Concentrations Of Inorganic Salts Research Articles

Effect of inorganic salt concentration and types on electrophoretic migration of oil droplets in oil-in-water emulsion: A molecular dynamics study

Oil-in-water (O/W) wastewater generally contains inorganic salt ions, which cause energy consumption in the process of electric demulsification. To reveal the influence mechanism of inorganic salt ions on the micro movement of oil droplets in O/W emulsion, the electrophoretic migration of oil droplets with different ion concentration was studied based on molecular dynamics simulation. The results showed that Na+ adsorbed the negative charge on the surface of the oil droplets while Cl- repelled it, leading to a decrease in the electrophoretic mobility and deformation of the oil droplets with the increase of ion concentration. The inhibitory effect of three inorganic salts on oil droplet electrophoretic migration was MgCl2 > CaCl2 > NaCl. The weak interaction between oil, water and ions was mainly van der Waals interaction. When the NaCl concentration was 0.4 mol/L, the oil–water interfacial tension was at its maximum value of 85.14 mN/m. and the deformation degree of oil droplets reached the minimum values of 0.45. The formation of hydrated ions reduces the freedom of water molecules. The above findings uncovered the effect of inorganic salt ions on the electrophoretic migration of oil droplets in O/W emulsions under a DC electric field, which can provide theoretical guidance for the purification of oily wastewater from the molecular level.

Impact of ultrasound and medium condition on production of selenium-enriched yeast

BackgroundUltrasonication was used to stimulate the growth and selenium (Se) biotransformation in Saccharomyces cerevisiae. An optimization study for maximal Se accumulation in S. cerevisiae was conducted using the Plackett–Burman screening method and response surface methodology (RSM) for optimization of conditions. The variables influencing Se biotransformation by yeast, including duration and power of ultrasound, inoculum treatment with ultrasound, duty cycle, growth phase, time, shaking rate, inorganic salt concentration (Se, Zn, Mg, and K), and nitrogen and carbon sources as well as their concentrations were screened using the Plackett–Burman design. ResultsThe main variables were carbon and Se concentration as well as ultrasound power and duty cycle. The lack of fit was insignificant (P > 0.01). The optimum condition for Se accumulation was obtained at Se concentration of 60 µg/ml, carbon source brix of 15, ultrasound of 90 W/L, and duty cycle of 40%. ConclusionsThe results showed that optimization of parameters and application of ultrasonication lead to a successful enhancement (2.78-fold) in the accumulation of selenium by S. cerevisiae. Such enriched yeast can be utilized in bread for increasing consumption of Se in the diet of patients with Se deficiency.How to cite: Alijan S, Hosseini M, Esmaeili S, et al. Impact of ultrasound and medium condition on production of selenium-enriched yeast. Electron J Biotechnol 2022;60. https://doi.org/10.1016/j.ejbt.2022.09.004.

Efficient Separation of Proteins and Polysaccharides from Dendrobium huoshanense Using Aqueous Two-Phase System with Ionic Liquids.

By applying the hydrophilic ionic liquid, 1-butyl-3-methylimidazolium chloride ([C4mim]Cl), and inorganic salts (K3PO4), an ionic liquid aqueous two-phase system (ILATPS) was established for the separation of Dendrobium huoshanense polysaccharides (DhPs) and proteins. The effects of inorganic salt concentration, IL quantity, crude DhPs concentration, pH value and temperature were studied to achieve the optimal condition. With the best combination of ILATPS (1.75 g K3PO4, 1.25 g [C4mim]Cl, 10 mg crude DhPs and 5.0 mL ddH2O at pH 7.0 under 25 °C), the extraction efficiency rates for DhPs and proteins were 93.4% and 90.2%, respectively. The processed DhPs retrieved from the lower salt-rich phase comprised mannose, glucose, galactose, arabinose, and galacturonic acid with a molar ratio of 185:71:1.5:1:1 and the molecular weight was 2.14 × 105 Da. This approach is fast, simple and environmentally friendly. It provides a new insight into purifying functional polysaccharides of plant origin.

