Screening of Mineral Elements in Cistus ladanifer and Cistus libanotis Essential Oils and their Leaves

peer reviewedThe aim of this study was to determine the levels of mineral compounds in Cistus ladanifer and Cistus libanotis growing in Eastern Morocco from two different regions Jerada (arid climate) and Tafoughalt (humid climate). A total of fifteen elements (Cd, Co, Cr, Cu, Hg, Na, Ni, P, Pb, Zn, Al, Ca, Fe, K and Mg) has been measured by inductive coupled plasma atomic emission spectrometry. Their concentrations have been found to vary in leaves and their essential oils. From the results of the study, P, Al, Ca, Fe, K and Mg are highest in all the samples analysed. Cr and Pb were not detected in essential oil of Cistus libanotis from Jerada and Tafoughalt, respectively. These plants were found to contain appreciable amounts of the elements K, Ca, Fe, Mg, P, Al, Ni, Li, Zn and Cu Witch are important in many biological mechanisms. This study also provides a comprehensive survey of the concentration of elements in plants due to their wide utilisation as herbal fusion or decoction in Eastern Morocco

Methionine derivatives as green corrosion inhibitors: Review

This review exposed the inhibitory effect of methionine as green compound and its derivatives. The efficacy of these kind of molecules is related to two combined groups: amine and carboxylic acid as well as the presence of sulphur atom. Search on Scopus showed that a hundred publications in various aggressive solutions as HCl, H2SO4, H3PO4, HNO3, NaCl. The corrosion of iron, aluminium, lead, copper, nickel, tin … can be retarded using methionine derivatives which adsorbed on several kind of adsorption isotherms depending on the nature of metal/solution interface

Comparative study of inhibitory efficacy of methionine and its derivatives in acidic medium by mild steel

Corrosion inhibition effect of L-Methionine (MT1), L-Methionine sulfoxide (MT2) and L-Methionine sulfone (MT3) on mild steel corrosion in 1M HCl solution was studied by using weight loss, electrochemical polarization and electrochemical impedance spectroscopy (EIS) techniques. The experimental results showed that the inhibitory efficiency of the three aminoacids improves with the increase of concentration to reach the maximum value of 95.20% for MT1, 94.14% for MT2 and 88.92% for MT3 for a concentration of 10-3M, which translates that the surface covered by the inhibitor increases with the concentration. The effect of temperature on the corrosion rate was investigated and some thermodynamic parameters were calculated. Polarization studies show that three studied inhibitors suggested that three inhibitors control the anodic as well as cathodic reactions and act as mixed type in nature. The results show that MT1, MT2 and MT3 are good inhibitors, and the adsorption of each inhibitor on mild steel surface obeys Flory-Huggins and Langmuir, with a better fit of the Langmuir isotherm through mixed adsorption (physisorption as well as chemisorption) process. In addition, the quantum approach based on density functional theory (DFT), monte Carlo (MC) and molecular dynamics (MD) simulations was confirmed the reactivity of the studied compound towards the corrosion process

(Z)-2-benzylidene-2H-[1, 4] benzothiazin-3-one(T1) as New Synthesized Corrosion Inhibitor for Mild Steel in 0.5 M H2SO4

The corrosion inhibition of mild steel in 0.5 M H2SO4 solution by (Z)-2-benzylidene-2H-[1,4]benzothiazin-3-one: (T1)  has been studied using electrochemical polarization , electrochemical impedance spectroscopy (EIS) and weight loss methods. The corrosion inhibition efficiency measured by all the three techniques was in good agreement with each other. The results showed that T1 is a very good inhibitor for mild steel in acidic media. The inhibition efficiency increases with increasing inhibitor concentration. It acts as a mixed-type inhibitor. EIS plots indicated that the addition of T1 increases the charge-transfer resistance (Rct), decreases the double-layer capacitance (Cdl) of the corrosion process, and hence increases inhibition efficiency. The adsorption of the T1 on the mild steel surface in acid solution obeys the Langmuir adsorption isotherm

Salinité et pollution par les nitrates des eaux souterraines de la plaine des Triffa

Les eaux souterraines de la plaine des Triffa (Basse Moulouya) deviennent de plus en plus polluées. Les résultats analytiques montrent que la plupart des puits sont chargés en sels et en nitrates, donc impropres à la consommation humaine et peuvent avoir un effet négatif sur les cultures maraîchères de la région. Dans la zone étudiée, des teneurs de 2,32 à 174,70 mg/l de NO3-, de 134 à 3614 mg/l de Cl- et de 103 à 1518 mg/l de Na+ ne sont pas exceptionnelles. Elles dépassent largement les normes fixées par l’OMS et la CEE (50 mg/l pour les NO3 -, de 250 mg/l pour Cl- et de 175 mg/l pour Na+). L’intensification de l’agriculture dans la plaine, notamment dans les périmètres irrigués, l’épandage excessif des engrais, les applications répétées, et à quantités fortes, de fumiers, l’irrigation, les précipitations et la remontée de la nappe dans certaines régions ont engendré une pollution croissante des ressources en eau

The Influence of Some Pyrazole Derivatives on The Corrosion Behaviour of Mild Steel in 1M HCl Solution

Abstract The inhibitive action of some pyrazole derivatives, namely N1, N1-bis (2-(bis ((3,5-dimethyl-1H-pyrazol-1-yl) methyl) amino)ethyl)-N2, N2-bis ((3,5-dimethyl-1H-pyrazol-1-yl) methyl) ethane-1,2-diamine: PAP and diethyl 1,1'-(((4-acetylphenyl) azanediyl) bis (methylene)) bis (5-methyl-1H-pyrazole-3-carboxylate): PAC against the corrosion of mild steel in 1 M HCl solution has been investigated using weight loss measurements, Tafel polarisation and electrochemical impedance spectroscopy (EIS) techniques. The experimental results obtained revealed that these compounds inhibited the steel corrosion in acid solution, the protection efficiency increased with increasing inhibitors concentration. The results obtained from the different corrosion evaluation techniques are in good agreement. Potentiodynamic polarisation studies clearly showed that PAP and PAC acted as mixed inhibitors affecting both cathodic and anodic corrosion currents. Adsorption of these inhibitors on steel surface obeyed to Langmuir adsorption isotherm. Thermodynamic data of adsorption showed that inhibition of steel corrosion in 1M HCl solution by pyrazole compounds is due to the formation of a chemisorbed film on the steel surface. SEM and EDX supported the adsorption conclusions

ERRATA: "THERMODYNAMIC STUDY OF CORROSION AND INHIBITOR ADSORPTION PROCESSES ONTO C38 STEEL/PIPERAZINES/PHOSPHORIC ACID SYSTEMS"

No abstract received.