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Membrane distillation (MD) has been increasingly explored for treatment of various hyper saline waters, including lithium chloride (LiCl) solutions used in liquid desiccant air-conditioning (LDAC) systems. In this study, the regeneration of liquid desiccant LiCl solution by a pilot direct contact membrane distillation (DCMD) process is assessed using computer simulation. Unlike previous experimental investigations, the simulation allows to incorporate both temperature and concentration polarisation effects in the analysis of heat and mass transfer through the membrane, thus enabling the systematic assessment of the pilot DCMD regeneration of the LiCl solution. The simulation results demonstrate distinctive profiles of water flux, thermal efficiency, and LiCl concentration along the membrane under cocurrent and counter-current flow modes, and the pilot DCMD process under counter-current flow is superior to that under cocurrent flow regarding the process thermal efficiency and LiCl concentration enrichment. Moreover, for the pilot DCMD regeneration of LiCl solution under the counter-current flow, the feed inlet temperature, LiCl concentration, and especially the membrane leaf length exert profound impacts on the process performance: the process water flux halves from 12 to 6 L/(m2·h) whilst thermal efficiency decreases by 20% from 0.46 to 0.37 when the membrane leaf length increases from 0.5 to 1.5 m.

Photocatalytic degradation using TiO2 is one of the most effective techniques for treating residual emerging compounds present in water. However, practical applications are limited since it only absorbs ultraviolet irradiation. Nitrogen and sulfur (N, S) co-doped TiO2 nanomaterials (N,S-TiO2) were prepared by a controlled sol–gel method; the characterization and photocatalytic activity have been studied for the removal of ciprofloxacin antibiotic under UV–Visible light. The interstitial doping of nitrogen and sulfur substitute oxygen and titanium into the TiO2 lattice, which increases the valence band and decreases the conduction band, respectively. The lowest value band-gap of 2.5 eV and the crystallite size of 5.13 nm compared to other available synthesis methods was observed on N,S-TiO2 which allowed to broaden the light absorption to the visible region. The low level electron and hole recombination was related by the N, S doping. The optimal ciprofloxacin removal was obtained at pH 5.5, a dosage of 0.05 g, initial concentration of 30 mg L−1 with a removal efficiency of 78.7%. A comparison of the effectiveness of antibiotic treatment of N,S-TiO2 with synthetic TiO2 and commercial TiO2 was also made, taking the potential for regeneration into account. The photocatalytic degradation of ciprofloxacin catalyzed by N,S-TiO2 was described by pseudo-first-order kinetics.

N,S-TiO2 deposited on three kinds of pre-treated sugarcane bagasse was synthesized via a sol–gel method. The obtained composites were characterized by various techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and photoluminescence spectroscopy (PL). UV-visible induced degradation of ciprofloxacin was investigated. The influence of some experimental parameters such as contact time, pH, dosage, and initial concentration on the efficiency of ciprofloxacin elimination was also evaluated. The highest efficiency was observed for the alkaline pre-treated sugarcane bagasse combined with N,S-TiO2, about 86% under optimal conditions (contact time 150-min irradiation, pH 5.5–6, dosage 0.5 g L−1, and the initial concentration CIP 30 ppm). There may be a rapid ciprofloxacin transition from the adsorption site to the photocatalytic site, and the alkaline pre-treated sugarcane bagasse/N,S-TiO2 prevented the recombining of holes and electrons of the photocatalyst. Furthermore, the alkaline pretreatment sugarcane bagasse/N,S-TiO2 composite material was sustainable, with only a 10% reduction after reusing the material three times. The presence of sugarcane bagasse made the material easy to recover from the liquid phase.

Silicic acid and soluble Fe are among the most abundant components in acid mine drainage. During the oxidation of Fe(II), the interaction between silicic acid and freshly formed Fe oxides might change the colloidal dynamics, altering surface charge properties. However, the effects of silicic acid on colloidal Fe oxides formed from acid mine drainage are not fully understood. In this work, we examined the colloidal dynamics of freshly formed Fe oxides in synthetic acid mine drainage (prepared from FeSO solution) under the effect of silicic acid as a function of changes in pH and ionic strength. The results demonstrate that through adsorption, silicic acid progressively slows oxidation and enhances the dispersion of freshly formed Fe oxides by shifting the surface charge toward more negative values. This effect was most prominent between pH 5 and 9. The current results demonstrate that silicic acid enhances the dispersion and transport of freshly formed Fe oxides and suggest that aggregation-based techniques for the treatment of Fe-rich drainage may require further consideration of this effect.

