نشریه علوم و مهندسی آب و فاضلاب
سال نهم شماره 2 (تابستان 1403)

Hydrological drought affects water allocation and hydropower generation. Therefore, hydrological drought prediction can help for optimal water resources management. In this paper, short-term hydrological drought was predicted using deep learning. Doing so, Standardized Hydrological Drought Index (SHDI) was calculated in one-, three- and six-month periods. Then, 36 combinations and three different modes of input variables were considered to predict SHDI. In the next step, various optimization algorithms, including grasshopper optimization algorithm, salt swarm algorithm, biogeography-based optimization, and particle swarm optimization combined with ANN were used to predict SHDI. Here, 70% of the data were considered for training and the remaining 30% for test. Finally, the performance of deep learning (DNN) compared to the combined ANN-SSA, -BBO, -PSO and -GOA were discussed. The results of ANN compared to the combined models showed that the combined models performed better, but they were less campatible to DNN. The DNN on one hand, does not need to define the input combination, and on the other hand could reduce the value of RMSE to 0.32.

One of the most important approaches of governance in water sector in recent years is the transition from policies to deal with drought to adaptation to water scarcity. Curbing the consequences of drought and adapting to water scarcity requires applying practical management and adopting correct policies in the field of demand and consumption. Choosing the right method to adapt to water scarcity is considered as one of the complex issues due to the existence of various parameters and influencing factors. In this research, while studying the status of water resources and uses in Bushehr province and identifying strategies to adapt to water scarcity in the province and effective criteria, a comprehensive decision-making method is also presented. First, the criteria effective on water scarcity adaptation strategies are identified and prioritized using hierarchical analysis. Then, using TOPSIS technique, the solutions are ranked. The statistical population of the research is the experts and the heads of departments of water and sewage and regional water companies, 40 of the relevant experts are randomly selected and examined. According to the findings of the research, the development of desalination systems and water softeners, management of water consumption and reduction of water wastage, and the implementation of emergency projects for the supply and management of water consumption in cities and villages are identified as three important solutions in adapting to Dehydration.

One of the problems in the field of water is its wastage in water supply networks due to water leakage due to high pressure. Therefore, keeping the pressure at a suitable range is necessary. The most effective equipment for this purpose is pressure relief valves and PAT2. In this article, by linking the DE algorithm with the EPANET hydraulic solver, in the first step, by using the double-objective DE algorithm, the appropriate location of the pressure relief valves and its regulating pressure, as well as the optimal location of the reverse pump and the type of reverse pump, are determined at the same time. In the second step, by using the DE single objective algorithm, keeping the location of the pressure relief valves constant (resulting from the first step) and also keeping the location and type of PAT, the rotational speed of the pump and the regulating pressure of the pressure relief valve constant are optimized in 24 hours, to increase the production energy. The obtained results showed that it is possible to provide 160 kilowatt hours per day of salable energy to the city power grid from the network.

In the present study, the surface modification of Polymeric Microfiltration (MF) membranes was done to develop cheap water disinfection systems for areas that suffer from a lack of access to drinking water. Two strategies have been used to remove bacteria. Their capture occurs through the electrostatic interaction of bacteria with the cationic surface of the membrane and the antibacterial effects of zinc oxide/chitosan/silver oxide nanocomposite, which is much cheaper compared to silver nanoparticles used in previous reports. Polytetrafluoroethylene (PTFE) microfiltration, with an average pore size of 450 nm, was modified through the polymerization of Polydopamine (PDA) and polyethyleneimine (PEI), and the incorporation of ZnO/CS/Ag2O nanoparticles. The nanoparticles and membranes were analyzed through various characterization methods such as XRD, FTIR, FE-SEM, EDAX, contact angle, zeta potential and antibacterial tests. The results showed that the surface modification of the membranes significantly enhanced their hydrophilicity. Moreover, no considerable reduction in water flux was detected (37% decrease in flux). The bacterial removal efficiency (S. aureus) after filtration with the modified membrane was estimated at about 99.98%, which met WHO standards for drinking water. Therefore, the modified MF membrane can be considered a platform for developing cheap gravity-driven technologies to supply safe water to people.

In this article, the long-term hydraulic performance of water distribution networks in peak consumption conditions is investigated by applying the uncertainty of model parameters and leakage variation. Applying the uncertainty of the leakage parameter and defining network operation planning based on leakage variation are research innovations. For this purpose, first, the model parameters are estimated in deterministic conditions in the desired years. Then, their non-deterministic values are calculated using statistical distributions and Monte Carlo method and applied to the model. Finally, the network performance levels are determined probabilistically. The Nodal Pressure Reliability Index (NPRI) is used to calculate the hydraulic performance of the network by coding in MATLAB linked with the EPANET simulator. The proposed method has been applied to a sample and real network. The results showed that by implementing the operational planning, the network performance increased by 15.3% in the middle year of the operation period, compared to non-operational planning. In general, by applying operational planning, the network's life increases in peak consumption conditions in terms of hydraulic performance.

Looking at the ups and downs and the experience of more than six decades of implementing the water supply plan to the country's villages, the creation and proper development of rural water supply services with the characteristics of quantity, quality and sustainability, just like other construction projects, strongly requires commitment and adherence to the disciplines engineering (the definition of planning, development and implementation) and its management and through the four stages of recognition and evaluation, design and engineering, execution and exploitation. Identifying the obstacles ahead and the ways out of the obstacles ahead, with special attention to the course of development, the rural population of the country and the experiences gained from the management of the rural water supply projects, in three headings, special and professional trustees, avoiding haste, simplicity and comprehensiveness in the implementation of projects, with an emphasis on predicting the appropriate organizational structure and financial management for the maintenance and management of rural water supply facilities is summarized, success in implementation will ensure its sustainability and relative efficiency.