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The increase in dye-containing effluents that are discharged into the environment and the need to remediate the water bodies from the adverse effect of these dye pollutants have motivated a lot of research work. In this study, ZnO and TiO2 heterojunction systems (MO) embedded in cellulose nanocrystals (CNC), derived from sawdust, are reported. The nanocomposites (CNC/MO) were subsequently used as photocatalyst for the degradation of methyl blue (MB). The nanocomposites were characterized using SEM/EDs, XRD, and the degradation of MB were determined by UV-vis spectrophotometer. The XRD analysis showed characteristic peaks of CNC and the metal oxide (MO) upon the nanocomposite formation. A reduction in the intensity of peak at 30°, attributed to the cellulose 1β phase of pristine CNC, was observed. The morphological evaluation revealed that the nanocomposite exhibited intertwined spherical and rod-like shape on the surface. The effects of some key operating parameters, such as initial pH, catalyst dosage, and initial dye concentration on the degradation of MB were investigated. Higher degradation percentage (98.52%) of MB was observed for the CNC/MO at optimum pH 6. The adopted kinetics models showed that MB degradation was well described by the pseudo-second order model. The application of this nanocomposites in real industrial sample will confirm its robustness.

Background Application of chemical bactericides, for controlling soft rot bacteria, causes environmental pollution and toxic hazards to human. In addition, it is ineffective, expensive, and limited. Therefore, application of bio-control agents, plant extracts, or safe chemicals may play an important role as safe alternative approaches for controlling phyto-pathogenic bacteria. Objective This work is aimed to apply bio-control agents (Bacillus subtilis, Bacillus pumilus, Trichoderma harzianum, and Trichoderma virens), aqueous plant extracts (lantana flowers and leaves, lemongrass leaves, and olive cake), and citric acid as pre-sowing treatment for controlling bacterial soft rot pathogen and study their ability for improving yield and quality of potato tubers in field and storage. All treatments were applied as soil treatment and/or foliar spray, except citric acid applied as foliar spray only. Results The cultural filtrates of bio-control agents of B. subtilis, B. pumilus, T. harzianum, and T. virens; aqueous plant extracts of lantana, lemongrass, and olive cake; and citric acid could protect daughter potato tubers against bacterial soft rot disease in field application, except lemongrass (as soil treatment). The bio-control agents highly increased the activities of peroxidase, polyphenol oxidase, and chitinase enzymes, than other treatments. The bio-control agents also improved the shoot parameters, viz, shoot length, number of shoots/pit, and number of leaves/pit and yield parameters, viz, tuber weight/pit, tubers number/pit, and total tubers weight/pit, compared to citric acid and plant extracts, respectively. The treatments as foliar spray have good results for protecting the potato tubers through storage, than soil treatment. The treatments highly enhanced the stored potato tubers quality, viz, dry matter, reducing sugars, total carbohydrates, specific gravity, and starch content. Conclusions The tested treatments could protect the potato tubers in field and/or storage against soften development. The treatments could improve the plant growth and yield parameters in field as well as enhanced the stored potato tubers quality and increase the stored time. It is clear that the treatments can be applied as pre-sowing treatment for controlling Erwinia soft rot bacteria.

The thymus is a primary lymphoid organ that plays an essential role in T lymphocyte maturation and selection during development of one arm of the mammalian adaptive immune response. Although transcriptional mechanisms have been well documented in thymocyte development, co-/post-transcriptional modifications are also important but have received less attention. Here we demonstrate that the RNA alternative splicing factor MBNL1, which is sequestered in nuclear RNA foci by C(C)UG microsatellite expansions in myotonic dystrophy (DM), is essential for normal thymus development and function. Mbnl1 129S1 knockout mice develop postnatal thymic hyperplasia with thymocyte accumulation. Transcriptome analysis indicates numerous gene expression and RNA mis-splicing events, including transcription factors from the TCF/LEF family. CNBP, the gene containing an intronic CCTG microsatellite expansion in DM type 2 (DM2), is coordinately expressed with MBNL1 in the developing thymus and DM2 CCTG expansions induce similar transcriptome alterations in DM2 blood, which thus serve as disease-specific biomarkers., The activity of the RNA splicing factor MBNL1 is altered in myotonic dystrophy (DM) patients. Here the authors characterize the thymic phenotype of Mbnl1 knockout mice, including developmental defects, transcriptome changes, and RNA mis-splicing of transcripts encoding thymic transcription factors.

Combined anaerobic digestion (AD) and photodegradation of slaughterhouse wastewater (SWW) was carried out to remove biodegradable chemical oxygen demand (COD) and biorecalcitrant aromatic compounds which were mainly p-cresol and dibutyl phthalate (DBP). The synergy between the two processes was analyzed through biodegradability enhancement by photodegradation and supply of bioenergy through AD to supplement the energy requirement of the photodegradation process. Degradation products of each process were determined using gas chromatography coupled with a mass spectrometer (GC–MS). Anaerobic digestion as a stand-alone process removed up to 80% COD, while it could only remove about 35% of the aromatic compounds. Photodegradation, as a post-treatment to the AD, removed 92% of the aromatic compounds and enhanced the biodegradability of the digester effluent by 50%, which could be recycled to the AD unit. The aromatic compounds were photodegraded via phthalic acid and hydroquinone. Also, AD as an initial step removed fats, oils, and grease which otherwise would have hindered catalytic activity during photodegradation post-treatment. The biomethane produced could supplement up to 20% of the electricity requirement by the energy-intensive photodegradation process to achieve total pollutants removal, making the integrated process to be a viable option for SWW management.

The use of biomass as low cost and eco-friendly adsorbent has been investigated as alternative to current chemically synthesized media, which are used for the removal of toxic metals from wastewate...

