نشریه راهبردهای فنی در سامانه های آبی
پیاپی 2 (پاییز 1402)

A new nano adsorbent was prepared using zinc oxide nanoparticles supported on graphene oxide to separate copper from electroplating industry wastewater. Graphene oxide was synthesized via Hummer's modified method, and its surface morphology was characterized through FTIR spectroscopy and scanning electron microscopy (SEM). A systematic study of the adsorption process was conducted, varying pH, initial copper concentration, contact time, adsorbent dosage, and temperature. The experimental results revealed that the maximum adsorption capacity, with 89.77% efficiency, was achieved at a pH of 7 when 0.5 g of adsorbent was in contact with a 200 mg/L copper solution at 20°C for 30 minutes. The nano adsorbent exhibited a high adsorption capacity in both simulated and real industrial wastewater samples, effectively removing up to 99% of copper from industrial samples. Adsorption isotherm, kinetic, and thermodynamic studies were performed to elucidate the adsorption mechanism. The adsorption process followed pseudo-second-order models and the Freundlich isotherm. Thermodynamic studies indicated that the adsorption of copper ions on ZnO/GO was a spontaneous and exothermic reaction with an enthalpy of -6361.21 J/mol. This study demonstrates that nano ZnO/GO can be utilized as an effective, low-cost, and environmentally friendly nano adsorbent for electroplating wastewater treatment.

Today, one of the favorite subjects of structural engineering researchers is the methods based on the optimization of structures called RBDO, or the optimization based on the reliability of structures. In this field, optimization problems are designed and optimized according to probabilistic constraints. In the current research, the problem of optimizing the circular water tank has been optimally designed. The target function in this research is the cost of building a reinforced concrete tank, and its possible limitations include resistance and serviceability limitations such as the ratio of demand to capacity, the amount of crack width, and deformations of the structure. Designing resistance and serviceability criteria is Regulation 123 of the country's management and planning organization. Finally, to show the efficiency and proper performance of the MCMC simulation and optimization method used in this research to solve the problem of tank design, a water tank with a volume of 113 m³ has been investigated. Also, the modeling of this reservoir has been done in SAP2000 software and computer programming by MCMC method in MATLAB software.

Water, as one of the most basic needs of life, currently includes our drinking, agriculture, industry, economic-social and security-political issues for survival and expansion. Due to the importance of this issue, the basic management and exploitation of water resources has become one of the important global issues. Nowadays, remote sensing technique has many uses in agriculture, such as determining the area under cultivation and predicting crop yield. In this research, the evaluation of the detection method of zones, water levels and rivers with Normalized Difference Water Index (NDWI) using Landsat 9 satellite images in the period of 1984-2022 was used to separate the water cover. The obtained results showed that there is a noticeable trend in reducing the water level in the desired points, which can be directly related to water harvesting for agricultural purposes in different parts of the route. In other words, the amount of water that the NDWI index shows in each station has a significant difference with other stations, which indicates significant water extraction in all parts of the Zayandeh-Rood. Therefore, in the present study, it was found that the normalized differential water index was easily able to extract water from satellite images and is a suitable index for predicting the condition of the Zayandeh-Rood Watershed

Many countries around the world are facing important problems in the field of water resources manage-ment. Due to reasons such as corruption, lack of civil society and inefficiency of the administrative structure in developing countries, and issues such as unsustainable consumption patterns, excessive use of resources, etc., have made the water governance system face challenges in industrialized or developed countries. In Iran, the problem of water shortage has become critical, serious and widespread, which has involved many sectors, including economy, society, environment, agriculture, etc. Because water govern-ance refers to all the activities that are involved in the policy-making and decision-making process regarding the development and management of water resources, and It also represents a change in gov-ernment-society relations in countries that have fundamentally developed water-related activities, There-fore, according to the current conditions and the global water crisis, the necessity of a fundamental change in the management of water resources is inevitable. The results of the research show that the water crisis in Iran, especially in the case of the Zayandeh River, is caused by the lack of water management and neglect of the role of water governance. On the other hand, good governance, as a type of governance that guarantees public welfare and individual rights, has indicators that are considered as the basic foun-dations needed to evaluate the state of water governance in each region. The Zayandeh River of Isfahan, has experienced an intensification of the drying process every year more than the previous year, which has had several consequences, and the solution to the water crisis in this region is to transition to good governance, efficient and compatible with historical, cultural, social and economic conditions of the region. This article was prepared in a review method with the help of library and internet sources, and its purpose is to examine the role of good governance in manageming the water crisis of the Zayandeh Rood River in Isfahan.

Analyzing the frequency of floods and understanding the probability of their occurrence, as well as the return period of this phenomenon, is crucial for reservoir management. Flood occurrences are inherently multivariate, and the use of classical multivariate functions for their analysis is limited. Therefore, it is recommended to employ copula functions for multivariate flood frequency analysis. These functions combine the distribution functions of univariate variables while considering the correlation between them. In the case of this phenomenon, the variables of peak discharge, flood volume, and flood duration are utilized. This study was conducted using statistical data from the Zayandehrood dam. The best function for each variable was determined based on goodness-of-fit criteria. The correlation between each pair of variables was calculated, and the copula function was selected using Akaike, NSE, and RMSE criteria. For the peak dischargeflood volume relationship, Joy's copula function was chosen, while the peak discharge-flood duration and flood volume-flood duration relationships used the AMH function. Subsequently, the univariate and combined return periods were calculated and can be used for risk estimation.

Piano key weirs have a longer crown length than linear weirs. Increasing the length of the weir crest in a limited width increases the water flow coefficient. Considering the importance of these weirs and the solution to increase the energy loss and finally reduce scour in them; therefore, in this research, it used a C-type trapezoidal piano key weir. Four flow rates of 0.025, 0.03, 0.035 and 0.04 cubic meters per second were also used. Three barriers with heights of 0.01, 0.03 and 0.05 meters were also used at the end of the overflow output keys. The results show that with the increase in the height of the obstacles, the amount of energy loss also increases. Also, by increasing the flow rate, the amount of energy loss is reduced. In barriers of 0.01, 0.03 and 0.05 meters, the amount of energy loss increases by 1.20, 2.13 and 2.53%, respectively, compared to the weir without obstacles. The average energy loss in weirs with barriers of 0, 0.01, 0.03 and 0.05 meters at the end of the outlet switches is equal to 57.8, 58.5, 59.06 and 59.3, respectively. At the end, a relationship was obtained to calculate the amount of energy loss in the C-type trapezoidal piano key weir along with the barrier at the end of the output keys with a correlation coefficient of 98.9%.