Search

publishedVersion

The distinct polarity of biomolecule surfaces plays a pivotal role in their biochemistry and functions as it is involved in numerous processes, such as folding, aggregation, or denaturation. Therefore, there is a need to image both hydrophilic and hydrophobic bio-interfaces with markers of distinct responses to hydrophobic and hydrophilic environments. In this work, we present a synthesis, characterization, and application of ultrasmall gold nanoclusters capped with a 12-crown-4 ligand. The nanoclusters present an amphiphilic character and can be successfully transferred between aqueous and organic solvents and have their physicochemical integrity retained. They can serve as probes for multimodal bioimaging with light (as they emit near-infrared luminescence) and electron microscopy (due to the high electron density of gold). In this work, we used protein superstructures, namely, amyloid spherulites, as a hydrophobic surface model and individual amyloid fibrils with a mixed hydrophobicity profile. Our nanoclusters spontaneously stained densely packed amyloid spherulites as observed under fluorescence microscopy, which is limited for hydrophilic markers. Moreover, our clusters revealed structural features of individual amyloid fibrils at a nanoscale as observed under a transmission electron microscope. We show the potential of crown ether-capped gold nanoclusters in multimodal structural characterization of bio-interfaces where the amphiphilic character of the supramolecular ligand is required. publishedVersion

Low-toxicity perovskite-inspired Cu2AgBiI6 is a potential candidate for indoor photovoltaics. Cu2AgBiI6-based photovoltaics with an optimized mesoporous TiO2 thickness ensure high fill factor and a power conversion efficiency of 4.64% at 200 lux.

The rapid growth of megacities has led to higher levels of air pollution in cities. To supplement fixed air quality monitoring sites, the megacities offer an unprecedented opportunity to deploy air quality sensors on public transportation systems, and thus enable air quality monitoring at different locations in the city within the routes of the transport means. In this paper, we leverage this opportunity and show the feasibility of deploying air quality sensors on the means of the transport system by installing three low-cost sensors on three trams that operate on three different routes in the city of Helsinki. Our measurement campaign took place during the summer and autumn of 2019, during which we measured main traffic pollutants and meteorological variables. Specifically, we show the variability of pollution levels in different locations using pollution hotspots captured by one of the sensors for two of the main air pollutants. That is, we demonstrate the potential of deploying the sensors on public transport systems and show the feasibility and effectiveness of such an approach for pollution hotspot detection; this can enable real-time air quality information streaming, and thus contribute to the cities' air quality repositories used for the public.

Till date, oxidative ethanol steam reforming use Ni-based catalysts to produce syngas. However, Ni catalysts suffer from easy deactivation due to the coke formation at low temperatures. Therefore, oxidative ethanol dry reforming is a promising method and was investigated over 10 %Co/Al2O3 catalyst due to their high activity and stability to produce high-quality syngas. More importantly, the syngas can be upgraded to produce liquid biofuels and chemicals. The catalyst was evaluated in a quartz fixed-bed reactor under atmospheric pressure at PCO2 =PO2= 5 kPa, PC2H5OH = 15 kPa, with reaction temperature ranging between 773 and 973 K. The γ-Al2O3 support and 10 %Co/Al2O3 catalyst had BET surface areas of 175.2 m2 g−1 and 143.1 m2 g−1, respectively. Co3O4 and spinel CoAl2O4 phases were detected through X-ray diffraction measurements on the 10 %Co/Al2O3 catalyst surface. H2-TPR measurements indicate that the 10 %Co/Al2O3 catalyst was completely reduced at a temperature beyond 1000 K. NH3-TPD measurements indicated the presence of the weak, medium, and strong acid sites on the γ-Al2O3 support and 10 %Co/Al2O3 catalyst. Due to increased reaction temperature from 773 to 973 K, C2H5OH and CO2 conversions improved from 22.5 % to 93.6 % and 16.9–52.8 %, respectively. Additionally, the optimal yield of H2 and CO obtained at 68.1 % and 58.3 %, respectively. Temperature-programmed oxidation experiments indicated that the amount of carbon deposition was the lowest (28,92 %) at 973 K and increased by 41.48 % at 773 K. publishedVersion

Biological hydrogen methanation (BHM) is a biocatalytic process for biogas upgrading. Integrating ex-situ BHM processes into biogas facilities has the advantage of using inoculum, CO2, and nutrients directly from anaerobic digestion (AD) processes to enhance CH4 productivity. This study investigated the potential of biowaste digestate as an inoculum and digested biowaste reject water as the trickling liquid and nutrient source in thermophilic trickle bed reactors (TBRs). Use of reject water improved H2 conversion efficiency to up to 99 %, thus achieving a H2 loading rate of 10.8 LH2 L Rv-1 d-1 at a gas retention time (GRT) of 1.8 h and CH4 productivity of 2.6 L LRv-1 d-1 implying that reject water contains macronutrients beneficial to enriching hydrogenotrophic methanogens. However, at high H2 loading rates, a trace element supply was necessary to stabilize process performance. Hydrogenotrophic methanogens Methanothermobacter and Methanobacterium were selectively enriched, mainly due to the increased H2 loading rate. publishedVersion

Early warning systems monitoring the quality of drinking water need to distinguish between normal quality fluctuations and those caused by contaminants. Thus, to decrease the number of false positive events, normal water quality fluctuations, whether periodic or aperiodic, need to be characterized. For this, we used a novel flow-imaging particle counter, a light-scattering particle counter, and electrochemical sensors to monitor the drinking water quality of a pressure zone in a building complex for 109 days. Data were analyzed to determine the feasibility of the sensors and particle counters to distinguish periodic and aperiodic fluctuations from real-life contaminants. The concentrations of particles smaller than 10 μm and N, Small, Large, and B particles showed sudden changes recurring daily, likely due to the flow rate changes in the building complex. Conversely, the concentrations of larger than 10 μm particles and C particles, in addition to the responses of electrochemical sensors, remained in their low typical values despite flow rate changes. The aperiodic events, likely resulting from an abnormally high flow rate in the water mains due to maintenance, were detected using particle counters and electrochemical sensors. This study provides insights into choosing water quality sensors by showing that machine learning-based particle classes, such as B, C, F, and particles larger than 10 μm are promising in distinguishing contamination from aperiodic and periodic fluctuations while the use of other particle classes and electrochemical sensors may require dynamic baseline to decrease false positive events in an early warning system. publishedVersion

Iron-based coatings are often considered as replacement of hard chromium and WC-Co, as they pose lower health and environmental impact. In many cases, the combination of mechanical and chemical properties of iron-based alloys may be satisfactory and their relatively low cost makes these coatings an interesting candidate for many applications. This study is inspired by opportunities to harden the iron-base materials by strain hardening, solid solution strengthening, and precipitation hardening. Already commercially available Fe-based coating materials with precipitates of mixed carbides and borides in the metastable austenitic matrix achieve a high hardness. In this study, the cavitation erosion and abrasion resistance of various Fe-based coatings produced by HVAF and HVOF processes were investigated. Four experimental precipitates containing materials were prepared, and the sprayed coatings were tested for abrasive wear and cavitation erosion. In addition to precipitates, the contributions of martensite and retained austenite phases were investigated by influencing the microstructure through heat treatments, as the ability of these phases to influence ductility and toughness can be crucial to achieve the desired material properties. The properties of experimental and two commercial Fe-based alloys are compared with WC-Co and Cr3C2-NiCr coatings by property mapping.