Lotus pollen-derived hierarchically porous carbons with exceptional adsorption performance toward Reactive Black 5: Isotherms, kinetics and thermodynamics investigations

The removal of azo dye from wastewater is urgent due to its massive discharge from various industries and high toxicity. Adsorption is an efficient removal method, but it is limited by the low adsorption capacity of the present adsorbents. Herein, a high-efficiency and sustainable adsorbent for Reactive Black 5 (RB5) was developed, which was obtained using lotus pollen as carbon precursors followed by carbonization and activation with KOH. The as-prepared lotus pollen-derived hierarchically porous carbons (LPHPCs) showed exceptional adsorption performance for RB5, the maximal equilibrium adsorption capacity can reach 615.6 mg/g on LPHPC-2.5, and 269.6 mg/g on LPHPC-1.0, which were far superior to that of commercial activated carbon (CAC) (94.7 mg/g). Their adsorption performance for RB5 under different conditions was examined, such as different initial concentration, adsorbent dosage, inorganic salt concentration, temperature and pH. The adsorption isotherms, kinetics, thermodynamic properties and mechanisms were systematically investigated in depth. The results demonstrated that the adsorption process of RB5 onto LPHPCs involved dominant physical adsorption together with necessary chemical adsorption. The comparative advantages of LPHPCs over CAC for RB5 adsorption were ascribed to the higher specific surface area and larger appropriate pore volume, higher degree of graphitization and better affinity. The findings revealed that LPHPCs are promising adsorbents for the adsorption removal of anionic dyes from wastewater.

Effects of the sample matrix on the photobleaching and photodegradation of toluene-derived secondary organic aerosol compounds

Abstract. Secondary organic aerosol (SOA) generated from the photooxidation of aromatic compounds in the presence of oxides of nitrogen (NOx) is known to efficiently absorb ultraviolet and visible radiation. With exposure to sunlight, the photodegradation of chromophoric compounds in the SOA causes this type of SOA to slowly photobleach. These photodegradation reactions may occur in cloud droplets, which are characterized by low concentrations of solutes, or in aerosol particles, which can have highly viscous organic phases and aqueous phases with high concentrations of inorganic salts. To investigate the effects of the surrounding matrix on the rates and mechanisms of photodegradation of SOA compounds, SOA was prepared in a smog chamber by photooxidation of toluene in the presence of NOx. The collected SOA was photolyzed for up to 24 h using near-UV radiation (300–400 nm) from a xenon arc lamp under different conditions: directly on the filter, dissolved in pure water, and dissolved in 1 M ammonium sulfate. The SOA mass absorption coefficient was measured as a function of irradiation time to determine photobleaching rates. Electrospray ionization high-resolution mass spectrometry coupled to liquid chromatography separation was used to observe changes in SOA composition resulting from the irradiation. The rate of decrease in SOA mass absorption coefficient due to photobleaching was the fastest in water, with the presence of 1 M ammonium sulfate modestly slowing down the photobleaching. By contrast, photobleaching directly on the filter was slower. The high-resolution mass spectrometry analysis revealed an efficient photodegradation of nitrophenol compounds on the filter but not in the aqueous phases, with relatively little change observed in the composition of the SOA irradiated in water or 1 M ammonium sulfate despite faster photobleaching than in the on-filter samples. This suggests that photodegradation of nitrophenols contributes much more significantly to photobleaching in the organic phase than in the aqueous phase. We conclude that the SOA absorption coefficient lifetime with respect to photobleaching and lifetimes of individual chromophores in SOA with respect to photodegradation will depend strongly on the sample matrix in which SOA compounds are exposed to sunlight.

Simple Preparation of Injectable Hydrogels with Phase-Separated Structures That Can Encapsulate Live Cells.

