The presence of antibiotic residues such as ciprofloxacin (CIPR) in an aqueous environment is dangerous when their concentrations exceed the allowable. Therefore, eliminating these residues from the wastewater becomes an essential issue to prevent their harm. In this work, the potential of efficient adsorption of ciprofloxacin antibiotics was studied using eco-friendly ZSM-5 nanocrystals‑carbon composite (NZC). An inexpensive effective natural binder made of the sucrose-citric acid mixture was used for preparing NZC. The characterization methods revealed the successful preparation of NZC with a favorable surface area of 103.739 m2/g, and unique morphology and functional groups. Investigating the ability of NZC for adsorbing CIPR antibiotics conducted at different conditions showed that 0.3 g of NZC achieved outstanding adsorption for 150 ppm CIPR antibiotic from 100 mL solutions at mixing speed of 200 rpm, solution pH of 4–6, and solution temperature of 25–30 ◦C. Estimating the values of ΔH◦, ΔS◦, and ΔG◦ confirmed that the adsorption process of CIPR antibiotics by NZC was feasible, exothermic and spontaneous. The Freundlich and pseudo-second-order models well fitted the adsorption process's experimental data. The results of both the kinetic and isotherm studies showed that the adsorption process of CIPR antibiotics by NZC is simultaneously composed of physical and chemical adsorption on the heterogeneous adsorption sites in multilayers. Also, the intra-particle diffusion was not the controlling step and the external surface adsorption influenced the adsorption of CIPR. From the abovementioned results, NZC is recommended as a highly efficient adsorbent for the removal of CIPR-loaded effluents.
Pharmaceuticals have been widely remaining contaminants in wastewater, and diclofenac is the most common pharmaceutical pollutant. Therefore, the removal of diclofenac from aqueous solutions using activated carbon produced by pyrocarbonic acid and microwaves was investigated in this research. Apricot seed powder and pyrophosphoric acid (45 wt%) were selected as raw material and activator respectively, and microwave irradiation technique was used to prepare the activated carbon. The raw material was impregnated in pyrophosphoric acid at 80◦C with an impregnation ratio of 1: 3 (apricot seeds to phosphoric acid), the impregnation time was 4 h, whereas the power of the microwave was 700 watts with a radiation time of 20 min. A series o
... Show MoreThe electrochemical behavior of carbon steel in water sweetening station in Libya has been studied in the range of ( 293–333 oC) using weight loss technique. Measurements were carried out over a range of Reynolds number (5000 – 25000).An apparatus was designed for studying the corrosion process in the turbulent regime, which is of industrial significance. It was found that The corrosion rate of carbon steel in water sweetening station is under diffusion control and increases with increasing Reynolds number. On the other hand the variation of corrosion rate with temperature in the range of (293–333 oC) was found to follow Arrhenius equation and the activation energy approximately the same except at low Reynolds
... Show MoreThe photoactive behaviour of rose bengal dye sensitized (ZnO/ Polystyrene (PS)) composites was studied. Two concentrations of composite(30% Zn0/70% PS) and (50% ZnO 150% PS) with (0.05 0.1.0.3,1%)weight percentages of dye were used. The composites are photoconductive and the photoconductivity action spectrum gives the effect of the dye in the visible region.
In the absence of dye within the composites, no photoactivity is
observed in this region of the spectrum. The photoconductivity is affected by the dye content.
Time of flight technique was used to measure response time. The
rise time of the photocurrent is fast and the decay is slow.
Gallium arsenide diamondoids structural and vibrational properties are investigated using density functional theory at the PBE/6-31(d) level and basis including polarization functions. Variation of energy gap as these diamondoids increase in size is seen to follow confinement theory for diamondoids having nearly equiaxed dimensions. Density of energy states transforms from nearly single levels to band structure as we reach larger diamondoids. Bonds of surface hydrogen with As atoms are relatively localized and shorter than that bonded to Ga atoms. Ga-As bonds have a distribution range of values due to surface reconstruction and effect of bonding to hydrogen atoms. Experimental bulk Ga-As bond length (2.45 Å) is within this distribu
... Show MoreOxidation of sulfur compounds in fuel followed by an adsorption process were studied using two modes of operation, batch mode and continuous mode (fixed bed). In batch experiment oxidation process of kerosene with sulfur content 2360 ppm was achieved to study the effect of amount of hydrogen peroxide(2.5, 4, 6 and 10) ml at different temperature(40, 60 and 70)°C. Also the effect of amount acetic acid was studied at the optimal conditions of the oxidation step(4ml H2O2 and 60 °C).Besides, the role of acetic acid different temperatures(40, 60, 70) °C and 4ml H2O2, effect of reaction time(5, 30, 60, 120, 300) minutes at temperatures(40,60) °C, 4ml H2O2 and 1 mlHAC)&
... Show More Aluminum alloys widely use in production of the automobile and the aerospace because
they have low density, attractive mechanical properties with respect to their weight, better
corrosion and wear resistance, low thermal coefficient of expansion comparison with traditional
metals and alloys. Recently, researchers have shifted from single material to composite materials
to reduce weight and cost, improve quality, and high performance in structural materials.
Friction stir processing (FSP) has been successfully researched for manufacturing of metal
matrix composites (MMCs) and functional graded materials (FGMs), find out new possibilities
to chemically change the surfaces. It is shown th