A magnetic nanocomposite (NC), Fe3O4@PPy-MAA, was synthesised via in situ oxidative polymerisation of the pyrrole monomer in a thioglycolic acid (mercaptoacetic acid) solution (as a dopant), in the presence of iron oxide (Fe3O4). The newly developed NC was characterised using ATR-FTIR, FE-SEM, HR-TEM, XRD, TGA, BET and VSM. The performance of the NC for silver ion (Ag+) adsorption was carried out through batch studies as a function of pH, adsorbent dose, temperature and initial Ag+ concentration. The maximum adsorption capacity of Ag+ was determined to be 806.4 mg/g at 25 °C using Langmuir adsorption isotherm at a solution pH of 5.6. The kinetics studies indicated that the Ag+ adsorption onto the Fe3O4@PPy-MAA NC surface was rapid and was well described by the pseudo-second-order kinetics equation. Also, the present study emphasised the reusability of Ag+-adsorbed waste material for the disinfection of microorganisms, which was demonstrated through the excellent antimicrobial activity of the NC against Escherichia coli in both synthetic and natural water samples. Therefore, the as-prepared Fe3O4@PPy-MAA NC has an excellent ability to successfully remove Ag+ ions from aqueous solutions and subsequently, the Ag-loaded waste material could be used as a potential candidate disinfectant.

The presence of toxic metals in surface and natural waters, even at trace levels, poses a great danger to humans and the ecosystem. Although the combination of adsorption and coagulation techniques has the potential to eradicate this problem, the use of inappropriate media remains a major drawback. This study reports on the application of NaNO2/NaHCO3 modified sawdust-based cellulose nanocrystals (MCNC) as both coagulant and adsorbent for the removal of Cu, Fe and Pb from aqueous solution. The surface modified coagulants, prepared by electrostatic interactions, were characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS). The amount of coagulated/adsorbed trace metals was then analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). SEM analysis revealed the patchy and distributed floccules on Fe-flocs, which was an indication of multiple mechanisms responsible for Fe removal onto MCNC. A shift in the peak position attributed to C2H192N64O16 from 2θ = 30 to 24.5° occurred in the XRD pattern of both Pb- and Cu-flocs. Different process variables, including initial metal ions concentration (10–200 mg/L), solution pH (2–10), and temperature (25–45 °C) were studied in order to investigate how they affect the reaction process. Both Cu and Pb adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 111.1 and 2.82 mg/g, respectively, whereas the adsorption of Fe was suggestive of a multilayer adsorption process, however, Fe Langmuir maximum adsorption capacity was found to be 81.96 mg/g. The sequence of trace metals removal followed the order: Cu &gt, Fe &gt, Pb. The utilization of this product in different water matrices is an effective way to establish their robustness.

Water quality degradation due to noxious heavy metals has become a serious concern because of their impact on human health and the ecosystem. In this study cellulose nanocrystal (CNC) derived from sawdust as a green renewable and sustainable resource was functionalized and used as adsorption media to remove vanadium(V) from aqueous solution. The physicochemical properties of the adsorbent were studied using various characterization techniques such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The performance of the functionalized CNC adsorbent was explored as a function of solution pH, temperature, adsorbent mass, time and initial concentration in batch adsorption. X-ray diffraction results confirmed the crystalline nature of the CNC. The SEM micrograph revealed rough surface and high porosity, which suggested that the CNC possessed prerequisite properties of a good adsorbent. From the FTIR spectra results the interaction between anionic vanadium species and functionalized CNC was confirmed by the reduction in wavelength of carboxylic groups (–COOH) of the CNC. Meanwhile, from the adsorption results, V removal efficiency was found to be affected by solution pH, temperature, adsorbent mass, and initial concentration. The Langmuir maximum adsorption capacity was 37.9-47.2 mg/g in the temperature range studied. In evaluating the reusability of the CNC through adsorption-desorption studies, results confirmed that the functionalized CNC could be used more than once but with a reduction in affinity of V in each adsorption-desorption cycle. More studies using environmental water samples are therefore still required to explore the robustness of the functionalized CNC adsorption media.

The continuous increase in the wastes generated from forestry, timber, and paper industries has engendered the need for their transformation into economically viable materials for the benefit of mankind. This study reports the preparation and application of sawdust-derived cellulose nanocrystals (CNC) incorporated with zinc oxide as a novel adsorbent for the removal of methylene blue (MB) from water. The CNC/ZnO nanocomposite was characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy. The amount of MB adsorbed was determined by a UV–vis spectrophotometer. The microscopic analysis revealed that the nanocomposite had a narrow particle size range and exhibited both spherical and rod-like morphologies. The XRD analysis of the nanocomposite showed characteristic high-intensity peaks in the range of 30–75° attributed to the presence of ZnO nanoparticles, which were responsible for the enhancement of the crystallinity of the nanocomposite. The results revealed a relationship between the MB removal efficiency and changes in solution pH, nanocomposite dosage, initial concentration, temperature, and reaction time. The adsorption equilibrium isotherm, measured in the temperature range of 25–45 °C and using a concentration of 20–100 mg/L, showed that the MB sorption followed the Langmuir isotherm with a maximum adsorption capacity of 64.93 mg/g. A pseudo-second-order kinetic model gave the best fit to the experimental data. Based on adsorption performance, the CNC/ZnO nanocomposite offers prospects for further research and application in amelioration of dye-containing effluent.

