solar energy

Natural disasters, such as earthquakes, can disrupt water distribution systems, leading to prolonged water shortages and associated crises. Tehran, with its high seismic risk, necessitates robust emergency water management solutions to ensure adequate potable and non-potable water supply during critical conditions.

Using GIS and WaterGEMS software, we evaluated the design and placement of emergency water reservoirs in ASP Town, Shahriar. Hydraulic modeling was conducted to optimize the piping, pressure, and flow dynamics for potable water supply under emergency conditions. Additionally, non-potable water reservoirs utilizing treated wastewater were designed for irrigation and fire suppression, incorporating solar-powered pumping systems to ensure energy efficiency.

A 50 m3 cylindrical steel emergency tank, connected to the urban water network, was proposed to provide 3 L of potable water per person for three days in a crisis. The system includes solar panels, a 250-W pump, and a hydraulic shut-off valve to maintain water quality and availability. For non-potable uses, a wastewater reservoir with a variable-speed pumping station supports irrigation and supplies 12 fire hydrants, meeting pressure and flow requirements during emergencies.

This study highlights the importance of integrated water management strategies, including solar-powered systems and treated wastewater reuse, to improve resilience against natural disasters. The proposed designs ensure sustainable water supply and effective crisis management for drinking and non-potable applications in high-risk urban areas.

The study involved the preparation of CoFe2O4 -CNT nanocomposites through the dispersion of CNT and ferrites into Xylene. Cobalt ferrites were synthesized using a chemical co-precipitation method. The main objective was to investigate the structural, optical and photocatalytic properties of the synthesized nanocomposites using Rose Bengal dye as a model pollutant. Structural analysis was conducted using Transmission Electron Microscopy (TEM) and XRD, confirming the formation of a Single-phase spinal structure of ferrites and nanocomposites with an average particle size of around 25 nm. UV-Vis. spectroscopy and Photoluminescence (PL) were used to study the optical properties of the samples, indicating that the bandgap of the sample is within the visible range, making it suitable for visible light photocatalysis. The band gap shifted to a slightly lower side after the formation of the nanocomposite, and the PL revealed that recombination time increased after the formation of nanocomposites compared to pure CoFe2O4. FTIR spectroscopy confirmed the formation of the spinal structure of ferrites and identified various bonds present in the sample. The photocatalytic activity of the sample showed a significant increase in the dye degradation capacity of ferrites. This increase in photocatalytic activity was consistent with earlier results obtained by PL spectroscopy, which confirmed the formation of a Z-scheme visible light photocatalyst.

Accessibility to safe drinking water is an important human health issue, so water reuse and water resources management are critical in arid parts of developing  regions. This study aimed to investigate the use of a combined simple designed solar geyser/photocell for drinking water disinfection.

In this study, a solar geyser with a simple design was combined with a solar cell and its efficiency on the disinfection of contaminated water was investigated. This study was carried out with artificially polluted tap water by a solar geyser joined with a solar photovoltaic cell. The heated water (55°C) was kept for 2 hours using a solenoid valve. The pilot plant was operated and monitored for one year. The volume of the collected effluent was measured every 24 h. The most probably number (MPN) of total coliforms and fecal coliforms in 100 mL of 24-hour composed samples were measured.

The mean volume of disinfected water production was calculated as 2095.74 ± 270.28 mL/day. The strongest correlation was found between disinfected water and the maximum daily ambient air temperature with a linear model (R2 = 0.9937). The results showed that by increasing the sunny time, the volume of water outlet increased. Therefore, sunny time and UV radiation have direct effect on volume of disinfected water.

The simple designed solar geyser for drinking water disinfection was efficient and recommended for tropical areas, emergency conditions, and farms for agricultural activities.