Triterpenoids are among the largest groups of functional plant secondary metabolites but with intrinsically low water solubility. Because of their rigid backbone, multiple chiral centers, and functional groups, they are suitable for synthesizing water-soluble and conformationally rigid triterpenoid amphiphiles with unique self-assembly behavior. In this context, we present the aqueous self-assembly, structural transition, and antimicrobial properties of nanoscale oleanolic acid–spermine conjugates (2–4). The conjugates contain either one or two spermine moieties connected through a 1,4-disubstituted 1,2,3-triazole linker. We use cryogenic transmission electron microscopy (cryo-TEM) imaging to show that conjugates 2 and 3 self-assemble in water initially into kinetically favored metastable micellar nanoparticles (d ≈ 6–10 nm). The nanoparticles further reorganize to form thermodynamically stable helical nanofibers. Notably, cryo-TEM imaging also suggests the formation of spherulite-like structures. Time-dependent infrared (IR) spectroscopy reveals the role of hydration and dehydration in the structural transition of initial micelle-like structures into thermodynamically stable nanofibers. Electronic and vibrational circular dichroism (ECD and VCD, respectively) spectroscopy in the solution state suggests the formation of chiral superstructures with a left-handed helical twist. The conjugates display antibacterial properties with high selectivity against Gram-positive bacterial strains. The results help us understand fibrillar network formation in supramolecular gels, and demonstrate that the position and number of spermine groups influence the self-assembly behavior of the conjugates in aqueous media and their biological properties. acceptedVersion

Due to the ability of oils to penetrate into the structure of polymers, it is possible to create slippery surfaces with low water droplet sliding angles based on polymer coatings. Polylactic acid, polybutylene succinate and low-density polyethylene extrusion coatings were used as such surfaces in this study. The process of penetration of vegetable oils into the polymers was studied with the subsequent investigation of slippery behaviour of such system. Cottonseed oil and castor oil showed promising properties as lubricants. For oil infused polymer surfaces the water droplet sliding angles were significantly lower than for the untreated extrusion coating. The penetration of the permeant into the upper layers of the coating was confirmed by alteration of the static water contact angle, sliding angle and also by the cross section images. LDPE extrusion coating infused with castor oil showed the lowest water sliding angle − 8°. Biopolymers, being a main focus in this study, exhibited also promising results, PLA reached sliding angle of 14° with both olive and castor oil. Dependence of polymer permeability on various factors is rather complex and the wide range of oils used in this work helps to interpret the barrier performance of the studied materials. Degree of bond saturation, viscosity and polarity were found to influence mostly on the oil permeation through the studied polymers. publishedVersion

A putative novel methanotrophic genus, Candidatus Methylumidiphilus (Methylococcales), was recently shown to be ubiquitous and one of the most abundant methanotrophic genera in water columns of oxygen-stratified lakes and ponds in boreal and subarctic areas. However, it has probably escaped detection in many previous studies that used 16S rRNA gene amplicon sequencing due to insufficient database coverage, as previously analysed metagenome-assembled genomes (MAGs) affiliated with Ca. Methylumidiphilus do not contain 16S rRNA genes. Therefore, we screened MAGs affiliated with the genus for their 16S rRNA gene sequences in a recently published lake and pond MAG data set. Among 66 MAGs classified as Ca. Methylumidiphilus (with completeness over 40% and contamination less than 5%) originating from lakes in Finland, Sweden and Switzerland as well as from ponds in Canada, we found 5 MAGs, each containing one 1532 bp sequence spanning the V1-V9 regions of the 16S rRNA gene. After removal of sequence redundancy, this resulted in 2 unique 16S rRNA gene sequences. These sequences represented 2 different putative species: Ca. Methylumidiphilus alinenensis (GenBank accession OK236221) and another unnamed species of Ca. Methylumidiphilus (GenBank accession OK236220). We suggest that including these 2 sequences in reference databases will enhance 16S rRNA gene-based detection of members of this genus from environmental samples.

Optical fibers are a key component in modern photonics, where conventionally used polymer materials are derived from fossil-based resources, causing heavy greenhouse emissions and raising sustainability concerns. As a potential alternative, fibers derived from cellulose-based materials offer renewability, biocompatibility, and biodegradability. In the present work, we studied the potential of carboxymethyl cellulose (CMC) to prepare optical fibers with a core-only architecture. Wet-spun CMC hydrogel filaments were cross-linked using aluminum ions to fabricate optical fibers. The transmission spectra of fibers suggest that the light transmission window for cladding-free CMC fibers was in the range of 550–1350 nm, wherein the attenuation coefficient for CMC fibers was measured to be 1.6 dB·cm–1 at 637 nm. CMC optical fibers were successfully applied in touch sensing and respiratory rate monitoring. Finally, as a proof-of-concept, we demonstrate high-speed (150 Mbit/s) short-distance signal transmission using CMC fibers (at 1310 nm) in both air and water media. Our results establish the potential of carboxymethyl cellulose-based biocompatible optical fibers for highly demanding advanced sensor applications, such as in the biomedical domain. publishedVersion

Biomimetic calcium phosphate (CaP) systems mono-substituted with zinc (Zn2+) and magnesium (Mg2+) ions were prepared from a biogenic source (cuttlefish bone) by wet precipitation method. The results revealed that the as-prepared powders were composed of calcium-deficient carbonated hydroxyapatite (HAp), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP), while the heat-treated powders consisted of HAp, α-tricalcium phosphate (α-TCP), and β-tricalcium phosphate (β-TCP). In addition to Zn2+ and Mg2+ ions, the presence of CO32−, Sr2+ and Na + ions was detected with elemental analysis, which can be attributed to the use of cuttlefish bone as a natural precursor of Ca2+ ions. The data obtained by XRD study demonstrated the decrease in lattice parameters in the OCP and β-TCP phases for Zn-substitution and Mg-substitution in the HAp, OCP, and β-TCP phases. Zn2+ occupies the Ca(1,3,4,6,7,8) sites in OCP and Ca(1,2,3,4) sites in β-TCP, while Mg2+ occupies the Ca(2) sites in HAp and the Ca(4,5) sites in β-TCP. Phase transformation study under simulated physiological conditions for 7 days showed the transformation of OCP and ACP into the thermodynamically more stable HAp. Characterization of the zeta-potential showed positively charged populations for all prepared CaP powders, while all samples showed high bovine serum albumin adsorption capacity. The culture of human embryonic kidney cells showed that the prepared CaPs are non-cytotoxic and that viability of the cells increases during the culture period. All powders obtained showed antibacterial activity towards Gram-negative Escherichia coli and low antibacterial effect against Gram-positive Staphylococcus aureus, as determined by viability analysis during 48 h. Inhibition zone analysis and observation of the morphology after 24 h showed no antibacterial properties. publishedVersion