Significance Myotonic dystrophy type 1 (DM1) is a model for RNA-mediated disease in microsatellite expansion disorders. DM1 is caused by CTG expansions (CTGexp) and expression of CUGexp RNAs that sequester muscleblind-like (MBNL) proteins, while also triggering hyperphosphorylation of CUGBP1/ETR3-like factor 1 (CELF1). These proteins regulate developmental transitions in RNA processing, so DM1 is characterized by retention of fetal RNA processing patterns in adults. Although current evidence indicates that CELF1 is a specific antagonist of MBNL activity, this study reveals that another protein, HNRNPA1, is also downregulated during normal development but upregulated in DM1, where it also induces fetal splicing shifts. Thus, DM1 disease results from an imbalance in the expression of multiple RNA processing factors important for both proliferation and differentiation., Studies on myotonic dystrophy type 1 (DM1) have led to the RNA-mediated disease model for hereditary disorders caused by noncoding microsatellite expansions. This model proposes that DM1 disease manifestations are caused by a reversion to fetal RNA processing patterns in adult tissues due to the expression of toxic CUG RNA expansions (CUGexp) leading to decreased muscleblind-like, but increased CUGBP1/ETR3-like factor 1 (CELF1), alternative splicing activities. Here, we test this model in vivo, using the mouse HSALR poly(CUG) model for DM1 and recombinant adeno-associated virus (rAAV)-mediated transduction of specific splicing factors. Surprisingly, systemic overexpression of HNRNPA1, not previously linked to DM1, also shifted DM1-relevant splicing targets to fetal isoforms, resulting in more severe muscle weakness/myopathy as early as 4 to 6 wk posttransduction, whereas rAAV controls were unaffected. Overexpression of HNRNPA1 promotes fetal exon inclusion of representative DM1-relevant splicing targets in differentiated myoblasts, and HITS-CLIP of rAAV-mycHnrnpa1-injected muscle revealed direct interactions of HNRNPA1 with these targets in vivo. Similar to CELF1, HNRNPA1 protein levels decrease during postnatal development, but are elevated in both regenerating mouse muscle and DM1 skeletal muscle. Our studies suggest that CUGexp RNA triggers abnormal expression of multiple nuclear RNA binding proteins, including CELF1 and HNRNPA1, that antagonize MBNL activity to promote fetal splicing patterns.

Pollution of water sources by pathogens is a major concern worldwide. This study investigated critical disinfection aspects such as bacterial regrowth or decay and evaluation of metal-ion leaching during photocatalytic disinfection. The inactivation of waterborne bacterial pathogens (Escherichia coli, Salmonella species, Shigella species and Vibrio cholerae) using ultraviolet and solar photocatalysis was evaluated. Bare and metal-ion (silver, copper and iron)-doped titanium dioxide photocatalysts were used to explore comparative performance. The influence of photocatalyst concentration (0.1–1.0 g/L), source of radiation (ultraviolet or solar light) and water type (synthetic and municipal wastewater) was examined. The disinfection data were fitted to the pseudo-first-order model. The disinfection efficiency was higher in saline deionized water (99.9998–100%) that was spiked with the target pathogens (106 colony forming units/mL), compared to actual wastewater samples. Within 180 min of treatment under solar irradiation, disinfection efficacy of 86.8–100% was achieved, while 99.4–100% disinfection efficacy was attained under ultraviolet irradiation within 60 min. A significant difference (p

A composite of magnetized natural zeolite and polypyrrole (MZ-PPY) was synthesized and used to explore Cr(VI) removal from aqueous solution and environmental water. A column dynamic set up was employed to analyse adsorption breakthrough performance under different process conditions. Material characterization was done to assess morphology and functional groups and to elucidate Cr(VI) removal mechanism. Results indicate that Cr(VI) removal is a function of bed mass, flowrate and initial Cr(VI) concentration. Sharp breakthrough curves were obtained which are fingerprints of reaction kinetics controlled adsorption process. Consequently, three simple kinetic models; Yoon–Nelson, Thomas and Bohart–Adams were applied to the experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column that are useful for process design. The Yoon–Nelson and Thomas models were found to appropriately describe the breakthrough curves. From material characterization, Cr(VI) removal proceeded mainly by adsorption and reduction. Meanwhile using adsorbent exhaustion rate (AER) as performance indicator, a low value of 0.25 was obtained for environmental water from a chrome mine suggesting that MZ-PPY is a highly efficient adsorption media.

The present study investigated the potential of clay/manganese oxide (CMnO) hybrid adsorbent for the removal of manganese (Mn2+) from mine impacted water (MIW). The adsorbent was characterised by X-ray diffraction, Fourier transform infra-red (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmet–Teller and X-ray photoelectron spectroscopy (XPS) techniques. The equilibrium sorption capacity was depended on solution pH, MnO content of the clay, concentration and temperature. Isothermal adsorption highly inclined towards Freundlich isotherm model while thermodynamic parameters directed that the adsorption process was spontaneous and endothermic in nature. The adsorption kinetics of Mn2+ onto CMnO fitted well with the pseudo-second-order model and the value of activation energy of adsorption (Ea) was 32 kJ/mol, inferring that the adsorption proceeded by activated chemisorption process. Both intra-particle and film diffusion mechanisms were found to be the sorption rate-controlling steps. Experiments with real MIW water revealed that CMnO exhibited high Mn2+ removal efficiency in the presence of interfering ions but anions removal posed a great challenge. The XPS, FT-IR and pH analyses suggested that oxidation, complexation and ion-exchange mechanisms were responsible for Mn2+ removal by CMnO. These findings demonstrate that CMnO could serve as an inexpensive adsorbent for polishing Mn2+ polluted water.

In this study, eggshell (ES) powder was evaluated as a cheap and biocompatible waste material for the pre-treatment of acid mine drainage (AMD) leachate from coal dump. First, the composition of the AMD and physiochemical properties of the ES powder were determined using various standard characterization techniques. Then the removal efficiency of the target metal contaminants and the acid-neutralisation effect were explored in batch and kinetic set-ups. Thereafter, the settling rate of sludge formed after separately reacting ES and limestone powders with AMD was explored. Results revealed that the AMD leachate was highly acidic and contaminated with both cations and anions. Thermogravimetric analysis (TGA) and X-ray fluorescence (XRF) analyses demonstrated that ES powder was thermally stable up to 700 °C and CaO was the main component, respectively. Scanning electron microscopy (SEM) and EDX spectra confirmed the removal of contaminants. Both the decrease in particle size and increase in mass of ES enhanced the treatment efficiency. Although complete Fe and Al removal was achieved, Mn and sulphates posed a challenge as they were partially removed. Meanwhile, ES demonstrated superior acid-neutralizing effect to limestone and the mine water clarity and pH were shifted to acceptable levels. Both Fe and Al removal proceeded through an exothermic process while it was opposite for Mn. Kinetics were rapid and the sludge from ES powder settled faster compared with that from limestone powder. Cost analysis indicated that significant financial savings can be realised by substituting limestone with ES material. The findings suggest that ES waste could be an efficient and cheap material in the pre-treatment of AMD effluents.