Understanding of the fate of phytolith in soils is important because of its role as an agronomical nutrient resource and for carbon sequestration. Accumulation of phytolith derived silica occurs in paddy soils when phytolith input, here through straw incorporation, is higher than silica removal through crop offtake, dissolution and leaching. Phytolith dissolution is thought to be the main reason for diminishing of phytolith derived silica in soil, with this dissolution being highly dependent on soil chemical properties. In this study, phytolith content from 78 paddy soils sampled in the Red River (RRD) and Mekong River (MRD) Deltas, Vietnam, were quantified and related to pH, electrical conductivity (EC), oxalate-extractable Al and Fe (Alox and Feox), organic carbon (OC) and clay content. Average phytolith contents within the topsoil (0–20 cm) were 4.8 ± 1.98 and 7.74 ± 2.97 mg g−1 for the RRD and MRD, respectively. Positive correlation coefficients obtained for Alox, OC, clay content and EC, implying that these parameters might enhance phytolith resistance to dissolution. Soil pH had a negative correlation coefficient with phytolith content. Lower pH and higher Alox content explained the predominance of the phytolith in the MRD compared to the RRD. Soil pH adjustment can be proposed as an active management strategy to maintain phytolith added Si, source for crops and for carbon sequestration.

Fixed-film biofilm reactors are considered one of the most effective wastewater treatment processes, however, the cost of their plastic bio-carriers makes them less attractive for application in developing countries. This study evaluated loofah sponges, an eco-friendly renewable agricultural product, as bio-carriers in a pilot-scale integrated fixed-film activated sludge (IFAS) system for the treatment of municipal wastewater. Tests showed that pristine loofah sponges disintegrated within two weeks resulting in a decrease in the treatment efficiencies. Accordingly, loofah sponges were modified by coating them with CaCO3 and polymer. IFAS pilot tests using the modified loofah sponges achieved 83% organic removal and 71% total nitrogen removal and met Vietnam&rsquo, s wastewater effluent discharge standards. The system achieved considerably high levels of nitrification and it was not limited by the loading rate or dissolved oxygen levels. Cell concentrations in the carriers were twenty to forty times higher than those within the aeration tank. Through 16S-rRNA sequencing, the major micro-organism types identified were Kluyvera cryocrescens, Exiguobacterium indicum, Bacillus tropicus, Aeromonas hydrophila, Enterobacter cloacae, and Pseudomonas turukhanskensis. This study demonstrated that although modified loofah sponges are effective renewable bio-carriers for municipal wastewater treatment, longer-term testing is recommended.

F-box proteins function as substrate adaptors for the S-phase kinase-associated protein 1 (SKP1)-cullin 1 (CUL1)-F-box protein (SCF) ubiquitin ligase complexes, which mediate the proteasomal degradation of a diverse range of regulatory proteins. 20 years since the F-box protein family has been discovered, our understanding of substrate-recognition regulation and the roles F-box proteins play in cellular processes has continued to expand. Here, we provide an introduction to the discovery and classification of F-box proteins, the overall structural assembly of SCF complexes, the varied mechanisms by which F-box proteins recognize their substrates, and the role F-box proteins play in diseases and their potentials in targeted therapies.

Small molecule-mediated inhibition of protein function is the rational behind therapeutic efficacy of the majority clinically used drugs. In order for a drug to achieve pharmacologically relevant inhibition, efficient target engagement at high selectivity and specificity is necessary to obtain the desired therapeutic effect minimizing offtarget outcomes. Majority of small molecules approaches developed so far have failed in their attempt to reach clinical efficacy because of low selectivity and low specificity in achieving close to 100 % target inhibition. Recently, approaches that directly control cellular protein levels have opened the potential to accomplish a high grade of efficacy not imaginable with traditional small-molecule inhibitors. Research in this area has just started opening avenues to effectively degrade a cellular target of choice and will soon impact clinical efficacy.

