDH@Cu(OH)2/CF. Meanwhile, the ZnNiFe-LDH@Cu(OH)2/CF//AC device can achieve an energy density of 44 Wh kg-1 and a corresponding power density of 720 W kg-1 and possess the capability to light up a multi-function monitor for 33 min just using two ASC equipments connected in series. Therefore, the prepared ZnNiFe-LDH@Cu(OH)2/CF composite materials with unique structure has great application potential in energy storage devices.

Quantifying global warming potential of alternative biorefinery systems for producing fuels from Chinese food waste.

Biorefining of Chinese food waste (FW) into transport fuels was assessed in terms of amount of fuel produced and over all Global Warming Potential (GWP) for six different scenarios including biogas, biomethane, bioethanol and biodiesel in different combinations. The life-cycle perspective used included GWP aspects of material and energy use, emissions during biorefining and management of residues, as well as substitution of fossil fuels according to the energy content of biofuels. All of the six FW biorefineries revealed savings in GWP ranging from -19 to -138 kg CO2 eqv. per ton of wet FW. Compared to the reference scenario with only anaerobic digestion (S0), introducing biogas upgrading to biomethane (S1) improved the GWP by 37%; while producing bioethanol prior to anaerobic digestion (S2) decreased the savings in GWP. Introducing biodiesel prior to anaerobic digestion (S3) revealed around 60% improvement in GWP, while combining biodiesel and biomethane gave the largest improvement in GWP, 84% compared to the reference scenario, and the most fuels (around 2400 MJ in terms of 30 kg biodiesel and 35 kg biomethane per ton of wet FW). A sensitivity analysis revealed that the electricity production based on the biogas was an important parameter and appears in all refineries, while the results was less sensitive to the production of biodiesel and biomethane. The residue management contributed also to the GWP, but did not vary much among the biorefinery scenarios.

Global warming potential of typical rural domestic waste treatment modes in China: a case study in Ankang.

The global problem of domestic waste management increases with rapid population growth and with economic and urban development. In developing countries, treatment of rural domestic waste (RDW) is distinguished from urban waste. Quantitative assessment of greenhouse gas emissions from RDW disposal treatment is needed to achieve carbon neutrality. Reliable global warming potential (GWP) assessments of RDW are not differentiated in the widely accepted "urban-rural integration" centralized disposal model. We considered five different scenarios for RDW management. Scenario 1 (S1), unsanitary landfill (open-air dump); scenario 2 (S2), sanitary landfill; scenario 3 (S3), incineration; scenario 4 (S4), biological + incineration; and scenario 5 (S5), classification + composting + sanitary landfill + recycling. Life cycle assessment was used for GWP, and sensitivity analysis was calculated to point out the sensitive parameter. We found that the mean GWP ranged from 5.14 × 104 to 2.31 × 105 kg CO2-equivalents. Pollution from untreated RDW with landfill gas emissions led to large contributions under all scenarios. The collection and transportation ratio was sensitive to all scenarios, and we found that, if the recyclable materials separated at source were not used efficiently, the impact on GWP would be greater than under the unclassified waste scenarios. A "new urban-rural integration" mode (S5) that included household classification, village collection, town transfer, and county and urban disposal was introduced for RDW management. These quantitative results have a great potential for promoting effective RDW management in China and other developing countries.

Hemoglobin autofluorescence as potential long-term glycemic marker in the rat animal model.

Diabetes is a serious disease whose patients often require long-term care. Blood glucose and intermediate glycation product of glycated hemoglobin (HbA1c) are, at best, surrogate biomarkers of disease progression. There is indication that advanced glycation end products (AGEs) better reflect diabetic risks. In this study, we explored the use of red blood cells (RBCs) and lysed hemoglobin (Hb) autofluorescence (AF) as potential biomarkers of diabetic complication. AF spectra measured under 370 nm excitation reveals that both RBC and Hb fluorescence in the 420 to 600 nm region. At early time points following diabetic induction in rats, AF increase in lysed Hb is more dramatic compared to that of RBCs. Moreover, we found significance variance of Hb autofluorescence despite relatively constant HbA1c levels. Furthermore, we found that although a correlation exists between AGE autofluorescence and HbA1c levels, the lack of complete correspondence suggests that the rate of AGE production differs significantly among different rats. Our results suggest that with additional development, both RBC and Hb autofluorescence from lysed RBCs may be used act long-term glycemic markers for diabetic complications in patients.

Material flow analysis and life cycle assessment of food waste bioconversion by black soldier fly larvae (Hermetia illucens L.).