Clinoptilolite modified with polypyrrole and iron oxide nanoparticles (Cln-PPy-Fe3O4) nanocomposite as a potential adsorbent for V (V) ions was prepared via polymerization of pyrrole monomer using FeCl3 oxidant in aqueous medium in which clinoptilolite-Fe3O4 nanoparticles were suspended. The structure and morphology of the prepared adsorbent was analysed with the Fourier transform infrared (FTIR) spectrometer, field-emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and high-resolution transmission electron microscope (HR-TEM). Column fixed bed studies were performed to test the ability of the adsorbent to remove V (V) ions from aqueous solution. Low values of adsorbent exhaustion rate (AER) and large bed volumes were observed at lower metal ion concentration, higher bed mass and lower flow rate for V(V) removal indicating good performance. The volume of treated water processed at breakthrough point were found to be 0.09; 0.63 and 1.26 L for bed mass of 1, 2.5; and 5 g, respectively. The Yoon–Nelson and Thomas models appropriately described the breakthrough curves.

The use of solar and ultraviolet titanium dioxide photocatalytic ozonation processes to inactivate waterborne pathogens ( Escherichia coli , Salmonella species, Shigella species and Vibrio cholerae ) in synthetic water and secondary municipal wastewater effluent is presented. The performance indicators were bacterial inactivation efficiency, post-disinfection regrowth and synergy effects (collaboration) between ozonation and photocatalysis (photocatalytic ozonation). Photocatalytic ozonation effectively inactivated the target bacteria and positive synergistic interactions were observed, leading to synergy indices (SI) of up to 1.86 indicating a performance much higher than that of ozonation and photocatalysis individually (SI ≤ 1, no synergy; SI > 1 shows synergy between the two processes). Furthermore, there was a substantial reduction in contact time required for complete bacterial inactivation by 50–75% compared to the individual unit processes of ozonation and photocatalysis. Moreover, no post-treatment bacterial regrowth after 24 and 48 h in the dark was observed. Therefore, the combined processes overcame the limitations of the individual unit processes in terms of the suppression of bacterial reactivation and regrowth owing to the fact that bacterial cells were irreparably damaged. The treated wastewater satisfied the bacteriological requirements in treated wastewater for South Africa.

This study evaluated the photocatalytic activity of polyaniline (PANI)-capped titanium dioxide and zinc oxide (TiO2/ZnO) hybrid, for the degradation of P-Cresol. The hybrid was synthesized by preci...

This study focuses on the performance of nanostructured banana peels in lanthanide-laden mine water treatment. Specifically, nanostructure formation via mechanical milling, characterization in detail and application of this sorbent media in rare earth elements (REEs) removal from synthetic and real mine water are thoroughly investigated. The sorbent samples were characterized by transmission electron microscopy, Brunauer–Emmett–Teller, X-ray diffraction and Fourier transform infrared analyses, while the amount of REEs adsorbed was analysed using inductively coupled plasma optical emission spectroscopy. Results revealed that the particle and crystallite sizes were reduced from

Montmorillonite modified with hexadecyltrimethylammonium bromide was used to remove vanadium (V) from synthetic and real mine water. Fourier transform infrared, X-ray diffraction, and scanning electron microscopy were used to characterise the adsorbent before and after adsorption, while the amount of V adsorbed was determined by ICP-OES. Batch adsorption was evaluated for dissolved V concentrations of 50–320 mg/L and V tailings seepage water from a South African mine. Adsorption capacity was affected by solution pH, temperature, sorbent mass, and the initial concentration. Electrical conductivity of the mine water before and after adsorption was measured to estimate the total dissolved solids. Equilibrium isotherm results revealed that V sorption follows the Freundlich isotherm, indicating that the sorbent surface was heterogeneous. A pseudo-second order kinetic model gave the best fit to the kinetic experimental data. The results of this study allow us to predict uptake efficiency of South African montmorillonite for V removal from mine water. However, the best adsorbent for the uptake of V or other contaminants will depend on the effluent to be treated.

Wastewater may contain antibiotic-resistant bacteria (ARB) that can alter both plant and animal growth. The review focused on the inhibition of bacterial growth and the removal of ARB from wastewater. The outcome revealed that nanomaterials and biochar combined with other treatment methods and coagulation processes are recent strategies regarding ARB removal. Ultraviolet radiation as a treatment method can damage the nucleic acids in the cells of microorganism, thereby reducing ARB abundance in the wastewater. Appropriate regulation on discharge of pharmaceutical waste will aid access to safe and affordable drinking water in line with the sustainable development goals.

How actin monomers are distributed to different networks remains poorly understood. One emerging concept is that the monomer pool is limited and heterogenous, causing biased assembly and internetwork competition. However, most knowledge regarding monomer distribution comes from studies where competing networks are discrete. In metazoans, many actin-based structures are complex, containing competing networks that overlap and are functionally interdependent. Addressing how monomers control the assembly and organization of these complex structures is critical to understanding how actin functions in cells. Here, we identify the monomer-binding protein profilin 1 (PFN1) as a major determinant of actin assembly, organization, and network homeostasis in mammalian cells. At the leading edge, PFN1 controls the localization and activity of the assembly factors Arp2/3 and Mena/VASP, with discrete stages of internetwork competition and collaboration occurring at different PFN1 concentrations. This causes substantial changes to leading edge actin architecture and the types of structures that form there.

This study describes the preparation, characterisation and application of pelletised immobilised alginate/montmorillonite/banana peels nanocomposite (BPNC) in a fixed-bed column for continuous adsorption of rare earth elements and radioactive minerals from water. The materials was characterised by Fourier transform infrared, X-ray diffraction and scanning electron microscopy analyses. Analyses indicated that the pellets are porous and spherical in shape. FT-IR analysis showed that the functional groups responsible for the coordination of metal ions were the carboxylic (-COO-) and siloxane (Si-O-Si and Si-O-Al) groups. XRD analysis showed two additional peaks which were attributed to alginate and montmorillonite. The influence of the initial concentration, bed depth and flow rate were investigated using synthetic and real mine water in order to determine the breakthrough behaviour of both minerals. The processed bed volume, adsorbent exhaustion rate and service time, were also explored as performance indices for the adsorbent material. Furthermore, the breakthrough data were fitted to both the Thomas and Bohart-Adams models. The BPNC exhibited high affinity for U, Th, Gd and La in the real mine water sample. However, studies may still be required using waters from different environments in order to determine the robustness of BPNC.

