Min Of Treatment Research Articles

Simultaneous degradation of p-nitrophenol and reduction of Cr(VI) in one step using microwave atmospheric pressure plasma

Different physicochemical properties between Cr(VI) and phenolic compounds pose serious challenges for the effective treatment of co-contamination. This study developed an electrodeless high-flow microwave atmospheric plasma jet for the single-step simultaneous degradation of p-nitrophenol (PNP) and reduction of Cr(VI). Following a 15 min treatment with microwave atmospheric pressure plasma, the removal efficiency of Cr(VI) and PNP reached 97.5% and 93.6%, respectively, whereas that of total organic carbon reached 30.2%. Adding PNP to the solution significantly improved Cr(VI) reduction, whereas PNP degradation increased slightly with Cr(VI). The results indicate that the PNP intermediates significantly affected Cr(VI) reduction. Additionally, long-lived H2O2 and short-lived ·H aided the reduction of Cr(VI) during plasma treatment. The addition of hydroxyl scavengers during treatment implied that ·OH was largely responsible for PNP oxidation. High-performance liquid chromatography–mass spectroscopy (HPLC-MS) revealed that PNP intermediates, including p-nitrocatechol and 5-nitrobenzene-1,2,3-triol, function as Cr(VI) reductants. On the basis of the examined intermediate products, the potential PNP degradation pathway was investigated. The factors that could influence simultaneous dehgradation and reduction, including solution pH, gas velocity, and distance between the plasma outlet and the water surface were researched. Low pH supports Cr(VI) reduction, and the promotion of PNP for Cr(VI) reduction applies to all pH values. The degradation of PNP is insensitive to pH values with or without Cr(VI). The optimal gas velocity for PNP degradation and Cr(VI) reduction was revealed to be 6 L/min. The simultaneous removal of PNP and Cr(VI) benefits from a shorter distance between the plasma outlet and the water's surface.

Wüstite as a catalyst source for water remediation: Differentiated antimicrobial activity of by-products, action routes of the process, and transformation of fluoroquinolones

Wüstite under simulated solar irradiation with addition of H2O2 was used to treat enrofloxacin and levofloxacin in water. Wüstite was characterized, showing 2.1 eV of bandgap and species of Fe3+ on the surface that favor its catalytic ability. The effect of light intensity, wüstite dose, concentration of H2O2, and pH on the removal of antimicrobial activity (AA, against S. aureus and E. coli), was tested, finding as suitable conditions: [intensity]: 500 W m−2, [wüstite]: 10 mg L-1, [H2O2]: 1.0 mmol L-1, and pH 6.5. Under such conditions, up to 100% of AA elimination occurred at 180 min of treatment. The Light-Wüstite-H2O2 system involved, the action of light, O2•−, 1O2, and HO•, where wüstite acted as a semiconductor and a catalyst for heterogeneous photo-Fenton. Furthermore, this system mineralized 21% of ENR, and the wüstite catalyst promoted 100% of AA removal up to the fourth reuse cycle. Interestingly, the application of Light-Wüstite-H2O2 to an actual effluent led to complete AA removal after 180 min treatment. The process action on ENR generated six stable products, exhibiting the loss of the fluorine atom (induced by light directly) and modifications on the ethyl-piperazyl group (reactive region according to calculations of atomic charge) by radical attacks. The relationship between the AA and structural transformations showed that those products that retained quinolone and piperazyl moieties had AA.

Subcellular damages of Colletotrichum asianum and inhibition of mango anthracnose by dielectric barrier discharge plasma

Colletotrichum asianum (C. asianum) is a new pathogenic fungus that causes mango anthracnose. Cold plasma is a novel non-thermal decontamination technology, which has been proven to be effective in controlling postharvest fungus. Herein, dielectric barrier discharge (DBD) plasma was used to treat C. asianum spores in sterile phosphate-buffered saline, the damages in subcellular structures of C. asianum and inhibition of mango anthracnose were evaluated. Results showed that after 9 min treatment, the spore germination rate and spore viability were decreased by 95.48% and 98.82%, respectively, and the subcellular structures were damaged (P < 0.05), leading to spores death. Besides, DBD plasma treatments could control mango anthracnose and maintain mango quality, and the disease incidence and lesion diameter of mango treated for 9 min were decreased by 48.00% and 62.95%, respectively. Therefore DBD plasma inactivated C. asianum spore, providing an alternative technique for preventing and controlling mango anthracnose.