Background Bacillus subtilis is generally regarded as a ubiquitous facultative anaerobe. Oxygen is the major electron acceptor of B. subtilis, and when oxygen is absent, B. subtilis can donate electrons to nitrate or perform fermentation. An anode electrode can also be used by microorganisms as the electron sink in systems called anodic electro-fermentation. The facultative anaerobic character of B. subtilis makes it an excellent candidate to explore with different electron acceptors, such as an anode. This study aimed to optimise industrial aerobic bioprocesses using alternative electron acceptors. In particular, different end product spectrum of B. subtilis with various electron acceptors, including anode from the electro-fermentation system, was investigated. Results B. subtilis was grown using three electron acceptors, i.e. oxygen, nitrate and anode (poised at a potential of 0.7 V vs. standard hydrogen electrode). The results showed oxygen had a crucial role for cells to remain metabolically active. When nitrate or anode was applied as the sole electron acceptor anaerobically, immediate cell lysis and limited glucose consumption were observed. In anode-assisted electro-fermentation with a limited aeration rate, acetoin, as the main end product showed the highest yield of 0.78 ± 0.04 molproduct/molglucose, two-fold higher than without poised potential (0.39 ± 0.08 molproduct/molglucose). Conclusions Oxygen controls B. subtilis biomass growth, alternative electron acceptors utilisation and metabolites formation. Limited oxygen/air supply enabled the bacteria to donate excess electrons to nitrate or anode, leading to steered product spectrum. The anode-assisted electro-fermentation showed its potential to boost acetoin production for future industrial biotechnology applications.

Increasing generation of electronic waste (e-waste) is a major concern for emerging rare earth elements (REEs) pollution if not appropriately disposed of. Nevertheless, e-waste could be considered as a secondary source for critical REEs mining. Under the context of circular economy, this review focuses on selective recovery of REEs from e-waste using ionic liquid (IL) extraction. ILs demonstrate a sustainable alternative to organic volatiles used in traditional solvent extraction process. Despite insufficient literature on applications of ILs for REEs extraction from limited categories of real e-waste, the review comprehensively summarizes the latest studies on recovery of REEs from e-waste (mostly uncontaminated) using IL extraction and the existing data indicate encouraging outcomes in terms of extractability and selectivity. Roles of ILs in REEs recovery have been critically analyzed. The review has systematically illustrated the fundamental design of ILs for selective extraction of REEs, including bifunctional and task-specific ILs, incorporation of dilutant/extractant, non-fluorinated ILs, etc. This fundamental knowledge could greatly facilitate cost-effective and selective extraction of REEs from e-waste. ILs must be completely assessed in terms of extractability, selectivity, and reusability. Synergistic extraction based on quaternary phosphonium salts are discussed to realize excellent extraction of REEs into IL phase leaving non-REEs in the aqueous phase for easier separation. Overall, regeneration of spent ILs and subsequent separation of extracted REEs from ILs are also crucial to selective recovery of REEs from e-waste using novel ILs. Nevertheless, industrialization of this technology would require more fundamental data on extraction efficiency and recovery rate of REEs from real e-waste. publishedVersion

Antimony-based perovskite-inspired materials (PIMs) are solution-processable halide absorbers with interesting optoelectronic properties, low toxicity, and good intrinsic stability. Their bandgaps around 2 eV make them particularly suited for indoor photovoltaics (IPVs). Yet, so far only the fully inorganic Cs3Sb2ClxI9−x composition has been employed as a light-harvesting layer in IPVs. Herein, the first triple-cation Sb-based PIM (CsMAFA-Sb) in which the A-site of the A3Sb2X9 structure consists of inorganic cesium alloyed with organic methylammonium (MA) and formamidinium (FA) cations is introduced. Simultaneously, the X-site is tuned to guarantee a 2D structure while keeping the bandgap nearly unchanged. The presence of three A-site cations is essential to reduce the trap-assisted recombination pathways and achieve high performance in both outdoor and indoor photovoltaics. The external quantum efficiency peak of 77% and the indoor power conversion efficiency of 6.4% are the highest values ever reported for pnictohalide-based photovoltaics. Upon doping of the P3HT hole-transport layer with F4-TCNQ, the power conversion efficiency of CsMAFA-Sb devices is fully retained compared to the initial value after nearly 150 days of storage in dry air. This work provides an effective compositional strategy to inspire new perspectives in the PIM design for IPVs with competitive performance and air stability. publishedVersion

Polymer self-assembly leading to cooling-induced hydrogel formation is relatively rare for synthetic polymers and typically relies on H-bonding between repeat units. Here, we describe a non-H-bonding mechanism for a cooling-induced reversible order-order (sphere-to-worm) transition and related thermogelation of solutions of polymer self-assemblies. A multitude of complementary analytical tools allowed us to reveal that a significant fraction of the hydrophobic and hydrophilic repeat units of the underlying block copolymer is in close proximity in the gel state. This unusual interaction between hydrophilic and hydrophobic blocks reduces the mobility of the hydrophilic block significantly by condensing the hydrophilic block onto the hydrophobic micelle core, thereby affecting the micelle packing parameter. This triggers the order-order transition from well-defined spherical micelles to long worm-like micelles, which ultimately results in the inverse thermogelation. Molecular dynamics modeling indicates that this unexpected condensation of the hydrophilic corona onto the hydrophobic core is due to particular interactions between amide groups in the hydrophilic repeat units and phenyl rings in the hydrophobic ones. Consequently, changes in the structure of the hydrophilic blocks affecting the strength of the interaction could be used to control macromolecular self-assembly, thus allowing for the tuning of gel characteristics such as strength, persistence, and gelation kinetics. We believe that this mechanism might be a relevant interaction pattern for other polymeric materials as well as their interaction in and with biological environments. For example, controlling the gel characteristics could be considered important for applications in drug delivery or biofabrication. publishedVersion

Determination of the soil parameters in the foundation design analyses for offshore and nearshore platforms subjected to cyclic loading from wind and waves requires extensive advanced laboratory testing. The amount of such testing can be reduced by drawing on the experience that has been gained during the design of offshore structures in the past. It is outlined how an existing data base can be used to estimate the soil parameters needed in the foundation design analyses based on conventional parameters, like undrained static shear strength, plasticity index and overconsolidation ratio for clays, and relative density and/or water content, fines content and overconsolidation ratio for sand and silt. The estimated soil parameters can be used in feasibility analyses before site-specific parameters are available and to reduce the amount of site-specific advanced laboratory testing in the final design phase. The application of the data base is demonstrated by examples for clay and for sand with different fines content. publishedVersion

The long-term performance of natural fibre reinforced thermoplastic (NFRP) composites is critical for developing more sustainable structures. The defects developed in NFRP due to fibre swelling and shrinkage in wet service conditions constitute a significant issue. Here, a method for restricting the in-service swelling and shrinkage of NFRP is proposed. The NFRP composites were processed with swollen fibres stored in moist conditions before thermoplastic resin infusion. The swelling of water-saturated NFRP was decreased up to 56% by non-dry fibres. The similar in-plane shear strength and transverse tensile strength of NFRP composites processed with oven-dried and preconditioned fibres (at 50% RH) showed the in-situ polymerisation of poly (methyl-methacrylate) (PMMA) to be insensitive to moisture. Processing composites with preconditioned fibres (at 90% RH) decreased the water immersion ageing sensitivity for in-plane shear properties of NFRP from 30% to nearly zero. publishedVersion Non