Magnetized natural zeolite-polypyrrole (MZ-PPY) composite as a potential adsorbent for vanadium was prepared via polymerization of pyrrole monomer using FeCl 3 oxidant in aqueous medium in which magnetized natural zeolite particles were suspended. The MZ-PPY composite was characterized by attenuated total reflectance Fourier transform infrared spectroscope (ATR-FTIR), field emission scanning electron microscope (FE-SEM) and high resolution transmission electron microscope (HR-TEM). Batch adsorption studies were performed to test the ability of the adsorbent to remove V(V) ions from aqueous solution. From sorption equilibrium modelling, the equilibrium data is well described by Langmuir, Sips and Redlich–Peterson isotherms while the adsorption kinetics is described by the pseudo-second order model. The Langmuir adsorption capacity is 65.0 mg/g at 298 K. Thermodynamic parameters confirm the spontaneous and endothermic nature of the vanadium adsorption process. Meanwhile V(V) removal process is found not to be affected by co-existing ions. Furthermore, the material can be used in two adsorption cycles without compromising its capacity.

Photocatalysis and ozonation processes have tremendous potential in wastewater treatment. However, photocatalysis is a slow process, and ozonation is highly selective. Combining these processes overcomes these drawbacks. In the present study, metal-ion (Ag, Cu, and Fe)-doped titanium dioxide (TiO2) nanoparticles were employed in photocatalytic ozonation of phenol solutions and secondary municipal wastewater. The concentrations of phenol and dissolved organic carbon (DOC), chemical oxygen demand (COD), and UV absorbance (UV254) were monitored and the data modeled using pseudo-first-order kinetics. Synergy index values between 1.03 and 4.31 were obtained between ozonation and photocatalysis, resulting in faster degradation of organic contaminants using UV–vis and solar photocatalytic ozonation, compared with photocatalysis and ozonation alone. The treated water satisfied South African water treatment standards in terms of COD, phenol, and DOC levels. The use of solar radiation makes the process environmentally benign and less costly and therefore of major significance.

This study investigated UV and solar photocatalysis of organic pollutants in municipal wastewater using metal-ion (Ag, Cu and Fe) doped TiO2 photocatalysts. The effects of pH and catalyst dosage on photocatalytic performance were determined. The best performance was obtained using 0.5 g/L catalyst concentration and pH 6, and the treated water met specific requirements of the drinking water quality standards (phenol ≤10 μg/L) and wastewater effluents for discharge chemical oxygen demand (COD) levels (

The study investigates the influence of process parameters on the effectiveness of ozonation in the removal of organic micro-pollutants from wastewater. Primary and secondary municipal wastewater containing phenol was treated. The effect of operating parameters such as initial pH, ozone dosage, and initial contaminant concentration was studied. An increase in contaminant decomposition with pH (3–11) was observed. The contaminant removal efficiencies increased with an increase in ozone dose rate (5.5–36.17 mg L−1 min−1). Furthermore, the ultraviolet absorbance (UV 254 nm) of the wastewater decreased during ozonation indicating the breakdown of complex organic compounds into low molecular weight organics. Along the reaction, the pH of wastewater decreased from 11 to around 8.5 due to the formation of intermediate acidic species. Moreover, the biodegradability of wastewaters, measured as biological and chemical oxygen demand (BOD5/COD), increased from 0.22 to 0.53. High ozone utilization efficiencies of up to 95% were attained thereby increasing the process efficiency; and they were dependent on the ozone dosage and pH of solution. Ozonation of secondary wastewater attained the South African water standards in terms of COD required for wastewater discharge and dissolved organic carbon in drinking water and increased significantly the biodegradability of primary wastewater.

Suspension freeze desalination is a promising technique for producing clean water from mine wastewaters. The principle is that growing ice crystals reject impurities during freezing. As a result, pure water is separated from mine wastewaters as clean ice. Actually, there is a need for improved techniques to increase water yield and purity. Here we tested ice formation in complex synthetic solutions during cooling and addition of seed. Solutions included: pure distilled water, 50, 33 g/L NaCl and 17, 50 g/L Na2SO4, 50 g/L NaCl and 50 g/L Na2SO4. Results show that heat of crystallization was the highest with pure distilled water at 8859 J, whereas the lowest heat of crystallization, of 4608 J, was for the solution of 50 g/L NaCl and 50 g/L Na2SO4, indicating that the presence of the salt enhances ice formation. As an application, we designed a new flow diagram, which, in addition to heat exchanger and ice filter, now includes a fluidized bed reactor for salt crystallization and recovery, and a separate heat exchanger for ice crystallization.

Molasses wastewater (MWW) is characterised by a biorecalcitrant dark brown colour caused by melanoidin pigments and a high organic load. Anaerobic digestion (AD), mostly applied as a first step treatment method for MWW, can effectively remove the high organic load, but with minimal colour mitigation. Photodegradation is among the preferred advanced treatment methods to complement AD for the colour abatement. This study looked into the effect of employing zeolite as a biomass and catalyst support in AD and photodegradation, respectively. Zeolite was applied in a fixed bed bioreactor for biodegradation, while a composite of TiO2/zeolite catalyst was prepared and used in a fluidised bed photoreactor. The zeolite and TiO2 were characterised using scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) where it was found that the zeolite surface area and pore volume were almost twice that of TiO2. Introduction of zeolite improved chemical oxygen demand (COD) reduction by 20% during AD with a fivefold increase in biogas production. However, a 40% increase in colour was recorded during AD due to a possible re-polymerisation of the recalcitrant colour-causing melanoidins. The photodegradation process was effective in colour remediation with 99% colour removed on employing the TiO2/zeolite composite catalyst, as compared to 44% removed when TiO2 was solely used. Degradation of melanoidins into simpler products was responsible for the colour disappearance. Zeolite due to its large specific surface area and good adsorption properties was found suitable for application as a biomass and catalyst support in AD and photodegradation, respectively.

