Water is a critical component for humans to survive, especially in arid lands or areas where fresh water is scarce. Hence, desalination is an excellent way to effectuate the increasing water demand. Membrane distillation (MD) technology entails a membrane-based non-isothermal prominent process used in various applications, for instance, water treatment and desalination. It is operable at low temperature and pressure, from which the heat demand for the process can be sustainably sourced from renewable solar energy and waste heat. In MD, the water vapors are gone through the membrane's pores and condense at permeate side, rejecting dissolved salts and non-volatile substances. However, the efficacy of water and biofouling are the main challenges for MD due to the lack of appropriate and versatile membrane. Numerous researchers have explored different membrane composites to overcome the above-said issue, and attempt to develop efficient, elegant, and biofouling-resistant novel membranes for MD. This review article addresses the 21st-century water crises, desalination technologies, principles of MD, the different properties of membrane composites alongside compositions and modules of membranes. The desired membrane characteristics, MD configurations, role of electrospinning in MD, characteristics and modifications of membranes used for MD are also highlighted in this review.
The oxygenated hydro diesel (OHD) is prepared from hydrogen peroxide (H2O2), acetone, and seaweed polysaccharide. A long-term study was carried out on the OHD fuel blend stability for about a year at various temperatures. The long-term stability shows very stable properties, no easy emulsion breaking, and a long storage period. The neat diesel and blend fuel performance test was conducted at various engine speeds, 1700-3100 RPM the diesel blend with 5 wt.% and 10 wt. % of H2O2 revealed the best fraction for reducing smoke and emissions. The blend contains 15 wt.% H2O2, revealing a significant reduction in exhaust temperature without considering the engine's performance. Moreover, the performance of the OHD also revealed an economizing rate, decreasing environmental pollution and prolonging the engine's service life. The diesel engine performance and environmental evaluation leading to exhaust emissions characterization ([Formula: see text], [Formula: see text], and others). Based on the results, the various concentrations of H2O2 are an effective method for reducing the emission of diesel engines. Decreased CO, SO2, unburned hydrocarbons, and NO2 were also observed as percentages of H2O2. Due to increased oxygen content, water content and cetane number, the number of unburned hydrocarbons from diesel fuel decreased with the addition of H2O2. Therefore, the OHD blend can significantly curtail the exhaust emission of conventional diesel fuel, which will help reduce the harmful greenhouse gas emissions from diesel fuel sources.