Wind turbine operators usually use data from a Supervisory Control and Data Acquisition system to monitor their conditions, but it is challenging to make decisions about maintenance based on hundreds of different parameters. Information is often hidden within measurements that operators are unaware of. Therefore, different feature extraction techniques are recommended. The pitch system is of particular importance, and operators are highly motivated to search for effective monitoring solutions. This study investigated different dimensionality reduction techniques for monitoring a hydraulic pitch system in wind turbines. These techniques include principal component analysis (PCA), kernel PCA and a deep autoencoder. Their effectiveness was evaluated based on the performance of a support vector machine classifier whose input space is the new extracted feature set. The developed methodology has been applied to data from a wind farm consisting of five 2.3 MW fixed-speed onshore wind turbines. The available dataset is composed of nine pitch events representing normal and faulty classes. The results indicate that the features extracted by the deep autoencoder are more informative than those extracted by PCA and kernel PCA. These features led to the achievement of a 95.5% F1-score, proving its superiority over the traditional usage of original features. publishedVersion

The aim of this study was to investigate the potential for elemental sulphur recovery from sulphurous solutions under aerobic and anoxic conditions by haloalkalophilic Thioalkalivibrio denitrificans at 0.8–19.6 g S2O32−-S L−1 and 0.2–0.58 g NO2 L−1, respectively. The experiments were conducted as batch assays with haloalkaline (pH 10 and ≥ 14 g Na+ L−1) thiosulphate solution. Aerobically, the highest biotransformation rate of thiosulphate obtained was 0.03 h−1 at 8.5 g L S2O32−-S. Based on Monod model, the maximum substrate utilisation rate (qm) was 0.024 h−1 with half saturation constant (Ks) 0.42 g S2O32−-S L−1 at initial [S2O32--S] of 14 g L−1. S0 accumulated at [S2O32−-S] ≥ 1.5 g L−1 (10% yield at initial 9.5 g S2O32−-S L−1) and the highest S0 yield estimated with the model was 61% with initial [S2O32--S] of 16.5 g L−1. Anoxically, the maximum nitrite removal rate based on Monod modelling was 0.011 h−1 with Ks = 0.84 g NO2− L−1. Aerobically and anoxically the maximum specific growth rates (µm) were 0.046 and 0.022 h−1, respectively. In summary, high-rate aerobic biotransformation kinetics of thiosulphate were demonstrated, whereas the rates were slower and no S0 accumulated under anoxic conditions. Thus, future developments of biotechnical applications for the recovery of S0 from haloalkaline streams from the process industry should focus on aerobic treatment. Haloalkaline S2O32− biotransformations kinetics by Thioalkalivibrio denitrificans Aerobic thiosulphate-S bioconversion up to 0.024 h−1 with Ks = 0.42 g S2O32−-S L−1 10% S0 yield with initial 9.5 g S2O32--S L−1 in aerobic condition Anoxic NO2 removal up to 0.01 h−1 with Ks = 0.84 g NO2− L−1

Contamination of groundwater by arsenic (As(III/V)) is a serious global issue, and phosphate (P(V)) is known to be the biggest interference in adsorption-based remediation methods. The present study is focused on understanding the interaction between phosphate and iron oxides/oxy-hydroxides with two well-known classes of potential adsorbents in the important pH range of 5–9 and the effect of such interactions on the uptake of arsenite and arsenate. Spectroscopic studies such as X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy were used to understand the binding of various oxyanions of phosphorous and arsenic with the iron oxides/oxy-hydroxides, exploring the core levels of P 2p and Fe 2p. Materials used for adsorption experiments were magnetite (MAG) and a nanocomposite, confined metastable two-line ferrihydrite (CM2LF); CM2LF is used for arsenic remediation in the affected states in India. Further, we studied the interference of P(V) in As(III/V) adsorption. The kinetics of adsorption was quantified using ion chromatography (IC), where P(V) alone followed a pseudo-second-order model. In the case of mixed solutions, namely, APmix1 (P(V) + As(III)) and APmix2 (P(V) + As(V)), kinetics data suggested that P(V) or As(III/V) oxyanions partially follow the pseudo-second-order model. Results also confirmed that CM2LF performed better than magnetite (MAG) for As(III/V) uptake in the presence of P(V). As(III) and As(V) species are more competitive than P(V) at neutral pH. A model for the adsorption of P(V) species in water on ferrihydrite particles was developed using density functional theory (DFT). This accounted for phosphate complexation at various pH values. The study is highly useful in developing an affordable solution for sustainable arsenic remediation. Various aspects of sustainability are discussed. acceptedVersion

publishedVersion

The present study evaluates the effect of water and acetic acid washing on the chemical composition of spruce bark in-depth. Also, washing with steam explosion condensate (SEC) was investigated which is a novel attempt. The leaching kinetics of troubling elements (TE) was studied to understand the leaching behavior of TEs and for upscaling the process. Furthermore, to study the ash transformation behavior of TEs in pre-treated and raw bark at high temperatures (500–1500 °C), thermodynamic equilibrium modeling (TEM) was also performed. The result of washing pre-treatment shows high removal of TEs: 22–97% Na, 46–82% Cl, 14–79% K, 14–65% Mg, 25–50% S, 3–22% Ca, 12–36% P, 3–43% Si, and 6–35% N. Continuous removal of TEs was seen with increasing washing duration where most of TEs followed a second-order leaching kinetics. Acid washing results in a much higher and quicker removal for all TEs than water washing. Due to the acidic nature of the SEC, it shows similar removal of TEs as the 0.1 M acetic acid solution. TEM reveals that the transformation behavior of TEs in bark changes considerably after pre-treatment. Pre-treated bark shows the formation of fewer problematic compounds responsible for fouling, slagging, and corrosion at typical gasification and combustion temperatures, such as KCl, K2SO4, K2CO3, KOH, Na2SO4, NaCl, and K-, Na-, P-, and Ca-slag. Though best washing efficiency was seen for longer washing durations, 10 min washing with 0.1 M acetic acid or SEC may be adequate for practical applications. publishedVersion

Biomass chemical looping gasification (BCLG) offers significant advantages over the conventional biomass gasification process in terms of enhanced gasification efficiency, inherent CO2 capture, process circularity, and mitigated emissions of pollutants. This review discusses the prevailing status of research and development of BCLG in terms of production of high-quality syngas and negative carbon emissions based on the latest experimental and modelling studies. In particular, the design of the BCLG process and reactors is compared with conventional gasification. This review suggests that the BCLG process could be 10–25 % more efficient than the conventional combustion and gasification system in terms of economical H2-production cost (3.37 USD/kg H2-produced) and negative life cycle emissions of CO2 (−14.58 kg-CO2e/ kg-H2 produced). This review has extensively considered the effects of process parameters and oxygen carriers (OCs) on gasification chemistry and reaction engineering during BCLG experiments. More specifically, the properties of OCs have been holistically analysed from technological, economic, and environmental perspectives to screen appropriate and affordable OCs for BCLG. In addition, the state-of-the-art modelling studies on BCLG are compared in terms of thermodynamic equilibrium, kinetics, and integrated processes. Technological challenges and research gaps in experiments and modelling have been highlighted in order to advance the BCLG process for industrial applications. In particular, further experimental work is needed to tackle issues related to stability and deactivation of OCs, fluidisation and circulation, the mechanical strength of OCs, the optimisation of feed conversion, and the integration and management of various thermal reactors. It is also desired to enhance the accuracy of models by incorporating optimisation of integrated processes and a more detailed reaction mechanism. Overall, BCLG is a promising negative emissions technology for renewable energy production, yet more innovative efforts in experimental and modelling studies are imperative to move towards more practical applications.

