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Herein, cobalt embedded in nitrogen-doped porous carbon (Co@NC) was developed as a robust heterogeneous catalyst for the dehydrogenative coupling of primary alcohols and hydroxides. With Co@NC as the first earth-abundant metal/carbon composite material for this transformation, numerous aromatic and aliphatic carboxylic acids were efficiently afforded. Notably, the newly prepared Co@NC was fabricated in a facile and straightforward manner and reused up to 15 recycle rounds without activity decay. It is also worth emphasizing that the catalyst recycling was realized via magnetic separation with no special treatment or activation. Additionally, further experiments elucidated the pivotal role of the cobalt and nitrogen elements dispersed in the carbon matrix as well as the hierarchical porosity (micro-/meso-pores) in the catalytic activity and recyclability. Considering the active sites of Co@NC, we envisioned that the Co–N species was the most active site, while other active sites such as Co–O, Co0 species and free N-doped carbon were also present, but demonstrating lower activity or stability in comparison with the Co–N species. Additional mechanistic investigations were carried out to gain more insights into the possible reaction pathways. We found that the aldehyde was identified as a crucial intermediate, and two possible pathways were proposed for this catalytic process.

Oxazolidinones and α-hydroxyl ketones are two series of fine chemicals that have been generally utilized in biological, pharmaceutical, and synthetic chemistry. Herein, a AgNO3/ionic liquid (IL) catalytic system was developed for the simultaneous synthesis of these compounds through the atom-economical three-component reactions of propargyl alcohols, 2-aminoethanols, and CO2. Notably, this system behaved excellent catalytic activity with the lowermost metal loading of 0.25 mol%. Meanwhile, it is the first reported metal-catalyzed system that could efficiently work under atmospheric CO2 pressure and be recycled at least five times. Evaluation of the green metrics proved the AgNO3/IL-catalyzed processes to be relatively more sustainable and greener than the other Ag-catalyzed examples. Further mechanistic investigations revealed the derivative active species of N-heterocyclic carbene (NHC) silver complexes and CO2 adducts generated during the process. Subsequently, their reactivity in this reaction was assessed for the first time, which was finally identified as beneficial for the catalytic activity.

Facile strategies for noble metal dispersion in the shell-layer of core–shell structured metal–organic frameworks based on Zr-MOFs (UiO-66@Pd-UiO-67-BPY) was developed. The robust structure of the core-structure UiO-66 was firstly synthesized before covering up with a shell-structure of UiO-67-BPY obtaining the core–shell structure (UiO-66@UiO-67-BPY). The metallation with active palladium species (PdII) was designed on the shell-layer of core–shell MOFs via a post-synthetic method. The Pd species were coordinated explicitly in a bidentate manner to the bipyridyl linkers of the shell-structure (UiO-67-BPY). Excellent dispersion of Pd in the shell structure was obtained, resulting in UiO-66@Pd-UiO-67-BPY, as confirmed from characterizations. Taking advantage of the designed catalyst, the synthesized UiO-66@Pd-UiO-67-BPY was examined for the catalytic hydrogenation reaction. The results revealed an excellent catalytic performance of UiO-66@Pd-UiO-67-BPY compared with the traditional catalyst Pd-UiO-67-BPY. Moreover, the designed catalyst structure exhibited outstanding performance and paved the way towards a cost-effective catalyst synthesis based on MOFs combined with a noble metal.

Mercury speciation in groundwater affects its removal effectiveness and methylation potential. Yet, most studies focus on the removal of inorganic dissolved Hg(II) and few studies explored the mercury methylation before and after the treatment. This study comprehensively explored the removal performance of three model mercury species, namely, dissolved inorganic divalent Hg (Hg(II), including free Hg2+ and Hg2+ complexes with Cl− and OH−), Hg2+ bound to dissolved organic matter (Hg-DOM), and HgS nanoparticles by FeS nanoparticles and further investigated the resultant impacts on the microbial methylation of Hg. Among three different stabilizers (starch, carboxymethyl cellulose (CMC), carboxymethyl starch (CMS)), CMC stabilized FeS nanoparticles (CMC-FeS) demonstrated best physical stability and highest mercury uptake. The CMC-FeS nanoparticles efficiently immobilized the three mercury species within 20 h. The sorption isotherm data of Hg(II) and Hg-DOM were well fitted by the dual-mode isotherm model and the maximum sorption capacities were 3358.28 and 2396.38 mg/g, respectively. Hg(II) and Hg-DOM were predominantly removed via ion exchange, chemical precipitation, and surface complexation whereas HgS was mainly immobilized through heteroaggregation. The simple treatment greatly reduced the bioavailable Hg species, thereby diminishing the net MeHg production by 70.2 %, 32.7 %, and 11.3 %, respectively. This study provides compelling evidence that FeS nanoparticles efficiently removed various mercury species in groundwater and remarkably inhibited the microbial methylation of mercury.

