Advanced Journal of Chemistry, Section A
Volume:3 Issue: 3, Summer 2020

Via Box-Behnken method, we evaluated the influence of various factors on absorption, including the amount of absorbent, the speed of stirring the solution and absorbent, pH of solution, time of contact, and various concentrations of violet methyl colour, to obtain optimum conditions. The maximum extent of violet methyl removal was found at 100 mg/L concentration, pH = 4.6, contact time = 50 minutes, 120 rotation speed, and absorbent dose = 1.488 g/L (0.0744 gram in 50 millilitre). In order to determine the reaction mechanism, two kinetic models were used, namely pseudo-first-order and pseudo-second kinetics models. The adsorption kinetics followed pseudo-second order model, and the mechanism of chemical reaction was the rate-limiting step. Furthermore, the Langmuir and Freundlich Isotherms were considered for absorbing the violet methyl on the palm fiber absorbent. The adsorption isotherms showed a balanced relationship between the materials adsorbed on the adsorbent (qe) and a balanced concentration in the solution (Ce) at a constant temperature. This method was used to remove the violet methyl colour from real samples such as industrial sewage, tap and river water.

The current ongoing scientific debate deals with accumulation of hydronium ions (H3O+) on water surface. Elevated interfacial concentration measured by using Raman spectroscopy. A strong surface affinity of H3O+ indicated by Raman spectroscopy under similar conditions. Ion adsorption phenomena, H3O+ formation and its structural activity emphasized in our study. Asymmetric water ion adsorption clearly observed in our research.

Propylene oxide-ethylene oxide block polymer (PO-EO) is a surfactant with low cloud point. It has been used for separation of Cu2+, Fe3+, Mn2+, Cd2+ and Cr3+ ions in aqueous media. The effect of different factors on recovery percent, like pH, temperature, amount of chelating agent, and amount of surfactant have been studied. A very good separation of metal ions could be achieved at different pH values with good effeciency of separation under the optimum conditions. The analyses of metal ions were carried out using flame atomic absorption spectrometer with duterium lamp background correction and calibration curve method curve method.

Nanocrystalline CoyZn1-yHozFe2-zO4 (where y = 0.0, 0.25, 0.5, 0.75, 1.00 and z=0.0, 0.03, 0.06, 0.08, 0.1) ferrites were prepared by sol-gel auto combustion method at pH of 8. Samples were obtained by annealing at relatively low temperature 600 °C for 4 h and characterized by thermo gravimetric/differential thermal analysis (TG/DTA) all the samples were annealed at 600 °C for 4 h. The prepared samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy. Particle size measured from XRD and TEM are in good agreement with each other. The TEM study reveals the fine particle nature of the ferrites with little agglomerations. The cation distribution suggests that Zn2+ ion mainly on tetrahedral-A sites, Ho3+ ions shows strong preference towards octahedral-B site, Co2+ and Fe3+ ions are randomly distributed at the tetrahedral-A and octahedral-B site. FT-IR study confirmed two main absorption bonds in the frequency range 400-600 cm-1, assigned due to the tetrahedral-A and octahedral-B stretching vibrations.

Modification of chitosan any Schiff base reaction with acetophenone derivatives was done. Fourier transformer infrared analysis (FT-IR), scanning electron microscope (SEM), and X-ray diffraction (XRD) were used as the appropriate characterize the Schiff base derivatives. Thermal behavior of the prepared materials was also studied. Various biological activities were examined for the prepared materials antimicrobial activity including antibacterial (studied against Streptococcus sp. Bacillus subtilis and Sarcina lutea as an example for gram-positive bacteria and Pseudomonas aeruginosa and Escherichia coli as an example for Gram-negative bacteria), anti-fungal (against Candida albicans) and anti-protozoal (against Trypanosoma cruzi and Leishmania donovaniwas). Antioxidant activity of chitosan and its Schiff base derivatives was detected using the FRAP and DPPH techniques. Colon carcinoma (Colo 205), hepatocellular carcinoma (Hep G2), urinary bladder carcinoma (T24P) and embryonic kidney adenocarcinoma (293) used to examine the anticancer activity of chitosan and its modified derivatives. The new chitosan Schiff base derivatives showed superior anti-bacterial, antifungal, anti-protozoal and antioxidant activity than parent chitosan. But in case of anticancer test of HebG2 and T24P chitosan was more effective than the modified derivatives.

Determination of mercury in the existence of various other metal ions, a transparent speedy and accurate complexometric method is described, depending on the selective masking ability of L-Tyrosine towards Hg (II). Along with other associated metal ions, Hg (II) present in a given sample solution is first complexed with an surplus of EDTA and the leftover EDTA is titrated with Zinc sulfate solution in the presence of xylenol orange as an indicator at pH 5.0-6.0.A known excess of 0.02M L-Tyrosine solution is then added to discharge the EDTA from Hg (II)-EDTA complex and then it is mixed well. The displaced EDTA is again titrated with a Zinc sulfate solution. The method goes well in the range 4-80 mg of mercury (II) with the relative error ±0.4 and standard deviation ≤0.05 mg. The issue of the existence of various metal ions on the exactitude of the results has been studied. And the method can be applied for the determination of Mercury in alloys, in its synthetic mixtures of ions and its complexes.