This study reports the tolerance of chemolithoautotrophic biotransformation of sulphurous compounds towards pulp and paper (P&P) mill wastewaters (primary filtrate of bleaching (PFB) and composite wastewater (WW)) and their constituents under haloalkaline conditions. The effects of organic compounds (methanol, acetate, D(+)-xylose, phenol and benzene) that may be present in P&P wastewaters, and yeast extract, a complex organic compound on thiosulphate biotransformation by Thioalkalivibrio versutus were investigated. All experiments were carried out in batch bioassays at pH 10 and 13–23 g Na+/L. Phenol and benzene reduced thiosulphate biotransformation by 88 and 94% at 0.25 and 1 g/L, respectively in 10 days. 20 g/L methanol, 20 g/L yeast extract and 10 g/L xylose reduced the biotransformation by 90, 88 and 56%, respectively. No inhibition of biotransformation occurred with acetate at concentrations up to 20 g/L. The growth was also enhanced by 1 to 10 g/L yeast extract likely serving as additional nutrients. At pH (∼10), the studied organic acids remain mostly unprotonated and, thus control their access through the cell membrane. Therefore, the inaccessibility of these compounds to the cytosol is a likely mechanism for having non-inhibitory effects. The 87% (v/v) WW did not affect thiosulphate biotransformation efficiency while 87% (v/v) PFB reduced it by 36% by day 10. The resistance of T. versutus to common organics present in P&P wastewaters indicates its potential use for sulphur recovery from P&P mill wastewaters at haloalkaline conditions and thus, supports the circular economy approach. publishedVersion

Digital polymerase chain reaction (dPCR) is emerging as a reliable platform for quantifying microorganisms in the field of water microbiology. This paper reviews the fundamental principles of dPCR and its application for health-related water microbiology. The relevant literature indicates increasing adoption of dPCR for measuring fecal indicator bacteria, microbial source tracking marker genes, and pathogens in various aquatic environments. The adoption of dPCR has accelerated recently due to increasing use for wastewater surveillance of Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) - the virus that causes Coronavirus Disease 2019 (COVID-19). The collective experience in the scientific literature indicates that well-optimized dPCR assays can quantify genetic material from microorganisms without the need for a calibration curve and often with superior analytical performance (i.e., greater sensitivity, precision, and reproducibility) than quantitative polymerase chain reaction (qPCR). Nonetheless, dPCR should not be viewed as a panacea for the fundamental uncertainties and limitations associated with measuring microorganisms in water microbiology. With dPCR platforms, the sample analysis cost and processing time are typically greater than qPCR. However, if improved analytical performance (i.e., sensitivity and accuracy) is critical, dPCR can be an alternative option for quantifying microorganisms, including pathogens, in aquatic environments. publishedVersion

Increasing textile production is associated with an environmental burden which can be decreased with an improved recycling system by digitalization. The collection of textiles is done with so-called curbside bins. Sensor technologies support dynamic-informed decisions during route planning, helping predict waste accumulation in bins, which is often irregular and difficult to predict. Therefore, dynamic route-optimization decreases the costs of textile collection and its environmental load. The existing research on the optimization of waste collection is not based on real-world data and is not carried out in the context of textile waste. The lack of real-world data can be attributed to the limited availability of tools for long-term data collection. Consequently, a system for data collection with flexible, low-cost, and open-source tools is developed. The viability and reliability of such tools are tested in practice to collect real-world data. This research demonstrates how smart bins solution for textile waste collection can be linked to a dynamic route-optimization system to improve overall system performance. The developed Arduino-based low-cost sensors collected actual data in Finnish outdoor conditions for over twelve months. The viability of the smart waste collection system was complemented with a case study evaluating the collection cost of the conventional and dynamic scheme of discarded textiles. The results of this study show how a sensor-enhanced dynamic collection system reduced the cost 7.4% compared with the conventional one. We demonstrate a time efficiency of −7.3% and that a reduction of 10.2% in CO2 emissions is achievable only considering the presented case study. publishedVersion

This study investigated heterotrophic bioleaching of rare earth elements (REEs) and base metals from spent nickel-metal-hydride (NiMH) batteries. Furthermore, the impacts of phosphorous source [Ca3(PO4)2, KH2PO4 and K2HPO4] and its concentration on organic acid production by Gluconobacter oxydans and Streptomyces pilosus were evaluated. Phosphorous source affected microbial acid production and metal leaching. Among the studied phosphorous sources, use of K2HPO4 resulted in highest organic acid production by both bacteria. Increasing K2HPO4 concentration from 2.7 to 27 mM enhanced pyruvic acid production by S. pilosus from 2.2 to 10.7 mM. However, no metal was leached from the spent NiMH batteries with S. pilosus using either one-step, two-step or spent-medium bioleaching. With G. oxydans, highest gluconic acid concentration of 45.0 mM was produced at the lowest K2HPO4 concentration of 2.7 mM. When using two-step bioleaching with G. oxydans, higher leaching efficiencies were obtained for base metals (88.0% vs. 68.0% Fe, 41.5% vs. 35.5% Co, 18.5% vs 16.5% Ni), while more REEs were leached using spent-medium bioleaching (9.0% vs. 6.0% total REEs). With both bioleaching methods, base metals leaching was faster than that of REEs. Surplus of phosphorous should be avoided in bioleaching cultures as precipitation especially with REEs is possible. Graphic Abstract

openaire: EC/H2020/894511/EU//SUREFIT | openaire: EC/H2020/856602/EU//FINEST TWINS To achieve carbon neutrality in the EU, it is important to renovate the existing EU residential buildings for a higher building energy efficiency. This study examines the impacts of several novel renovation technologies on energy consumption, CO2 emissions and indoor climates in southern European residential buildings through building-level simulations. Three typical residential buildings in South Europe were chosen as the demo buildings to implement the novel technologies. The technologies were classified into passive, ventilation and generation packages, and then simulated independently under the intermittent and continuous heating schedules. Additionally, two final combinations of renovation technologies were also simulated to demonstrate the maximum energy and CO2 emissions reduction potential of the demo buildings. All novel retrofit technologies manifested obvious effects on the energy consumption and CO2 emissions. Nevertheless, the effects were significantly affected by the heating schedule. When the intermittent heating schedule was switched to the continuous heating schedule, the relative energy conservation and CO2 emissions reduction potential of the thermal insulation improvement measures (e.g., bio-aerogel thermal insulation) increased, while those of the generation measures (e.g., solar assisted heat pump) diminished. Renovation with the final combinations reduced the primary energy consumption by up to 66%, 74% and 65% in the continuously heated Greek, Portuguese and Spanish demo buildings, the corresponding CO2 emissions reductions of which were 65%, 75% and 74%, respectively.