This study provided a systematic analysis on material flow and environmental impacts of a food waste (FW) bioconversion plant using black soldier fly larvae (BSFL), with a daily capacity of 15 tons of FW (wet weight). Food waste feed (FWF) used for BSFL bioconversion consisted of 80% FW (collected from households, restaurants, and canteens) and 20% rice hull powder. Material flow analysis conducted on a dry weight basis showed that 6% of FWF was transformed into BSF pre-pupae, 51% was stored in matured compost, and 43% was emitted to the air. Emissions of high environmental concern such as methane, nitrous oxide and ammonia (NH3) were sampled and quantified by laboratory analysis. The life cycle assessment revealed that the overall impact was 17.36 kg CO2-eq/t FW for global warming potential, 5.54 kg SO2-eq/t FW for acidification, 24.05 mol N-eq/t FW for terrestrial eutrophication, 0.54 kg N-eq NH3/t FW for marine eutrophication, and 0.18 kg PM2.5-eq/t FW of particulate matter up to 2.5 µm diameter. Moreover, emissions from post-composting, energy consumptions of drying and chemical fertilizer substitution ratio were detected by contribution analysis as the main contributors to those impacts. Finally, sensitivity analysis indicated that the substitution ratio of mineral fertilizer and protein feed as well as energy consumption were the most influential parameters, therefore control of the post-composting process of residual material should be closely monitored because it was responsible for significant environmental load caused by N-related emissions.

Effects of conductive carbon materials on dry anaerobic digestion of sewage sludge: Process and mechanism.

Dry anaerobic digestion of sewage sludge (SS-DAD) is often inhibited by excessive acidification due to low water content and high organic loading. The effects of conductive carbon materials including powdered activated carbon (PAC) and powdered graphite (PG) on SS-DAD under mesophilic condition (35℃) were investigated. The results demonstrated that the addition of PAC increased methane production of SS-DAD. The methane yield of PAC50% reactor (dosage of PAC is 50% of the volatile solids) amounted to 210 mL·gVSadded-1, which is 49% higher than that of control. PAC addition significantly enhanced the biodegradation process, as the reduction rate of total solids (TS) and volatile solids (VS) were increased by 36.4% and 34.1%, respectively, compared to the control. Inhibitory substrate adsorption experiments showed that PAC has significant adsorption (13.6 mg g-1) for VFAs, while PG showed almost no adsorption (0.81 mg g-1). Microbial community structure analysis showed hydrogenotrophic methanogens (Methanobrevibacter and Methanosphaera) were reduced in the PAC50% reactor, while methanogens (Methanobacterium) which can also use formate as electron donor were increased. PAC amendment reshaped the microbial community in the SS-DAD system which may result in shifting of the major electron carrier from hydrogen to formate and increasing electron transfer efficiency of the SS-DAD system.

New molecular method to detect denitrifying anaerobic methane oxidation bacteria from different environmental niches.

The denitrifying anaerobic methane oxidation is an ecologically important process for reducing the potential methane emission into the atmosphere. The responsible bacterium for this process was Candidatus Methylomirabilis oxyfera belonging to the bacterial phylum of NC10. In this study, a new pair of primers targeting all the five groups of NC10 bacteria was designed to amplify NC10 bacteria from different environmental niches. The results showed that the group A was the dominant NC10 phylum bacteria from the sludges and food waste digestate while in paddy soil samples, group A and group B had nearly the same proportion. Our results also indicated that NC10 bacteria could exist in a high pH environment (pH9.24) from the food waste treatment facility. The Pearson relationship analysis showed that the pH had a significant positive relationship with the NC10 bacterial diversity (p<0.05). The redundancy analysis further revealed that the pH, volatile solid and nitrite nitrogen were the most important factors in shaping the NC10 bacterial structure (p=0.01) based on the variation inflation factors selection and Monte Carlo test (999 times). Results of this study extended the existing molecular tools for studying the NC10 bacterial community structures and provided new information on the ecological distributions of NC10 bacteria.

Fugitive halocarbon emissions from working face of municipal solid waste landfills in China.

Halocarbons are important anthropogenic greenhouse gases (GHGs) due to their long lifetime and large characteristic factors. The present study for the first time assessed the global warming potential (GWP) of fugitive halocarbon emissions from the working face of landfills in China. The national emissions of five major halocarbons (CFC-11, CFC-113, CH2Cl2, CHCl3 and CCl4) from the working face of municipal solid waste landfills in China were provided through observation-based estimations. The fluxes of halocarbons from working face of landfills were observed much higher than covered cells in landfills hence representing the hot spots of landfill emissions. The annual emissions of the halocarbons from landfills in China were 0.02-15.6kt·y-1, and their GWPs were 128-60,948kt-CO2-eq·y-1 based on their characteristic factors on a 100-year horizon. CFC-113 was the dominant species owing to its highest releasing rate (i.e. 15.4±19.1g·t-1) and largest characteristic factor, resulting in a GWP up to 4036±4855kt-CO2-eq·y-1. The annual emissions of CFC-113 from landfills (i.e. 0.61kt·y-1) made up ∼76% of the total national CFC-113 emissions. The GWPs of halocarbons were estimated ∼14.4% of landfill methane emissions. Therefore, fugitive halocarbons emissions from working face are significant sources of GHGs in landfill sites in China, although they comprise a small fraction of total landfill gases.