A core-shell structure metal-organic framework based on the Zr clusters bridging with BDC linkers (UiO-66) as a core-structure and BPYDC linkers (UiO-67-BPY) as a shell-structure was developed (UiO-67-BPY@UiO-66). The combination of several techniques such as XRD, FTIR, SEM, TEM, and surface area analysis etc. were applied for the characterization and confirmed a core-shell structure of UiO-67-BPY@UiO-66. Taking advantage of the high porous stability of the core-structure (UiO-66) and the presence of active Lewis basic sites from the bipyridinic linker in the shell layer (UiO-67-BPY) could be advantageous for basic-catalyzed reactions. The synthesized core-shell material was applied as a heterogeneous catalyst for the Knoevenagel condensation as a model reaction. An excellent catalytic performance was obtained by the core-shell material over traditional MOFs and other previous reports based on MOFs. The excellent dispersion of the active sites (Lewis basic) in the outer layer of the designed core-shell structure was a breakthrough to prevent mass diffusion limitation during catalysis. Additionally, the catalyst can be recycled and maintained its high catalytic performance at least for four cycles.

A core-shell metal-organic frameworks (MOF@MOF) based on the Zr-MOFs assembly from core-structure UiO-66 combined with shell-structure UiO-67-BPY were explored. The synthesized materials were characterized via XRD, FTIR, SEM, TEM, and surface area analysis, etc. indicating the presence of a core-shell structure of UiO-66@UiO-67-BPY. Furthermore, incorporation of the bipyridinic (BPY) group in the linker used to construct the shell layer (UiO-67-BPY) could coordinate with active metal species and thus create an advantage for site-selective metal incorporation in the core-shell structure. Silver (Ag) was selected for the selective metal incorporation and an excellent Ag-dispersion via coordination with the bipyridinic groups in the UiO-67-BPY layer of the core-shell material was obtained. The synthesized material (UiO-66@UiO-67-BPY-Ag) was successfully applied as a heterogeneous catalyst for the CO2 fixation via carboxylation of terminal alkynes. The catalytic material showed excellent yields using at a low Ag-loading under mild reaction condition (50 °C, 1 bar). Moreover, the catalyst can be recycled for at least 5 times maintaining a stable catalytic performance. Interestingly, the high catalytic activity of the synthesized material demonstrated clearly the beneficial advantage of the metalated core-shell structure over the reported routes to synthesize silver catalysts such as encapsulated Ag nanoparticles (AgNP@MOF) or Ag-bidentately coordinated on traditional MOFs applying the same reaction model.

Nanoplastics (NPs) pollution of aquatic systems is becoming an emerging environmental issue due to their stable structure, high mobility, and easy interactions with ambient contaminants. Effective removal technologies are urgently needed to mitigate their toxic effects. In this study, we systematically investigated the removal effectiveness and mechanisms of a commonly detected nanoplastics, carboxyl-modified polystyrene (PS-COOH) via coagulation and sedimentation processes using aluminum chloride (AlCl3) as a coagulant. PS-COOH appeared as clearly defined and discrete spherical nanoparticles in water with a hydrodynamic diameter of 50 nm. The addition of 10 mg/L AlCl3 compressed and even destroyed the negatively charged PS-COOH surface layer, decreased the energy barrier, and efficiently removed 96.6% of 50 mg/L PS-COOH. The dominant removal mechanisms included electrostatic adsorption and intermolecular interactions. Increasing the pH from 3.5 to 8.5 sharply enhanced the PS-COOH removal, whereas significant loss was observed at pH 10.0. High temperature (23 °C) favored the removal of PS-COOH compared to lower temperature (4 °C). High PS-COOH removal efficiency was observed over the salinity range of 0 − 35‰. The presence of positively charged Al2O3 did not affect the PS-COOH removal, while negatively charged SiO2 reduced the PS-COOH removal from 96.6% to 93.2%. Moreover, the coagulation and sedimentation process efficiently removed 90.2% of 50 mg/L PS-COOH in real surface water even though it was rich in inorganic ions and total organic carbon. The fast and efficient capture of PS-COOH by AlCl3 via a simple coagulation and sedimentation process provides a new insight for the treatment of NPs from aqueous environment.