Impact of Deep Ultraviolet-Ozone Photoactivation on Dielectric Properties of Amorphous SrTiO&lt;sub&gt;3&lt;/sub&gt; Thin Films

Strontium titanate SrTiO3 thin films have been fabricated by radio frequency magnetron sputtering on P-type Si at substrate temperature of 200°C. Two different postdeposition annealing methods were applied on the sputtered films. Specifically, conventional thermal annealing at 300°C for 60 min and photoactivation treatment under deep ultraviolet-ozone for 30 min. The dielectric properties of the SrTiO3 thin films were investigated by fabricating Au/STO/p-Si MOS capacitors. A dielectric constant (κ) with a value of 13 was obtained for as-deposited film, which has a thickness of 107 nm. While post-annealed samples showed elevated values of κ, precisely, 15.33 and 19.32 for films exposed to deep ultraviolet-ozone photoactivation and films annealed at 300°C, respectively. All devices showed a leakage current in the order of 10-8 A/cm2 at 1V. Based on XPS analysis, photo-activated films revealed the lowest percentage of oxygen vacancies, which designates the capability of this technique to enhancing films quality at a lower temperature.

Evaluation of the Effects of Cold Plasma on Cell Membrane Lipids and Oxidative Injury of Salmonella typhimurium.

Salmonella typhimurium (S. typhimurium) is a major causative agent of foodborne illness worldwide. Cold plasma (CP) was used to inactivate S. typhimurium and to investigate the effect of CP on cell membrane lipids and oxidative injury of cells. Results indicated that the inactivation effect of CP on S. typhimurium was positively correlated with the treatment time and voltage. S. typhimurium was undetectable (total number of surviving colonies <2 log CFU/mL) after 5 min treatment with the voltage of 50 V. CP treatment caused damage to the cell membrane of S. typhimurium and the leakage of cell contents, and the relative content of unsaturated fatty acids in cell membrane decreased. Cell membrane lipids were oxidized; the malondialdehyde content increased from 0.219 nmol/mL to 0.658 nmol/mL; the catalase activity of S. typhimurium solution increased from 751 U/mL to 2542 U/mL; and the total superoxide dismutase activity increased from 3.076 U/mL to 4.54 U/mL, which confirmed the oxidative damage in S. typhimurium cell membrane caused by CP treatment. It was demonstrated that the potential application of plasma-mediated reactive oxygen species is suitable for destroying the structures of the cell membrane and ensuring the microbial safety of fresh food samples.

Degradation of emerging contaminant coumarin based on anodic oxidation, electro-Fenton and subcritical water oxidation processes

The degradation of emerging contaminant coumarin was separately investigated in anodic, electro-Fenton and subcritical water oxidation processes. With respect to the anodic and electro-Fenton oxidation, the influence of constant current, treatment time and initial concentration of coumarin was studied. Regarding subcritical water oxidation, the effect of the oxidant concentration, temperature, treatment time and initial coumarin concentration was investigated. In anodic and electro-Fenton oxidation processes, coumarin degradation proceeded in a similar manner, achieving 99% degradation, after 180 min at a constant current of 200 mA. In both set-ups, further increasing the applied current lowered the degradation efficiency due to the formation of by-products and the increasing occurrence of side-reactions. The highest degradation of 88% was achieved in subcritical conditions, specifically at 200 °C, using 150 mM H2O2 and after 37.5 min of treatment. Under subcritical conditions, temperature was the most prominent parameter, followed by the H2O2 concentration. Under all methodologies, increasing treatment time had a small positive effect on coumarin degradation, indicating that time is not the most influential parameter. A comparison of the three methodologies in terms of performance as well as energy consumption and simplicity of operation highlighted the advantages of subcritical water oxidation.