We report the design and synthesis of three star-shaped non-fullerene (NFA) acceptors, TPA-2T-INCN, TPA-2T-BAB, and TPA-T-INCN, based on triphenylamine (TPA) core and linked through π-conjugated thiophene (T) spacers to different terminal units (3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile, INCN, and 1,3-dimethylbarbituric acid, BAB). These materials were blended with the widely used poly(3-hexylthiophene-2,5-diyl) (P3HT) donor polymer and tested in flexible organic photovoltaics (OPVs). The NFAs capped with the strong electron withdrawing INCN unit performed best in OPVs. Both P3HT:TPA-T-INCN, and P3HT:TPA-2T-INCN blends also showed the highest photoluminescence quenching efficiency (95.8% and 92.6%, respectively). Surprisingly, when reducing the number of T spacers from 2 to 1, the solubility of the NFAs in o-dichlorobenzene increased, leading to easier processing during the OPV fabrication and better surface morphology. This explains the best performance of TPA-T-INCN-based blends in OPVs, with a champion power conversion efficiency of 1.13%. publishedVersion

Actively controllable photoluminescence is potent for a wide variety of applications from biosensing and imaging to optoelectronic components. Traditionally, methods to achieve active emission control are limited due to complex fabrication processes or irreversible tuning. Here, we demonstrate active emission tuning, achieved by changing the ambient humidity in a fluorescent dye-containing hydrogel integrated into a metal-insulator-metal (MIM) system. Altering the overlapping region of the MIM cavity resonance and the absorption and emission spectra of the dye used is the underlying principle to achieving tunability of the emission. We first verify this by passive tuning of cavity resonance and further experimentally demonstrate active tuning in both air and aqueous environments. The proposed approach is reversible, easy to integrate, and spectrally scalable, thus providing opportunities for developing tunable photonic devices. publishedVersion

Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO2. A possible solution for the transport of H2 in a safe and low-cost way is in the form of liquid organic hydrogen carriers (LOHCs). As an alternative to loading LOHC with H2 via a two-step procedure involving preliminary electrolytic production of H2 and subsequent chemical hydrogenation of the LOHC, we explore here the possibility of electrochemical hydrogen storage (EHS) via conversion of proton of a proton donor into a hydrogen atom involved in covalent bonds with the LOHC (R) via a protoncoupled electron transfer (PCET) reaction: . We chose 9-fluorenone/ fluorenol (Fnone/Fnol) conversion as such a model PCET reaction. The electrochemical activation of Fnone via two sequential electron transfers was monitored with in-situ and operando spectroscopies in absence and in presence of different alcohols as proton donors of different reactivity, which enabled us to both quantify and get the mechanistic insight on PCET. The possibility of hydrogen extraction from the loaded carrier molecule was illustrated by chemical activation. Funding Agencies|Swedish Research Council [2016-05990]; Knut and Alice Wallenberg Foun-dation [H2O2]; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Mate-rials at Link?ping University [2009-00971]

The pulp and paper industry's mixed sludge represents waste streams with few other means of disposal than incineration. Hydrothermal carbonization (HTC) could be advantageous for the sludge refinement into value-added products, thus complementing the concept of pulp and paper mills as biorefineries. Laboratory HTC was performed on mixed sludge (at 32% and 15% total solids) at temperatures of 210–250 °C for 30 or 120 min, and the characteristics of the HTC products were evaluated for their potential for energy, carbon, and nutrient recovery. The energy content increased from 14.9 MJ/kg in the mixed sludge up to 20.5 MJ/kg in the hydrochars. The produced filtrates had 12–15-fold higher COD and 3–5-fold higher volumetric methane production than untreated sludge filtrates, even though the methane yield against g-COD was lower. The increased value of the hydrochars in terms of energy content and carbon sequestration potential promote HTC deployment in sludge treatment and upgrading. publishedVersion

Lead-free perovskite-inspired materials (PIMs) are gaining attention in optoelectronics due to their low toxicity and inherent air stability. Their wide bandgaps (≈2 eV) make them ideal for indoor light harvesting. However, the investigation of PIMs for indoor photovoltaics (IPVs) is still in its infancy. Herein, the IPV potential of a quaternary PIM, Cu2AgBiI6 (CABI), is demonstrated upon controlling the film crystallization dynamics via additive engineering. The addition of 1.5 vol% hydroiodic acid (HI) leads to films with improved surface coverage and large crystalline domains. The morphologically-enhanced CABI+HI absorber leads to photovoltaic cells with a power conversion efficiency of 1.3% under 1 sun illumination—the highest efficiency ever reported for CABI cells and of 4.7% under indoor white light-emitting diode lighting—that is, within the same range of commercial IPVs. This work highlights the great potential of CABI for IPVs and paves the way for future performance improvements through effective passivation strategies. publishedVersion

The use of pyrolysis process to valorize digestate from anaerobic digestion (AD) of municipal sewage sludge for biochar production was piloted in a central biogas plant. The pyrolysis also generates pyrolysis liquid with high organics and nutrient contents that currently has no value and requires treatment, which could potentially be done in AD. As the pyrolysis liquid may contain inhibitory compounds, we investigated the effects of adding the pyrolysis liquid on AD of sewage sludge and thermal hydrolysis pretreated sewage sludge (THSS) simulating the full-scale centralized biogas plant conditions. In batch assays, the pyrolysis liquid as such did not produce any methane, and the 1% and 5% (v/w) shares suppressed the methane production from THSS by 14–19%, while a smaller decrease in methane production was observed with sewage sludge. However, in the semi-continuous reactor experiments, pyrolysis liquid at a 1% (v/w) share was added in sewage sludge or THSS feed without affecting the methane yields or digestate characteristics. The laboratory results indicated that pyrolysis liquid can be treated in AD, while extrapolating the results to the centralized biogas plant indicated minor increase in the overall methane production and an increased potential for ammonium recovery. publishedVersion

This study focuses on the strain hardening and adiabatic heating of two stainless steels after a sudden increase of strain rate. Tensile tests were performed where the strain rate was rapidly increased from ~ 10–4 s−1 to 1.3 × 103 s−1. Synchronized full field strain and temperature measurements were carried out with Digital Image Correlation and Infrared Thermography to analyze the materials behavior immediately after the strain rate jump. The results show that the temperature increases gradually while the strain hardening rate drops immediately after the strain rate jump. The temperature increase due to adiabatic heating does not seem to explain the drop in the strain hardening rate, thus the strain rate seems to have a direct effect on the strain hardening rate of the studied steels.