Lead (Pb) contamination in soil has been a major concern. Yet, cost-effective remediation technologies have been lacking. This study pilot-tested a new type of carboxymethyl cellulose (CMC) bridged chlorapatite microparticles (CMC-CAP) for immobilization of Pb at an abandoned chemical plant site, and monitored long-term (1 year) stability of Pb under the field conditions. Concentrated CMC-CAP (18 g L−1) was prepared at the pilot scale and then used for amending the soil on the site. CMC-CAP appeared as interwoven flocks of CAP microparticles with a hydrodynamic diameter of 2442 nm, which is 2.2 times smaller than that for bare CAP. CMC-CAP at a dosage of 0.5 wt% resulted in the highest immobilization of Pb, and decreased the acid-leachable Pb in the soil from 1.46 mg L−1 to 0.008 mg L−1 after 1 day of reaction, and further to 0.005–0.006 mg L−1 when aged for 180 and 365 days under the field conditions. The long-term aging consolidated the Pb immobilization, securing the compliance with the Chinese regulatory limit (0.010 mg L−1 for Pb). CMC-CAP served as a long-term sink for leachable Pb in soil and a pH buffer to maintain an alkaline soil pH. Sequential extraction data confirmed that the CMC-CAP amendment converted the more leachable Pb fractions into the less available Pb species. The soil amendment reduced the risk assessment code from “High risk” for the untreated soil to “Low risk” after 120 days of aging. XRD and FTIR results revealed the immobilization of Pb by CMC-CAP was achieved through the formation of the highly stable pyromorphite, surface complexation, and/or ion exchange reactions. Based on the field data, the remediation cost of the CMC-CAP based technology was estimated to be $36.2/m3. This study provides important field data on the effectiveness of CMC-CAP for cost-effective immobilization of Pb in soil.

A novel biochar supported nanoscale iron sulfide (FeS) composite (CMC-FeS@biochar) combining the advantages of biochar, carboxymethyl cellulose (CMC), and FeS was synthesized and tested for Cr(VI) removal efficiency and mechanisms. FeS particles were effectively soldered onto the surface of biochar through OH, C C, O C O, C O, and Si O functional groups. The composite at a mass ratio of FeS:CMC: biochar = 1:1:1 displayed an enhanced Cr(VI) adsorption capacity of 130.5 mg/g at pH 5.5 compared to 38.6 mg/g for FeS and 25.4 mg/g for biochar. Surface sorption and reduction were the dominant removal mechanisms. At the equilibrium Cr(VI) concentration of 13.4 mg/L, 57% of Cr(VI) removal was attributed to reduction and 43% was ascribed to surface sorption. The adsorption kinetic data were adequately simulated with pseudo second-order kinetic model and mass transfer model, suggesting that sorption kinetics were the combination of chemisorption and external mass transfer. The Redlich-Peterson model fitted better than the Langmuir and Freundlich models in simulating the adsorption isotherm data, again suggesting a hybrid chemical reaction-sorption process. The Dubinin–Radushkevich isotherm model resulted in an adsorption energy of 10.0 kJ/mol, implying a chemisorption between Cr(VI) and CMC-FeS@biochar. The present study demonstrated the promise of CMC-FeS@biochar composite as a low-cost, “green”, and effective sorbent for removal of Cr(VI) in the environment.

