Characterization and evaluation of nanoparticles ceramic membrane for the separation of oil-in-water emulsion.

The mixture of oil with water from industrial activities creates an emulsion which is now termed as Oil-in-Water (O/W) emulsion. Several chemical and physical methods have been successfully used for the separation of O/W emulsions; however, the trace amounts of oil remain unfiltered in the separated water. This research aims at comparing two nanoparticles (Iron and Silver) coated ceramic membrane with self-cleaning ability for the effectively separation of low concentration ([less than] 250mg/L) of O/W Emulsion. Preliminary experiments have been done to determine the morphology and pure water flux of unmodified commercial ceramic membrane using Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Analysis (EDAX) and in-house installed separation rig respectively. An uneven pore size with a densely packed image from SEM indicates an increase in flux. Steady pure water permeate flux shows possibility of anti-fouling in ceramic membrane

Metal oxide modified tubular ceramic membrane for the separation of oil-in-water emulsion.

Separating lower concentrations of oil-in-water (O/W) emulsion (< 250 mg/l) and smaller oil droplet size (< 20 μm) has been an industry challenge using conventional methods, including adsorption, electrocoagulation, flocculation, bioremediation, centrifugation, membranes, etc. This is mostly due to the oil droplet size falling in the emulsified range or nano range, which is easily stabilised with surfactant present in the O/W. Recently, membrane technology has been the most researched approach for the separation of O/W emulsion. This springs from the massive potential of its usage for future water purification and effluent treatment, with it being environmentally friendly and facilitating a high permeate rate, high percentage oil rejection, and low-cost separation processes. This study, therefore, focuses on modifying microporous asymmetric Aluminium Oxide (Al2O3) tubular ceramic membranes with metal oxides nanoparticles for surface wettability to improve hydrophilicity and increase O/W emulsion separation efficiency. A novelty material – Magnesium Oxide (MgO) - nanoparticles modified tubular ceramic membrane was investigated and discovered to have a high hydrophilicity and O/W emulsion separation efficiency in this study. This investigation, which includes modification of MgO nanoparticles on commercial Al2O3 tubular ceramic membrane using a deep coating method of membrane modification, was also applied to other naturally hydrophilic nanoparticle compounds (Manganese Oxide (MnO2) and Chromium Oxide (Cr2O3)), where MgO nanoparticles emerged as the most hydrophilic on tubular ceramic membranes measured using contact angle measurement. The MgO-modified tubular ceramic membrane was characterized to determine morphology, elemental composition, hydrophilicity, porosity and pore size, and was compared with unmodified an Al2O3 tubular ceramic membrane using various analytical instruments and methods. A novelty method of testing MgO-modified tubular ceramic membranes for the separation of lower concentration (< 500 mg/l) of synthesized O/W emulsion was investigated and achieved using an in-house rig set up. The MgO-modified tubular ceramic membrane test for O/W emulsion included test parameters for percentage oil rejection, flux, and flux recovery ratio. Where results from these tests were compared to results from unmodified Al2O3 tubular ceramic membrane, the MgO-modified membrane displayed a higher percentage oil rejection efficiency of 98%, leaving behind an O/W emulsion concentration of 11.63 mg/l from the 500 mg/l initial O/W emulsion concentration. Meanwhile, an Al2O3 unmodified ceramic membrane shows 69% oil rejection, leaving behind 156.25 mg/l from 500 mg/l O/W emulsion. This generated over 30% difference in the percentage of oil rejection between Al2O3 unmodified and MgO-modified ceramic membranes. This MgO-modified ceramic membrane percentage oil rejection concentration of only 11.63 mg/l falls within the OSPAR regulatory limit. Compared to Al2O3 unmodified ceramic membrane, the MgO-modified tubular ceramic membrane demonstrated a lesser performance in terms of permeate flux, with a higher flux decline due to quick concentration polarization and smaller pores sizes during O/W emulsion cross-filtration analysis. With this result, an MgO-modified ceramic membrane can be an alternative to other metal oxide ceramic membranes to improve separation efficiency of more than 90%. The success of this MgO-modified ceramic membrane can tackle the lower oil concentrations (250 mg/l) and oil droplet size (< 20 um) challenges that arise from unmodified ceramic membranes and conventional methods of O/W emulsion separation

Comparattive [sic] evaluation of oil-in-water emulsion separation with aluminium oxide and zinc oxide nanoparticles ceramic membrane.