There are many different actin networks within a cell, but it is poorly understood how they assemble from a common monomer pool. One emerging concept is that monomers are limited and heterogenous, which manipulates network assembly through biased polymerization and internetwork competition. Previous work demonstrated that actin bound to the monomer-binding protein profilin favors filament assembly by formins and Mena/VASP over Arp2/3. Although, profilin can transfer monomers to Arp2/3 networks through nucleation promoting factors. It remains largely unknown how profilin influences network behavior in complex environments where multiple assembly factors are present. Here, we assess assembly factor dependence on profilin 1 (PFN1) in mammalian cells by carefully controlling PFN1 concentration. We demonstrate that PFN1 determines global actin assembly, organization, and network homeostasis. At the leading edge, PFN1 is required for both Arp2/3 and Mena/VASP activity, with discrete stages of internetwork competition and collaboration occurring at different PFN1 concentrations. These results demonstrate that the majority of actin assembly is gated by PFN1 and that dramatic changes to actin architecture can be made by modifying PFN1 availability.

While membrane distillation (MD) is considered a promising cost-effective and efficient desalination process, it remains severely affected by membrane fouling that compromises the quantity and quality of water recovered. In this study, superhydrophobic PVDF membranes modified with organically-functionalised silica (f-SiO2) nanoparticles (NPs) were synthesized. Silica nanoparticles (SiO2NPs) were functionalised with three different silane reagents, namely: octadecyltrimethoxysilane (OTMS), N-octadecyltrichlorosilane (ODTS), and chlorodimethyl-octadecyl silane (Cl-DMOS), and finally embedded on polyvinylidene fluoride (PVDF) nanofibre membranes using an in-situ electrospinning technique. The resulting superhydrophobic membranes were coated with a thin layer containing carboxylated multiwalled carbon nanotubes (f-MWCNTs) and silver nanoparticles (AgNPs) to reduce membrane fouling. Fouling tests were conducted using sodium alginate, colloidal silica, and thermophilic bacteria effluent as model organic, inorganic, and bio-foulants, respectively, in direct contact membrane distillation (DCMD). The uncoated membranes were characterized by flux decays ranging from 30 to 90% and salt rejection decays of 1.4–6.1 %. Membrane coating reduced the flux and salt rejection decays to 10–24 % and 0.07–0.75 %, respectively. The hydrophilic coating layer of the nanofibre membrane induced a decrease in the initial water flux (i.e., from 36-42 LMH to 16–17 LMH). However, this coating layer also proved to be efficient in maintaining high salt rejection and resistance to flux decline. This approach is a suitable one-step solution for fouling mitigation in DCMD

A simple pilot-scale magnetic adsorption separation (MAS) device was designed, fabricated and tested in treating aqueous solution stream laden with highly toxic and mobile hexavalent chromium [Cr(VI)] ions using super-paramagnetic crystalline polypyrrole–magnetite nanocomposite (PPy–Fe3O4 NC) as a mobile scavenger. In the first experiment, the kinetics of Cr(VI) adsorption on PPy–Fe3O4 NC containing three different quantities of Fe3O4 nanoparticles were explored in a continuously stirred tank reactor (CSTR) operated in a batch mode. Thereafter, combined adsorption and magnetic separation process studies were conducted in semi-continuous and continuous operations modes whereby Cr(VI) loaded PPy–Fe3O4 NC particles were continuously isolated from the treated stream using a rare-earth permanent magnet. In the adsorption and magnetic separation systems, Cr(VI) removal and magnetic separation efficiency were used as key performance indicators. Results on batch adsorption kinetic studies showed that the quantity of Fe3O4 nanoparticles in the PPy–Fe3O4 NC influenced Cr(VI) removal whereby equilibrium uptakes of 119 mg/g, 109 mg/g and 103 mg/g were achieved using 50.4%, 58.5% and 40.3% Fe3O4 loaded NCs, respectively. Meanwhile, for semi-continuous operations, a decrease in initial Cr(VI) concentration in the reactor and an increase in the quantity of Fe3O4 nanoparticles in the NCs resulted in improved magnetic separation efficiency. Moreover, the introduction of stainless steel (SS) wool in the separation chamber enhanced the entire separation process. Finally, results obtained from a continuously operated MAS system revealed that it is possible to achieve 100% Cr(VI) removal when the residence time was set at 30 min, at a flow rate of 0.2 L/min. At those prevailing conditions, the magnetic separation efficiency was 92%.

Aspirin and paracetamol are used as drugs by animals and humans but are not totally metabolized inside their bodies and hence they often find way into the raw wastewaters. This study presents kinetic and thermodynamic studies of the sorption and removal of aspirin and paracetamol from aqueous solutions using N-CNT/β-CD and Fe/N-CNT/β-CD nanocomposite polymers and the parameters that determine the sorption process. The polymers were prepared via a benign method of microwave-assisted synthesis of the nanocomposites and characterized using Spectrum 100 Fourier transform infrared spectroscopy (FTIR) and focused ion beam scanning electron microscopy (FIB-SEM). The sorption process for aspirin and paracetamol was described by Freundlich and Langmuir isotherms, respectively. The maximum sorption capacities of aspirin and paracetamol onto N-CNTs-β-CD were 71.9 and 41.0 mg g−1 and Fe/N-CNTs-β-CD were 101.0 and 75.2 mg g−1, respectively, at 298 K. The nanocomposites effectively removed aspirin and paracetamol within 30 min of contact time, suggesting that the materials are effective and economically viable. Furthermore, the sorption kinetics of aspirin and paracetamol onto the N-CNT/β-CD and Fe/N-CNT/β-CD sorbents well fitted onto the pseudo second order and Elovich kinetic models, respectively as a minimum SSE was observed. Sorption thermodynamics indicated that the sorption process was feasible, spontaneous and exothermic in nature.