Injectable hydrogels are biomaterials that can be administered minimally invasively in liquid form and are considered promising artificial extracellular matrix (ECM) materials. However, ordinary injectable hydrogels are synthesized from water-soluble molecules to ensure injectability, resulting in non-phase-separated structures, making them structurally different from natural ECMs with phase-separated insoluble structural proteins, such as collagen and elastin. Here, we propose a simple material design approach to impart phase-separated structures to injectable hydrogels by adding inorganic salts. Injecting a gelling solution of mutually cross-linkable tetra-arm poly(ethylene glycol)s with potassium sulfate at optimal concentrations results in the formation of a hydrogel with phase-separated structures in situ. These phase-separated structures provide up to an 8-fold increase in fracture toughness while allowing the encapsulation of live mouse chondrogenic cells without compromising their proliferative activity. Our findings highlight that the concentration of inorganic salts is an important design parameter in injectable hydrogels for artificial ECMs.

Biomass burning and marine aerosol processing over the southeast Atlantic Ocean: a TEM single-particle analysis

Abstract. This study characterizes single-particle aerosol composition from filters collected during the ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) and CLoud–Aerosol–Radiation Interaction and Forcing: Year 2017 (CLARIFY-2017) campaigns. In particular the study describes aged biomass burning aerosol (BBA), its interaction with the marine boundary layer and the influence of biomass burning (BB) air on marine aerosol. The study finds evidence of BBA influenced by marine boundary layer processing as well as sea salt influenced by BB air. Secondary chloride aerosols were observed in clean marine air as well as in BB-influenced air in the free troposphere. Higher-volatility organic aerosol appears to be associated with increased age of biomass burning plumes, and photolysis or oxidation may be a mechanism for the apparent increased volatility. Aqueous processing and interaction with the marine boundary layer air may be a mechanism for the presence of sodium on many aged potassium salts. By number, biomass burning potassium salts and modified sea salts are the most observed particles on filter samples. The most commonly observed BC coatings are inorganic salts. These results suggest that atmospheric processes such as photolysis, oxidation and cloud processing are key drivers in the elemental composition and morphology of aged BBA. Fresh BBA inorganic salt content, as it has an important role in the particles' ability to uptake water, may be a key driver in how aqueous processing and atmospheric aging proceed.

Efficiently combined technology of precipitation, bipolar membrane electrodialysis, and adsorption for salt-containing soil washing wastewater treatment

Wastewater of that washing of soil that results in concentrations of inorganic salts, toxic metals, chelating agents, and refractory dissolved organic matter may threaten the surrounding environment. Simultaneously, the removal of contaminants and the recovery of resources from this wastewater remain challenging. This study investigated the probability of a novel combined treatment (chemical precipitation + bipolar membrane electrodialysis (BMED) + activated carbon (AC) adsorption) on salt-containing soil washing wastewater treatment. The results showed that the proposed combined treatment could achieve proficient removal of heavy metals, inorganic salts, and total organic carbon (TOC) with low energy consumption (removal efficiency of heavy metals and inorganic salts > 94%; TOC removal > 58%). Meanwhile, the efficient recovery of acid and alkali could also be realized in the proposed treatment (acid-production rate = 7.76 ± 0.38 mmol/h and base-production rate = 5.47 ± 0.42 mmol/h at 50 mA/cm2). The mechanism result indicated that the chemical precipitation process could achieve high removal of heavy metals. Then, the BMED process induced an efficient separation of organic matter and inorganic salts. Accordingly, the AC adsorption process could efficiently remove organics. Preliminary economic evaluation results revealed that the combined process could proficiently treat the soil washing wastewater with economic viability. Together, these findings provide meaningful information for soil washing wastewater treatment with resource recovery.

Strong-Weak Response Network-Enabled Ionic Conductive Hydrogels with High Stretchability, Self-Healability, and Self-Adhesion for Ionic Sensors.

