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Background: Tomato is one of the most important and popular vegetable crop grown mainly in dry seasons in Bangladesh. The southern part of the country is suffering from soil salinity problem due to tidal floods. The increasing salinity in the cultivatable land causes huge crop failure. A dozen of tomato varieties have been developed but they are not been tested for salinity tolerance. Therefore, this study was conducted to evaluate the tolerance level of tomato varieties against NaCl salinity stress at the vegetative stage. Methods: The study comprised of four levels of electrical conductivity (EC) based NaCl salinity viz., EC 2 (control), EC 4, EC 6 and EC8 mS/cm and eight varieties of tomato. The two-factor pot experiment was carried out in a randomized complete block design with four replications. NaCl salinity was imposed on the tomato plants through a hydroponic culture system and the effects of salinity on shoot-roots traits were measured. Result: Results showed that morphological traits of tomato plants varied significantly with the salinity levels and variety. It is also noticed that all the vegetative traits reduced as salt concentrations increased in the solution. In combined effects of variety and salinity levels, it was found that BARI Tomato-17 performed superior. It can be concluded that variety BARI Tomato-17 showed comparatively salt tolerant than the other varieties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Removal of toluene examines with honeycomb catalyst for industrial application. • Uniform corona plasma with a high flowrate with negligible pressure drop. • The surface resistance of dielectric monolith reduces by the water vapor coat. • Plasma strength largely depends on the humidity of the inlet gas. • Metal clusters on the honeycomb surface can act as floating grounds. Efficiently processing volatile organic compounds (VOCs) with nonthermal plasma and honeycomb catalyst for practical industrial applications presents a sizable challenge. An attempt has been made to generate a large volume of uniform plasma at atmospheric pressure in a practical-scale honeycomb catalyst. H-ZSM-5, a type of zeolite, was washcoated on a commercial bare honeycomb monolith as the catalyst-supporting material, after which the monolith was impregnated with Pd. The plasma discharge power can be controlled by controlling the humidity in the feed gas, metal content, applied voltage, and total flow rate of the feed gas. The plasma was characterized by the voltage and current waveforms, and optical emission spectroscopy (OES). In this study, 85% of dilute toluene (15 ppm) was successfully removed from an airstream at a large flow rate of 60 L/min with an energy density of 84 J/L. Under this condition, the selectivity of CO 2 was 76%. This investigation demonstrated the practical applicability of the plasma-honeycomb catalytic reactor to process a fast-flowing feed gas without resulting in a significant large pressure drop, which can hardly be achieved with typical packed-bed plasma reactors. [ABSTRACT FROM AUTHOR]

· Oxalic acid extracted ∼100% P from digested poultry wastewater at pH 2.5. · Bubble column electrolytic reactor achieved a pH boost from 2.5 to 7 in 6 minutes. · Seeding improved phosphate recovery by 11.5 % and energy efficiency by 52.6 %. · Seeding increased the particle size of struvite by 97.86 % with a purity of 94.7 %. · Estimated operating cost of the process was $12/ kg of struvite. Limited mineralization of organic phosphorus to phosphate during the anaerobic digestion process poses a significant challenge in the development of cost-effective nutrient recovery strategies from anaerobically digested poultry wastewater (ADPW). This study investigated the influence of organic acids on phosphorus solubilization from ADPW, followed by its recycling in the form of struvite using a bubble column electrolytic reactor (BCER) without adding chemicals. The impact of seeding on the efficiency of PO 4 3− and NH 3 -N recovery as well as the size distribution of recovered precipitates from the acid pre-treated ADPW was also evaluated. Pre-treatment of the ADPW with oxalic acid achieved complete solubilization of phosphorus, reaching ∼100% extraction efficiency at pH 2.5. The maximum removal efficiency of phosphate and ammonia-nitrogen from the ADPW were 88.9% and 90.1%, respectively, while the addition of 5 and 10 g/L struvite seed to the BCER increased PO 4 3− removal efficiency by 9.6% and 11.5%, respectively. The value of the kinetic rate constant, k , increased from 0.0176 min−1 (unseeded) to 0.0198 min−1, 0.0307 min−1, and 0.0375 min−1 with the seed loading rate of 2, 5, and 10 g/L, respectively. Concurrently, the average particle size rose from 75.3 μm (unseeded) to 82.1 μm, 125.7 μm, and 148.9 μm, respectively. Results from XRD, FTIR, EDS, and dissolved chemical analysis revealed that the solid product obtained from the recovery process was a multi-nutrient fertilizer consisting of 94.7% struvite with negligible levels of heavy metals. [Display omitted] [ABSTRACT FROM AUTHOR]