This research aims at comparing two nanoparticles (Aluminium oxide and zinc oxide) coated ceramic membrane with self-cleaning ability for the effectively separation of low concentration ([less than] 250mg/L) Oil-in-Water O/W Emulsion. Preliminary experiments have been done to determine the morphology and pure water flux of unmodified commercial ceramic membrane using Scanning Electron Microscope (SEM) and in-house installed rig separator respectively. An uneven pore size with a densely packed image from SEM indicates an increase in flux. Steady pure water permeate flux shows possibility of anti-fouling in ceramic membrane

Comparison of Body Mass Index between Pubertal and Prepubertal Females in Okrika

This research work is aimed at examining the effect of pubertal development on body fat in females. 920 female students drawn from 5 secondary schools in Okrika of Rivers State in Nigeria were used as respondents. 460 of these are pubertal while the other 460 are prepubertal. With the aid of a questionnaire, their pubertal or prepubertal status; i.e. presence of pubic hair and/or breast bud, commencement of menstruation was gotten. Their height and weight was also gotten. BMI was calculated for prepubertal and pubertal females and compared statistically. The mean BMI of pubertal females, 19.7, is arithmetically higher than that of prepubertal females, 17.7 and the difference between the mean BMI is very statistically significant (P&lt;0.05). For each age, the BMI of pubertal females was found to be higher than that of prepubertal females and as exemplified by the age groups 12 years and 13 years, the differences between the mean BMI for each age was found to be significant (P&lt;0.05). Irrespective of the pathway the respondents took to puberty, adrenarche or thelarche, the BMI of pubertal females were significantly (P&lt;0.05) higher than that of prepubertal females. BMI significantly (P&lt;0.05) increased with progression in pubertal development. The BMI of pubertal females is greater than the BMI of prepubertal females: hence pubertal females have greater body fat than prepubertal females. Females that have reached puberty and are undergoing pubertal development should be careful not to give in wholly to weight reduction programmes. Keywords: BMI, Pubertal, Prepubertal, Body fat

Comparative Study of Trace amount of Hydrocarbon in Polluted soil on Bean (Vigna unguiculaga) and Waterleaf (Talimum triangulase)

The effect and comparison of plants grown in polluted soil containing trace amount of hydrocarbon was investigated and the stem length, leaf length, leaf width, and germination were observed and measured in water leaf and bean plants. Loamy soils (3kg) were measured into a container and polluted with a 1:1 dilution of hydrocarbon (diesel) giving a 1M concentration. The same loamy soils were measured into another container which was not polluted. These crops planted on polluted soil were compared with the same crops planted on unpolluted soil in a container. Observation on growth and morphology were noted and recorded. Percentage germination in the bean crop in polluted and unpolluted soil was 67% and 100% respectively. Plant height, leaf width and leaf length of bean crop were measured in centimeters in polluted and unpolluted soil as 2.9, 1.0, 1.8 and 3.2, 1.5, 2.0 respectively. The same measurement and unit was done in water leaf plant in polluted and unpolluted soil which resulted in 2.1, 0.7, 1.0 and 2.5, 0.9 1.25 respectively. The percentage germination in water leaf plant was 67% in polluted soil as against 83% in unpolluted soil. From the data obtained, it was concluded that trace amount of hydrocarbon can affect plant germination and growth

Using nanoporous core-samples to mimic the effect of petrophysical parameters on natural gas flowrate in an unconventional gas reservoir.

Natural gas was for quite a long time regarded as an unwanted by-product of oil exploration and production that was mostly flared to the atmosphere. This happened because there was no feasible economic means of bringing it to the market. In this work ceramic core technology, which has gained significant attention over the last decades, will be applied to enable laboratory study of the permeation of gases continuously under mild conditions and under realistic pressure drops with very low consumption of energy with no required additives. The study is designed to mimic the effect of petrophysical parameters on gas flow in a tight reservoir using nano-porous core samples. Experiments were carried out, involving a procedure that requires the release of different gases contained in a gas cylinder to an assemblage of nano-cores fitted into the centre of an anulus of a shell and tube arrangement. The nano-core samples had varying pore throats and were studied at different temperature and pressure conditions. Suitable data were collected and analysed with statistical tools to showcase the influence of petrophysical parameters on the flowrate associated in extracting gas from unconventional reservoirs. The results established that several factors impact on the accumulation and migration of gas in an unconventional gas reservoir and these factors determine the rate at which gas flows from the reservoir to the well-bore

Characterization of membranes for advanced direct carbon capture.

Carbon capture is essential for lowering anthropogenic carbon emissions and, as a result, limiting global warming. Membrane technology has a lot of potential for extremely efficient carbon capture because of its energy-efficient and environmentally friendly properties. This research focuses on the development of a clean carbon dioxide (CO2) capture technique based on a ceramic membrane. DAC (direct air carbon capture) is a new method of extracting CO2 from the atmosphere with the potential to remove massive amounts of CO2. This study presents experimental results on the permeation of gases such as carbon dioxide and air through ceramic membranes with pore size of 200nm and 6000nm at temperatures of 20°C, 100°C and 150°C. The behaviour of gases across the membrane was depicted in the experimental results, demonstrating that pressure is a major determining factor in determining the rate of flow for gases through the membrane, as the flow rate of both CO2 and air gases increased exponentially regardless of membrane geometry of operating conditions. Experimental results showed that the gas permeance of CO2, Air, through a ceramic membrane with different pore sizes of 200nm, 6000nm, decreases with increasing pressure drop. It interested to note for ceramic membranes, with different pore sizes (200nm, 6000nm) the permeance of Air is larger than that of CO2. This indicated that CO2 can be adsorbed by ceramic membranes. The ceramic membrane's inner surface morphology was studied. The particles are equally scattered across the ceramic membrane's surface. The ceramic membrane's surface is crack-free and smooth, contact angle measurements were also used for ceramic membrane characterization. The ceramic membrane's water contact angle is 43.54 degrees, indicating that it has a hydrophilic surface. This is due to the presence of hydroxyl (OH-) groups having hydrophilic properties on their surface and pores