A novel thiol-functionalized graphene oxide/Fe-Mn composite (SGO/Fe-Mn) was synthesized via three different methods, i.e., acetic acid method (SGO/Fe-Mn-ac), neutral method (SGO/Fe-Mn-ne), and ammonium hydroxide method (SGO/Fe-Mn-am). The composites were characterized and tested for aqueous methylmercury removal. SGO/Fe-Mn was prepared using 3-mercaptopropyltrimethoxysilane (3-MPTS) as a silanizing reagent, and hydrolyzed 3-MPTS mainly interacted with GO/Fe-Mn through surface oxygen-containing groups (i.e., OH, C O, epoxy C O C, carboxyl O C O, and C O) and π-π interactions, partially through self-polymerization. SGO/Fe-Mn-am showed the largest hydrodynamic diameter, strongest π-π bond, fewest S oxidation products, most thiol groups, negative charge, sp 3 defects, and FeOOH. Pseudo-second-order kinetic model and Langmuir and Freundlich isotherm models fitted well with methylmercury sorption kinetic and isotherm data, respectively, resulting in a CH 3 Hg + maximum sorption capacity of 43.88 mg/g for SGO/Fe-Mn-am, 36.33 mg/g for SGO/Fe-Mn-ac, and 28.00 mg/g for SGO/Fe-Mn-ne. The removal mechanism was described by electrostatic attraction, ligand exchange, and surface complexation. This study demonstrates potential and viability of SGO/Fe-Mn for enhanced immobilization of CH 3 Hg + in surface water, groundwater, and soil/sediments.

This study investigated the effects of 3 model oil dispersants (Corexit EC9500A, Corexit EC9527A and SPC 1000) on photodegradation of pyrene under simulated sunlight. Both Corexit dispersants enhanced photodegradation of pyrene, while SPC1000 slightly inhibited the reaction. Span 80 and Tween 85 were the key ingredients causing the effects, though the underlying mechanisms differed. Span 80 enriches pyrene in the upper layer of water column, whereas Tween 85 induces a photosensitization process. Two reactive oxygen species, 1O2 and O2-, were found responsible for pyrene photodegradation, though the presence of EC9500A suppressed the 1O2 pathway. In terms of photodegradation products, EC9500A enhanced generation of polyaromatic intermediates, i.e., phenaleno[1,9-cd][1,2]dioxine, 1-hydroxypyrene, and 1,8-pyrenequinone, but did not alter the classical photodegradation pathway. The Corexit dispersants were more prone to photochemical decomposition, with multiple by-products detected. The information aids in our understanding of the effects of dispersants on photochemical weathering of oil compositions.

As the traditional anode material of lithium-ion batteries, tin dioxide (SnO2) has the characteristics of a high theoretical capacity and stable crystal structure. However, the alloying/de-alloying reaction between tin and lithium ions causes volume expansion and continuously generates an SEI film, which causes the electrode to fall off the current collector and the capacity fade rapidly. Generally, a composite of carbon materials and SnO2 can alleviate the expansion and pulverization phenomena. However, the microstructure of carbon materials is complex and changeable, which makes it difficult to definitively state the influence mechanism of the microstructure on the lithium storage performance of composite materials. Here, three kinds of lignin-based porous carbons (LPCs) with different microstructural characteristics, along with a high graphitization, high specific surface area and hierarchical porosity, are obtained by regulating the process of gas exfoliation and in situ activation. Furthermore, a series of LPC/SnO2 composites are obtained by an ultrasonic dispersion and ball milling method. Electrochemical property results show that the hierarchical porous LPCs are more conducive to the dispersion/coating of SnO2 nanoparticles and that the reversible specific capacity of the electrode material increases from 64 to 620 mA h g−1, effectively mitigating the expansion and pulverization of SnO2 during the lithium storage process.

Rapid industrialization, urbanization, and population growth have led to the common occurrence of black-stinking urban rivers. Assessing regional anthropogenic influences is beneficial to develop effective remediation strategies. This study comprehensively investigated the occurrence and fate of linear alkylbenzenes (LABs) as molecular markers of anthropogenic influences in three media (filtered water, suspended particulate matter (SPM), and sediment) in a highly urbanized river (Baihaimian River) in Guangzhou, South China. The concentrations of LABs ranged from 41 to 215 ng/L in the dissolved phase, from 7122 to 46,640 ng/g dry weight in the SPM phase, and from 73 to 3650 ng/g dry weight in surface sediments (0–10 cm depth). The spatial distribution of LABs was probably affected by the surrounding environment, river flux, and sediment properties. No biotransformation of LABs in water samples and a slight biotransformation in sediments were observed. Significant correlations were found between total nitrogen, ammonia nitrogen, and LABs in river water, indicating the same domestic wastewater sources. The positive correlation between total organic carbon (TOC) and LABs in sediments suggested that TOC worked as the controlling factor for the redistribution of LABs and that local sewage discharge was the dominant TOC input. The total mass inventory of LABs in sediment in Baihaimian River was 21 kg. The total mass of LABs released into Baihaimian River was 183 kg per year, among them, 63% was discharged into the adjacent Liuxi River.

