Using foam fractionation to estimate PFAS air-water interface adsorption behaviour at ng/L and µg/L concentrations.

PFAS are biologically recalcitrant compounds that are persistent in the environment and have subsequently contaminated groundwater, landfill leachate and surface water. Due to their persistence and toxicity, there are environmental concentration limits imposed on some PFAS compounds that extend down to a few nanograms per litre and even proposals for reducing these to picogram per litre levels. Since PFAS concentrates at water-air interfaces as a result of their amphiphilic nature, this characteristic is important for the successful modelling and prediction of transport behaviour of PFAS through various systems.

Effect of different co-foaming agents on PFAS removal from the environment by foam fractionation.

Per- and poly-fluoroalkyl substances (PFAS) are recalcitrant, synthetic chemicals that are ubiquitous in the environment because of their widespread use in a variety of consumer and industrial products. PFAS contamination has become an increasing issue in recent years, which needs to be urgently addressed. Foam fractionation is emerging as a potential remediation option that removes PFAS by adsorption to the surface of rising air bubbles which are removed from the system as a foam.

Foam fractionation of per- and polyfluoroalkyl substances (PFASs) in landfill leachate using different cosurfactants.

Foam fractionation is one solution to recover per- and polyfluoroalkyl substances (PFASs) from aqueous sources. The separation process is based on the sorption of PFASs to the air-water interface of bubbles. In many practical cases, the PFAS concentration in the polluted liquid is too low to sustain foam formation and requires the support of a cosurfactant not only to act as a collector of PFAS but also to produce and sustain foam for effective separation.

Integrating a Top-Gas Recycling and CO Electrolysis Process for H-Rich Gas Injection and Reduce CO Emissions from an Ironmaking Blast Furnace.

Introducing CO electrochemical conversion technology to the iron-making blast furnace not only reduces CO emissions, but also produces H as a byproduct that can be used as an auxiliary reductant to further decrease carbon consumption and emissions. With adequate H supply to the blast furnace, the injection of H is limited because of the disadvantageous thermodynamic characteristics of the H reduction reaction in the blast furnace. This paper presents thermodynamic analysis of H behaviour at different stages with the thermal requirement consideration of an iron-making blast furnace.

Effect of selected monovalent salts on surfactant stabilized foams.

Surfactant-stabilized foams have been at the centre of scientific research for over a century due to their ubiquitous applications in different industries. Many of these applications involve inorganic salts either due to their natural presence (e.g.

Modulated Sn Oxidation States over a CuO-Derived Substrate for Selective Electrochemical CO Reduction.

Pursuing high catalytic selectivity is challenging but paramount for an efficient and low-cost CO electrochemical reduction (COR). In this work, we demonstrate a significant correlation between the selectivity of COR to formate and the duration of tin (Sn) electrodeposition over a cuprous oxide (CuO)-derived substrate. A Sn electrodeposition time of 120 s led to a cathode with a formate Faradaic efficiency of around 81% at -1.

Nanostructured NiMoS₂/Carbon Catalysts for Syngas Conversion to Higher Alcohols.

Syngas conversion to higher alcohols remains a very attractive alternative due to the abundance of syngas feedstock, such as renewable carbon and waste-carbon resources. Catalysts suitable for syngas conversion still show low selectivity to alcohols. In this article, we present nanostructured NiMoS₂ and CoMoS₂ catalysts supported on activated carbon pellets and design strategies to improve its selectivity towards higher alcohols.

Catalyst-Electrolyte Interactions in Aqueous Reline Solutions for Highly Selective Electrochemical CO Reduction.

Invited for this month's cover is the group of Tom Rufford at the University of Queensland. The image shows how choline chloride and urea in a reline solution interact with the surface of a silver cathode to enhance the selectivity of electrochemical CO reduction to CO. The Full Paper itself is available at 10.

Catalyst-Electrolyte Interactions in Aqueous Reline Solutions for Highly Selective Electrochemical CO Reduction.