The requirement of ionic conductive hydrogels with tailor-made superelasticity and high chain mobility is highly desired while meeting a challenge. Herein, ionic conductive hydrogels with the design of strong-weak response networks were synthesized via the free-radical copolymerization of monomers of 1-methyl-3-(4-vinylbenzyl)imidazolium chloride and sodium 2-acrylamino-2-methylpropanesulfonate in water. The as-formed strong-weak response networks in ionic conductive hydrogels included binary interactions of strong electrostatic forces and weak hydrogen bonds. The electrostatic forces imparted excellent mechanical elasticity, and the hydrogen-bonded interactions served as highly active and reversible networks to dissipate fracture energy during the deformation. Importantly, the resultant ionic conductive hydrogels exhibited high toughness of ∼2205 kJ m-3, satisfying fatigue resistance, and excellent healing efficiency of >90%. Moreover, the tailoring of counterion concentrations in hydrogels by adding various concentrations of inorganic salts could regulate the electrostatic forces within hydrogels as well as the finally mechanical strengths. Ascribing to the combination of large stretchability and large chain mobility, the resultant ionic conductive hydrogels could directly act as a stretchable ionic conductor for the assembly of self-healable and self-adhesive capacitance-type ionic sensors which are capable of detecting large and tiny human activities. This study could offer a promising strategy for the design and manufacturing of emerging ionic conductors with high mechanical elasticity and large segment mobility.

The sustainable utilization of anaerobic digestion effluents treating in suspended filler algae assisted systems

Significant amounts of anaerobic digestion effluents (ADE) containing high concentration of inorganic salts (source of nitrogen and phosphorus) and hardly degradable organic matter are produced during the generation of biogas using livestock manure. Without appropriate treatment, the imbalanced carbon to nitrogen ratio may lead to severe pollution of the environment. Considering different environmentally friendly processes such as recycling, energy regeneration, and sustainable development, suspended fillers were added to traditional algal-bacterial symbiosis (ABS) systems. In the present research, three systems including suspended filler algae assisted bio-reactor (SFA-PBR), no filler algae assisted bio-reactor (NFA-PBR), and single activated sludge system (ABS) were examined. Changes in bacterial communities were analyzed using high throughput sequencing. In addition, the mechanisms of ADE degradation in the presence and absence of suspended algae fillers were studied by comparing their effect on the degradation of COD (chemical oxygen demand), TN (total nitrogen), AN (ammonia nitrogen), and TP (total phosphorus). Systems where the ratio of active microalgae to bacteria was higher promoted the interaction between the two types of microorganisms, accelerating the stability of the ABS. Thus, the daily COD degradation rate in the stage was still high. Flora such as microalgae and bacteria were embedded in the filler spheres, which increased the microorganisms resistance to the poor environment induced by high concentrations of inorganic nutrients and organic matter present in the ADE. This favored the sustainable water utilization of ADE. After the treatment in the SFA-PBR system, the COD degradation rate was 75.32 %. The effluent COD concentration was 334.21 ± 39.18 mg/L. TN and AN degradation rates were 89.34 and 91.32%, respectively. The TN and AN concentrations in the effluent were 35.42 ± 2.65 and 29.97 ± 2.65 mg/L, respectively. The degradation rate of TP was 95.39 %. The effluent TP concentration was 0.86 ± 0.18 mg/L. The Chao diversity and ACE index values in the SFA-PBR system were higher than those of other groups. This result further supports the conclusion formulated with the Shannon diversity index result. Specifically, the effective sequence in the SFA-PBR system group presented a higher degree of homogeneity and abundance.

Heterogeneous Fenton-like catalytic degradation of phenazine dye over CeO2 (CP-2) nanoscale powder

A heterogeneous Fenton-like process was explored for oxidation of phenazine dye using ceria polishing material (CP-2). XRD, SEM, FTIR, UV-vis DRS, and pHPZC techniques were applied to characterize the catalyst features. The performance of the heterogeneous Fenton-like process was investigated under various parameters (reaction time, pH, H2O2 concentration, catalyst dosage, initial dye concentration, temperature of the medium, and inorganic salt content). Results indicated that the main content of CP-2 catalyst was CeO2 (60-70%) with lower contents of La2O3 (30-40%), Pr6O11 (≤6%), Nd2O3, and CaF2 (≤5%). CP-2 possessed a typical CeO2 cubic fluorite structure with high content of rare earth oxides (REO) and α-Fe2O3. The average crystallite size and band gap energy of CP-2 were found to be 37.2 nm and 3.0 eV, respectively. Over 81.3% of neutral red (NR) oxidation efficiency was achieved in 60 min. Pseudo-first-order kinetic model gave the best fit with an acceptable coefficient of determination R2. The activation energy (Ea) was 16.4 kJ/mol suggesting that the degradation reaction proceeded with a low energy barrier and the removal process was feasible, spontaneous, and endothermic. The synergistic effect of Fe- and/or REO-CP-2 and H2O2 greatly enhanced the reactive oxygen species (ROS) such as •OH, O2 •-, 1O2, and HO2 • for effective oxidation of NR via a heterogeneous Fenton-like process.

