mohammad mahdi zerafat

Solid waste disposal and accumulation from various packaging materials made of synthetic polymers have led to intensified environmental concerns during the last decades. However, extensive research has been conducted on bio-nanocomposites as an alternative material for synthetic polymers in packaging applications during recent years. In this study, gelatin-based films modified with nano-caly and chitosan are proposed for food packaging. Nano-clay is used to improve various features such as mechanical strength and water vapor barrier properties. Also, chitosan is added to the gelatin matrix for anti-microbial and anti-fungal properties. The as-prepared nanocomposite films were characterized using FTIR, XRD and SEM techniques. Also, tensile strength, transparency, swelling behavior, water contact angle and permeability tests were performed. Based on the results, increasing nano-clay up to 5 wt. %, results in 25% tensile strength enhancement in the nano-composite film. Higher nano-clay contents led to strength decline. Elongation at break is reduced by increasing the nano-clay content from 25% to 40%. The contact angle was also reduced by increasing the nano-clay content from 95o to 90o showing a small hydrophobicity reduction.

Liquid desiccants such as glycols are used in dehydration process, among which Triethylene Glycol (TEG) is considered as a common choice. The addition of nanoparticles to TEG as the base fluid is one of the prevalent method to improve thermal properties of TEG. In this study, an experimental investigation was performed on thermal conductivity of TEG-based nanofluids with 20 and 40 nm diameter copper oxide (CuO) nanoparticles analyzed at different conditions. Thermal conductivity was measured using a Decagon thermal analyzer (KD2 Pro Model) in the 20 °C-60 °C temperature range, and also 0.1- 0.9 wt.% range. The experimental results showed that thermal conductivity of the nanofluid enhances with temperature increasing. In addition, thermal conductivity of nanofluids increased with nanoparticle concentration in both cases of 20 and 40 nm nanoparticles. The highest enhancement was also ~ 13.5%, for the nanofluid with 20 nm nanoparticles at 60 °C and a 0.9 wt.% concentration.

Generation of electrical energy requires water as well as water conveyance and treatment to energy. For encounter to challenges and uncertainty about the water and energy nexus, requires to understand the nature of this linkage to identify, approve and execute the appropriate policies. The aim of this study is the evaluation of water and energy nexus at freshwater production by SWRO desalination. For this purpose, assuming that the electric power supplier for the desalination plant is a thermal power plant with a cooling tower or once-through-cooled, the specific water withdrawal in a thermal wet tower- and once-through-cooled plants using S-GEM model and specific energy consumption in RO plants using solution–diffusion model was calculated. The results indicate in the production energy sector, the practical power effect on fuel consumption and consequently water withdrawal. Also, in the desalination plant, the physio-chemical parameter, and temperature of feed water, and ERD type effect on specific energy consumption. Finally, the indirect volume of water withdrawal, fuel and thermal energy consumption to produce a cubic meter of desalting water was obtained which could be used by effective institutions to better manage the supply and demand of water and energy.

Phenol is among toxic pollutants with a resilient degradability behavior the total removal of which via traditional techniques is impossible. In this research, Carbon-doped TiO2 nano-photocatalyst is produced via sol-gel technique. Various techniques are used to characterize TiO2 nano-photocatalyst such as XRD, FT-IR, EDX, and FE-SEM. Based on the results, the carbon introduced into titania structure has led to response towards visible light. The synthesized catalyst was implemented for photocatalytic removal of phenol in a fluidized bed reactor under UV and visible light. The effects of several significant parameters were investigated such as phenol concentration, pH, time, C/Ti molar ratio and catalyst content. The degradation of Phenol using this nanocomposite is 84 % under UV irradiation during a 180 min period and 70 % under visible irradiation during a 420 min period.