I .. Rates of ionic mass transfer at nickel electrodes rotating about their axes In the center of stationary electrodes were studied using the ferri-ferrocyanide oouple In alkaline solutions. A general mass transfer correlation was found to apply equally well to the dissolution rates of rotating solids and to the rates of ionlo mass transfer at rotating electrodes. This correlation takes into account the physioal properties of the system as well as geometric and hydro dynamic factors. The correlation enables the prediction of limiting currents and concentration polarisation at rotating electrodes under a wide range of conditions. The nature of the polarisation involved in the reduotion of Fe(CNfe~» and the oxidation of Fe(CN#* was also Investigated. The polarisation was found to depend strongly on the presence of "electrode poisons." With freshly prepared solutions, under exclusion of light and with eathodlcally treated nickel electrodes relatively small ehesdcal polarisations were determined. For rotational speeds not exceeding Reynolds number 11,000, the chemical polarisation was found to be negligicle in comparison with the concentration polarisation* Under such conditions the ferro-ferrioyanide oouple can be conveniently used to obtain mass transfer rates for various hydrodynamic conditions, or, conversely, to verify the validity of mass transfer equations by a comparison of experimental .and calculated values of limiting currents and concentration polarisation. The rotating electrode model was found to be most suitable for studying the nature of eleotrolytio polarisation phenomena on aocount of the uniformity of the current distribution as well as of the hydrodynamio diffusion laver at the electrode surfsee.

Mass transfer in electrode processes. 3. ionic mass transfer and concentration polarization at rotating electrodes

Synthesis and evaluation of nonionic surfactants based on dimethylaminoethylamine: Electrochemical investigation and theoretical modeling as inhibitors during electropolishing in-ortho-phosphoric acid

Recent trends in adsorption of Chromium (Cr), Copper (Cu), Lead (Pb) and Mercury (Hg) in wastewater using (i) carbonaceous materials including activated carbon (AC) and biochar (BC), and (ii) nanomaterials including nano zero-valent iron (nZVI) and MXenes have been discussed in this paper. It has been found that adsorption capacity depends largely on the adsorbent modification technique, initial pH of wastewater, dosage of adsorbent, contact time and initial concentration of the pollutants. The pH value ranges for maximum removal of Cr, Cu, Pb and Hg have been reported as 2-4, 5-6, 5-8 and 3-8, respectively. Up to 99% removal of metals has been reported using AC, BC, nZVI and MXene. The mechanism involves the reduction and chemical adsorption of metals. AC and BC have a higher surface area (up to 5000 m2/g) compared to nZVI (up to 500 m2/g) and MXene (up to 67.66 m2/g). However, the higher reactivity and regeneration capacity of nZVI and MXene make them suitable adsorbents. From a practical point of view the application of adsorbents for real effluents, cost analysis, regeneration capability and reuse of heavy metals are some aspects that need attention in future studies. The removal efficiencies of AC and BC are comparable to the nZVI and MXene. The cost analysis may be an attractive aspect to decide the future application of these adsorbents at large scale. 

Adsorption of chromium, copper, lead and mercury ions from aqueous solution using bio and nano adsorbents: A review of recent trends in the application of AC, BC, nZVI and MXene.

Water contamination is one of the most urgent concerns confronting the world today. Heavy metal poisoning of aquatic systems has piqued the interest of various researchers due to the high toxicity and carcinogenic consequences it has on living organisms. Due to their exceptional attributes such as strong reactivity, huge surface area, and outstanding mechanical properties, nanomaterials are being produced and employed in water treatment. In this review, recent advances in the use of nanomaterials in nanoadsorptive membrane systems for wastewater treatment and heavy metal removal are extensively discussed. These materials include carbon-based nanostructures, metal nanoparticles, metal oxide nanoparticles, nanocomposites, and layered double hydroxide-based compounds. Furthermore, the relevant properties of the nanostructures and the implications on their performance for water treatment and contamination removal are highlighted. The hydrophilicity, pore size, skin thickness, porosity, and surface roughness of these nanostructures can help the water permeability of the nanoadsorptive membrane. Other properties such as surface charge modification and mechanical strength can improve the metal adsorption effectiveness of nanoadsorptive membranes during wastewater treatment. Various nanocomposite membrane fabrication techniques are also reviewed. This study is important because it gives important information on the roles of nanomaterials and nanostructures in heavy metal removal and wastewater treatment.