Zinc (Zn2+) and cadmium (Cd2+) in water pose serious threats to human health and the environment. In search for a more effective treatment technology, we prepared a type of carboxymethyl cellulose (CMC) bridged chlorapatite (CMC-CAP) nanoparticles and tested the material for removal of Zn2+ and Cd2+ from water. CMC macromolecules were attached to CAP by bidentate bridging and hydrogen bonding, preserving the high adsorption capacity of CAP nanoparticles while allowing for easy gravity-separation of the nanoparticles. CMC-CAP showed rapid adsorption kinetics and 22.8% and 11.2% higher equilibrium uptake for Zn2+ and Cd2+, respectively, than pristine CAP. An extended dual-mode isotherm model, which takes into account both sorption and chemical precipitation, provided the best fits to the sorption isotherms, giving a maximum Langmuir sorption capacity of 141.1 mg g−1 for Zn2+ and 150.2 mg g−1 for Cd2+ by CMC-CAP. Na+ at up to 5 mM showed modest effects on the uptake of the heavy metals, while 2–5 mM of Ca2+ exerted notable inhibitive effects. Dissolved organic matter (up to 5 mg L−1 as TOC) inhibited the Zn2+ uptake by 16.5% but enhanced the Cd2+ removal by 8.6%. Material characterizations and surface binding analyses revealed that ion exchange, surface precipitation, and surface complexation were the removal mechanisms for the heavy metals. This study demonstrates stabilizer bridging may serve as a convenient strategy to facilitate water treatment uses of nanoparticles.

This work developed a new method to determine concentration of Corexit EC9500A, and likely other oil dispersants, in seawater. Based on the principle that oil dispersants decrease surface tension, a linear correlation was established between the dispersant concentration and surface tension. Thus, the dispersant concentration can be determined by measuring surface tension. The method can accurately analyze Corexit EC9500A in the concentration range of 0.5-23.5mg/L. Minor changes in solution salinity (

Rapid industrialization and urbanization have resulted in elevated concentrations of hazardous inorganic and organic contaminants in groundwater and soil, which has become a paramount concern to the environment and the public health. In recent years, iron sulfide (FeS), a major constituent of acid-volatile sulfides, has elicited extensive interests in environmental remediation due to its ubiquitous presence and high treatment efficiency in anoxic environment. This paper provides a comprehensive review on recent advances in: (1) synthesis of FeS particles (including nanoscale FeS); and (2) reactivity of FeS towards a variety of common environmental contaminants in groundwater and soil over extended periods of time, namely, heavy metals (Hg(II), Cu(II), Pb(II), and Cr(VI)), oxyanions (arsenite, arsenate, selenite, and selenate), radionuclides (e.g., uranium (U) and neptunium (Np)), chlorinated organic compounds (e.g., trichloroethane, trichloroethylene, and p-chloroaniline), nitroaromatic compounds, and polychlorinated biphenyls. Different physiochemical and biological methods for preparing FeS with desired particle size, structure, and surface properties are discussed. Reaction principles and removal effectiveness/constraints are discussed in details. Special attention is placed to the application of nanoscale FeS particles because of their unique properties, such as small particle size, large specific surface area, high surface reactivity, and soil deliverability in the subsurface. Moreover, current knowledge gaps and further research needs are identified.