Cold atmospheric plasma: an effective approach for fast benazoxystrobin degradation via generating reactive oxygen species

ABSTRACT Cold atmospheric plasma (CAP) has demonstrated its efficacy in degrading organophosphorus or organochlorine pesticide residues without generating secondary pollution. Yet its potential in degrading triazole pesticides and methoxyacrylate pesticides that are gaining popularities in more and more countries remains unexplored. Using benazoxystrobin as the modelling molecule to be degraded, we demonstrated in this paper that CAP could effectively degrade triazole or methoxyacrylate pesticides, with the efficacy being influenced by many factors such as the voltage, flow rate, and frequency. Specifically, CAP could effectively degrade benazoxystrobin via destroying the benzene ring structure; the degradation efficacy can reach 90%, with ‘ionized oxygen’, ‘60 V voltage’ ‘2 L.min−1 oxygen flow rate’ and ‘9 min treatment duration’ being associated with the optimal degradation effect; active CAP articles capable of degrading benazoxystrobin are enriched with ROS, where more oxygen is needed to degrade higher concentration of benazoxystrobin. Our study, for the first time, showed the efficacy of CAP in degrading triazole and methoxyacrylate type of pesticides, providing experimental support for its industrial translation.

Transient computer simulation of the temperature profile in different packaging materials: An optimization of thermal treatment of tender coconut water

AbstractUnderstanding the temperature profile of different packaging materials would be useful for selecting appropriate packaging material for in‐bottle pasteurization. The temperature profile of polypropylene, polyethylene (PE), and polyethylene terephthalate bottles was investigated using COMSOL Multiphysics software to understand the temperature–time correlation with thermal treatments. PE bottles exhibited the least temperature difference between cold and hot spots. Optimization of thermal treatment processing parameters such as temperature (80–95°C) and treatment time (5–15 min) for inactivation of enzymes, namely polyphenol oxidase (PPO) and peroxidase (POD), in tender coconut water (TCW) was performed to the extent its shelf life. The quality parameters of heat‐treated TCW such as pH, total soluble solids (TSS), titratable acidity (TA), turbidity, phenolic content, PPO, POD, and sensory evaluation were analyzed. The multiple linear regression models were developed for each quality parameter using a central composite design (CCD). The optimized treatment conditions were 84°C temperature and 5 min treatment time with the desirability of 0.926. The responses recorded were pH = 5.4, TSS = 5.52, turbidity = 7.1 NTU, TA = 0.06% of malic acid, relative PPO = 0.099, relative POD = 0.093, phenolic content = 44.712 mg gallic acid equivalent/L, and overall acceptability score = 8.Practical ApplicationsUnderstanding the temperature profile of different packaging materials during pasteurization or sterilization is imperative to select the suitable packaging material, and also it would be helpful for designing the heating system. Tender coconut water (TCW) is the most popular natural drink in Asian countries. However, the pasteurization conditions are yet to be optimized to preserve TCW without affecting its bioactive and functional components. The current practice followed for in‐bottle sterilization of TCW is polyethylene terephthalate (PET). This is due to PET being cheaper and readily available than other packaging materials. However, the quality of the TCW could affect PET due to improper heat distribution which can lead to damage of bioactive components. The present study has optimized the suitable pasteurization conditions and packaging material for bottling and marketing TCW. The findings of the present study will boost the market potential of the tender coconut processing industries.

Effects of Hydrothermal and Microwave Dual Treatment and Zein on the Enzymolysis of High Amylose Corn Starch.

Resistant starch (RS) type 2-high-amylose corn starch (HACS) was subjected to simultaneous hydrothermal (25% moisture content, 90 °C for 12 h) and microwave (35% moisture content, 40 W/g microwaving for 4 min) treatment and zein (at a zein to treated starch ratio of 1:5, 50 °C for 1 h) to improve its resistance to enzymolysis. Scanning electron microscopy (SEM) highlighted the aggregation and adhesion of the composite. The average particle size of the composite (27.65 μm) was exceeded that of both the HACS (12.52 μm) and the hydrothermal and microwave treated HACS (hydro-micro-HACS) (12.68 μm). The X-ray diffraction results revealed that the hydro-micro-HACS and composite remained B-type, while their crystallinity significantly decreased to 16.98% and 12.11%, respectively. The viscosity of the hydro-micro-HACS and composite at 50 °C was 25.41% and 35.36% lower than that of HACS. The differential scanning calorimetry (DSC) results demonstrated that the composite displayed a new endothermic peak at 95.79 °C, while the weight loss rate and decomposition temperature were 7.61% and 2.39% lower than HACS, respectively. The RS content in HACS, the hydro-micro-HACS, and composite was 47.12%, 57.28%, and 62.74%, respectively. In conclusion, hydrothermal and microwave treatment combined with zein provide an efficient physical strategy to enhance the RS type 2-HACS.