https://www.mdpi.com/1996-1944/15/15/5392/pdf?version=1659692362

Recent Advances in Adsorptive Nanocomposite Membranes for Heavy Metals Ion Removal from Contaminated Water: A Comprehensive Review

http://www.cell.com/article/S2405844022005679/pdf

A unique, inexpensive, and abundantly available adsorbent: composite of synthesized silver nanoparticles (AgNPs) and banana leaves powder (BLP)

Adsorption isotherm, kinetic, and optimization studies for copper (II) removal from aqueous solutions by banana leaves and derived activated carbon

Electropolishing of steel in presence of some amines



Jordan is a well-known country for its diversity in wild plants and for many decades, folk medicines represent part of its cultural heritage. In the present study, investigations have been focused on the therapeutic potential of Silybum marianum and Pergularia tomentosa on type 2 diabetes mellitus. In type 2 diabetes, which is considered a global health worry, the body cannot respond to or produce insulin hormone that raises the blood glucose level and the accompanied mortality, morbidity, healthcare expenses, and reduces the life quality. Dipeptidyl peptidase-IV (DPP-IV) enzyme, a serine protease, is responsible for deactivating incretin hormones that promote insulin secretion. Accordingly, DPP-IV inhibitory activity of these plant extracts that prolong the hypoglycemic effect of incretins was evaluated.



The aerial parts of S. marianum and P. tomentosa were dried, ground, and extracted with ethanol. The ethanol extract was dried under reduced pressure and was partitioned by methanol, butanol, and hexane according to a systematic procedure. The inhibition of DPP-IV enzyme by the different extracts was studied (at 10.0 mg/ mL concentration). Sitagliptin was used as the positive control.



Fortunately, most of the plant extracts have noticeable inhibitory activity against DPP-IV enzyme. It was found that the tested methanol extract of S. marianum has an inhibitory activity = 75.6% and the butanol extract of P. tomentosa = 73.6% which are analogous to DPP-IV inhibition of sitagliptin (78.5%), the used positive inhibitor. A superior inhibition of 98.1% was displayed for the butanol extract of S. marianum at 10.0 mg/ mL concentration.



The revealed DPP-IV inhibitory activity of tested extracts advocates that their active constituents, particularly flavonoids, are capable of binding to the enzyme’s active cleft.


Therapeutic Potential of Silybum Marianum and Pergularia Tomentosa Extracts from Jordanian Origin in Diabetes Mellitus

/pdf/author-correction-electrical-conductivity-and-thermodynamic-mwtfmqfn.pdf

Author Correction: Electrical conductivity and thermodynamic studies on Sodium Dimethyldithiocarbamate in non aqueous solvents Dimethylformamide (DMF), at different temperatures

W.A. Hammad

Papers

Adsorption isotherm, kinetic, and optimization studies for copper (II) removal from aqueous solutions by banana leaves and derived activated carbon

A unique, inexpensive, and abundantly available adsorbent: composite of synthesized silver nanoparticles (AgNPs) and banana leaves powder (BLP)

Electropolishing of steel in presence of some amines

Therapeutic Potential of Silybum Marianum and Pergularia Tomentosa Extracts from Jordanian Origin in Diabetes Mellitus

Author Correction: Electrical conductivity and thermodynamic studies on Sodium Dimethyldithiocarbamate in non aqueous solvents Dimethylformamide (DMF), at different temperatures