Environmental considerations have motivated the present study to develop and to investigate Cd(II) and Pb(II) removal process from aqueous solutions. This was carried out through the application of ultrasound onto sodium dodecyl sulfate coated palladium nanoparticles (SDSPdNPs). The recovered palladium chloride of petroleum’s spent catalyst used as a precursor for the nanoparticle synthesis. The size, morphology and the structure of the synthesized adsorbent has been fully characterized using transmission electronic microscope (TEM), scanning electron microscope (SEM), and X-ray diffractometer (XRD) spectroscopy measurements. The mean diameter of the SDSPdNPs as typically 23.4 nm for a generally homogeneous size regardless of agglomeration is reported. Statistically designed experiments with the support of central composite design (CCP) and response surface methodology (RSM) were applied to evaluate the main physiochemical parameters that would affect the interactions among the variables with the aim to define optimization criteria for the adsorption efficiency with respect to both of the metal ions. The optimized condition is reported as follows: pH: 4.2; contact time: 92 min; adsorbent dosage: 65 mg. Further to the above findings, the experimental equilibrium data efficiency fitted the Langmuir model with a high adsorption capacity of 323.14 and 207.81 mg/g-1 in the case of Pb(II) and Cd(II), respectively.

The present study conducted to investigate the potential use of PG in cement industry. This was accomplished by preparing mortar mixes contain Portland cement clinker (PPC) with thermally treated PG at different temperatures (200, 400, 600, 800 and 1000 °C) instead of raw gypsum (RG) at different proportions. The characteristics of prepared mortars were investigated after curing in water for different periods (3, 7, 28 and 90 days) by determination of setting time, compressive strength, bulk density, and total porosity. The hydration kinetics was evaluated by determination of free lime and chemically combined water contents. FTIR spectroscopic analysis was used to investigate the change in structure of some mortars after curing. The change in morphology and microstructure of hardened pastes was investigated using scanning electron microscopy (SEM). The results approved the possibility for the utilization of treated PG at 800 and 1000 °C instead of raw gypsum in cement industry.

In this study, ten indigenous dried market fishes were selected to analyze the proximate composition, microbial analysis, and organoleptic properties. Proximate compositions were found to be varied among the species. Moisture content ranged from 15.66% to 35.50%, protein content ranged from 42.06% to 65.78%, lipid content varied from 4.20% to 13.03% and ash content ranged of 5.28% to 18.60%. The results of TVB-N in different fish species ranged from 11.15 mg/100 g to 18.33 mg/100 g with highest in Puti (Puntius sophore) whereas lowest in Chanda (Chanda ranga) species. The bacterial load of dried fish species ranged from 3.13×107 to 3.67×108 (CFU/gm) with highest in Katchki (Corica soborna) and lowest in Puti (Puntius sophore). The sensory evaluation results revealed that Chapila (Gudusia chapra) is superior among the other dried fish species with color, flavor and appearance aspect. Overall, Chanda (Chanda ranga) was the better quality regarding all parameter among other dried fish species except protein content highest in Churi (Trichiurus lepturus) which was significantly different (P≤0.05) from Chanda (Chanda ranga) species.

The present study deals with the development and validation of two simple, accurate and precise spectrophotometricmethods for estimation of Aspirin (AS) and Omeprazole (OMP) in their binary mixture. The first method was developed using Vierordt’s simultaneous equation method. It involves absorbance measurement at 257 and 300 nm (λmax of AS and OMP) in methanol. Second method involves the formation of Q-absorbance equation using the respective absorptivity values at 284.5 nm (isoabsorptive point) and 300 nm (λmax of OMP). The drugs obey Beer’s Lambert’s law in the concentration range of 4-20 µg/mL and 2-10 µg/mL for AS and OMP respectively for both the methods. Limit of quantitation for Vierordt’s method for both the drugs was found to be 0.85 µg/mL, whereas for absorbance ratio method it was 0.68 and 0.88 µg/mL for AS and OMP respectively. % recovery for both the drugs was in the range of 99.78-100.31% indicating excellent accuracy for both the methods. The methods were precise, with a relative standard deviation of less than 1.25% for both drugs. The developed methods were validated according to ICH guidelines and values of accuracy, precision and other statistical analysis were found to be in good accordance with the prescribed values. Thus, both methods can be used for routine monitoring of drugs in industry for the assay of bulk drugs and commercial formulation (Yosprala).

