Synthesis of zero-valent iron nanoparticles via electrical wire explosion for efficient removal of heavy metals

In this paper, electrical wire explosion (EWE) was used as a simple, clean, in situ method to synthesise nano zero-valent iron (nZVI) particles in liquid mediums. The structural and physical properties of the synthesised nZVI particles were characterised by x-ray diffraction, Brunauer–Emmett–Teller analysis, field emission scanning electron microscopy and transmission electron microscopy. The synthesised spherical nanoparticles, at a specific size of 10–50 nm, possessed large surface areas of approximately 13.27 m/g, reinforcing the significant advantages of EWE, that is, less aggregation and in situ production of nanoparticles with enhanced removal efficacy, for groundwater treatment. After 1 h the adsorption capacity for Cr(VI), Ni(II), and Cd(II) (Q = C/C (mg/g)) at pH 4 was approximately 143.4 (89.0%), 137.5 (79.0%), and 132.6 mg/g (72.0%), respectively. The effect of temperature was also examined at initial metal ions concentration of 70 mg/L, nZVI dosage of 0.2 g/L and pH 4. The results showed 45°C was the optimum temperature for adsorption of Cr(VI), Ni(II), and Cd(II) ions, and over a 60-min period at this temperature adsorption capacity increased to 153.56 (95.3%), 158.91 (91.3%), and 163.90 mg/g (89.0%), respectively

Enhancement in permeation and antifouling properties of PVC ultrafiltration membranes with addition of hydrophilic surfactant additives: Tween-20 and Tween-80

The effects of Tween-20 and Tween-80 as hydrophilic and non-ionic surfactants on morphology, mechanical and separation efficiency of PVC ultrafiltration membranes was studied widely. The membranes were fabricated via phase inversion method and different percentages of Tween-20 and Tween-80 from 1 wt% to 7 wt% was added to casting polymeric solution. Ultrafiltration of pure water and BSA, as the foulant, was done at the operating pressure of 2 bar. The results indicated great changes in morphology, and the membrane became more porous with macro-voids in the sub-layer, due to miscibility of surfactants with non-solvent and thermodynamic instability of the casting solution. The fabricated membranes have more hydrophilic surface and water contact angle has decreased from 70° for PVC membrane to 55° to 58° for the ones with 7 wt% Tweens. Pure water flux increased continuously with Tween addition because of higher surface hydrophilicity and more porosity. In addition, the membranes showed much better fouling resistance and were able to recover their water flux after three filtration cycles acceptably. PVC/7 wt% Tween-20 and PVC/7 wt% Tween-80 membranes showed 33% and 28% better flux recovery ratio compared to bare PVC membrane, respectively. Slight reduction in BSA rejection was observed, which was not very significant to affect the whole efficiency of the prepared membranes. The membranes have lower mechanical resistance due to more porous structure. Water flux and recovery ratio of the PVC/Tween-20 membranes were slightly higher than that of the PVC/Tween-80 membranes which can be due to more instability in thermodynamic of casting solution

The Iranian blood pressure measurement campaign, 2019: study protocol and preliminary results

Purpose Hypertension is one of the most important risk factors for premature mortality and morbidity in Iran. The objective of the Iranian blood pressure (BP) measurement campaign was to identify individuals with raised blood pressure and providing appropriate care and increase the awareness among the public and policymakers of the importance of tackling hypertension. Methods The campaign was conducted in two phases. The first (communication) phase started on May 17th (International Hypertension Day). The second phase started on June 8th, 2019, and lasted up to July 7th during which, blood pressures were measured. The target population was Iranians aged >= 30 years. Participants voluntarily referred to health houses in rural and health posts and comprehensive health centers in urban areas in the setting of the Primary Health Care network. Additionally, over 13,700 temporary stations were set up in highly visited places in urban areas. Volunteer healthcare staff interviewed the participants, measured their BP, and provided them with lifestyle advice and knowledge of the risks and consequences of high blood pressure. They referred participants to physicians in case their BP was high. Participants immediately received a text message containing the relevant advice based on their measured BP and their past history. Results Blood pressure was measured for a total of 26,678,394 participants in the campaign. A total of 13,722,148 participants (51.4%) were female. The mean age was 46 +/- 14.1 years. Among total participants, 15,012,693 adults (56.3%) with no past history of hypertension had normal BP, 7,959,288 participants had BP in the prehypertension range (29.8%), and finally, 3,706,413 participants (13.9%) had either past medical history of hypertension, used medications, or had high BP measured in the campaign. Conclusion The campaign was feasible with the objective to increase the awareness among the public and policymakers of the importance of tackling hypertension in Iran