F-box proteins function as substrate adaptors for the S-phase kinase-associated protein 1 (SKP1)-cullin 1 (CUL1)-F-box protein (SCF) ubiquitin ligase complexes, which mediate the proteasomal degradation of a diverse range of regulatory proteins. 20 years since the F-box protein family has been discovered, our understanding of substrate-recognition regulation and the roles F-box proteins play in cellular processes has continued to expand. Here, we provide an introduction to the discovery and classification of F-box proteins, the overall structural assembly of SCF complexes, the varied mechanisms by which F-box proteins recognize their substrates, and the role F-box proteins play in diseases and their potentials in targeted therapies.

Phytoliths are common biogenic silica materials which can be derived from heat-treatment of Si-rich plant residues. However, there have been few studies identifying its environmental applications. This work, based on the batch experiments with quantification of surface charge and determination of colloidal properties, is an attempt to evaluate the ability of phytolith-based material (PBM) for removing Fe from aqueous solution. Oxidation and aggregation of a synthetic Fe-rich solution were examined under the presence of a PBM sample (obtained from fern Dicranopteris linearis) as functions of pH and ionic strength. Obtained results showed that through electrostatic interaction, the PBM can affect oxidation and aggregation of newly-formed Fe oxides at different extents depending on pH change. The fastest aggregation of the newly-formed Fe oxides was found at the pH range from 4 to 6 and in the presence of phytolith. As the PBM can make the newly-formed Fe oxides less dispersive and less transportable in aqueous solution, it suggests that practices for treatment of Fe-rich drainage or remediation of Fe-contaminated groundwater by supporting aggregation need to consider this effect.

Summary Aggregation properties of iron oxide particles have received much attention because of their environmental importance in soil and aquatic environments. The effects of silicic acid on the pH-dependent surface charges that govern the aggregation of goethite have received little attention. In this study we determined the effect of silicic acid as a function of pH and ionic strength (IS) on the aggregation of a synthetic goethite by a combination of particle-size analysis using dynamic light scattering and test tube experiments to quantify particles in suspension. We investigated silicic acid adsorption on goethite quantitatively by batch adsorption isotherms, and the changes in surface charge on the adsorption of silicic acid were identified by the zeta potential (ζ). Our results revealed that silicic acid can lead to a significant decrease in ζ. A change in the pHiep (iep: isoelectric point) from 8.5 to lower pH values, typically pH 4–5.5, in the presence of silicic acid suggests enhanced aggregation of goethite in the acidic pH range. At alkaline pH, both goethite and silicic acid were negatively charged because of strong deprotonation, and silicic acid adsorption promoted goethite dispersion. Ionic strength affected the aggregation of goethite by shifting ζ towards the iep and it can also obscure the role of silicic acid. Highlights Effect of silicic acid on surface charge and aggregation of goethite was investigated. Adsorption of silicic acid reduces ζ and allows goethite to aggregate at lower pH. Ionic strength can also affect aggregation of goethite by shifting ζ towards the isoelectric point. Silicic acid in soil might maintain goethite particles in an aggregated state.

The development of Industrial Zones in Vietnam will put pressure on water resources at local as well as national scale, due to the large amounts of water consumed and discharged to environment. This study, via water mass balance, provides analyses and assessments on water demand and wastewater generated in each trading groups (industrial sectors) of the Long Thanh Industrial Zone and the Nhon Trach III Industrial Zone phase 2, Dong Nai – the province with the most industrial zones in Vietnam. According to the water mass balance calculation results, the water demand of industrial sectors depends on their manufacturing characteristics. Of which, Textile and Garment are the sectors with the highest demand, as well as highest water loss rate and highest amount of wateswater dischared. Meanwhile, Electronic and Construction Materials cosume the least amount of water. Machinery sector has the lowest amount of water loss. The wastewater/supply water ratio of the Long Thanh Industrial Zone is always 1,1 (for Textile) to 1,5 (for Machinery) times higher than the Nhon Trach III Industrial Zone phase 2, while the wastewater/supply water ratio of the Nhon Trach III Industrial Zone phase 2 is always less than 80%.