• Low-temperature oxidation of toluene by plasma conjugated with Pd/ZSM-5 catalyst. • Stopping emission of O 3 and NO x by covering the ground electrode with oil. • Reducing power consumption by insulating the ground electrode. • Enhanced energy efficiency by cyclic adsorption/plasma-catalytic oxidation. This work investigated the removal of toluene using cyclic adsorption/oxidation operation in a fixed-bed dielectric barrier discharge (DBD) plasma-catalytic reactor containing Pd/ZSM-5 catalyst. The modification of ZSM-5 with Pd catalyst (2 wt %) substantially improved the adsorption capability for toluene. The catalyst adsorbing toluene was readily regenerated during the plasma-catalytic oxidation step. The synergistic effect of the catalyst promoted the toluene oxidation process as well as improved the selectivity towards CO 2. As a method of reducing the energy in generating plasma, two cases (when the ground electrode was exposed to the external air and when the ground electrode was immersed in insulating oil) were compared. No micro-discharge occurred outside the ground electrode surface after oil jacketing, which prevented NO x and ozone from forming, improved energy efficiency, and promoted CO 2 selectivity to 91%. The energy consumption with the oil insulation was 14.5 J/L, while that without it was 58.0 J/L. The catalyst was characterized using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). [ABSTRACT FROM AUTHOR]

Abstract The conditions for the deposition of stable superhydrophobic coatings on glass substrates using a dielectric barrier discharge plasma jet with tetramethylsilane (TMS) and 3-aminopropyl(diethoxy)methylsilane (APDMES) as precursors were investigated. The coatings, which were formed under different plasma conditions, were characterized by various methods including atomic force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, static water contact angle (WCA) and sliding angle measurement, and a scratch test. The results presented that superhydrophobic and mechanically stable plasma coatings could be obtained by optimizing the treatment time, applied voltage, gas flow rate into the plasma chamber, and APDMES/TMS ratio. The results indicated that the use of TMS on its own as the coating precursor led to the formation of unstable coatings. However, the mechanical stability increased significantly when APDMES and TMS were used in combination. As a result, a durable coating layer with a WCA of 163° and sliding angle of 3° was achieved for an APDMES/TMS ratio of 1.7. Highlights • Superhydrophobic coatings using non-thermal atmospheric-pressure plasma jet. • Plasma copolymerization of tetramethylsilane and an aminosilane for stable coating. • Maximum water contact angle of 163° with a sliding angle of 3°. [ABSTRACT FROM AUTHOR]

This work focused on the factors affecting the effective generation of corona discharge plasma in a honeycomb catalyst reactor. Pd, Co, and Ag were used as the active metal catalysts to investigate the plasma formation and decomposition of ethylene. Unlike the Ag-coated honeycomb catalyst, which resulted in excessive arcing, the Co-coated honeycomb monolith was able to generate stable plasma, but the discharge power was insufficient to decompose ethylene at an acceptable level. The incorporation of a small amount of Pd with Co significantly enhanced the discharge power and the ethylene removal performance. The catalytic activity of the prepared catalyst for the removal of ethylene was evaluated using plasma catalytic oxidation and thermal catalytic oxidation. ANOVA was used to assess the effect of single process factors and their relationships in the plasma process. All the process factors such as specific energy input (SEI), ethylene concentration, and flow rate were found to affect the ethylene conversion, CO 2 selectivity, and energy efficiency (EE). Under the optimal conditions, i.e., an SEI of 80 J/L, an ethylene concentration of 20 ppm, and a flow rate of 20 L/min, the ethylene conversion was 85 %, CO 2 selectivity was 70 %, and EE was 0.86 g/kW h. [Display omitted] • Stable corona plasma formation using Co/ZSM-5/monolith and Co-Pd/ZSM-5/monolith. • Bimetallic catalyst shows better catalytic activity than monometallic catalyst. • Ag/ZSM-5/monolith creates numerous arcing and poor plasma formations. • ANOVA with F-test investigates the relationship between the influential factors and NTP reaction activity. [ABSTRACT FROM AUTHOR]