Microplastics (MPs) have aroused rising social concerns. Although amounts of surfactants exist in wastewater and are expected to alter the surface properties of MPs significantly as they are designed to be adsorbed by hydrophobic particles. However, rare works have been done on the influence of surfactants on the coagulation removal process of MPs which was thought to be an effective way to remove MPs together with other natural particles, such as clay. We used 3-D fluorescence imaging to track the coagulation removal process of polystyrene MPs. Our results indicate that nonionic surfactant, tween 20 in ppm scale, could inhibit the coagulation removal of polystyrene MPs significantly. Residue MPs in the effluent is proportional with the surfactant concentration and increases up to tens of times, which will lead to a dramatic increase in their potential environmental risks. Apparent size effect exists in the coagulation in which smaller MPs can escape from the coagulation removal more easily. Mechanism study suggests that the steric resistance of the hydrophilic flexible polyethylene glycol (PEG) layer formed by tween 20 adsorbed on MP surface inhibits clay deposition and thus hinders subsequent agglomeration and precipitation. A surfactant stealth effect, which is used in the design of nanomedicine to avoid the human immune recognition and clearance of nano-drugs from blood circulation, also exists in the coagulation removal process of MPs. Our finding not only proves the strong influence of surfactants on MPs but also will stimulate related studies on other latent surfactant effects of MPs.

Mercury contamination poses a serious threat to the ecological system and human health. Yet, removal of mercury at parts per billion (ppb) level in surface water is difficult to achieve. This study developed a Mg2Al layered double hydroxide supported iron sulfide composite (FeS@Mg2Al-LDH) and investigated its removal effectiveness and mechanisms of mercury from surface water. FeS was successfully soldered onto Mg2Al-LDH via surface complexation and surface adsorption. The composite (FeS:Mg2Al-LDH mass ratio of 1:1) at 20 mg/L effectively removal 89.4% of 110 µg/L mercury at pH 7.0 within 72 h. A pseudo-second-order kinetic model well simulated the sorption kinetic data and a Sigmoidal Langmuir isotherm model perfectly fitted the sorption isotherm data with a maximum monolayer sorption capacity of 116.96 mg/g. X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses suggested that mercury was removed via chemical precipitation, ion exchange, and surface complexation. The supporting material Mg2Al-LDH greatly enhanced the antioxygenic and pH-resistant properties of FeS, and the composite offered high selectivity for mercury. FeS@Mg2Al-LDH and immobilized mercury remained stable over 6 months. This study demonstrated the potential and viability of FeS@Mg2Al-LDH for efficient removal of aqueous mercury.

Mercury contamination in groundwater has been considered as an environmental and public health issue all over the world. Yet, effective in situ remediation techniques have been lacking. A thiol-modified graphene oxide/Fe–Mn composite (SGO/Fe–Mn) was employed as a reactive sorbent of permeable reactive barrier (PRB) for in situ remediation of mercury contaminated groundwater using fixed-bed columns. Mercury existed as HgCl2, Hg(OH)2, and HgClOH, and was mainly removed through surface complexation. The Brunauer-Emmett-Teller sorption isotherm model provided adequate fitting of the sorption isotherm data with a maximum monolayer sorption capacity of 112.03 ± 16.59 mg g−1. Breakthrough time, the time when 5% of initial Hg concentration is measured in the effluent, increased with the decrease of influent mercury concentration, pore velocity, dissolved oxygen (DO), and dissolved organic matter (DOM). The resultant column sorption capacity was enhanced at higher influent mercury concentration, lower groundwater pore velocity, lower DOM and DO. Moreover, when the SGO/Fe–Mn was thoroughly mixed with quartz sand in the column, the breakthrough time was increased and the resultant sorption capacity was improved compared to the case that SGO/Fe–Mn was packed between two layers of quartz sand. Mathematically, the Adams-Bohart model satisfactorily reproduced the initial behavior of mercury breakthrough curves (

Mercury (Hg) is one of the most toxic heavy metals in soil and groundwater, and mercury methylation is the key step for invasion of Hg into the food chain. Iron sulfide nanoparticles stabilized by carboxymethyl cellulose (CMC-FeS) have demonstrated excellent sorption/immobilization for mercury in water and soil. However, information has been lacking pertaining to the effects of CMC-FeS on speciation and microbial methylation of Hg at part per billion (ppb) level in groundwater. This work studied Hg speciation in the presence of CMC-FeS and the inhibitive effect of CMC-FeS on the microbial methylation of Hg in groundwater. CMC-FeS (CMC-to-FeS molar ratio of 0.0004) offered unusually high Hg sorption capacity, fast sorption rate, and good selectivity for mercury. The maximum Langmuir sorption capacity of CMC-FeS reached 3358.28 mg/g, which was enhanced by 8.81% compared to non-stabilized FeS. X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses suggested that mercury removal was attributed to surface complexation, ion exchange, and chemical precipitation, resulting in the formation of FeS-Hg complexes and mercury sulfide (HgS). Dissolved oxygen had negligible effect on mercury uptake. The simple nanoparticle treatment inhibited mercury methylation by up to 60.8% when tested with a model metal-reducing bacterium Geobacter sulfurreducens PCA. When aged for 6 months, the nanoparticles exhibited excellent physical stability and high mercury capacity, and the immobilized mercury did not show any leaching. The present study provides direct evidence that immobilization of Hg by CMC-FeS remarkably inhibits microbial methylation of Hg, and thus mitigates toxic effects of mercury in water on human and the environmental health.

