Recent progress in renewable energy based-desalination in the Middle East and North Africa MENA region.

BACKGROUND: The Middle East and North Africa (MENA) countries are rapidly growing in population with very limited access to freshwater resources. To overcome this challenge, seawater desalination is proposed as an effective solution, as most MENA countries have easy access to saline water. However, desalination processes have massive demand for energy, which is mostly met by fossil fuel-driven power plants. The rapid technological advancements in renewable energy technologies, along with their gradually decreasing cost place renewable energy-driven power plants and processes as a promising alternative to conventional fuel-powered plants. AIM OF REVIEW: In the current work, renewable energy-powered desalination in the MENA region is investigated. Various desalination technologies and renewable energy resources, particularly those available in MENA are discussed. A detailed discussion of suitable energy storage technologies for incorporation into renewable energy desalination systems is also included. KEY SCIENTIFIC CONCEPTS OF REVIEW: The progress made in implementing renewable energy into power desalination plants in MENA countries is summarized and analyzed by describing the overall trend and giving recommendations for the potential amalgamation of available renewable energies (REs) and available desalination technologies. Finally, a case study in the MENA region, the Al Khafji solar seawater reverse osmosis (SWRO) desalination plant in the Kingdom of Saudi Arabia KSA, is used to demonstrate the implementation of REs to drive desalination processes.

Scale-up of the bioelectrochemical system: Strategic perspectives and normalization of performance indices.

Electrochemists and ecological engineers find environmental bioelectrochemistry appealing; however, there is a big gap between expectations and actual progress in bioelectrochemical system (BES). Implementing such technology opens new opportunities for novel electrochemical reactions for resource recovery and effective wastewater treatment. Loopholes of BES exist in its scaling-up applications, and numerous attempts toward practical applications (200, 1000, and 1500 L) are key successive indicators toward its commercialization. This review emphasized the critical rethinking of standardization of performance indices i.e. current generation (A/m2), net energy recovery (kWh/kg·COD), product/resource yield (mM), and economic feasibility ($/kWh) to make fair comparison with the existing treatment system. Therefore, directional perspectives, including modularity, energy-cost balance, energy and resource recovery, have been proposed for the sustainable market of BES. The current state of the art and up-gradation in resource recovery and contaminant removal warrants a systematic rethinking of functional worth and niches of BES for practical applications.

Thermosensitive injectable graphene oxide/chitosan-based nanocomposite hydrogels for controlling the in vivo release of bupivacaine hydrochloride.

Local anesthetics are commonly used for the management of intraoperative and postoperative acute and chronic pain caused by small invasive procedures. However, their short half-life and duration of action limit their clinical benefits. In this study, we proposed the incorporation of graphene oxide (GO) nanosheets to chitosan (CS)/ß-glycerophosphate (GP) thermosensitive hydrogel system to form an injectable nanocomposite hydrogel (NCH) with improved mechanical properties and better control over the release of bupivacaine hydrochloride (BH). The prepared NCHs were characterized for their gelation time, porosity, swelling ratio, injectability, mechanical strength and in vitro drug release. In vivo, the efficacy of the prepared NCH containing 0.5 % w/v BH was evaluated using a thermal nociceptive assay in a rat model. The incorporation of GO significantly enhanced the physicochemical and mechanical properties of the hydrogel scaffolds in a concentration-dependent manner. Inclusion of 0.1% w/v GO resulted in 84% reduction in gelation time and 16% and 40% decrease in the porosity and swelling ratio of the NCHs, respectively. The mechanical strength of the CS/GP hydrogel scaffolds was also significantly improved in presence of GO. BH was slowly released from the NCHs containing 0.1% w/v GO and resulted in a 55% and 86.43% drug release after 6 and 24 h, respectively. In vivo studies showed that BH-loaded NCH significantly prolonged the local anesthetic effect and resulted in a 6.5-fold increase in blocking the pain sensory reflex compared to BH solution. These results indicate that the incorporation of GO significantly improved the physical and mechanical properties of CS/GP thermosensitive hydrogels and successfully sustained the effect of local anesthesia for more effective pain management.

Scalability of microbial electrochemical technologies: Applications and challenges.

During wastewater treatment, microbial electrochemical technologies (METs) are a promising means for in situ energy harvesting and resource recovery. The primary constraint for such systems is scaling them up from the laboratory to practical applications. Currently, most research (∼90%) has been limited to benchtop models because of bioelectrochemical, economic, and engineering design limitations. Field trials, i.e., 1.5 m3 bioelectric toilet, 1000 L microbial electrolysis cell and industrial applications of METs have been conducted, and their results serve as positive indicators of their readiness for practical applications. Multiple startup companies have invested in the pilot-scale demonstrations of METs for industrial effluent treatment. Recently, advances in membrane/electrode modification, understanding of microbe-electrode interaction, and feasibility of electrochemical redox reactions have provided new directions for realizing the practical application. This study reviews the scaling-up challenges, success stories for onsite use, and readiness level of METs for commercialization that is inexpensive and sustainable.