Nonthermal plasma combined with a practical-scale honeycomb catalyst of 5.0 cm in height and 9.3 cm in diameter was investigated for the removal of toluene. The creation of plasma in the honeycomb catalyst greatly depended on the humidity of the feed gas and the presence of metals on the honeycomb surface. Compared to the bare ceramic honeycomb, the metal-loaded one gave higher toluene removal efficiency because the decomposition of toluene by the plasma-generated reactive species occurred not only homogeneously in the gas phase but also heterogeneously on the catalyst surface. The present plasma-catalytic reactor was able to successfully remove about 80% of dilute toluene (15 ppm in air) at a large flow rate of 60 L/min with a specific energy input of 58 J/L. The honeycomb-based plasma-catalytic reactor system is promising for practical applications since it can overcome such problems as high-pressure drop and difficulty in scale-up encountered in packed-bed reactors. ga1 • The removal of toluene investigates on a practical-scale honeycomb catalyst. • A large flow rate without significant pressure drop is used to generate plasma. • Plasma intensity largely depends on the humidity of the feed gas. • The metal clusters dotted on the honeycomb surface can act as floating grounds. [ABSTRACT FROM AUTHOR]

The SrNiO3 perovskite catalyst was synthesized by the citrate sol-gel method and supported on γ-Al2O3 and Nickel foam, which was used to produce syngas (CO and H2) via dry reforming of propane (DRP). Several techniques characterized the physicochemical properties of the fresh and spent perovskite catalyst. The X-ray diffractograms (XRD) characterization confirmed the formation of the perovskite compound. Before the catalytic activity test, SrNiO3 perovskite catalyst was reduced in the H2 atmosphere. Results indicated that the H2 reduction slightly increased the activity of the SrNiO3 perovskite catalyst. The catalytic activity was examined for the CO2/C3H8 ratio of 3 and reaction temperatures in the range of 550 °C–700 °C. The results from the catalytic study achieved 88% conversion of C3H8 and 66% conversion of CO2 with SrNiO3/NiF at 700 °C. Also, syngas with a maximum concentration of 21 vol.% of CO and 29 vol.% of H2 was produced from the DRP. The strong basicity of SrNiO3 perovskite enhanced the CO selectivity, resulting in minimal carbon formation. Post reaction catalyst characterization showed the presence of carbon deposition which could have originated from propane decomposition. [ABSTRACT FROM AUTHOR]

This work presents the effects of the insulation of ground electrode and operating parameters on CO 2 reforming of CH 4 to syngas in a coaxial-cylindrical dielectric barrier discharge (DBD) plasma reactor coupled with Ni/α-Al 2 O 3 catalyst. For the conventional plasma reactor, abnormal outside discharge inevitably ignites and develops from the ground electrode, giving rise to the formation of harmful substances (e.g. , NO x) and the waste of energy. The power dissipation for the conventional reactor therefore includes both that used for the dry reforming reactions and the loss of energy due to the air discharge. The new finding of this work is that by covering the ground electrode with an insulating oil jacket, not only the NO x formation is prevented but also the conversion rates, product selectivity and energy efficiency are largely enhanced by roughly 30, 10 and 100% at a specific energy input of about 47 kJ, respectively. The results are associated with the extinguishment of the discharge occurring outside the reactor, which is usually neglected when designing DBD reactors. Image 1 • Avoiding outside discharges by immersing the ground electrode in insulating oil. • Improvement of plasma-assisted catalytic dry reforming of CH 4 by oil immersion. • Increasing conversion rates, selectivity and energy efficiency by oil immersion. • Eliminating NO x emission using a plasma reactor with oil-immersed ground electrode. • An advanced dielectric barrier discharge reactor proposed for CO 2 reforming of CH 4. [ABSTRACT FROM AUTHOR]