Cadmium (Cd) is one of the most commonly detected toxic heavy metals in the environment. Ferrous sulfide (FeS) nanoparticles were prepared using sodium carboxymethyl cellulose (CMC) as a stabilizer and tested for removal of Cd from aqueous solutions. Effects of CMC concentration, initial Cd concentration, pH, humic acid (HA) and dissolved oxygen were examined. Fully stabilized FeS (100 mg/L) nanoparticles were obtained using 0.01 wt% CMC. Batch kinetic tests showed that the nanoparticles at 100 mg/L as FeS rapidly removed 93% of 1 mg/L Cd within 4 h at pH 7.0, and the kinetic data were well interpreted by a pseudo-second-order rate model with a rate constant of 6.68 g·mg−1·hr−1. Sorption isotherm was well simulated by a dual-mode isotherm model with a maximum Langmuir sorption capacity of 497.5 mg/L at pH 7.0. Fourier transform infrared (FTIR) spectroscopy and X-ray powder diffraction (XRD) analyses suggested that chemical precipitation and surface complexation between Cd and FeS were dominant immobilization mechanisms. Increasing pH from 4.0 to 8.0 enhanced Cd removal rate from 73.0% to 98.8%, whereas addition of 3 mg/L HA (as total organic matter) inhibited the removal rate by 2.7% and the presence of molecular oxygen had negligible effect. Increasing NaCl or CaCl2 from 0 to 10 mM suppressed Cd removal by 10.1% and 27.7%, respectively. The immobilized Cd remained insoluble when aged for 717 days under anoxic or oxic conditions. This study demonstrated that CMC-stabilized FeS nanoparticles can facilitate long-term immobilization of cadmium in contaminated water.

Effects of a model oil dispersant (Corexit EC9500A) on sorption/desorption of phenanthrene were investigated with two marine sediments. Kinetic data revealed that the presence of the dispersant at 18 mg/L enhanced phenanthrene uptake by up to 7%, whereas the same dispersant during desorption reduced phenanthrene desorption by up to 5%. Sorption isotherms confirmed that at dispersant concentrations of 18 and 180 mg/L, phenanthrene uptake progressively increased for both sediments. Furthermore, the presence of the dispersant during desorption induced remarkable sorption hysteresis. The effects were attributed to added phenanthrene affinity and capacity due to sorption of the dispersant on the sediments. Dual-mode models adequately simulated sorption isotherms and kinetic data in the presence of the dispersant. Water accommodated oil (WAO) and dispersant-enhanced WAO increased phenanthrene sorption by up to 22%. This information is important for understanding roles of oil dispersants on the distribution and transport of petroleum PAHs in seawater-sediments.

1-alky-3-methylimidazolium taurate ionic liquid, [Cnmim]Tau (n = 3,4) were synthesized by neutralization method and were confirmed by 1H NMR and 13C NMR. Standard addition method was applied to determine the densities, surface tensions and refractive indexes for [Cnmim]Tau (n = 3,4). By using Tong's vaporization enthalpy model, the vaporization enthalpies of [Cnmim]Tau (n = 3,4) and some other ILs were estimated. The association enthalpies, ΔAHm0 of them in gas phase were estimated. Combined gs with Lorentz–Lorenz equation, a semi-empirical surface tension predicting equation can be obtained. The surface tensions of [Cnmim][Tau](n = 3,4), some other ILs and some molecular liquids were predicted. The predicted values are highly similar with the corresponding experimental ones. In current work, we put forward a new method for predicting ΔlgCp,m0,which was used for [Cnmim]Tau (n = 3,4) and other ILs. Our results are in the same order magnitude with Verevkin's, but ours are relatively higher.