Knudsen number sensitivity to pressure drop in a nanoscale membrane.

According to the kinetic theory of gases, gas molecules are in constant random motion and frequently collide with one another and with the walls of their container. They continuously experience changes in velocity and direction. Between collisions, molecules move in a straight line at a constant velocity. The actual path length between two successful collisions of a molecule, known as a free path, cannot be established as its calculation requires the knowledge of the path of every molecule in a containment system. The average of all the path lengths between collisions is known as the mean free path (λ). Unlike free path, mean free path is measurable and it is a better measure of the random motion of gas molecules in a gaseous system which is very difficult to measure directly. However, the finding relating to pressure drop with Knudsen number (Kn) in a nanoparticle is limited. This study focuses on understanding the pressure gradient in a nonporous membrane structure and calculating the mean free path. The Knudsen number of selected gases was plotted against pressure drop at 1000C for the three gases and generated several plots. Each plot represents the profile of the respective Knudsen number of the gases in membranes with a pore size of 15nm, 200nm and 600nm respectively. The investigation established that there is an inverse relationship between Kn and Pressure. The correlation is strong as indicated by the R2 of 0.89. The three gases show a dramatic relationship of Kn with pressure in the 15nm pore membrane. The rate of change or slopes of Kn with pressure is higher for all the gases in 15nm than for the 200nm and 6000nm pore sizes. Kn for H2 has the most response to pressure in the 15nm with a response of -0.70 Kn/KPa, followed by CO2 (-0.54 Kn/KPa) and Air (-0.37 Kn/Kpa). The lowest magnitude of Kn at the extended experimental pressure 300KPa is compared and a qualitative deduction can be drawn that the Kn/KPa parameter dampens as the pore size increases

Using contact angle measurements for determination of the surface free energy of the ceramic membranes.

The surface free energy is one of the factors that characterises the surfaces of materials. The sessile drop method is the most popular method for determining its value. A contact angle between the surface and the edge of liquid droplets is measured in this scenario. The substrate surface free energy was frequently determined using contact angle measurements for unique liquids. As shown in Table 1, contact angles were evaluated at room temperature with a model liquid (water) for all samples. It's important to note that a smaller contact angle indicates a solid's wettability (Ali, 2012). As a result, a higher contact angle indicates less model liquid absorption by the sample and consequently less interaction between the two. The largest contact angle was seen with the 200nm ceramic membrane sample, and the lowest contact angle was observed with the 15nm ceramic membrane sample. Apart from 200nm ceramic membrane sample, the DIM contact angles of the samples are quite near to each other. Scanning electron microscopy (SEM) examination was used to characterise the ceramic membrane. The ceramic membrane has a porous, rough morphological feature apart from 15nm pore size ceramic membrane appeared to have smooth on its surface. A close examination of the image reveals that the membrane was free of defects such as pinholes and cracks

Effect of pore size and porosity on contact angle of ceramic membrane for oil-in-water emulsion separation.

The main objective of this work is to study the effect of pore size and porosity on contact angle of ceramic membrane (CM) for Oil-in-water (O/W) emulsion separation. This would include using commercially produced unmodified CM pore size 6000nm and 15nm. The Archimedes equation is used to measure the overall porosity of 6000 and 15nm pore size ceramic membranes and the porosity of the interconnecting pores. Subsequently, the contact angle for the ceramic membranes is measured using Attention Theta Lite Optical Tensiometer to test for the hydrophilicity. The average contact angle of 6000 and 15nm CM over a 20 second period at 50 frames per seconds (FPS) were 67.70 and 76.60 respectively. The porosity of CM1 (6000nm) and CM2 (15nm) were 23 and 21% respectively. From the Porosity and contact angle result, it is observed that porosity and pore size have influence of contact angle or hydrophilicity of a CM. the higher the pore size and porosity of a CM, the higher the hydrophilicity of the CM. This means contact angle of a higher porosity and pore size CM is expected to be closer to zero degree in contact angle. The proximity of contact angle results of CM 1 and 2 considering pore size might be due to dead end pores in CM1 (6000nm) which constitute 95% of pores making up the CM1 reducing porosity