The effects of the position of the current probe on electrical measurements as well as those of typical materials on the current of a He plasma jet during the interaction of the plasma jet with surface materials were investigated using a dielectric barrier discharge reactor, in which the two electrodes were isolated from ambient air by electrical insulating oil. Here, we demonstrate accurate discharge power measurement obtained by positioning the current probe between the two electrodes rather than on the ground wire. The emission current of the plasma jet increased sharply upon the interaction with a ground-connected metal surface, because in this case, the surface functioned as a second ground electrode. Similarly, important is that the average velocity of a plasma bullet can be estimated from the phase shift of the current waveforms at different positions. The phase shift can be monitored by an oscilloscope using a cursor tool during the plasma discharge process. The average velocity of the plasma bullets in this paper ranged from 56 to 266 km/s. [ABSTRACT FROM AUTHOR]

Abstract Deposition of superhydrophobic coatings on glass substrates from hexamethyldisiloxane (HMDSO) precursor using an argon plasma jet at a relatively low power frequency (11.5 kHz) was studied. The coating hydrophobicity was first found to be strongly dependent on the gaseous shield. Nitrogen (N 2) rather than inert gases (argon, Ar, and helium, He) had an excellent shielding effect against the interference of ambient air on the plasma jet. The evolution of water contact angle (WCA) of the prepared coating was investigated upon the variations of the operating parameters, such as N 2 /Ar ratio, HMDSO concentration, deposition time and nozzle-to-substrate distance. Generally, the measured WCA gradually increased with increasing the values of these parameters and then leveled off at some specific values, except for the nozzle-to-substrate distance. The wettability of glass was completely switched from hydrophilicity to superhydrophobicity with the WCA reaching 168° and the sliding angle of about 3° at optimum conditions. The surface morphology analyses by scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that the prepared coating had a very high surface roughness and micro-nano structure, which intensely promoted the water repellence property. The chemical examination by X-ray photoelectron spectroscopy (XPS) clearly showed the shielding effect on the surface chemical composition of the coating. N 2 shield preserved a high carbon content (in CH 3 groups) from the precursor, while minimizing the incorporation of oxygen into the coating surface. Also, it was found that O (from O and OH radicals) has replaced C to form silica-like coating in case of without shielding gas or with Ar and He shields. Highlights • Superhydrophobic coatings using atmospheric pressure plasma jet • N 2 possessing an excellent shielding effect due to its high ionization potential • Plasma jet capable of producing micro-nano structured coatings [ABSTRACT FROM AUTHOR]

• A plasma reactor for practical-scale environmental plasma applications. • Successful plasma generation in a commercial honeycomb monolith. • Increased volume of plasma discharge with humidified air at high flow rates. Large-volume atmospheric-pressure plasma based on corona discharge was successfully generated in a sandwich-type plasma reactor by controlling the humidity of the feed gas. The reactor comprised a 5-cm-high and 9-cm-wide commercial honeycomb monolith and two perforated stainless-steel disk electrodes with 3-mm holes, which covered up both sides of the monolith. The high-voltage applied disk electrode was placed 2 ~ 6 mm away from the monolith, whereas the counter ground electrode typically touched it. The characteristics of air plasma such as power delivery, breakdown voltage, current, and impedance were found to strongly depend on the water vapor content in the feed gas as well as in the monolith, exhibiting an exponential increase of discharge power with increasing the humidity. The discharge characteristics also depended on the gas flow rate and the electrode-monolith distance. Better discharge performance was observed as the electrode was closer to the monolith, and as the air flow rate was higher. Discharge power above 30 W was achieved under the condition of gas flow rate 75 L/min, applied voltage 25 kV, and humidity 2.1%(v/v) when the high-voltage electrode was 2 mm away from the monolith, and the ground electrode kept up against it. The air plasma produced reactive species, being demonstrated by the formation of ozone at several tens of ppm, depending on specific energy input. The plasma source has potential applications in the abatements of odor, organic compounds, and NO x with high throughputs. [ABSTRACT FROM AUTHOR]

