Nowadays, integrated microfiltration (MF) membrane systems treatment is becoming widely popular due to its feasibility, process reliability, commercial availability, modularity, relative insensitivity in case of wastewater of various industrial sources as well as raw water treatment and lower operating costs. The well thought out, designed and implemented use of membranes can decrease capital cost, reduce chemical usage, and require little maintenance. Due to their resistance to extreme operating conditions and cleaning protocols, ceramic MF membranes are gradually becoming more employed in the drinking water and wastewater treatment industries when compared with organic and polymeric membranes. Regardless of their many advantages, during continuous operation these membranes are susceptible to a fouling process that can be detrimental for successful and continuous plant operations. Chemical and microbial agents including suspended particles, organic matter particulates, microorganisms and heavy metals mainly contribute to fouling, a complex multifactorial phenomenon. Several strategies, such as chemical cleaning protocols, turbulence promoters and backwashing with air or liquids are currently used in the industry, mainly focusing around early prevention and treatment, so that the separation efficiency of MF membranes will not decrease over time. Other strategies include combining coagulation with either inorganic or organic coagulants, with membrane treatment which can potentially enhance pollutants retention and reduce membrane fouling.

Synthetic industrial wastewater samples containing mercury (Hg), arsenic (As), and lead (Pb) ions in various concentrations were prepared and treated by air gap membrane distillation (AGMD), a promising method for heavy metals removal. Three different membrane pore sizes (0.2, 0.45, and 1 μm) which are commercially available (TF200, TF450, and TF1000) were tested to assess their effectiveness in combination with various heavy metal concentrations and operating parameters (flow rate 1–5 L/min, feed temperature 40–70 °C, and pH 2–11). The results indicated that a high removal efficiency of the heavy metals was achieved by AGMD. TF200 and TF450 showed excellent membrane removal efficiency, which was above 96% for heavy metal ions in a wide range of concentrations. In addition, there was no significant influence of the pH value on the metal removal efficiency. Energy consumption was monitored at different membrane pore sizes and was found to be almost independent of membrane pore size and metal type.

Several Membrane Distillation (MD) technologies have been employed to remove boron from various concentrations. In this study, Vacuum Membrane Distillation (VMD), Permeate Gap Membrane Distillation (PGMD), and Air Gap Membrane Distillation (AGMD) are examined to evaluate their effectiveness when combined with several boron concentrations (1.5, 7 and 30 ppm) and operating parameters (circulation rate from 0.9 L/min to 5 L/min, feed temperature from 40 to 70 °C, and pH from 3–11). Those concentrations of boron are selected on the basis of the concentration of boron in the permeate side of the single-pass reverse osmosis (RO) system, Arabian Gulf, and contaminated brackish water. Moreover, synthetic seawater is treated to assess MD technologies’ effectiveness. A high removal efficiency of boron is accomplished by MD. AGMD, PGMD, and VMD are promising methods for the desalination industry. AGMD shows excellent boron removal, which was above 99% with a wide ranging concentration. In addition, VMD demonstrates good permeate flux compared to the other MD technologies, which were about 5.8 kg/m²·h for synthetic seawater. Furthermore, there is no noteworthy influence of the pH value on the boron removal efficiency.

Four natural dyes were extracted from different fruits used in the Dye-sensitized solar cell (DSSC). It includes ber, blackberry, black grapes, and blueberry by individual dye or combined with other dyes. The dye solution's absorption spectra were extended to the whole visible region 200–750 nm. FTIR spectroscopy was employed to identify the possible functional group vibrations responsible for the dyes' chemical activity and optical behaviour. The TiO₂ powder was coated on the ITO conducting surface to form a thin film. The experimental results showed that the ber dye produces the highest solar cell efficiency (η), ˜13%, among all four extracted anthocyanin studied. It also found that ber combination with other dyes is higher conversion efficiency than blackberry, black grapes, and blueberry with another and vice versa. Ber dye can be helpful in the development of more eco-friendly and cost-effective solar cells with commercially promising DSSC. GRAPHICAL ABSTRACT

Membrane fouling is the main problem that limits the use of membrane technology. This work focuses on using the Hermia models to determine the controlling fouling mechanisms, including intermediate pore blocking, complete pore blocking, standard pore blocking, and cake formation. Also, it investigates the estimation of the manufacturing costs, which included the costs of preparation materials and energy consumed during the preparation and casting processes of the polyvinylidene fluoride/polyethylene glycol (PVDF/PEG) and PVDF/PEG-tin oxide nanoparticles (PVDF/PEG-SnO2 NPs) membranes. The results of Hermia’s models were applied on the first, third, and fifth cycles of the rhodamine B dye solution filtration processes. Depending on linear fitting parameters, the membrane fouling occurred in all fouling mechanism types simultaneously. However, the predominating fouling mechanism was cake formation followed by intermediate pore blocking. Analysis of the parameters of the fouling models validated that the irreversible fouling exceeded the reversible fouling when the correlation factor (R2) value was higher than 0.95, which explains the continuous reduction of the permeate flux for both studied membranes. The estimated cost of the locally manufactured PVDF-based membranes did not surpass 80 $/m2 of the membrane. Also, the locally fabricated flat sheet ultrafiltration membranes are cheaper than other pristine PVDF membranes manufactured by Guochukeji Technology (Xiamen) Company.