Information about the heavy metals release from industrial solid wastes is important for more reliable management of their environmental hazards. This study was conducted to investigate the effect of tissue of solid waste on the release of heavy metals from the steel smelting plant. After the investigation at the Khazar steel smelting (KSS) plant in Guilan province, its waste type, source, quantity and quality were characterized. The major wastes generated from the KSS plant were characterized to be the slag, furnace dust, and spent refractories. KSS solid wastes contained heavy metals in varying amounts, with the ranges of 1500-2200, 80–114, 6172-11100, 88-82, 48-29, 56-60, 4-14, 144-370 and 0.9-1.0 mg/kg−1 for Mn, Cu, Zn, Ni, Cr, Co, Cd, Pb and As, respectively. The concentration of the iron was high in these wastes (109900-672000 mg/kg−1). The results confirmed the high concentration of heavy metals except for Arsenic. The TCLP results of the KSS dust and slag showed the almost all the heavy metals concentrations by the leaching test were lower than the detection limits except Fe (524.5-187.6 mg/kg-1) and Mn (14-10.10 mg/kg-1). According to the results, all the wastes generated by the KSS plant were reusable and recyclable.

The oxidation of propane-1,3-diol by potassium permanganate in aqueous solution was investigated at λmax 525 nm. The rate of the reaction was found to increase with increase in [KMnO4] and [Propane-1,3-diol]. The reaction showed first order dependence each in [KMnO4] and [Propane-1,3-diol] and independent in the ionic strength of the solution. The values of 〖∆H〗^#(kJ mol-1), 〖∆S〗^# (kJK-1mol-1) and〖 ∆G〗^#(kJmol-1) were 24.98, -0.22 and 90.50 respectively. Negative entropy of activation revealed an ordered transition state for the reaction. Spectroscopic studies and FTIR analysis revealed the product of the reaction to be 3-hydroxyl-propanal.

In this research, barley bran mixtures with sugar beet pulp were used for polygalacturonase enzyme production by Aspergillus niger fungus in solid state fermentation method for the first time. Effect of some factors including carbon sources relative composition, fermentation time, fermentation temperature, inoculation amount, and moisture content were investigated and optimized amounts were selected. Different mixtures of barley bran and sugar beet pulp with various relative compositions were studied and highest enzyme activity was found for 50% w/w of barley bran and sugar beet pulp. Incubation temperature of 30 °C, time duration of 7 days, moisture content of 80% w/w, and 10 million spores per gram of dry substrate were selected as optimum amounts.

Geochemical study of toxic metal arsenic along with heavy metals (Fe. Mn and Cu), of borehole sediments of the Kushiara and Meghna, rivers in Bangladesh was conducted to investigate the mobilization, distribution and correlation of arsenic with depth, nature of sediment and locations of sampling site, had been included to the study. The Kushiara is the upstream part of Meghna river. Sampling locations were carried out at Sherpur (Moulvibazar) and Beanibazar (Sylhet) for Kushiara river, which is one of the upper stream part of Meghna river. Samplings of borehole sediments collection have been done from Mohonpur (Chandpur) and Chandpur town (Chandpur) for the Meghna river. The borehole sediments were dried in the oven till constant weight and digested it nitric and perchloric acid (3:2) in fume cup hood in the laboratory. The digested sample were analyzed by Ag-DDTC UV visible Spectrophotmeter for arsenic also analysis of Fe. Mn and Cu in borehole sediment by Flame AAS. The average concentration of arsenic was found 6.39 mg/Kg in Borehole sediment for Kushiara river (Beanibazar and Sherpur), 5.00 mg/Kg for Meghna river (Mohonpur and Chandpur). The highest amount of arsenic (12.30 mg/Kg) was found in grayish clay type sediment at upstream of Kushiara river at Beanibazar. It is evident from the study, that arsenic is mobilized from upper stream to lower stream. In addition, it also reveals that high amount of Fe and Mn was in sediment sample. Statistical analysis shows that arsenic is strongly correlated with Mn and Fe but weakly correlated with Cu. In nature FeOOH occurs is yellowish in color and MnOOH is gray in color, these two of oxy-hydroxides may be scavengers of arsenic. It was indicated that the occurrence of FeSO4, MnSO4 and CuSO4 is predominant in all of the borehole sediment of Kushiara and Meghna rivers.

Thermal insulation layer in solid rocket motors is a vital component during the rocket flight. Many factors can affect the performance of this insulation layer. Bonding property between rocket propellant and the thermal insulation layer are examined in this study. Hydroxyl terminated polybutadiene (HTPB) and isophorone diisocyanate (IPDI) as a curative was chosen as the most common type of rocket propellant. The effect of two types of polymeric insulation layer such as nitrile butadiene rubber (NBR) and ethylene-propylene-diene monomer (EPDM), on the bonding performance at the interface between (HTPB/IPDI) propellant and the respective insulation layer has been investigated. Results revealed that both types of insulation layer considerably decreased the interfacial bonding performance of the (HTPB/IPDI) propellant. NBR was proven to be more severe on weakening the adhesion strength than that of the EPDM. We further investigated the effects of the thickness and water content of NBR on the bonding performance, and proved that bonding strength was inversely proportional to the thickness and the water content.