This study was conducted to develop novel chitosan nanocomposites and to optimize the minimum amount and contact time required to achieve complete inactivation of bacteria in water. Gram-negative Escherichia coli and Gram-positive Enterococcus faecalis bacteria were used to test the antibacterial activity of chitosan cross-linked with glutaraldehyde and chitosan nanocomposites in water. The silver and zinc oxide nanoparticles supported on bentonite were synthesized using microwave-assisted synthesis method. The resulting bentonite-supported silver and zinc oxide nanoparticles were dispersed in a chitosan biopolymer to prepare bentonite chitosan nanocomposites. The obtained bentonite chitosan nanocomposites were characterized with BET surface area measurements, FTIR, XRD, ICP-AES and SEM. When using cross-linked chitosan, it was demonstrated that factors such as pH, particle size and surface area influenced the inactivation of bacteria. For instance, the antibacterial activity of cross-linked chitosan was illustrated to increase with an increase in contact time. Meanwhile, an improvement in the inactivation activity was indicated with the introduction of silver and zinc oxide nanoparticles containing bentonite into the chitosan matrix. Although both silver and zinc oxide containing bentonite chitosan nanocomposites exhibited good antibacterial activity against bacteria, with removal efficiencies of at least 51%, the best antibacterial activity was demonstrated for silver–zinc oxide bentonite chitosan nanocomposite, with a removal efficiency of at least 78%. Furthermore, the antibacterial activity of bentonite chitosan nanocomposites was identified to be influenced by the amount of material, contact time and bacterial concentration. Finally, leaching tests demonstrated that bentonite chitosan nanocomposites were stable and, consequently, could be effectively used as antibacterial materials for water disinfection.

Magnetic natural zeolite-polypyrrole (MZ-PPy) composite was prepared for enhanced removal of hexavalent chromium [Cr(VI)] from aqueous solution. The structure and morphology of the prepared adsorbent was analyzed with the Fourier transform infrared (FTIR), field-emission microscope (FE-SEM), energy dispersive X-ray (EDX), high resolution transmission electron microscope (HR-TEM) and X-ray diffraction (XRD). The effects of magnetic zeolite loading within the composite, initial pH, sorbent dosage, temperature and Cr(VI) concentration on Cr(VI) removal efficiency were investigated. Up to 99.99% removal efficiency was obtained when the pH was 2 and the initial Cr(VI) concentration was 300 mg/L. The sorption kinetic data fitted well to the pseudo-second order model and isotherm data fitted well to the Langmuir isotherm model. The maximum adsorption capacity determined from the Langmuir isotherm increased from 344.83 to 434.78 mg/g as the temperature was increased from 25 °C to 45 °C. Thermodynamic parameters revealed that the adsorption process is spontaneous and endothermic in nature. The results further indicated that the adsorption capacity is decreased in the presence of SO42− ions. The adsorption–desorption studies indicated that MZ-PPy retained its original Cr(VI) sorption capacity up to two consecutive cycles.

Hexavalent chromium [Cr(VI)] adsorption onto polypyrrole graphene oxide nanocomposite (PPy–GO NC) From aqueous solutions was explored using batch and packed-bed column modes. The performance of the PPy–GO NC for Cr(VI) removal was evaluated as a function of solution pH, initial Cr(VI) concentration, temperature, bed mass and time. The characterization of PPy–GO NC using HR-TEM, FE-SEM and Raman spectroscopy confirmed that graphite was successfully exfoliated to thin layered graphene sheets and also ensured the presence of the PPy in the PPy–GO NC. Meanwhile the zeta potential data showed that the point of zero charge of the nanocomposite was at pH 6.2. Batch sorption isotherm data at optimum solution pH of 2, was satisfactorily described by the Langmuir isotherm model with a maximum sorption capacity of 625 mg/g at 25 °C, while the kinetic data fitted well with the pseudo second order kinetic model. Sorption of Cr(VI) onto PPy–GO NC in binary ions systems was also evaluated and results showed that the presence of co-existing ions had no effect on Cr(VI) removal. Expressed through breakthrough curves, the packed-bed Cr(VI) sorption data showed consistency with the ideal s-shape. Moreover, a large volume of Cr(VI) contaminated water (64.08 L) was successfully treated to below allowable discharge limit at low influent Cr(VI) concentration (10 mg/L) using 2 g of PPy–GO NC at a flow rate of 3 mL/min. Breakthrough data were successfully described by the Thomas and Yoon–Nelson models.

In the present study, a new composite adsorbent, chitosan/bentonite/manganese oxide (CBMnO) beads, cross-linked with tetraethyl-ortho-silicate (TEOS) was applied in a fixed-bed column for the removal of Mn (II) from water. The adsorbent was characterised by scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR), N2 adsorption-desorption and X-ray photoelectron spectroscopy (XPS) techniques, and moreover the point of zero charge (pHpzc) was determined. The extend of Mn (II) breakthrough behaviour was investigated by varying bed mass, flow rate and influent concentration, and by using real environmental water samples. The dynamics of the column showed great dependency of breakthrough curves on the process conditions. The breakthrough time (tb), bed exhaustion time (ts), bed capacity (qe) and the overall bed efficiency (R%) increased with an increase in bed mass, but decreased with the increase in both influent flow rate and concentration. Non-linear regression suggested that the Thomas model effectively described the breakthrough curves while large-scale column performance could be estimated by the bed depth service time (BDST) model. Experiments with environmental water revealed that coexisting ions had little impact on Mn (II) removal, and it was possible to achieve 6.0 mg/g breakthrough capacity (qb), 4.0 L total treated water and 651 bed volumes processed with an initial concentration of 38.5 mg/L and 5.0 g bed mass. The exhausted bed could be regenerated with 0.001 M nitric acid solution within 1 h, and the sorbent could be reused twice without any significant loss of capacity. The findings advocate that CBMnO composite beads can provide an efficient scavenging pathway for Mn (II) in polluted water.