Investigation on mineralization performance and spore germination conditions of calcium carbonate mineralizing bacteria

Microbial induced calcium carbonate precipitation (MICP) provides a theoretical basis for repairing underground rocks. The optimal germination conditions and mineralization activities of Bacillus pasteurii with crack repair function were investigated. The growth and mineralization properties of microorganisms in different environments were explored by measuring the urease activity and calcium carbonate production of bacteria, and the influencing factors of bacterial biomass and urease activity were analyzed. The microscopic morphology of bacterial mineralization products was analyzed by SEM, XRD and TG-DSC test. The influencing factors of spore germination rate were studied by measuring the OD value of spore germination. The results showed that under the conditions of pH 7.3, urea concentration 0.25–0.5 mol l−1, and calcium ion concentration 0.4–0.6 mol l−1, the mineralization activity of B. pasteurii was the strongest, and the generated mineralization product was a stable calcite crystal. The optimum concentration of germination agent and inorganic salt were 10 mmol l−1 and 200 mmol l−1, respectively.

The Presence of Blood-Brain Barrier Modulates the Response to Magnesium Salts in Human Brain Organoids.

Magnesium (Mg) is fundamental in the brain, where it regulates metabolism and neurotransmission and protects against neuroinflammation. To obtain insights into the molecular basis of Mg action in the brain, we investigated the effects of Mg in human brain organoids, a revolutionary 3D model to study neurobiology and neuropathology. In particular, brain organoids derived from human induced pluripotent stem cells were cultured in the presence or in the absence of an in vitro-generated blood–brain barrier (BBB), and then exposed to 1 or 5 mM concentrations of inorganic and organic Mg salts (Mg sulphate (MgSO4); Mg pidolate (MgPid)). We evaluated the modulation of NMDA and GABAergic receptors, and BDNF. Our data suggest that the presence of the BBB is essential for Mg to exert its effects on brain organoids, and that 5 mM of MgPid is more effective than MgSO4 in increasing the levels of GABA receptors and BDNF, and decreasing those of NMDA receptor. These results might illuminate novel pathways explaining the neuroprotective role of Mg.

Laminated PAA nanofibers as a practical support for crude laccase: A new perspective for biocatalytic treatment of micropollutants in wastewaters

Increasing concentrations of endocrine disrupting pollutants from countless human activities represent an increasingly serious threat to the environment. However, crude microbial enzymes that are easily obtained from nature may serve as eco-friendly and cost-effective biocatalysts for polluted wastewater treatment. In this work, crude laccase, obtained from white-rot fungi Trametes versicolor , was covalently immobilized onto laminated poly(acrylic acid) nanofibers and its biocatalytic activity and stability tested on real wastewater effluent. The immobilized crude laccase retained almost 80% of its initial activity after 35 days of storage in wastewater, with no significant inhibition of enzymatic activity caused by the high concentrations of inorganic salts or cations. Most importantly, immobilized laccase proved highly effective in degrading a mixture of bisphenol A, 17 α -ethinylestradiol, triclosan and diclofenac in wastewater effluent over 14 days. Based on these results, crude laccase from T. versicolor could represent an important new perspective for wastewater treatment. • Crude laccase successfully immobilized onto laminated PAA support. • PAA-laccase displayed excellent activity, stability and reuse. • Exceptional stability against inorganic salts in wastewater confirmed. • Laminated PAA-laccase is suitable for real wastewater application.