Degradation of isoniazid by anodic oxidation and subcritical water oxidation methods: Application of Box–Behnken design

Pharmaceutical compounds released into the aquatic environment are known to cause toxic effects on the environment. Isoniazid is widely used in the treatment of tuberculosis and is, therefore, frequently encountered in environmental waters. In this study, the degradation of isoniazid was investigated by anodic oxidation and subcritical water oxidation method which are members of Advanced Oxidation Processes. The Box–Behnken Design was used to determine the effects of current, initial concentration, and electrolysis time on mineralization in the anodic oxidation process, which carried out a cell with a Pt cathode and boron-doped diamond anode. The highest mineralization value of 78.14% was achieved at optimal conditions of 300 mA, 3 h, and 100 mg/L initial concentration. The degradation of Isoniazid was also investigated under subcritical water conditions using an ecological oxidizing agent, H2O2. The maximum mineralization rate of 72.23% was obtained when 100 mM H2O2 was used for a 90 min treatment at 125 °C for 100 mg/L Isoniazid solution in the subcritical water oxidation process. The LC-MS results showed that the degradation products obtained by AO and SWO methods were different from each other. Finally, possible degradation mechanisms are proposed according to the degradation products obtained for both processes.

Application of plasma-activated water forEscherichia colidecontamination and shelf-life extension of kale

AbstractThe aim of this study was to examine the effectiveness of plasma-activated water (PAW) for inactivating Escherichia coli (E. coli) and retention of key quality factors for kale. Different plasma discharge times (1, 2, 3, 4, 5, and 10 min) and different exposure times (2, 4, 6, 8, 10, and 15 min) were used to investigate the inactivation effect of E. coli spot-inoculated on kale. The influence of different exposure times on the pH, hardness and color of kale was studied post-treatment. In addition, the effects of PAW on the shelf-life of kale over 12 d of storage at 4 °C were investigated. The results showed that after the treatment of 5-PAW-8 (8 min treatment by PAW generated by 5 min plasma discharge), the population of E. coli on kale was reduced by approximately 1.55 log colony-forming units (CFU)/g and the changes in pH, hardness and color of kale were not significant (P&amp;gt;0.05). During the storage period after 5-PAW-8 treatment, the hardness, weight loss, color, surface morphology and ascorbic acid were found to be better than those of the two control groups (P&amp;lt;0.05). Furthermore, no significant changes were observed in pH values, the content of total phenols, or 1,1-dipheny1-2-picrylhydrazyl radical scavenging capacity (P&amp;gt;0.05). It is indicated that PAW treatment is a promising method for improving microbiological safety and extending the shelf-life of kale.

A novel activated carbon-based nanocomposite for the removal of bisphenol-A from water via catalytic ozonation: Efficacy and mechanisms

Concerns have been raised about the increasing number and quantity of contaminants in water resources. For a sustainable future, advances for the elimination of these contaminants of emerging concern (CECs) are important. Advanced oxidation processes (AOPs) such as non-catalytic ozonation and catalytic ozonation, have been shown to be effective in removing dissolved contaminants in water and wastewater. Here, we have used a novel nano-composite bimetallic catalyst (AC/Bi2O3/V2O5) for the removal of 5 mg/L of Bisphenol-A (BPA) from water. The characterization of the bimetallic catalyst using Brunauer Emmet Teller surface area (BET) studies, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), raman spectra, and dynamic light scattering (DLS) studies showed that it binds to the activated carbon surface and no foreign bodies were found. Fourier transform infra red (FTIR) studies confirm the degradation and the robustness of the catalyst structure. Degradation studies with different variables found pH 8, 500 µg/L catalyst dosage and 60 min treatment time optimal for maximum BPA removal (97 %) and total organic carbon (TOC) removal (68 %). TOC analysis confirmed that catalytic ozonation with the novel catalyst is 32 % more efficient than non-catalytic ozonation. The degradation pathway of BPA was determined using liquid chromatography-mass spectrophotometer/liquid chromatography-quadrupole time of flight- mass spectrophotometer (LC-MS/LC-Q-TOF-MS) studies.