In soils, dispersion is a crucial step preceding the loss of clay-sized particles by surface run-off and leaching, which in turn results in soil degradation. Despite the fact that silicic acid is common in soil solutions, its effect on aggregation stability of fine sized particles in soils has not been detailed. Here we examined the effect of silicic acid on dispersion of a kaolinitic soil clay fraction rich in Fe-oxides (8.5%) at different pH values by combining dynamic light scattering for particle sizing and test tube experiments for examination of particles in suspension. Adsorption of silicic acid on the clay fraction was characterized by batch adsorption experiments and effects on surface charge by zeta potential (ζ) measurements over a pH range from 2 to 11. We found that silicic acid adsorbed onto clay and co-existing Fe oxides, made ζ more negative, and thereby counteracted aggregation of the clay fraction. Silicic acid showed its most effectivity for maintaining dispersion at a pH range of 4 to 6. Beyond this pH range, dispersion was either strongly favored or prevented, and the effect of silicic acid on dispersion was obscured. Given the ubiquitous presence of silicic acid in soils, our findings regarding its impact on aggregation stability have important implication for conservation of acidic soils.

This study was conducted to assess the removal of arsenic (As) and heavy metals from mining wastewater by the combination of adsorption, using modified iron-ore drainage sludge, and horizontal-subsurface-flow constructed wetland with common reed (Phragmites australis). The pilot-scale experiment with a constant flow rate of 5 m3/day was operated for four months using real wastewater from a Pb&ndash, Zn mine in northern Vietnam. Atomic absorption spectroscopy was used for elemental analysis in wastewater and plant. X-ray diffraction (XRD), surface charge measurements (by a particle charge detector (PCD)), Fourier-transform infrared (FTIR), and surface area Brunauer&ndash, Emmet&ndash, Teller (BET) measurements were performed to determine the characteristics of the adsorbent. The results showed that the average removals of As, Mn, Cd, As, Zn, and Pb by the combined system with limestone substrate during four months were 80.3%, 96.9%, 79.6%, 52.9%, and 38.7%, respectively. The use of another constructed wetland substrate, laterite, demonstrated better removal efficiency of As than limestone. The concentrations of As and heavy metals in the effluent were lower than the limits established by the QCVN 40:2011/BTNMT for industrial wastewater, which indicated the feasibility of combining adsorption and constructed wetland for the treatment of mining wastewater.

Additives used in food pose a risk to consumers' health, and cyclamate is one of the chemical sugars. In this study, cyclamate content in 38 food samples including beverage, cake, candy, milk, and juice was analyzed using Ultra-Performance Liquid Chromatography, Tandem Mass Spectrometry (UPLC-MS/MS). The optimal parameters of detector MS/MS for anion mode; the liquid chromatography column UPHR(R) BEH C18 2.1x100mm 1.7μm, waters, USA; mobile phase: MeOH:H2O (50:50) including 1% HCOOH, deionized water. The ultimate test sample which passed 0.2 μm membrane filter results in retention time: 4.05 minutes, and flow rate of 0.2 mL/min. The quantitative and confirmable ions are 79.7 and 177.9 m/z, respectively. Under the optimum conditions the calibration curve for cyclamate was linear in the range of 5-100 mg/L m with R2= 0.9955, LOD 2.92 mg/kg; LOQ 9.72 mg/kg, bias found 0.015 %, RSD 0.22; recovery ranged 83.38 to 93.40%. The results showed that 23/38 food product samples from markets and supermarkets in Hanoi city contained cyclamate, accounting for 62.53%, with concentrations ranging from 10.9 to 178.1 mg/kg. However, the content of cyclamate in all samples have met the standards as regulated in Circular No. 08/2015/TT-BYT. In addition, cake and candy samples used cyclamate more frequently compare to other analyzed food types.