Aqueous two-phase extraction of polysaccharides from Selaginella doederleinii and their bioactivity study

In this study, the ethanol/salt aqueous two-phase system was firstly used to extract Selaginella doederleinii polysaccharides (SDP). Through single factor and response surface analysis, the best extraction conditions were as follows: extraction time of 40 min, ultrasonic power of 280 W, ethanol concentration of 35%, inorganic salt concentration of 0.22 g/mL, and liquid/solid ratio of 25 mL/g with optimal predicted yield of 9.85%. The preliminary structure of SDP was analyzed by HPLC, SEM, Congo red experiment, FT-IR NMR, SEM, thermogravimetric analysis and XRD. In vitro antioxidant experiments indicated that SDP exhibition a potential antioxidant activity and the scavenging rate of SDP (120 μg/mL) against DPPH +·, ABTS+· and ferrous ions were 39.35%, 43.25% and 48.63%, respectively. Also, SDP had certain antitumor activity and the IC50 of SDP on A549 cells and HCT-116 cells were 1528 μg/mL and 2341 μg/mL, respectively.

Harmful algal bloom warning based on machine learning in maritime site monitoring

Forecasting harmful algal blooms (HABs) is an important part of marine environmental monitoring. Algae bloom observation channels includes satellite remote sensing and maritime station monitoring (MSM). Compared with satellite remote sensing image, MSM can collect more accurate data, which includes various seawater inorganic salt content related to the HABs. However, the measured data of MSM is easily affected by regional sediment content and seawater dynamic field, which leads to lack the accurate forecasting models. Therefore, this paper proposed a local spatio-temporal HABs forecasted model (STHFM) based on few impact factors in MSM. The advantage of this model is to first use principal component analysis to select main environment factors (MEFs) related to HABs. Then, this model distinguishes multiple warning levels of HABs in spatio-temporal according to the algae growth rate. Finally, this paper generates continuous MEFs time series information based on the Autoregressive Integrated Moving Average (ARIMA) model in the high-level warning area. And an improved LSTM network with MEFs time series as input is established to forecast HABs in future. The proposed model is tested on the NOAA website public dataset, which contains historical harmful algae Alexandrium data on the East Coast of US. The experimental shows that our model has good HABs monitoring performance. Under the public NOAA Alexandrium dataset, the proposed model can achieve the highest prediction accuracy of 82.1%, and has a small prediction error.

Enhancing anaerobic digestion of wild seaweed Gracilaria verrucosa by co-digestion with tofu dregs and washing pre-treatment

Marine biomass (such as wild seaweed Gracilaria verrucosa) is highly abundant in Indonesia and has been highlighted as a potential biomass resource for bioenergy production. Furthermore, agro-industrial waste (such as tofu dregs/TD which arises from large-scale production in the country) is rich in carbohydrates and proteins, and is therefore considered a viable feedstock for production of high-value added products. This study aimed to investigate the co-digestion of wild seaweed G. verrucosa (WGv) with TD and its impacts on biogas and methane production. The biochemical methane potential (BMP) test was operated for 28 days at temperature of 37 °C. The co-digestion of WGv with TD at 90:10 and 80:20 ratios significantly increased the specific methane potential (SMP), giving an average of 98 LCH4/kgVS and 120 L CH4/kgVS, respectively. Addition of co-digestion substrates promoted co-metabolism in the digesters, increasing the ability of the microorganism to effectively digest the organic matter present in the feedstock’s mixture. The washing pre-treatment reduced the concentration of inorganic compounds and salts within the wild seaweed G. verucosa, leading to an improvement in biogas and methane yield. The mass balance illustrated that this process configuration led to a reduction in the quantity of digestate to be managed (i.e. dewatering, transport, and land/soil application). This will subsequently reduce the cost and energy requirements for sludge management, estimated at 37%. Therefore, the co-digestion of WGv with TD and the application of a washing pre-treatment stage prior to AD can positively enhance biogas and methane production. In-depth investigation for optimal valorisation using AD technology is highly essential.

