Optimization of magnetic nanoparticles draw solution for high water flux in forward osmosis

In this study, bare iron oxide nanoparticles were synthesized using a co-precipitation method and used as a draw solute in forward osmosis. The synthesis conditions of the nanoparticles were optimized using the Box-Behnken method to increase the water flux of the forward osmosis process. The studied parameters were volume of ammonia solution, reaction temperature, and reaction time. The optimum reaction conditions were obtained at reaction temperature of 30 °C, reaction time of 2.73 h and 25.3 mL of ammonia solution. The water flux from the prediction model was found to be 2.06 LMH which is close to the experimental value of 1.98 LMH. The prediction model had high correlation factors (R2 = 98.82%) and (R2adj = 96.69%). This study is expected to be the base for future studies aiming at developing magnetic nanoparticles draw solution using co-precipitation method.This research is made possible by graduate sponsorship research award (GSRA6-1-0509-19021) from Qatar National Research Fund (QNRF). Also, the authors would like to thank Qatar University for funding this project through Collaborative Grant (CG)—Cycle 05—ID492. The statements made herein are solely the responsibility of the authors. The authors would like to thank Central Laboratories Unit (CLU) at Qatar University for generating TEM images.Scopu

Industrial sludge valorization and decontamination via lipid extraction and heavy metals removal using low-cost protic ionic liquid

Sludge is a heterogenous organic-rich matter that comprise of highly valuable biopolymers along with various contaminants including heavy metals. Sludge valorization as a renewable resource and inexpensive feedstock is key for sludge realization in circular economy context. This study presents the use of low-cost protic ionic liquid (PIL) as an integrated process medium to decontaminate heavy metal contaminated industrial sludge while selectively extract the lipid content. The treatment process focused on the use of 1-methylimidazole chloride for its higher heavy metal extraction performance compared to other screened ionic liquids (ILs). The treatment was also able to selectively extract lipids from industrial sludge, leaving a protein/carbohydrate rich solid product. Process temperature was shown to have a key impact on the biopolymers' fractionation. Operating at temperatures above 120 °C resulted in higher recovery of proteins in the lipid-rich fraction, compromising the quality of the lipid stream. Variation of the PIL acid/base (a/b) ratio also had a significant impact on the deconstruction of the sludge biopolymers, with a/b ratio of 1 resulting in highest recovery of all biopolymers. Optimal water concentration as co-solvent was found at 30 wt%, with lipid recovery reaching 60% and heavy metals extraction ranging between 29 and 89%.This research is made possible by the PDRA award ( PDRA6-0602-20007 ) from Qatar National Research Fund (QNRF). In addition, the authors wish to thank the Central Laboratories Unit (CLU) at Qatar University for the heavy metals analysis. Also, the authors wish to thank Ms. Touria Bounnit from the Center for Sustainable Development at Qatar University for the assistant in the lipids analysis. The statements made herein are solely the responsibility of the authors.Scopu

The impact of electric field on the demulsification efficiency in an electro-coalescence process

In this study, the influence of the electric field and its determining parameters such as voltage, inter-electrode distance and frequency on the demulsification efficiency of a water-in-oil emulsion was studied. The numerical analysis showed that the water droplets trapped onto the hydrophobic titanium dioxide (TiO2) coated electrodes and at 2 mm inter-electrode distance can increase the electric field intensity above 300 kV/m, where droplet rupture takes place. Experimental study showed highest demulsification efficiency of 76% while applying AC voltage of 250 V, frequency of 200 kHz and inter-electrode distance of 4 mm. 2023 Elsevier B.V.This study was made possible by the Qatar University internal grant # QUCG-CENG-19/20-1 . The authors would also like to thank Qatar National Research Fund for supporting one of the co-authors through GSRA7-1-0510-20046 .Scopu

Magnetic nanoparticles draw solution for forward osmosis: Current status and future challenges in wastewater treatment