Performance of non-thermal plasma reactor for removal of organic and inorganic chemical residues in aqueous media

In this work, the performance of an atmospheric air-assisted plasma reactor was evaluated for the oxidative degradation of azo (orange G and congo red) and non-azo (crystal violet, and coomassie brilliant blue) textile dyes and removal of hardness in an aqueous medium. Dye degradation efficiency was evaluated at different applied voltages (2–6 kV), pH (2.85–11.44), and initial dye concentrations (5–25 ppm). Nearly 99% degradation efficiency (at 5 ppm concentration) could be achieved in 30 min treatment time for all dyes. Degradation efficiency showed a direct relationship with applied voltage and an inverse relationship with the initial dye concentration. Moreover, higher degradation efficiencies were observed at neutral pH than in the acidic and alkaline ranges. The pseudo-first-order kinetic model exhibited a better correlation coefficient (R2 > 0.90) in explaining the degradation kinetics of dyes. The water hardness was dropped by 55.5% after 60 min of plasma treatment. Also, the crystalline structure and morphology of water samples containing salts before and after the treatments were analyzed using XRD and SEM. The average crystalline size of untreated and plasma-treated samples is calculated to be 197.9 nm and 98.1 nm respectively. The concentration of O3, OH., H2O2, NO2− and ROS species increased linearly with increasing treatment time. The energy yield and energy consumption for degradation and water hardness removal were ∼0.016 g kW/h and ∼0.3932 g kW/h, 1.08*107 J/L, and 2.16*106 J/L respectively. Moreover, atmospheric pressure gliding arc discharge-based air plasma discharge was computationally modeled and electrical characteristics such as electron density, electric potential, electron temperature, absolute electron flux and charged species (positive and negative) density were examined at different applied voltages. Overall, the atmospheric air-assistant cold plasma process shows promising potential for the removal of chemical residues in water.

Using Power of Calculated Electrons to Cut, Analyze and Exterminate the Outer and the Inner Biological Elements of Hepatitis C Virus without Blood Parameters Disorders: In Vitro Study

Recently, the prevention and treatment of hepatitis C virus (HCV) complications consider as major obstacles to reducing HCV outbreaks worldwide. Therefore, it is crucial to develop a new alternative therapy for HCV infection with low cost and low side effects. A smart device termed a Life Restoration Device (LRD) was designated to produce a low potential codified amount of ions. The specified codified amount of ions produced from LRD are designated to exterminate HCV. To investigate our hypothesis, we designated an experimental system for in-vitro studies. This system is composed of a glass tube that can be filled with HCV polymerase chain reaction (PCR)-positive serum. The result of this study showed that LRD can decrease the viral load of HCV PCR-positive serum to 99% after 2 hrs treatment. The viral load reduction of the LRD against low HCV PCR count was almost similar to that of high HCV PCR count. Furthermore, the efficacy of LRD to reduce the serum viral load after 30 min or 60 min treatment was 74%or 95% respectively while the viral load after2 hrs treatment was about 91%. The electron microscopy investigation of HCV PCR-positive serum after treatment with LRD showed degenerated HCV particles compared with the non-treated virus. The in vitro treatment of the HCV PCR-positive serum with LRD didn’t affect the blood contents such as red blood cells count, white blood cells count and hemoglobin levels. The sincerity of the codified amount of ions produced by LRD may affect the fragile fluidity of the viral envelope. Treatment of hepatitis viruses with a codified amount of ions is a new alternative therapy but needs more studies. It is crucial to develop an effective alternative viral therapy using such kind of technology to reduce the antiviral drugs side effects.

One-step preparation of Co2V2O7: synthesis and application as a Fenton-like catalyst in a gas diffusion electrode.