Solution Properties of a Composite System Containing Dynamic Borate Ester Bonds Formed by a Guar Gum and Polyboric Acid Compounds

Polymer systems containing dynamic covalent bonds have great application potential in the field of enhanced oil recovery. In this paper a series of polyboric acid compounds were synthesized by using polyamine and formylbenzeneboronic acid as raw materials, and then a binary composite system containing dynamic borate ester bonds was formed by mixing guar gum with the polyboric acid compound. The effects of the polyboric acid compound structure, composite system concentration, temperature, inorganic salt concentration and pH on the apparent viscosity and rheological properties of the composite system solution were investigated. The results showed that the higher the content of boric acid groups in the polyboric acid compound, the greater the solution viscosity of the composite system. The apparent viscosity of the guar gum solution increased from 350 mPa.s to 1854 mPa.s at room temperature, the highest value obtained, when the guar gum was mixed with a polyboric acid compound formed by the reaction of polyethyleneimine (PEI) and 2-formylphenylboric acid (2-FPBA) at a molar ratio of 1:4.5. Temperature and pH had a great influence on the apparent viscosity of the composite system, whereas NaCl addition had little effect on the apparent viscosity of the composite system. In addition, the rheological test results showed that the composite system had good shear resistance and structural elasticity, which meets the basic requirements of a polymer flooding agent used for enhanced oil recovery.

An Experimental Evaluation of Toxicity Effects of Sodium Chloride on Oviposition, Hatching and Larval Development of Aedes albopictus.

Dengue virus, one of the most important mosquito-borne viruses, has shown a sharp upward trend, spreading around the world in recent years. Control of vectors Aedes aegypti and Ae. albopictus remains crucial for blocking dengue transmission. The lethal ovitrap (LO) is one of the cost-effective traps based on the classic “lure and kill” strategy, and finding a proper long-lasting effective toxin is key to achieving the desired effect. The concentration of inorganic salts of habitat environment plays a strong role in affecting oviposition, hatching, and development of mosquitoes, but the potential insecticide activity of Sodium Chloride (NaCl) in habitat water as well as LO still lacks research. In this study, we carried out laboratory experiments to systematically explore the effects of different concentrations of NaCl solutions on oviposition, egg hatching, and larval development of Ae. albopictus. Consequently, Ae. albopictus was found to prefer freshwater to lay eggs; whereas 48.8 ± 2.6% eggs were laid in freshwater and 20% in ≥1.0% brackish water, few eggs were laid in 3.0% NaCl solution. Compared with egg hatching, larval development of Ae. albopictus presented a higher sensibility to NaCl concentration. The mortality of the 3rd–4th larvae in 1.0% NaCl solution was 83.8 ± 8.7%, while in 3.0% it reached 100%. Considering the cumulative effect of NaCl, when NaCl concentration was ≥1.0%, no eggs could successfully develop into adults. These data suggested that NaCl solutions with a concentration ≥1.0% can be used as an effective cheap insecticide for Ae. albopictus in subtropical inland aquatic habitats, and also as the “kill” toxin in LOs. Meanwhile, the concentration range from 0 to 2.0% of NaCl solution has the potential to be used as the “lure” in LOs. The technological processes of how to use NaCl as insecticide or in LOs still needs further in-depth exploration.

DPD Simulation on the Transformation and Stability of O/W and W/O Microemulsions.

The dissipative particle dynamics simulation method is adopted to investigate the microemulsion systems prepared with surfactant (H1T1), oil (O) and water (W), which are expressed by coarse-grained models. Two topologies of O/W and W/O microemulsions are simulated with various oil and water ratios. Inverse W/O microemulsion transform to O/W microemulsion by decreasing the ratio of oil-water from 3:1 to 1:3. The stability of O/W and W/O microemulsion is controlled by shear rate, inorganic salt and the temperature, and the corresponding results are analyzed by the translucent three-dimensional structure, the mean interfacial tension and end-to-end distance of H1T1. The results show that W/O microemulsion is more stable than O/W microemulsion to resist higher inorganic salt concentration, shear rate and temperature. This investigation provides a powerful tool to predict the structure and the stability of various microemulsion systems, which is of great importance to developing new multifunctional microemulsions for multiple applications.