There are various existing practices and future potential for turning mining waste into valuable products. The inventory of the tailings in the metal mines in Finland showed that considerable concentrations of many critical metals are contained in the waste. However, the amounts of generated waste are so significant that the full implementation of circular economy is challenging. A combination of several different circular economy approaches (reduce, reprocess, upcycle, downcycle and dispose for future) is needed to manage the waste streams in mining in a holistic way. Various technologies are already in use for the recovery of metals from the tailings and for the use of the mineral residues in high and low-value products. The institutional framework has an impact on the economics of the valorisation of mine waste. Digitalisation can support in identifying where the biggest potential for valorisation exists. The rising concepts of digital material and product passports would support the circularity and the traceability of waste-based materials. publishedVersion

In order to efficiently degrade ibuprofen (IBU) by peroxymonosulfate (PMS) activation, manganese cobalt oxide nanoparticles-decorated functionalized multi-walled carbon nanotubes (MnCo2O4/FCNTs) were prepared using a facile hydrothermal method. Comprehensive characterization of this PMS activator in multi-scale suggested that MnCo2O4 nanoparticles were uniformly decorated on FCNTs. The catalytic performance was systematical evaluated under various environmental conditions, including temperature, pH, and the presence of different common water matrix species (e.g., Cl-, HCO3-, and natural organic matter). The as-synthesized MnCo2O4/FCNTs demonstrated excellent catalytic activity with kapp ranging 0.285-0.327 min-1 under a wide pH range of 3-9 within 10 min, which achieved a complete removal of IBU and a mineralization rate higher than 90%. During oxidation process for stability and reusability test, recycled MnCo2O4/FCNTs was found durable with negligible leaching of metal ions from spent catalyst, exhibiting its high stability for PMS activation with merely slight decrease of kapp from 0.285 to 0.201 min-1 in the fourth cycle. Electron paramagnetic resonance analysis further confirmed that •OH, SO4•- and 1O2 were generated in the robust MnCo2O4/FCNTs-PMS system. Both radical and nonradical reactions were found to be responsible for the enhanced IBU degradation. Overall, this study sheds light on practical knowledge of IBU removal using MnCo2O4/FCNTs for PMS activation. publishedVersion

Sewage sludge chars were subjected to washing to produce a clean solid fuel of superior quality. First, sewage sludge was converted into chars at different carbonization temperatures (400–700 °C), and then the produced chars were washed with various washing techniques, i.e., water (W), hydrochloric acid (HCl), ethylenediamine tetraacetic acid (EDTA) and ultrasound-assisted water to further reduce ash and heavy metal contents. The washed chars were systematically characterized and their fuel properties were analyzed. The results indicated that all washing techniques decreased ash content of chars and improved their fuel ratio. The washed chars exhibited higher heating values, lower slagging and ash fouling indexes and higher combustion reactivity, indicating the better quality of the derived fuels. Among the washing techniques, HCl washing was the most efficient process as carbon content increased by 20%, while ash content decreased by 50%. The fuel ratio as well as slagging and ash fouling indexes were significantly improved. Furthermore, the combustion reactivity showed similar pattern to coal with high conversion rate suggesting the enhanced thermal stability of the fuel. In conclusion, pyrolysis as a single process seems inefficient to produce high quality chars; however, coupling pyrolysis with washing can yield chars with satisfactory fuel properties. Graphic abstract: [Figure not available: see fulltext.]. acceptedVersion

Source-separated urine can enable efficient nutrient recycling, but the removal of the organic fraction that is required to ensure a safe nutrient product typically also removes the nitrogen in urine (present as total ammonium nitrogen, TAN). In this study, a reagent-free pH control method was used with a two-chamber electrochemical cell with a boron doped diamond (BDD) anode to oxidize synthetic and real urine at different anodic pH values. Without pH adjustment (pH 8.4), all TAN in urine was oxidized in synthetic urine, but at pH ≤3, 79% ± 5% of TAN was retained. Simultaneously, ≥90% of organic content was removed at all pH values with a pH-independent rate. Two different TAN oxidation regimes with corresponding zero-order (i.e. current limited) TAN oxidation rates of -0.02 h-1 and -0.002 h-1 were identified, separated by a chloride to TAN concentration ratio of approximately 0.2 M/M. The higher TAN oxidation rate is linked to a breakpoint chlorination-type oxidation pathway, whereas the lower rate is linked to a direct oxidation pathway on the BDD surface. In addition to TAN, potassium and phosphorus were conserved at 101% ± 6% and 89% ± 4%, respectively. The proposed technology allows for the selective oxidation of the organic fraction in urine while retaining a high proportion of all other key nutrients for potential reuse as a fertilizer. This journal is publishedVersion

Some recent findings regarding the negative health effects of particulate matter increase the relevance of the detailed characteristics of particulate emissions from different sources and especially the nonvolatile fraction of particles. In this study, the nonvolatile fraction of ultrafine particulate emissions from a non-road diesel engine was studied. The measurements were carried out in an engine laboratory and the exhaust sample was taken from the engine-out location with various steady state driving modes. Four different fuels, including fossil fuel, soybean methyl ester (SME), rapeseed methyl ester (RME), and renewable paraffinic diesel (RPD), were used. In the sampling system, the sample was diluted and led through a thermodenuder removing the volatile fraction of particles. The measured particle size distributions of nonvolatile particles were found to be trimodal. Based on the size distribution data as well as the morphology and elemental composition of particles in transmission electron microscopy (TEM) samples, we were able to draw conclusions from the most probable origin of the different particle modes, and the modes were named accordingly. From larger to smaller in particle size, the modes were a soot mode, lubricating oil originated core (LC) mode, and a fuel originated core (FC) mode. All of these three modes were detected with every driving mode, but differences were seen, for example, between different fuels. In addition, a trade-off was observed in the concentrations of the LC mode and the soot mode as a function of the engine torque. publishedVersion

Sustainable coating solutions that function as a fire retardant for wood are still a challenging topic for the academic and industrial sectors. In this study, composite coatings of casein protein mixed with mica and aluminum trihydroxide (ATH) were tested as fire retardants for wood and plywood; coating degradation and fire retardancy performance were assessed with a cone calorimeter, and a thermogravimeter was used for the thermal stability measurement. The results indicated that casein–mica composites were beneficial as coatings. The heat release rate (HRR) and the total heat released (THR) of the sample coated with casein–mica composite were reduced by 55% and 37%, respectively; the time to ignition was increased by 27% compared to the untreated sample. However, the TTI of the sample coated with the casein–mica–ATH composite was increased by 156%; the PHR and THR were reduced by 31% and 28%, respectively. This is attributed to the yielded insulating surface layer, active catalytic sites, and the crosslink from mica and endothermic decomposition of ATH and casein producing different fragments which create multiple modes of action, leading to significant roles in suppressing fire spread. The multiple modes of action involved in the prepared composites are presented in detail. Coating wear resistance was investigated using a Taber Abrader, and adhesion interaction between wood and a coated composite were investigated by applying a pull-off test. While the addition of the three filler types to casein caused a decrease in the pull-off adhesion strength by up to 38%, their abrasion resistance was greatly increased by as much as 80%. publishedVersion

Recycling vital macronutrients, such as nitrogen, from wastewaters back to fertiliser use is becoming essential to ensure sustainable agricultural practices. Technologies developed for such purposes are typically evaluated for their capacity to recover nutrients; however, the presence of contaminants of emerging concern (CECs) in these waste-derived nutrient products must not be overlooked. In this study, nitrogen was recovered from real anaerobically digested municipal sewage sludge reject water using a novel set-up combining membrane-based electroconcentration (EC) with electrochemical advanced oxidation processes (EAOPs). Simultaneously, the fate of five spiked pharmaceuticals (carbamazepine, ciprofloxacin, diclofenac, erythromycin and metoprolol) as well as ten indigenous perfluoroalkyl substances (PFASs) was investigated. The EC-EAOP system was effective in up-concentrating nitrogen ca. 13 times to a final concentration of 12.7 ± 0.8 g L−1 in the nutrient product. At the same time, no up-concentration was observed for the pharmaceuticals and their concentrations in the recovered concentrated remained at ≤ 3.4 ± 1.3 µg L−1. The EAOPs were the main transformation mechanism for all the pharmaceuticals at 33–88% efficiency, while diclofenac also notably adsorbed in the system (30 ± 1.4%). Out of the ten studied PFASs, only three were found in the recovered nutrient concentrate, albeit at very limited concentrations of ≤ 0.024 ± 0.013 µg L−1. The EAOPs were found to degrade longer-chain PFASs into their shorter-chain counterparts. The low contaminant concentrations in the nutrient product pose a reduced risk for soil contamination compared to, e.g., biosolids that are more typically used as fertilisers. publishedVersion