Achieving high product selectivities is one challenge that limits viability of electrochemical CO reduction (CO R) to chemical feedstocks. Here, it was demonstrated how interactions between Ag foil cathodes and reline (choline chloride + urea) led to highly selective CO R to CO with a faradaic efficiency of (96±8) % in 50 wt % aqueous reline at -0.884 V vs.

Restaurant oil and grease management in Hong Kong.

Oil and grease (O&G) in wastewater can be considered as two parts or proportion contained in emulsion which exceeded O&G standard. Most of oil becomes emulsified with water when they pass through grease trap and discharged in the effluents. Thus, it may indicate that either treatment of grease traps or standards for O&G content stipulated in technical memorandum of Water Pollution Control Ordinance (WPCO) do not reflect the actual situation.

Ionic Liquids as the MOFs/Polymer Interfacial Binder for Efficient Membrane Separation.

Obtaining strong interfacial affinity between filler and polymer is critical to the preparation of mixed matrix membranes (MMMs) with high separation efficiency. However, it is still a challenge for micron-sized metal organic frameworks (MOFs) to achieve excellent compatibility and defect-free interface with polymer matrix. Thin layer of ionic liquid (IL) was immobilized on micron-sized HKUST-1 to eliminate the interfacial nonselective voids in MMMs with minimized free ionic liquid (IL) in polymer matrix, and then the obtained IL decorated HKUST-1 was incorporated into 4,4'-(hexafluoroisopropylidene)diphthalic anhydride-2,3,5,6-tetramethyl-1,3-phenyldiamine (6FDA-Durene) to fabricate MMMs.

Characterization of hard- and softwood biochars pyrolyzed at high temperature.

A wide range of waste biomass/waste wood feedstocks abundantly available at mine sites provide the opportunity to produce biochars for cost-effective improvement of mine tailings and contaminated land at metal mines. In the present study, soft- and hardwood biochars derived from pine and jarrah woods at high temperature (700 °C) were characterized for their physiochemical properties including chemical components, electrical conductivity, pH, zeta potential, cation-exchange capacity (CEC), alkalinity, BET surface area and surface morphology. Evaluating and comparing these characteristics with available data from the literature have affirmed the strong dictation of precursor type on the physiochemical properties of the biochars.

Copper and zinc adsorption by softwood and hardwood biochars under elevated sulphate-induced salinity and acidic pH conditions.

Biochar adsorption may lower concentrations of soluble metals in pore water of sulphidic Cu/Pb-Zn mine tailings. Unlike soil, high levels of salinity and soluble cations are present in tailing pore water, which may affect biochar adsorption of metals from solution. In the present study, removal of soluble copper (Cu) and zinc (Zn) ions by soft- (pine) and hard-wood (jarrah) biochars pyrolysed at high temperature (about 700 °C) was evaluated under typical ranges of pH and salinity conditions resembling those in pore water of sulphidic tailings, prior to their direct application into the tailings.

Mixed-Matrix Membranes with Metal-Organic Framework-Decorated CNT Fillers for Efficient CO2 Separation.

Carbon nanotube (CNT) mixed-matrix membranes (MMMs) show great potential to achieve superior gas permeance because of the unique structure of CNTs. However, the challenges of CNT dispersion in polymer matrix and elimination of interfacial defects are still hindering MMMs to be prepared for high gas selectivity. A novel CNT/metal-organic framework (MOF) composite derived from the growth of NH2-MIL-101(Al) on the surface of CNTs have been synthesized and applied to fabricate polyimide-based MMMs.

Synthesis and characterization of three amino-functionalized metal-organic frameworks based on the 2-aminoterephthalic ligand.

The incorporation of Lewis base sites and open metal cation sites into metal-organic frameworks (MOFs) is a potential route to improve selective CO2 adsorption from gas mixtures. In this study, three novel amino-functionalized metal-organic frameworks (MOFs): Mg-ABDC [Mg3(ABDC)3(DMF)4], Co-ABDC [Co3(ABDC)3(DMF)4] and Sr-ABDC [Sr(ABDC)(DMF)] (ABDC = 2-aminoterephthalate) were synthesized by solvothermal reactions of 2-aminoterephthalic acid (H2ABDC) with magnesium, cobalt and strontium metal centers, respectively. Single-crystal structure analysis showed that Mg-ABDC and Co-ABDC were isostructural compounds comprising two-dimensional layered structures.