Bimetallic oxides and MOFs have been used as catalysts for the ORR via two-electron and Fenton-based processes. This work reports the development of a new green one-step route for obtaining Co2V2O7. The Co2V2O7 oxide was immobilized on Printex-L6 carbon and used as a catalyst for the oxygen reduction reaction (ORR) and in heterogeneous Fenton-based processes. The PL6C/2.5% Co2V2O7 sample exhibited the best performance in the ORR via a two-electron pathway, increasing the selectivity for H2O2 generation. Electrochemical impedance spectroscopy analysis showed a decrease in charge transfer resistance in the Co2V2O7/PL6C matrix. The application of a gas diffusion electrode (GDE) modified with 2.5% Co2V2O7 resulted in a 30% increase in H2O2 production compared to the unmodified GDE. The unmodified GDE promoted methyl-paraben (MeP) removal of ∼80% after 90 min treatment, whereas the modified GDE promoted ∼90% of MeP removal in 30 min. The results obtained point to the potential of Co2V2O7 in improving the efficiency of GDE when applied for the treatment of organic pollutants.

Comparative Insecticidal Effects of Dry Ocimum Gratissium (Scent Leaves) and Rambo™ Paper on Mosquitoes in Jos, Nigeria

Insecticides are chemicals or biological substances that are used to kill or disable insects. Blood feeding mosquitoes are responsible for the intolerable biting nuisance and transmission of large number of diseases such as malaria, yellow fever, dengue fever, filarias is amongst others, causing serious health problems to humans and obstacles to socioeconomic development of developing nations like Nigeria. The insecticidal effect of scent leaves (Ocimum gratissum) and Rambo™ paper on mosquitoes was investigated. The study is aimed at comparing the insecticidal effects of Ocimum gratissimum and Rambo™ paper on mosquitoes in Jos. 100 mosquitoes were exposed to dried Ocimum gratissum and Rambo™ paper at different time intervals of 5, 10 and 12 min. Results obtained showed a time dependent insecticidal effect on mosquitoes, which was 54.2%, 54.0% and 55.6% total mortality of mosquitoes at respective time intervals on exposures to both Rambo™ paper insecticide and Osimum gratissum, indicating that there was a significant difference in the lethal effect of Rambo™ paper insecticide and scent leave on mosquitoes at (p&lt;0.05). In comparing the lethal effect of Rambo™ paper insecticide and Ocimum grasstisimum on mosquitoes at differnt locations in Jos, at Dogon Karfe, after 10 min of treatment, Rambo™ paper had the highest lethal effect of 21 (84.0%) compared to scent leaves 6 (24.0%) and at Abattoir Jos, after 12 min of treatment, Rambo™ paper had the highest lethal effect of 17 (94.4%) compared to Ocimum grasstisimum 3 (16.7%). These comparisons were significant at p 0.05. This study provides evidence that Ocimum grasstisimum has a mosquitocidal effect. However, the Rambo™ paper gave a better mosquitocidal effect than Ocimum grasstisimum. There is a need to discover better additive or extract options that could give Ocimum grasstisimum a better effect as a natural product available in Africa towards the malaria eradication programme.

Effects of N224 Glycosylation in Saccharomycopsis fibuligera R64 α-Amylase on Enzyme Activity and Stability

Background: The amino acid sequence of an α-amylase of the yeast Saccharomycopsis fibuligera R64 (SfamyR64) contains two putative N-linked glycosylation sites N153 and N224. N224 is hypothetically responsible for the binding of starch substrate because it is highly conserved among SfamyR64 homologs. Objective: To test whether N224 plays a key role in enzyme activity and stability. Methods: N224Q substitution was introduced by site-directed mutagenesis. The wild type and the mutant were independently over-produced in Pichia pastoris KM71. Activities of the wild type and of the mutant were compared, and their thermal-stability was assessed using heat treatments. The evolutionary relationship of SfamyR64 with its structural homologs with different glycosylation patterns was examined. Results: Activity of the N224Q mutant was approximately 80% lower than that of the wild type. The mutant showed no activity after 10 min of pre-incubation at 50 °C, whereas the wild type SfamyR64 showed activity until 30 min of treatment. Sfamy appeared to have evolved earlier than its structural homolog. Conclusion: SfamyR64 N224 is crucial for enzyme activity and thermal stability. This glycosylation site is unique for fungal and bacterial α-amylases.