The incredible growth of plastic waste is a major concern for the whole society in recent years. The accumulation of plastic waste has badly effects on wildlife, habitat, and humans. Plastics that act as pollutants are categorized into different sizes, from micro to macro. Disposable plastic waste was collected at the bakery shop and removed the residue food by tap water and NaOH 1M to remove residual food. This study focuses on modify waste plastic by sulfuric acid to bind the sulfonated function group on the structure of the polystyrene chain at room temperature. The sulfonated product was used for removing heavy metal ion in water with the mechanism of the ion exchange process. The prepared ion exchange material was characterized by FTIR and SEM to ensure that the sulfonation process has happened. The chromium (III) ion removal by modified ion exchange product in continuous mode was affected by an operational parameter such as the bed height of sulfonated material. The Yoon-Nelson and Thomas model were used to analyze the experimental result and the model parameters were evaluated. From this result, it can be concluded that with the increasing amount of sulfonated waste polystyrene, exchange capacity, and the time required for a 50% adsorbate breakthrough was higher.

This study aimed to identify the effects of a low cost polycation, i.e., polyDADMAC (PD), on the aggregation of newly formed Fe oxides. An evaluation was performed over a wide range of pH values and PD concentrations using combined zeta potential and aggregation measurements. PD adsorbs on the surface of the newly formed Fe oxides, altering their surface charge to less negative values, favouring colloidal aggregation. In the absence of PD, aggregation of the newly formed Fe oxides was favoured in a narrow pH range (i.e., 5–6), whereas the presence of PD resulted in faster aggregation over the entire pH range of 3 to 11. In general, PD showed more obvious efficacy at alkaline pH values, and its performance decreased at pH

The ability of the agricultural residue of sugarcane bagasse to serve as an absorbent material used to remove Ciprofloxacin, one of strong Fluoroquinolone antibiotic from aqueous solutions in fixed-bed columns was investigated. The properties of biochar sugarcane bagasse were characterized using scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy before and after modification. The results of fixed bed column experiment showed that the shape of the removal efficiency of CIP and exhaustion time was dependent on bed height, flow rate and initial concentration. The maximum adsorption capacity qo predicted from Thomas modelreached 0.955mg/g at the flow rate of 1mL/min, initial concentration of 15mg/L and bed height of 6cm. From Yoon-Nelson equation, 3.38 minutes was the time required for 50% exhaustion of 12cm bed height column with the flow rate 2mL/min and concentration 15mg/L. Thomas and Yoon-Nelson models were in good agreement with the experimental breakthrough curve data.

PolyDADMAC (PD) is a high charge density cationic polymer of diallyldimethylammonium chloride which has been recently developed as a coagulant in water purification. As PD has high affinity to fine negatively-charged colloids, it is worth to ascertain if PD can affect surface properties of clay-size particles in red mud waste and be applied to develop immobilization techniques for red mud storage areas. In the current study, a test tube method in combination with surface charge measurement was used for determination of the colloidal properties of a red mud sample under the variation of PD, soluble Al and Si, and variable pH conditions. Observations for the PD concentration range from 0.25 to 2.0 mM revealed that PD can increase surface charge and enhance aggregation or at least shift the aggregation zone to higher pH. This suggests a possible application of PD for immobilization of red mud in alkaline condition. It was also found that soluble Al and Si acted to modify the effect of PD and aggregation properties of red mud. While soluble Si supported aggregation, Al appeared as an enhancer for dispersion of red mud. It implies that development of PD-based techniques for immobilization of red mud needs to consider the effects of soluble Al and Si.

Over the last decade, research has been conducted to investigate the use of triboluminescence (TL) as the active element for impact sensors. TL is defined as the emission of light produced by mechanical action. For the last decade, the authors has obtained extensive experience in characterizing TL and has successfully measured it during impacts with speeds of 1 m/s to about 5.6 km/s. For the most part, zinc sulfide and europium dibenzoylmethide triethylammonium (europium tetrakis) compounds have been used as sample materials, since both emit strong TL. Recent ballistic results also show there is a ~1 nm shift in the triboluminescent peak wavelength between the high speed 30 caliber and low speed 9 mm projectiles augmented with ZnS:Mn powder. In fact, the 9 mm peak wavelength for triboluminescence is similar to what was found in earlier measurements. More significantly, collected results also show that the triboluminescent emission yield for ZnS:Mn appeared to be a function of speed for collisions up to 6 km/s using a two-stage light gas gun. These research programs expanded the knowledge base for using TL as the active element for sensors to detect high-speed impacts.