This paper reports on the ethyl acetate (EA) removal over a honeycomb catalyst using an experimental design methodology. A mathematical model based on the response surface methodology is developed to evaluate the effect of parameters such as specific input energy (SIE), humidity, and EA concentration on the response variables (i.e., removal and energy efficiency). A set of experiments based on a statistical three-level full-factorial design of the experimental method were performed to collect the removal data. The model (R 1 2 = 0.9858 and R 2 2 = 0.9305 for removal and energy efficiency, respectively) indicates a satisfactory correlation between the experimental and predicted values. The analysis results using the model show that SIE is the principal parameter affecting the EA removal. Besides, verification of the experimental results indicates that the EA removal of 90.93% and the energy efficiency of 2.91 g. kWh − 1 at 235 J L-1, 1.5%, and 30.3 ppm were achieved under optimal conditions. [Display omitted] • High-performance EA removal was obtained in honeycomb catalyst plasma system. • Establishing relationships of input variables to output results via a model evaluation. • Optimal operating condition for EA removal efficiency was determined. • Specific input energy (SIE) is the most important factor to enhance EA removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • A practice-scale sandwich-type honeycomb catalyst discharge reactor was developed. • High-throughput without significant pressure drop condition was obtained. • 94.5 % IPA was removed using the honeycomb catalyst discharge reactor. • Uniform discharge was created using Pd/Al2O3/honeycomb combined with plasma. • Byproducts formation and IPA oxidation pathways were elucidated. A practical-scale sandwich-type honeycomb catalyst reactor incorporating non-thermal plasma was developed for the high-throughput removal of isopropanol (IPA) from air. The Pd/γ-Al 2 O 3 /honeycomb catalyst was fabricated by coating a cordierite monolith with γ-alumina powder on which to support the palladium (Pd). The supported catalyst showed good activity and the combination of the honeycomb structure with plasma produced a uniform plasma inside the catalyst chamber. The influence of different parameters, including the energy density (SIE), humidity, initial concentration, and flow rate, on the plasma characteristics and IPA removal efficiency was investigated. The results showed that the SIE has the strongest effect on the IPA removal efficiency. The efficiency of IPA removal was 94.5% and the CO2 selectivity was 85% for an SIE of 180 J/L. Using optical emission spectroscopy, we found that the increased formation of atomic oxygen and reactive species plays an essential role in the oxidation of IPA by plasma catalysis. The main byproducts were identified by GC-MS, which indicated that acetone is the major liquid product. A plausible reaction mechanism for the plasma-catalytic oxidation of IPA is proposed based on the intermediates and byproducts. [ABSTRACT FROM AUTHOR]

A method based on the corona discharge produced by high voltage alternating current (AC) and direct current (DC) over a Pd/γ-Al 2 O 3 catalyst supported on a honeycomb structure monolith was developed to eliminate ethyl acetate (EA) from the air at atmospheric pressure. The characteristics of the AC and DC corona discharge generated inside the honeycomb structure monolith were investigated by varying the humidity, gas hourly space velocity (GHSV), and temperature. The results showed that the DC corona discharge is more stable and easily operated at different operating conditions such as humidity, GHSV, and gas temperature compared to the AC discharge. At a given applied voltage, the EA conversion in the DC honeycomb catalyst discharge is, therefore, higher compared with that in the AC honeycomb catalyst discharge (e.g., 96% of EA conversion compared with approximately 68%, respectively, at 11.2 kV). These new results can open opportunities for wide applications of DC corona discharge combined with honeycomb catalysts to VOC treatment. [Display omitted] • Uniform plasma generation inside honeycomb without significant pressure drop. • Positive DC discharge is more stable and easier to operate than AC discharge. • Ethylacetate removal was as high as 96% in the DC plasma/honeycomb catalyst. • Feasibility of DC plasma-in-honeycomb for practical pollution control applications. [ABSTRACT FROM AUTHOR]