Analytical Methods in Environmental Chemistry Journal
Volume:6 Issue: 3, Sep 2023

This study uses the UV-Vis technique to describe the elimination of methylene blue dye from an aqueous solution by adsorption on an Iraqi bentonite clay surface. The batch approach was used to conduct adsorption studies carried out to evaluate the influence of factors of experimental like contact time (0–90 min), clay dose (0.1–0.35 g), and initial dye concentration (10–125 mg L-1) at the range of temperatures (25-40oC). The Langmuir and the Freundlich isotherms were used to analyze the data; the Langmuir isotherm (R2 = 0.998) proved more appropriate for the equilibrium data. The thermodynamic properties of the adsorption process, including Gibbs free energy (ΔGO), entropy(ΔSO), and enthalpy (ΔHO), were also studied. Since the (ΔGO) and (ΔHO) values were negative, it was clear that the adsorption process constituted an exothermic, spontaneous reaction. This investigation revealed that Iraqi bentonite clay effectively removed the dye methylene blue because of its high surface area. Methylene blue may be removed with an adsorption efficiency of up to 99.39 % at 25oC. By employing bentonite clay as an adsorbent surface, this research offers practical adsorption technology that is affordable and effective for treating wastewater.

The research deals with the manufacture of an electrode using modified carbon pas te to determine 2,4-dinitrophenylhydrazine (2,4-DNPHZ), The modified carbon pas te electrode (NiO-NCQD/g-C3N4/MCPE). The results show the presence of oxidation and reduction peaks, and it is subject to a quasi-reversible sys tem; the bes t value of pH is (1) using sulfuric acid with a concentration of (0.1M), and scan rate is 100 mv sec-1, it was linearity range of (1-1000) μM for oxidation, and (100-1000) μM for reduction, with correlation coefficient (R2=0.9717) and (R2=0.9914) for each of them, respectively. The proposed electrochemical method was compared with two methods they are spectrophotometry at a wavelength 360 ( nm) and high-performance liquid chromatography (HPLC) at wavelengths (340 and 250) nm. It turned out that the electrochemical method (NiO-NCQD/g-C3N4/MCPE) was superior to the spectrophotometry method in terms of the detection limit. It turns out that there is no significant difference between (HPLC) and (NiO-NCQD/g-C3N4/MCPE) in terms of accuracy. The proposed electrochemical method is a new analytical method characterized by accuracy, repeatability, and reliability.

This s tudy focuses on the chemical analysis and prediction of Polyethylene Terephthalate (PET) nanoplas tics toxicity on aquatic organisms, considering the influence of particle size and properties. The effect PET NPs of different sizes (1, 4, 9, 16 and 25 nm coded NP1 to NP5) on aquatic organisms such as Terpedo californica (electric ray fish) and Danio rerio (zebrafish) as model species was evaluated by virtual chemical techniques and machine learning methodology based on Multilayer Perceptrons Artificial Neural Networks (MLP ANN) and Support Vector Machine. The PET NPs was built and characterized in silico and then docked on the acetylcholines terase (TcAChE) and cytochrome P450 (Zf CYP450) of the organisms, respectively. The results showed that the binding affinities of the NPs increased s teadily from – 7.1 kcal mol-1 to – 9.9 kcal mol-1 for NP1 to NP4 and experienced a drop at NP5 (– 8.9 kcal mol-1) for TcAChE. The Zf CYP450 also had a similar pattern ranging from -5.2 kcal mol-1 to -8.1 kcal mol-1. The MLP ANN showed an accuracy of 85.9 % and 77.3 %. In comparison, SVM showed a better PET NPs toxicity prediction with an accuracy of 99.5 % and 99.4% based on the inherent properties of TcAChE and Zf CYP450, respectively.

This s tudy focuses on the chemical analysis and prediction of Polyethylene Terephthalate (PET) nanoplas tics toxicity on aquatic organisms, considering the influence of particle size and properties. The effect PET NPs of different sizes (1, 4, 9, 16 and 25 nm coded NP1 to NP5) on aquatic organisms such as Terpedo californica (electric ray fish) and Danio rerio (zebrafish) as model species was evaluated by virtual chemical techniques and machine learning methodology based on Multilayer Perceptrons Artificial Neural Networks (MLP ANN) and Support Vector Machine. The PET NPs was built and characterized in silico and then docked on the acetylcholines terase (TcAChE) and cytochrome P450 (Zf CYP450) of the organisms, respectively. The results showed that the binding affinities of the NPs increased s teadily from – 7.1 kcal mol-1 to – 9.9 kcal mol-1 for NP1 to NP4 and experienced a drop at NP5 (– 8.9 kcal mol-1) for TcAChE. The Zf CYP450 also had a similar pattern ranging from -5.2 kcal mol-1 to -8.1 kcal mol-1. The MLP ANN showed an accuracy of 85.9 % and 77.3 %. In comparison, SVM showed a better PET NPs toxicity prediction with an accuracy of 99.5 % and 99.4% based on the inherent properties of TcAChE and Zf CYP450, respectively.

