جستجوی مقالات مرتبط با کلیدواژه « Water Resources » در نشریات گروه « پزشکی »

Groundwater contamination has major effects on human health, industrial activity, agriculture, and the environment. The present study determined the concentration of lead, cadmium, arsenic, chromium, and nickel metals in the groundwater around the landfill in Juybar City and compared them with the drinking water standards.

In this descriptive-analytical study, 12 samples were sampled from four wells for three consecutive months. The concentration of heavy elements was measured using the graphite furnace atomic absorption technique (GFAA) based on standard water and wastewater methods. Also, the hardness, temperature, pH, and total dissolved solids (TDS) parameters were measured with portable devices.

Investigations showed that the average concentration of nickel, lead, chromium, and cadmium in well water was 0.0425, 0.0071, 0.0268, and 0.0117 mg/l, respectively. The average concentration of arsenic was not observed in any sample. The average temperature, hardness, pH, and TDS were measured in the range of 20-21°C, 108.66-136.33 mg/L, 7.3-7.36, and 566.25-712.33 mg/L. Also, the correlation coefficient showed a positive correlation between the metals nickel, chromium, lead, and cadmium and the parameters of temperature, hardness, pH, and TDS, as well as with each other at a confidence level of 0.01.

The amount of arsenic, lead, chromium, pH, and hardness are acceptable in the investigated wells for drinking purposes, but the amount of cadmium, nickel, and TDS is higher than the standard.

Despite recent efforts to identify microplastics in the aquatic environment worldwide, identifying the various sources of its release remains a challenging task. Understanding and identifying the different sources of aquatic pollution and the processes affecting them is essential for a comprehensive description of the quality of water resources. The aim of this study is therefore to introduce statistical methods to determine the sources of microplastics in aquatic environments.

This review article first identifies the pathways of microplastic entry into the aquatic environment, followed by an examination of four commonly used multivariate statistical methods Principal Component Analysis (PCA), Cluster Analysis (CA), Hierarchical Cluster Analysis (HCA) and Positive Matrix Factorization (PMF).

Multivariate statistical analysis can be used to determine different variables such as size, shape, color, and density of microplastics. It can also determine the sources of microplastics (domestic wastewater, industrial effluents, agricultural activities, surface runoff, air currents, etc.). It also identifies which variables have the greatest impact on pollution and suggests the best solutions to reduce pollution.

the study of pollution based on multivariate statistical analysis can provide important information on the main sources of microplastic pollution and the relative contribution of different sources in the aquatic environment, which can help to improve environmental management and reduce pollution.

Water resources are often exposed to pollutants related to urban waste disposal. This study aimed to determine the quality of water sources around the landfill of Langrod City in 2021.

This cross-sectional study selected two springs upstream, two water sources (well and spring) downstream of the landfill site, and a river (with two sampling stations) near the landfill site as the studied water sources. Sampling and analysis of physical (temperature, turbidity and TSS), chemical (pH, EC, TDS, BOD5, COD, nitrate, sulfate and heavy metals) and microbial (coliform and E.coli) parameters of water quality and soil samples of the region with Standard methods were performed. The data were analyzed by comparison with Iranian standards, Schuler and Wilcox indices.

In all water samples, the turbidity was more than the desired level, and the concentration of all chemical parameters was lower than MCL in the Iranian standard for drinking and irrigation. In the downstream well of the landfill, the total concentration of nitrite and nitrate measured compared to the recommended values in drinking water was almost four times the Iranian standard. The number of coliform and E. coli in all water sources was higher than the permissible limit of Iran's standard for drinking. The quality of all water samples, based on the Schuler diagram (drinking), was acceptable to good, and according to the Wilcox index, except for the downstream river of the landfill, they were in the medium salty category and were relatively suitable for agriculture.

The quality of water sources upstream and downstream of the Langrod urban waste landfill site was similar, and the water quality of the river downstream of the landfill was high salty and suitable for agriculture with the necessary considerations (drainage).

Water quality is an important factor that affects all aspects of eco-system and health food-to-business activities to the sustainability and health of the echo systemThis study was carried out with the aim of investigating the qualitative changes in the Ziarat River water.