Forward osmosis is considered as the least energy intensive membrane process since it operates based on the osmotic pressure gradient. However, it is still considered as immature technology mainly due to the elevated cost for draw solution regeneration. Nevertheless, magnetic nanoparticles could be considered as a sustainable draw solute for forward osmosis due to high osmotic pressure and easy regeneration using magnetic force, but a significant development is still needed before implementing it for wastewater treatment and desalination. Herein, we analyzed the performance of the available magnetic nanoparticles draw solute and identified the challenges facing the use of magnetic nanoparticles as draw solute in the forward osmosis process. We first highlight the common synthesis methods of magnetic nanoparticles, and basics for generation of osmotic pressure using magnetic nanoparticles. Then, we analyzed the performance and limitations of available magnetic nanoparticles that were used as draw solute in the forward osmosis process. Later, we assessed the toxicity level of the magnetic nanoparticles and explored the regulations of using magnetic nanoparticles in the water treatment industry. Finally, new avenues of research were proposed to make magnetic nanoparticles draw solution more effective when applying it in desalination and wastewater treatment process.This research is made possible by graduate sponsorship research award ( GSRA6-1-0509-19021 ) from Qatar National Research Fund (QNRF). Also, the authors would like to thank Qatar University for funding this project through Collaborative Grant (CG) - Cycle 05 - ID492 . The statements made herein are solely the responsibility of the authors. Open access funding was provided by Qatar National Library .Scopu

Efficient extraction of lipids from microalgal biomass for the production of biofuels using low-cost protic ionic solvents

The valorization of lipids available in microalgal biomass supports the indispensable transition from fossil fuels to renewable energy systems such as biofuels. Ionic liquids have been long investigated for the effective extraction of those lipids, however; the complex and expensive synthesis of traditional ionic liquids (i.e., >$50/kg) hindered their employment in commercial applications. Protic ionic liquids are a class of ionic liquids that possess a simple method of preparation and a low cost of around$1-3/kg, rendering them viable for industrial implementation. This study investigates, for the first time, the deployment of protic ionic liquids with methanol co-solvent for the extraction of lipids from Coelastrella sp. and Haematococcus sp. microalgae. The treatment process focused on the use of N,N,N-dimethyl-butylammonium hydrogen sulfate due to its high lipid extraction performance of 323.3 mg lipids/g biomass from Coelastrella sp. (81% of available lipids) compared to other screened ionic liquids. Process parameters such as temperature, time, and ionic liquid to methanol mass ratio exhibited a key impact on the lipid yield. The fatty acid profile of the extracted lipids from Coelastrella sp. demonstrated suitability to produce biofuels. The treatment has also shown selectivity in extracting lipids while leaving behind a protein/carbohydrate rich solid residue. The results obtained suggest that protic ionic liquids are promising candidates for the cost-effective and eco-friendly treatment of microalgal biomass. 2023 Elsevier B.V.The authors gratefully acknowledge the financial support provided by Qatar National Research Fund , research grant ( PDRA6-0602-20007 ). The authors would like to express their appreciation for Dr. Touria Bounnit from the department for sustainable development at Qatar University for doing the GC-FID analysis. The statements made herein are solely the responsibility of the authors.Scopu

Enhancing the electrocoagulation process for harvesting marine microalgae (Tetraselmis sp.) using interdigitated electrodes

Marketable value of algal biomass has been increasing in recent years due to its wide range of applications. This study investigates the performance of a novel cylindrical interdigitated electrode array in electrocoagulation for the harvesting of marine microalgae (Tetraselmis sp.). The new electrode array is expected to exert a dielectrophoretic (DEP) force which would assist in the harvesting of the microalgae in the electrocoagulation process. Through numerical investigation, the induction of dielectrophoretic force was confirmed in the new electrode array. In this study, 10 min electrolysis time was found to be sufficient to harvest 82.4% microalgae with 1 cm electrode distance and 50 mA/cm2 current density. Furthermore, decreasing the electrode distance to 0.5 cm increased the algal harvesting efficiency to 96.18%. Energy analysis showed that the proposed electrode array shows 38% lower specific energy consumption than the conventional flat sheet electrode array