To understand how mutations in Matrin 3 (MATR3) cause amyotrophic lateral sclerosis (ALS) and distal myopathy, we used transcriptome and interactome analysis, coupled with microscopy. Over-expression of wild-type (WT) or F115C mutant MATR3 had little impact on gene expression in neuroglia cells. Only 23 genes, expressed at levels of >100 transcripts showed ≥1.6-fold changes in expression by transfection with WT or mutant MATR3:YFP vectors. We identified ~123 proteins that bound MATR3, with proteins associated with stress granules and RNA processing/splicing being prominent. The interactome of myopathic S85C and ALS-variant F115C MATR3 were virtually identical to WT protein. Deletion of RNA recognition motif (RRM1) or Zn finger motifs (ZnF1 or ZnF2) diminished the binding of a subset of MATR3 interacting proteins. Remarkably, deletion of the RRM2 motif caused enhanced binding of >100 hundred proteins. In live cells, MATR3 lacking RRM2 (ΔRRM2) formed intranuclear spherical structures that fused over time into large structures. Our findings in the cell models used here suggest that MATR3 with disease-causing mutations is not dramatically different from WT protein in modulating gene regulation or in binding to normal interacting partners. The intra-nuclear localization and interaction network of MATR3 is strongly modulated by its RRM2 domain.

Myotonic dystrophy (DM) is a progressive, multisystem disorder affecting skeletal muscle, heart, and central nervous system. In both DM1 and DM2, microsatellite expansions of CUG and CCUG RNA repeats, respectively, accumulate and disrupt functions of alternative splicing factors, including muscleblind (MBNL) proteins. Grey matter loss and white matter changes, including the corpus callosum, likely underlie cognitive and executive function deficits in DM patients. However, little is known how cerebral cortical circuitry changes in DM. Here, flavoprotein optical imaging was used to assess local and contralateral responses to intracortical motor cortex stimulation in DM-related mouse models. In control mice, brief train stimulation generated ipsilateral and contralateral homotopic fluorescence increases, the latter mediated by the corpus callosum. Single pulse stimulation produced an excitatory response with an inhibitory-like surround response mediated by GABAA receptors. In a mouse model of DM2 (Mbnl2 KO), we observed prolonged and increased responsiveness to train stimulation and loss of the inhibition from single pulse stimulation. Conversely, mice overexpressing human MBNL1 (MBNL1-OE) exhibited decreased contralateral response to train stimulation and reduction of inhibitory-like surround to single pulse stimulation. Therefore, altering levels of two key DM-associated splicing factors modifies functions of local cortical circuits and contralateral responses mediated through the corpus callosum.

The dominantly inherited, multi-systemic disease myotonic dystrophy type I (DM1) is caused by triplet repeat CTG expansions in the DMPK gene and is the most common form of adult-onset muscular dystrophy. Elimination of the toxic, repetitive CUG RNA constitutes a therapeutic for this disease. We report an RNA-targeting Cas9 (RCas9) system that supports efficient reversal of DM1 phenotypes via delivery to adult poly(CUG) DM1 mouse muscle using adeno-associated virus (AAV). We observe elimination of CUG RNA, restoration of CUG foci-associated Mbnl1 protein to wild-type subcellular localization, correction of DM1-type alternative splicing patterns in candidate genes including the voltage-gated chloride channel 1 (Clcn1) responsible for characteristic myotonia, recovery of Clcn1 staining, and reduction in centralized myonuclei. Our results establish RCas9 as a potential long-term in vivo therapeutic for DM1.One Sentence SummaryA repurposed CRISPR system termed RNA-targeting Cas9 reverses the molecular pathology associated with the most common type of adult onset muscular dystrophy in adult mouse muscle.

Significance Elevated leaf vein density is a key step in the evolution from C 3 to C 4 plants. We hypothesized that high vein density in C 4 leaves is due to elevated auxin biosynthesis and transport in developing leaves. We found higher expression levels of genes promoting auxin biosynthesis and higher auxin content in developing C 4 leaves than in developing C 3 leaves. We also found higher auxin content and vein density in loss-of-function mutants of MYC2 , an auxin biosynthesis suppressor. Moreover, treatment with an auxin biosynthesis or transport inhibitor reduced vein density in new leaves. Finally, mutations that reduce auxin efflux or influx reduce vein density. These observations support our hypothesis and provide a molecular basis for high vein density in C 4 leaves.

Polythiophene/graphene oxide (PTh/GO) nanocomposite (NC) was prepared through polymerisation of thiophene in the presence of GO and was used for mercury ions (Hg2+) adsorption in aqueous solutions. Equilibrium studies showed that mercury removal was strongly influenced by solution pH and GO composition in the NC. The equilibrium data were well described by both Langmuir and Freundlich isotherm models, with a Langmuir maximum adsorption capacity of 113.6 mg/g. Adsorption kinetics were rapid and correlated well with the pseudo-second-order model. The thermodynamic studies indicated that the adsorption was spontaneous and endothermic in nature, and occurred through a physicochemical mechanism. Desorption studies revealed that PTh/GO NC could be used repeatedly for three adsorption-desorption cycles without a significant loss in its capacity. Competing ions reduced mercury uptake although considerable values were still attained. The findings of this study suggest that PTh/GO NC is a potential adsorbent for Hg2+ removal from aqueous solutions.

Myotonic dystrophy type 1 (DM1) is a CTG microsatellite expansion (CTGexp) disorder caused by expression of CUGexp RNAs. These mutant RNAs alter the activities of RNA processing factors, including MBNL proteins, leading to re-expression of fetal isoforms in adult tissues and DM1 pathology. While this pathogenesis model accounts for adult-onset disease, the molecular basis of congenital DM (CDM) is unknown. Here, we test the hypothesis that disruption of developmentally regulated RNA alternative processing pathways contributes to CDM disease. We identify prominent alternative splicing and polyadenylation abnormalities in infant CDM muscle, and, although most are also misregulated in adult-onset DM1, dysregulation is significantly more severe in CDM. Furthermore, analysis of alternative splicing during human myogenesis reveals that CDM-relevant exons undergo prenatal RNA isoform transitions and are predicted to be disrupted by CUGexp-associated mechanisms in utero. To test this possibility and the contribution of MBNLs to CDM pathogenesis, we generated mouse Mbnl double (Mbnl1; Mbnl2) and triple (Mbnl1; Mbnl2; Mbnl3) muscle-specific knockout models that recapitulate the congenital myopathy, gene expression, and spliceopathy defects characteristic of CDM. This study demonstrates that RNA misprocessing is a major pathogenic factor in CDM and provides novel mouse models to further examine roles for cotranscriptional/post-transcriptional gene regulation during development.