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Novel corona virus (COVID-19) pandemic in the last 4 months stimulates the international scientific community to search for vaccine of antiviral agents suitable for in activating the virus inside and outside the human body. More than 4 million people globally are infected by the virus and about 300,000 dead cases until this moment. The ventilation and airborne filters are also investigated aiming to develop an efficient antiviral filtration technology. Human secretion of the infected person as nasal or saliva droplets goes as airborne and distributes the virus everywhere around the person. N95 and N98 filters are the must use filters for capturing particles of sizes around 300 nm. The average size of the novel corona virus (COVID-19) is 100 nm and there is no standard or special filter suitable for this virus. The nanoparticle-coated airborne filter is a suitable technique in this regard. While the efficiency of this type of filters still needs to be enhanced, new developed nanofiber filters are proposed. Most recently, the charged nanofiber filters of sizes below 100 nm are developed and provide an efficient viral filtration and inactivation. The efficiency of filter must be kept at accepted level without increasing the pressure drop. The present review outlines the most efficient antiviral nanoparticles including the recent functional nanoparticles. The filtration theory, filtration modeling, filter testing, and different types of filter with special concentration on the charged nanofiber filter were discussed. The charged nanofiber filter able to capture novel corona virus (COVID-19) with 94% efficiency and a pressure drop less than 20 MPa.

The continued burning of fossil fuels since the beginning of the last century led to higher emissions of greenhouse gases and thus leads to global warming. Microalgae are one of the most important sources of green hydrocarbons because this type of algae has a high percentage of lipids and has rapid growth, consumes the carbon dioxide in large quantities. Besides, the cultivation of these types of algae does not require arable land. This review aims to explain the suitability of microalgae as a biofuel source depending on the fat content, morphology, and other parameters and their effect on the conversion processes of microalgae oil into biofuels by different zeolite catalytic reactions. It also discusses in detail the major chemical processes that convert microalgae oil to chemical products. This review sheds light on one of the most important groups of microalgae (Chlorella vulgaris microalgae). This review includes a historical overview and a comprehensive description of the structure needed to develop this type of algae. The most important methods of production, their advantages and disadvantages are also deliberated in this work. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Microalgae is one of the most important sources of green hydrocarbons and it is likely to reduce dependence on fossil fuels due to the high percentage fats of microalgae, and also has a rapid growth rate and consumes the carbon dioxide in large quantities. Besides, the cultivation of microalgae does not require arable land. This short review aims to explain the suitability of microalgae as a biofuel source depending on the content of lipids, and catalytic chemical processes to convert the crude oil of microalgae into biofuels by using different types of modified HZSM-5 zeolites. Also, this review sheds light on the different methods to modify HZSM-5 zeolite toward enhancing the selectivity of cracking and deoxygenation processes by using modified HZSM-5 zeolite with rare earth metals.

Al-Dalmaj Marsh is considered one of the important brackish water body in Iraq as it has a huge fish wealth in addition to the possibility of investment in the place for tourism due to the presence of many archeological and historical sites nearby the Al-Dalmaj Marsh such as the ancient city of Nippur that demand to monitor the water quality of Al-Dalmaj Marsh and assure to be clean and pollution-free all the time. The physicochemical properties of Al-Dalmaj Marsh water (Temperature, pH, Conductivity, and Dissolved oxygen) were changed from October 2019 to October 2020 due to the decrease in the water level. The present study showed that the water body of the Al-Dalmaj Marsh has microplastics pollution in a ratio reached to 2.6% especially in the south and east sites of the study (S1, S2, S6, S7, S8). Moreover, different types of microplastics (MPs) were characterized using FTIR spectroscopy in the collected samples from the eight sites and it is found that the transparent Polyethylene (PE) is the most abundant MPs. MPs concentrations in the collected samples were changed from (1.9 x103- 2.8 x103) in October 2019 to (2.8 x103-3.6 x103) items/km2 in October 2020. The growth and chlorophyll content of the Spirulina platensis microalgae showed a clear decrease by adding the different types of MPs and PVC showed the most adverse effect on these two parameters. Besides, Spirulina p. showed great potential to uptake and aggregate MPs particles from the culturing media and work as a bioremediation agent.

The methyl ester of waste cooking oil (MEWCO) has been prepared from used cooking oils collected from different restaurants and investigated experimentally and theoretically. The suggested biodiesel is mixed with different percentages (10%, 20%and 100%) on a volume basis together with original diesel fuel and tested on a constant speed diesel engine. The experimental work deals with the impact of the blending ratio on the performance and emission parameters at different load conditions. The experimental side is verified with simulation study done by Diesel-rk software and it reveals that they are in good agreement. The maximum pressure reduced as a result of increasing MEWCO blends due to the reduction in the heating value of the blended fuels. Both sides are reported promising reduction in nitrogen oxides (NOx) on the behalf of carbon emissions. Mixing 20% MEWCO is the best compromise, mixing ratio and beyond that, dramatic reduction in the outcome of the performance has been observed. Keywords: Waste oil, Transesterification, Diesel engine, Performance, Emissions, Diesel-rk software

Density, viscosity, and surface tension for the DBSA-Acetone system at the temperatures (293.15, 298.15, 301.15 K) have been investigated experimentally. Excess molar volume, viscosity deviation, surface tension deviation, and molar excess Gibbs free energy deviation are calculated at (293.15, 298.15, 301.15 K). All the non-ideal properties calculated are fitted to Redlich-Kister (RK) equation. FTIR spectrum of the DBSA-Acetone mixture have been characterized for studying the intermolecular interaction. The result of molar excess Gibbs free energy deviation and FTIR studies showed a weak hydrogen bonding for the mixture solution. While, the intramolecular interaction is strong in the case of pure DBSA and acetone due to the self-association of DBSA molecule or decreasing the dipole-dipole of acetone molecule. The result of FTIR supported the result of thermodynamic excess where the excess molar volumes were positive. The calculated values of excess molar volume are positive for all the temperatures ranging from (293.15 - 301.15 K). while, the values of viscosity deviation, surface tension deviation, and molar excess Gibbs free energy deviation are negative for all the temperatures studied.