To review trends in drug therapy and concomitant outcomes of elderly heart failure patients in Ontario, Canada.Utilization of drug therapies, mortality, and rehospitalization rates from April 1992 to March 2000 were determined in 77,421 elderly (aged/=65 years), community-based heart failure patients using linked administrative databases. Treatment effects were identified from published meta-analyses and randomized trials. The effect of drug trends on mortality and morbidity were assessed based on their absolute treatment effects.From 1992 to 2000, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use increased from 58% to 62% (P = 0.001) while beta-blocker use increased from 6% to 22% (P0.001). There was a decrease in the use of treatments for which no survival advantage had been demonstrated in randomized trials, such as digitalis (49% to 35%, P0.001), Vaughan-Williams class I antiarrhythmic agents (3.5% to 1.4%, P0.001), and first-generation calcium antagonists (21.3% to 9.6%, P0.001). The trends in drug therapy were associated with a 2.8% reduction in age-, sex-, and comorbidity-adjusted 1-year mortality and a 4.1% reduction in 1-year hospitalization rates. The observed trends in therapy over time explained 37% of the decrease in mortality and 30% of the decrease in rehospitalization rates. The treatment effect from beta-blockers was most pronounced, explaining 30% of the decrease in mortality and 10% of the decrease in rehospitalization rates.During 1992 to 2000, mortality and morbidity improved among elderly patients with heart failure, with increased utilization of beta-blockers contributing most to the beneficial trends in outcomes.

A working group was convened by the Canadian Cardiovascular Society (CCS) in 2010 to identify quality indicators (QIs) for heart failure (HF). Using the CCS "Best Practices for Developing Cardiovascular Quality Indicators" methodology, a total of 49 "long-list" QIs was identified and rated. Subsequent ranking and discussion led to the selection of an initial "short-list" of 6 QIs to evaluate quality care, including daily assessment of blood chemistry indicators, chest radiography, patient education, in-hospital use of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, assessment of left ventricular function, and 30-day hospital readmission. The short-list QIs were selected as being important for quality assurance and because the patient information, for the most part, can be captured during the inpatient setting, which would allow these QIs to be adopted more easily. These 6 QIs were subjected to a feasibility test that found that even within the inpatient setting, there is a significant gap between the existing knowledge infrastructure and the necessary information-tracking processes to measure QIs. Only 1 QI (30-day hospital readmission) can currently be measured comparatively across Canada, although the other 5 of 6 short-list QIs can be measured using other data collected by jurisdictions. Standardization and enhancements to knowledge infrastructure are essential to provide the comprehensive patient data necessary to evaluate the quality of HF care across Canada.

Background:Coronary artery disease is a leading cause of heart failure. Statins are efficacious drugs for the primary and secondary prevention of coronary heart disease, but their value in persons with heart failure remains unknown. Methods:We performed a population-based retrospective cohort study involving the entire province of Ontario, Canada, restricting participants to those aged 66 to 85 years who were free of cancer and who survived at least 90 days following hospitalization for newly diagnosed heart failure. The primary study outcome was the risk of death from all causes, nonfatal acute myocardial infarction, or nonfatal stroke among persons newly dispensed statins (n=1146) relative to those who were not (n=27682). Results:Themeanageofallparticipantswas76.5years, and half were women. During the 7-year study period, death, acute myocardial infarction, or stroke occurred in 217statinrecipients(13.6per100person-years)vs12299 nonrecipients (21.8 per 100 person-years; adjusted hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.630.83). Most of the benefit from statins was related to a reduction in all-cause mortality (adjusted HR, 0.67; 95% CI,0.57-0.78).Nosignificantreductionwasseenforsubsequent myocardial infarction (adjusted HR, 0.81; 95% CI,0.63-1.03)orstroke(adjustedHR,0.81;95%CI,0.531.25). Conclusions: Statin use is associated with a lower risk of death among seniors newly diagnosed as having congestive heart failure. While statin use has been previously shown to be efficacious in patients with coronary heartdiseaseandstroke,wecouldnotcontrolforallprognosticriskfactorsinthepresentstudy,includingleftventricular ejection fraction and serum lipid levels. Better evidence can direct clinicians about which patients with heart failure might benefit from these drugs. Arch Intern Med. 2005;165:62-67