Plate-type thermal energy storage systems (PTESs) have been proposed to mitigate the effect of the low thermal conductivity of phase change materials on the performance and efficiency of thermal energy storage systems. Nevertheless, a prompt reduction in the thermal power of PTESs due to the drop/rise in the outlet temperature at the early stage of the charging/discharging process has not been well resolved. To remedy this, the current study proposes a modified PTES and presents a computational fluid dynamics model of this PTES for performance and efficiency analysis. The results show that the outlet temperature of the modified PTES is constant for 100 min in the melting and 33 min in the solidification processes, while this temperature drops/raises almost immediately in the similar PTESs after starting these processes. In addition, the presented PTES shows an improvement of 75 % and 28.6 %, respectively, in the energy storage capacity per unit volume and effectiveness than a roll-bonded PTES. publishedVersion

Due to relatively lower toxicity, bisphenol S (BPS) has become an alternative to previously used bisphenol A. Nevertheless, the occurrence of BPS and its ecological impact have recently attracted increasing attentions because the toxicology effect of BPS with life cycle or multigenerational exposure on aquatic organisms remains questionable. Herein, Daphnia magna (D. magna) multigenerational bioassays spanning four generations (F0–F3) and single-generation recovery (F1 and F3) in clean water were used to investigate the ecotoxicology of variable chronic BPS exposure. For both assays, four kinds of life-history traits (i.e., survival, reproduction, growth and ecological behavior) were examined for each generation. After an 18-day exposure under concentration of 200 μg/L, the survival rate of D. magna was less than 15 % for the F2 generation, whereas all died for the F3 generation. With continuous exposure of four generations of D. magna at environmentally relevant concentrations of BPS (2 μg/L), inhibition of growth and development, prolonged sexual maturity, decreased offspring production and decreased swimming activity were observed for the F3 generation. In particular, it is difficult for D. magna to return to its normal level through a single-generation recovery in clean water in terms of reproductive function, ecological behavior and population health. Hence, multi-generational exposure to low concentrations of BPS can have adverse effects on population health of aquatic organisms with short breeding cycles, highlighting the necessity to assess the ecotoxicology of chronic BPS exposure for public health. publishedVersion

To establish the characteristics and kinetics of dynamic softening in a Al0.3CoCrFeNi high–entropy alloy (HEA), isothermal compression tests were carried out in a suitable temperature range of 1273–1423 K at 10−2 and 10−1 s−1 in accord with our previous study. It was found that the discontinuous dynamic recrystallization (DRX) was the dominant microstructural reconstitution mechanism. The conditions of critical stress/strain for the onset of dynamic recrystallization were determined using the Poliak–Jonas analytical criterion. Further, a kinetic model was established based on the Avrami-type function in order to be able to predict the volume fraction of DRX. The DRX volume fraction expectedly increased with strain. The microstructural investigation of the isothermally compressed specimens revealed a good agreement with the proposed DRX kinetics model and validated its accuracy. Additionally, the evolution of DRX with strain was characterized by interrupting the test carried out at 1323 K/10−1 s−1 at different strains. The progress of DRX evolving as increased formation of new recrystallized grains further corroborated the predictions of the kinetic model. The micro-texture analysis revealed random texture in the recrystallized grains, whereas the unrecrystallized grains had shown their preferred orientation towards the fiber texture. publishedVersion

In this work, we integrate atomically precise noble metal nanoclusters (NCs) on gold nanorods (AuNRs) to create hybrid plasmonic-luminescent nanomaterials. Initially, we assemble luminescent Ag29(LA)12 NC (LA = lipoic acid) to silica shell-encapsulated AuNRs. The resulting nanostructure shows plasmon-enhanced luminescence in aqueous medium as well as in the solid state. Atomic precision of the fluorophores used in this case allows detailed characterization of individual nanocomposites by diverse techniques, including transmission electron microscopy (TEM) and 3D electron tomographic reconstruction. We extend this strategy to prepare similar structures with gold NC protected with bovine serum albumin (Au30BSA). These two examples demonstrate the generic nature of the present strategy in preparing plasmonic-luminescent hybrid nanostructures using atomically precise NCs. acceptedVersion

The analysis of microplastics in complex environmental samples requires the use of chemicals to reduce the organic matrix. This procedure should be evaluated in terms of the preservation of the microplastic's integrity, typically done with pristine reference microplastics. However, real microplastics are most likely degraded due to weathering, so pristine reference microplastics might not depict the appropriateness of the process. This study performed a purification process using sodium dodecyl sulfate and hydrogen peroxide on sewage sludge containing LLDPE, HDPE, PP, PS, PET, PA66 and SBR samples exposed to simulated environmental weathering. The degradation of the polymers was assessed by analyzing surface morphology, mass variation, and mechanical, thermal and chemical properties. Comparison with pristine polymers revealed that the purification process can lead to more detrimental effects if the polymers are weathered. After the purification process, some important observations were: 1) LLDPE, PP and SBR surfaces had cracks in the weathered samples that were not observed in the pristine samples, 2) weathered LLDPE, PP and PA66 experienced greater mass loss than pristine, 3) the fragmentation propensity of weathered LLDPE, HDPE, PP, PS and SBR increased compared to pristine samples and 4) the main characteristic peaks in FTIR spectrum could be identified and used for chemical identification of most polymers for pristine and weathered samples. Based on the findings of this study, when analyzing the efficiency and adequacy of a purification process with methods based on surface morphology, mass variation and particle counting indicators, it is recommended to consider the differences that potentially arise between pristine and weathered microplastics, especially for polyolefins (PEs and PP). publishedVersion

The two economically important shrimp species in Bangladesh are the tiger shrimp, Penaeus monodon, and the brown shrimp, Metapenaeus monoceros. However, a continuous decline in the landing of these species from the industrial trawling made it critical to assess their stock biomass status to explore their response to the present degree of removal. Given the minimum data requirement and robustness, this study employed the depletion-based stock reduction analysis (DB-SRA) to assess these fisheries rigorously. For the industrial fishing zone (beyond the 40 m depth in the EEZ of Bangladesh), the estimated historic mean carrying capacity (K) was 5015 metric tons for the Penaeus monodon and 35,871 metric tons for Metapenaeus monoceros. The estimated overfishing limits (OFL), which were much smaller than the reported catches throughout the time series, indicate the overfishing status of these fisheries. As a result, the estimated biomass for the reference year (B2020) for both species was lower than BMSY, indicating that these fisheries are not producing MSY. Therefore, for the rebuilding and sustainable management of these stocks, this study recommended a catch limit of 100 metric tons for P. monodon and 750 metric tons for M. monoceros for the next ten years from biomass projections.