The co-precipitation method synthesized the synthetic anionicMg–Al and Ni-Al clays with three molar ratios (Mg/Al, Ni/Al). The samples were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). No other crys talline phases were detected in the powder XRD patterns of the co-precipitated samples. The infrared spectra obtained all the functional groups that characterize these two types of anionic clays. SEM micrographs indicate the presence of particles and aggregates. The particles, or aggregates, are in the form of plates, supported by particles of acceptable sizes. The optimal pH for maximum lead adsorption is about 6.5 for both clays. The optimal adsorbent masses for the maximum percentages of lead removal are 0.2 g for Mg3AlCO3 and 0.25 g for Ni3AlCO3. The Mg3AlCO3 has a maximum adsorption capacity of lead, where qm=73.42 mg g-1. The adsorbed amount increases with increasing temperature for both types of clays s tudied. The equilibrium time of Pb2+ adsorption is reached after 5 min for both clays. The mos t appropriate models to describe the experimental data of adsorption kinetics and isotherms are pseudo-second-order and Langmuir. The detection limit (LOD) was 0.272 mg L-1. The linearity range was 1 to 5 mg L-1; the correlation coefficient in this range was 0.9997.

Using plant essential oils (EOs) as a pes ticide alternative has gained increasing interes t as a promising s trategy to reduce the harmful effects of chemical pes ticides. This s tudy aims to inves tigate the chemical composition of Eucalyptus globulus Labill and Rosmarinus officinalis L. essential oils and evaluate their impacts agains t Blattella germanica L. under laboratory conditions. The essential oils were prepared from dried leaves using hydro-dis tillation (HD) as a chemical extraction method. The gas chromatography-mass spectrometry (GC-MS) was employed to analyze and identify their chemical compounds. Bioassays were conducted using the s tandard contact method recommended by the World Health Organization, and the data were analyzed using the probit regression model. By GC-MS analysis, the major components included 1,8-cineole (50.67%), alpha-pinene (17.48%), limonene (4.26%) for eucalyptus and alpha-pinene (20.67%), camphor (10.69%), 1,8-cineole (9.38%), Borneol (9.02%), comphene (7.15%), and limonene (4.88%) for rosemary. The LD50values were 9. 27, 10.54, and 3.23 %, and LD95 values increased to 27.2, 22.3 %, and 14.3% for rosemary, eucalyptus, and their mixture. The EOs mixture had a higher repellent effect with a repellency rate of 98.9% at a concentration of 3% compared to 93.3% and 90% at a concentration of 5% for rosemary and eucalyptus alone. The mixture of eucalyptus and rosemary EOs can be a promising alternative for controlling the German cockroach.

The research presents a comparative analysis of the quality of locally produced groundnut oil (Arachis hypogaea) sold in the north-central zone of Nigeria markets (Benue, Nasarawa, Kogi, Kwara, Niger and Plateau S tates). The aim was to assess and compare the qualities of the oils and to know the safety of human consumption. The groundnut oil produced biodiesel, shampoo lubricants, and soap-making indus tries. The concentrations of the heavy metals were analyzed with atomic absorption spectrometry (AAS). It showed that the lead, zinc, and copper (Pb, Zn, Cu) were within the FAO/WHO recommended limit, while Cd (0.201-0.331 mg kg-1) was above the limit (0.07 mg kg-1). Also, the gas chromatography (GC-FID) results indicated that twelve fatty acids (linoleic > oleic > palmitic > s tearic > lignoceric > arachidic acid > behenic > erucic > arachidonic > margaric > linolenic > palmitoleic) were obtained in the groundnut oils in all markets and fatty acids include caprylic acid, capric acid, lauric acid, and myris tic acid were absent in oils. In addition, the magnitude of six phospholipids (phosphatidylcholine > phosphatidylethanolamine > phosphatidylinositol > phosphatidylserine > phosphatidic acid > lysophosphatidylcholine) were also achieved, respectively. The results showed that iodine, peroxide, saponification value and refractive index were below the FAO/WHO recommended level, and the acid value was higher than the normal range.