Effect of processing and preservation on L-ascorbic acid content in commercially cultivated jute leaves

Vitamin C, also known as ascorbic acid is essential nutrients that cannot produce in human body and meet up through diet. Jute leaves contain L-ascorbic acid. The amount of L-ascorbic is unknown in different varieties developed by Bangladesh Jute Research Institute. L-ascorbic acid content is affected by cooking or processing and preservation. Therefore, the experiment was conducted to investigate the content of vitamin C in the fresh jute leaves as well as the effect of cooking and preservation methods on L-ascorbic acid content in jute leaves. Fresh jute leaves of different varieties contain different amount of L-ascorbic acid 0.39g/10g to 0.64g/10g in Corchorus olitorius and 0.64g/10g to 0.92g/10g in Corchorus capsularis. C. capsularis contain more amount of L-ascorbic acid than the C. olitorius. Jute leaves of C. olitorius retain 95% L-ascorbic acid and C. capsularis retain 62% L-ascorbic acid after 15 min of boiling. Vinegar soaking leaves release more L- ascorbic acid by 5 min than the fresh leaves and then the L-ascorbic acid content was reduced by 15 min in both the species. Spraying vinegar treatment releases more L-ascorbic acid and increasing up-to 30 min treatment. Both oven dried and cold dried leaves retain small amount of L-ascorbic acid. L-ascorbic acid content was reduced in preserved jute leaf tea and soup powder also in both species. Usually, leafy vegetables are cooked before consumption and sometimes preserved vegetables are consumed when fresh vegetables may not available. So, this study may be useful to know the actual intake of L-ascorbic acid from the processed or preserved jute leaves.

Immobilization of xylanase on differently functionalized silica gel supports for orange juice clarification

The immobilization of xylanase from Trichoderma longibrachiatum via ion exchange on 3-propylsulfonic acid (Xyl/Si-SO3) and 3-aminopropyl (Xyl/Si-NH3) functionalized silica gel and covalently on 3-carboxypropyl (Xyl/Si−COOH) and silica gel functionalized with 3-aminopropyl and modified with glutaraldehyde (Xyl/Si-Glu) were performed and the prepared biocatalysts were used for clarification of orange juice. The supports and immobilized biocatalysts were characterized by scanning electron microscopy, and thermal gravimetric analysis. Free and all immobilized xylanase samples showed maximal catalytic activity at pH 6.0. The free xylanase and Xyl/Si-NH3 had a maximal catalytic activity at 50 °C, while Xyl/Si-Glu, Xyl/Si−COOH and Xyl/Si-SO3 exhibited their maximal catalytic activities at 60 °C. The Xyl/Si-Glu showed 4.2-fold higher thermal stability than the free xylanase at 50 °C and pH 6.0. The clarity of orange juice was increased by 74.7, 73.6, 59.3, 60.3, and 78.8 % respectively by using free xylanase, Xyl/Si-Glu, Xyl/Si−COOH, Xyl/Si-SO3 and Xyl/Si-NH3 at 50 °C after 180 min treatment time. The reusability studies showed that Xyl/Si-Glu, Xyl/Si−COOH, Xyl/Si-SO3 and Xyl/Si-NH3 retained 77, 71, 11 and 16 %, respectively, of their initial activities after 10 reuses. These results show that Xyl/Si-Glu and Xyl/Si−COOH are better potential candidates than Xyl/Si-SO3 and Xyl/Si-NH3 in fruit juice clarifying processes.

Removal of selected pesticides, alkylphenols, hormones and bisphenol A from domestic wastewater by electrooxidation process.

In this study, seven compounds of environmental and health concern were treated by electrooxidation to determine their removal efficiencies from domestic wastewater. A batch type lab-scale reactor was used for the treatment process, and the analytes studied included two obsolete pesticides, two alkylphenols, two hormones, and bisphenol A. Titanium oxide and graphite electrodes were used as anode and cathode, respectively. Parameters of the electrooxidation process including pH of wastewater, ionic strength, applied current and treatment period were optimized by the univariate approach to maximize the removal efficiency of the analytes from wastewater. The optimum conditions were determined as nonadjusted pH of wastewater, 1.5 A current, 15 min treatment period and 5.0 g/L sodium chloride. Dispersive liquid-liquid microextraction was used to preconcentrate analytes before and after treatment in order to calculate the removal efficiency of analytes. The removal efficiency obtained under the optimum conditions was satisfactory for all seven analytes at different influent concentrations.