Samples from the Ziarat River Station (5 stations) were sampled each year in 2018. Samples were transferred to the Golestan University of Medical Sciences in accordance with the standard conditions, along with ice. The parameters of nitrate, phosphorus, biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonium, total hardness and total Fecal coliform was measured according to standard method and the Water Quality Index (WQI) was calculated.

The results of the study, based on the WQI index, showed that the index for all stations was between 29.68 and 64.78, and in some of them the average was (50-70) and some stations had poor quality ( 50-25). The most effective parameter on the water quality of the river is the BOD parameter, and then it is the total solids, turbidity, phosphate, nitrate and total Fecal coliform.

The highest level of pollution in the terminal stations (4 and 5) due to more industrial activity is the entry of sewage and effluents into the river in Gorgan. Among the measured parameters of nitrogen and phosphorus as nutrients, if left unchecked, it poses a risk of eutrophication. Agricultural, livestock and recreational activities around the river affect the water quality of the river. So that a more appropriate quality was observed in the upstream stations. Considering that the Ziarat River is one of the most important sources of water supply needed in the agricultural and industrial sectors in Golestan province. Therefore, monitoring and control of pollutants entering this river is essential.

Due to the occurrence of dry season and exploitation of water resources for higher agricultural yields, the groundwater level in the Zanjan plain has subsided. The lowered of water level of aquifer have reduced the efficiency of wells and paralleled with water quality degradation. The underground structure of aquifer was destroyed and the quality of water resources contains more salt than fresh waters.

In order to survey on the salinity of water in this region, data from 45 sampling wells (1384-1394) has been used. In the first step by collecting valid information about the chemical quality of related aquifer, investigation on fluctuation trends of ions concentrations of Ca, Mg, Na, HCO3, Cl, SO4, from 1384 to 1394has been conducted. Then, pH and EC have been surveyed for ten years (1384-1394) to determine the general chemical quality of region groundwater. Finally, fluctuation trends of elements and water salinity have been plotted on descriptive diagrams, piper, statistical models, and other plans. In this study, all the ethical considerations have been observed and no conflict of interest was reported by the authors.

The data of this study demonstrated that average concentrations of sulfate and chloride are2.3 and 1.1meq/lit respectively. The concentration of these ions in water samples indicated the desirable quality of groundwater at present. However, if the current trend regarding the subsiding of groundwater level in the Zanjan plain, we could face a decrease in water quality and an increase in salinity in the coming years.

According to the results of the study, it can be said that the increasing trend in the concentrations of salts in the water and the declining trend of the output of the wells could reduce the chemical quality of water in near future

Today, the production of plastic materials has multiplied with the growth of population and the development of industry in the world. Micro-plastics are released into the environment by the decomposition of plastic materials. The World Health Organization (WHO) has called these particles emerging pollutants due to their highly durable and bioaccumulative. The present study reviews the characteristics, health hazards, values, as well as the efficiency of different methods of eliminating micro-plastics in aquatic environments.

In this review study, the keywords Micro-plastic, Water-drinking, Pollution, and Removal were searched and studied in articles from 2000 to 2020 published by Pubmed, Google scholar, Science direct, and Scopus.

Studies show that in addition to the food chain, this pollutant is also present in bottled drinking water, which can affect human health, the environment and living organisms in aquatic environments.

It is suggested that more studies be done on this pollutant in aquatic environments, especially in Iran. In addition, educate people about less use of plastic in everyday life, teach them how to recycle properly, and get help from the industry to provide a suitable alternative to plastic.

Water interfering anions can cause major problems in the quality of drinking water as well as entering water to the industry. The purpose of this study was to determine the efficacy of granulated metallic-magnetic chitosan nanocomposite for adsorption of interfering anions in aqueous solutions (sulfate, chloride, carbonate and bicarbonate.

Synthesis of granulated metallic-magnetic chitosan nanocomposite was conducted based on co-precipitation method. The anions chloride (300-50 mg / L), carbonate (150-50 mg / L), bicarbonate (50- 150 mg / L) and sulfate (50-300 mg / L) were considered. The pH range of the study was between 5- 8 and the remaining time was 0-90 minutes. For the study of the adsorption process, the Langmuir and Freundlich isotherms were considered as pseudo-first and pseudo-second kinetics order at temperatures in the range of 20-45 Celsius.