In situ synthesis of zeolitic imidazolate frameworks/carbon nanotube composites with enhanced CO₂ adsorption.

A series of ZIF-8 and hydroxyl-functionalized carbon nanotube (CNT) composites were successfully synthesized by the solvothermal method. The obtained ZIF-8/CNT composites were characterized by XRD, SEM, TGA and N2 adsorption at 77 K. The contents of ZIF-8 and CNTs in the composites were calculated from thermal analysis data.

Mixed matrix membranes with strengthened MOFs/polymer interfacial interaction and improved membrane performance.

MOFs-based mixed matrix membranes (MMMs) have attracted extensive attention in recent years due to their potential high separation performance, the low cost, and good mechanical properties. However, it is still very challenging to achieve defect-free interface between micrometer-sized MOFs and a polymer matrix. In this study, [Cd2L(H2O)]2·5H2O (Cd-6F) synthesized using 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) as an organic ligand was introduced into the 6FDA-ODA polyimide matrix to achieve novel MOF MMMs.

Study on the controllable scale-up growth of vertically-aligned carbon nanotube arrays.

Vertically aligned carbon nanotubes (VA-CNTs) with high purity have been grown on quartz substrate via the gas phase catalytic chemical vapour deposition (CVD) by using ferrocene as the catalyst source and camphor as the carbon source. The effects of catalyst concentration, flow rate and water assistance on the morphology and structure of VA-CNTs are investigated by SEM, TEM, Raman and XPS characterizations. Under the optimized CVD conditions with modest ferrocene concentration and flow rate, dense and well VA-CNT arrays have been obtained.

Influence of surface orientation on the organization of nanoparticles in drying nanofluid droplets.

The influence of droplet orientation on the flow directed organization of nanoparticles in evaporating nanofluid droplets is important for the efficiency of foliar applied fertilizers and contamination adhesion to the exterior of buildings. The so called "coffee ring" deposit resulting from the evaporation of a sessile nanofluid drop on a hydrophilic surface has received much attention in the literature. Deposits forming on hydrophobic surfaces in the pendant drop position (i.

Graphdiyne: a versatile nanomaterial for electronics and hydrogen purification.

We theoretically extend the applications of graphdiyne, an experimentally available one-atom-thin carbon allotrope, to nanoelectronics and superior separation membrane for hydrogen purification on a precise level.

Highly thermostable anatase titania-pillared clay for the photocatalytic degradation of airborne styrene.

Airborne styrene is a suspected human carcinogen, and traditional ways of mitigation include the use of adsorption technologies (activated carbon or zeolites) or thermal destruction. These methods presenttheir own shortcomings, i.e.

Phosphate removal from wastewater using red mud.

Red mud, a waste residue of alumina refinery, has been used to develop effective adsorbents to remove phosphate from aqueous solution. Acid and acid-thermal treatments were employed to treat the raw red mud. The effects of different treatment methods, pH of solution and operating temperature on adsorption have been examined in batch experiments.

Immersion frying for the thermal drying of sewage sludge: an economic assessment.

This paper presents an economic study of a novel thermal fry-drying technology which transforms sewage sludge and recycled cooking oil (RCO) into a solid fuel. The process is shown to have significant potential advantage in terms of capital costs (by factors of several times) and comparable operating costs. Three potential variants of the process have been simulated and costed in terms of both capital and operating requirements for a commercial scale of operation.

Interparticle van der Waals force in powder flowability and compactibility.

Particle flowability and compactibility are the two critical process parameters tested when a pharmaceutical material is formulated for a tabletting process. These behavioral descriptions are strongly affected by geometrical, physical, chemical and mechanical particle properties, as well as operational conditions. The property influences are broadly known in a qualitative sense, but have largely escaped fundamental quantitative description.