جستجوی مقالات مرتبط با کلیدواژه « آلودگی » در نشریات گروه « مهندسی آب »

The prevalence of COVID-19 causes many environmental problems, including increased medical waste and household waste, increased detergent consumption, reduced waste recycling and pollution of surface and groundwater resources through the entry of contaminated wastewater and leachate transfer, as well as increasing demand and water consumption in the household sector. COVID-19 virus RNA is found in feces, urine and sewage in different parts of the world, and in fact, hospital sewage, especially infectious disease units, contains the pandemic COVID-19 virus. Therefore, the study of this virus in wastewater is necessary to protect the quality of water resources. This study is based on a review of more than 200 published scientific literatures (articles, books, reports, valid scientific sites, etc.) in relation to the coronavirus. For this purpose, keywords such as "coronavirus contamination of water and wastewater resources", "environmental effects of coronavirus", "effects of physico-chemical indicators of wastewater on coronavirus survival" and "number of infected and deaths due to Coronavirus" have been used and downloaded through electronic tools from Springer, PubMed, ISI Web of Knowledge and Google Scholar databases. In addition, data on the amount of water consumption in different parts (residential and non-residential) of Mashhad city, and the concentration of physicochemical parameters (such as temperature (T), pH, suspended solids, total solids (Ammonia, etc.) of wastewater, related to Khin Arab and Parkandabad treatment plants in Mashhad, has been obtained from Mashhad water and sewerage company. The required diagrams were drawn in Excel software, and the environmental impact and the contamination of water resources with COVID-19 and variations in physico-chemical parameters of wastewater affecting the survival of COVID-19 in wastewater were examined and analyzed. The global prevalence of Coronavirus has many negative impacts on the environment and on water and wastewater resources and caused increased water consumption (in residential sector) and wastewater production. By January 2022, worldwide, Iran and Khorasan Razavi province levels, more than 312 million, 6 million and 75 thousand people, respectively, were suffering from coronavirus outbreak, and more than 5.5 million, 133 thousand and 11 thousand people died. In general, the effect of concentration of wastewater’s physico-chemical indicators on the concentration and survival of COVID-19 has been proven in the world (especially in the South African coazolonatal treatment plant). The results of this study show that the parameters of each wastewater and survival and concentration of COVID-19 depends on the characteristics of the wastewater source, which should be given special attention in research on the epidemiology of wastewater. The variations in the concentration of physico-chemical indicators of Mashhad treatment plants’ (Parkandabad and Khin Arab) wastewater shows increase in concentration of some wastewater indicators. This can be due to the high input of organic and chemical substances and of solids (suspended, soluble and volatile) such as: detergents and disinfectants and pharmaceuticals, hospital and medical waste were attributed to wastewater after the outbreak of COVID-19. The outbreak of Coronavirus in the world has not only caused the death and infection of many people, but it has also caused increasing and decreasing in water consumption in the residential and non-residential sectors. The concentrations of some wastewater’s physico-chemical indicators (such as pH, TS and ammonia) effects on the concentration, survival and shelf life of Coronavirus in wastewater. Therefore, by determining the concentrations of these indicators in wastewater at different times and monitoring its variations, it is possible to determine the survival of COVID-19 virus in wastewater, the rate of infection and the contaminated areas from the virus, and also to be able to control COVID-19 and to manage the pollution and infection.

Contamination of drinking water is known as a major threat of water security around the world. As contamination enters a water distribution network, it spreads rapidly into the network and poses health and safety risks to the community. Using a set of sensors to report the concentration of chlorine or any other chemical, useful observations can be made to detect, identify and manage pollution. Based on these observations, location, concentration and start time of contamination can be determined and decision makers can be informed. In this paper, a simulation-optimization approach is used to solve the problem of contamination source characterization in which the EPANET software is used as a simulator and the Genetic Algorithm is used as an optimizer. The model developed in this paper is implemented on EPANET example 3. Modeling of water distribution networks uses information as input data which can cause error in model simulation. Pipe roughness and chlorine deterioration rate are among these inputs. The model has been implemented to find the location, start time and concentration of inlet pollution and the effect of pipe roughness and chlorine deterioration rate on the model responses have been investigated. The pollution entry scenario is applied to the network and the model presented is accurate in finding the location and time of the contamination. As the variables increase, the model accurately estimates the location and time of entry of the contamination but does not have complete accuracy in estimating the concentration of contamination, which is calculated with standard deviation of σ = 4.8% -8.1%.

In recognition of the need for effective and efficient methods for protecting groundwater resources from future contamination, scientists and resource managers have sought to develop aquifer vulnerability assessment techniques for predicting which areas are more likely than others to become contaminated as a result of activities at or near the land surface. This research is focused on the evaluation of Tehran- Karj groundwater vulnerability to pollution. Among several assessment methods, DRASTIC has been selected for this study. A major portion of Tehran’s drinking water is supplied from groundwater. ArcGIS has been used to overlay and calculate different layers and obtain the vulnerability map. In addition, groundwater balance has been evaluated in order to calculate the net recharge parameter in DRASTIC index. About 50 percent of the aquifer has been classified as moderate and almost 20 percent has low pollution vulnerability. The Boolean algorithm is usually used in categorizing the index but it is proved that using the Boolean algorithm causes the discrepancy in classification. On the other hand, fuzzy algorithm can produce more accurate results. Therefore, in this research, both Boolean and Fuzzy algorithms were used and compared together. Fuzzy algorithm could recognize the areas with low and very low vulnerability potentials while the Boolean model was not able to do so, therefore, the fuzzy model showed better performance. According to the developed map, most of the areas in the moderate class and very high class had the minimum area in the region.