The results showed that the best removal efficiency of anions was obtained at pH = 5. With an increase in chlorine concentration from 50 mg / L to 300 mg / L, the removal efficiency decreased from 80.06% to 38.22%. This trend has also been observed for other anions in the study, which decreased from 57.82% to 37.69% for sulfate at similar concentrations. In carbonate and bicarbonate, at 50-50 mg / L concentrations, the removal efficiency decreased from 61.15% to 41.17% and 79.66%, respectively, to 49.36%. The percentage of removal of chlorine ion with an amount of adsorbent between 1-5 g / L increased from 62% to 91%. However, increasing the amount of absorbent after 4 g / L did not have a significant difference in removal of chlorine. The same effect was observed for other anions in the study, so that the removal efficiency of carbonate, bicarbonate and sulfate anions in exchange for an increase in the absorbent dose increased from 1 g / L to g / L 5, which was 56% to 93%, 52% to 96% and 53% to 80%. The results of the study showed that the adsorption process follows Langmuir isotherm model and the adsorption of anions is superficial. The absorption model also follows the pseudo-second order kinetic model. In addition, as the temperature rises, the removal efficiency decreases.

The results of the study showed that granulated metallic-magnetic chitosan nanocomposite adsorbent was able to remove the interfering anions from water resources.

Water resource management in order to preserving and supplying of high-quality water, plays an important role on communities health. For this reason, humans have always used different methods to provide high-quality water. One of these methods is the use of Radial Collector wells. In this study, the effect of Radial Collector wells on the microbial and physicochemical quality of Doogh River during 5 years has been investigated.

In this study, we assessed some water quality parameters on Dough River (DR) and its adjacent Radial Collector Well (RCW) which supplies water shortage of Gonbad Kavous city, Golestan province, Iran. For this purpose, monthly samples during 2012 to 2016 were collected from DR and RCW, then parameters included nitrate, phosphate, turbidity, pH, fecal coliform, and temperature were measured. Finally, effect of time variation and infiltration of water from DR to RCW on qualitative parameters was analyzed.

According to the results, nitrate, phosphate, turbidity, pH, and fecal coliforms significantly decreased during infiltration process (P-Value <0.05). In addition, the time variation of nitrate, phosphate, turbidity, temperature, and fecal coliforms had significant difference.

The present dataset demonstrated that RCW has a good efficiency for reduction of measured parameters. Also, monthly variations can be effective on water quality of resources.

Antibiotics are considered due to health and environmental problems and therefore they counted as a major threat to human health. The aim of this study was to determine the absorption efficiency of magnetic-chitosan nanocomposite in the removal of antibiotic tetracycline from aqueous solutions.

In this study, the experiments were performed by spectrophotometer. The magnetic-chitosan nanocomposite were considered as an antibiotic adsorbent which its adsorption efficiency was measured by changing the variables such as temperature, time, PH, dosage of magnetic-chitosan nanocomposite, concentration of tetracycline, concentration of interactive ions of chlorine, sulfate and carbonate. Synthesis of magnetic-chitosan nanocomposite was based on co-precipitation method. The Freundlich, Langmuir and Temkin isotherms were used to determine the isotherm and the absorption kinetics.

The results showed that the best antibiotic removal efficiency was obtained at pH = 6. The highest removal efficiency was obtained at 90 minutes and equal to 91.23%. Moreover, the removal efficiency of tetracycline was significantly reduced in alkaline pH. Also, by increasing the absorbent dose from 0.1 g/L to 0.5 g/L, the removal efficiency of the pollutant increased from 72.24% to 90.22% at 90 minutes. In addition, with an increase in pollutant concentration between 5-30 mg/L, the removal efficiency of the pollutant decreased from 93.4% to 53.7%. In order to study the thermodynamics of the tetracycline pollutant absorption process by magnetic-chitosan nanocomposite, the removal efficiency of the pollutant dropped from 91.23% to 45.1% at 20, 30 and 45 degrees of Celsius. The presence of interfering ions has a decreasing effect on the removal efficiency of tetracycline, which the removal efficiency were reduced from 91.23% at 90 minutes (in the absence of ions) to 70.16% (for chlorine ion), 65.96% (for ion Carbonate) and 54.2% (for sulfate ions).
               

Finally, the use of magnetic- chitosan nanocomposite adsorbent is recommended in the removal of antibiotic tetracycline.