فصلنامه پژوهش در بهداشت محیط
سال هشتم شماره 4 (زمستان 1401)

In recent years, concerns about the presence of pharmaceutical compounds in the wastewater have been increasing. Various types of residues of the widely used tetracycline family of antibiotic compounds are found in environmental waters in relatively low and persistent concentrations that have adverse effects on human health and the environment. The aim of this study was to synthesize high specific level organic aerogels to remove Minocycline antibiotics.

In this study, resorcinol formaldehyde aerogel was synthesized using sol-gel process and dried by ambient drying. The aerogel was then modified using graphene and finally the performance of the synthesized samples as adsorbent under various parameters such as solution pH (2 -12), the amount of adsorbent (4-10 mg) and the time of contact of the adsorbent with the antibiotic (3-24 h) were evaluated. Raman spectroscopy, electron microscopy (FE-SEM) and BET tests were used to characterize the samples and then the removal efficiency of Minocycline antibiotic was measured by the samples using UV-Vis analysis.

The results of BET test showed that the specific surface area of the resorcinol formaldehyde aerogel sample containing 1wt.% graphene was increased compared to the neat aerogel. Also, according to the results, it was found that the removal percentage of minocycline antibiotic for pure and modified samples is 71.6% and 92.1% at optimal pH of 4 and 6, respectively.

Graphene-modified resorcinol formaldehyde aerogel is a suitable adsorbent for removal of Minocycline antibiotic from aqueous solution.

Nitrate is used as a chemical water quality indicator. The aim of this work was investigation of nitrate adsorption from aqueous solution by Nanocomposite celloluse/Fe3O4/ZnO as a efficient adsorption.

This study was conducted in a laboratory batch reactor. The most important variables affecting adsorption process were pH (2, 4, 6, 8, 10), time (25, 50, 75, 100, 125, 150, 175, 200, 250, 300 min), nitrate concentration (0, 50, 100, 150, 200, 250 mg/L), adsorption dose (0, 2, 4, 6, 8, 10 g/ L), Mixing speed (0, 50, 100, 150, 200 r/ min) investigated and adsorption kinetic and isotherms were determinated. Spectrophotometer was used for nitrate measurement and adsorbent characteristics were determined by SEM and FTIR examinations

The results showed the optimum pH=6 and nitrate adsorption increased by increasing contact time and adsorbent dosage. The adsorbent specific surfact area of 10 m2/g was obtained and FTIR test revealed the finctional groups existing on adsorbent surface to have important role in nitrate adsorption. Experimental data was well fitted by pseudo second-order kinetic model. Langmuir isotherm model best represented the experimental data to describe adsorption.

Results showed that the nanocomposite cellulose/Fe3O4/ZnO can efficiently remove nitrate from aqueous solution

 Due to the complexities in the nature of ground water systems, it sounds like a demanding job to model either the time or the location of ground water. However, artificial neural networks have a high capability to model both complicated and non-linear models. Besides, Geostatistic Methods are, to a good extent, accurate in modelling ground water.

 The aim of this study is to simulate groundwater quality parameters (SAR, TDS and EC) of Dezful Andimeshk plain using ANN-PSO and geostatistical models. For this purpose, information from 61 observation wells in Dezful-Andimeshk plain has been used. Neural network model inputs including qualitative parameters SO42- ، pH ، HCO32-، Na+، Mg2+، Ca2+، TDS، SAR and EC were considered.

 The results of simulation with intelligent model showed that the highest accuracy of ANN-PSO model in simulation is related to EC, SAR and TDS parameters, respectively. The results of interpolation by geostatistical method showed that the highest accuracy of Kriging model in simulation is related to EC, TDS and SAR parameters, respectively. The general results obtained from the simulation of groundwater quality parameters showed that the ANN-PSO model is more accurate in simulating the groundwater quality parameters of the plain in Andimeshk than the Kriging model. So that the value of R2 for simulating SAR, TDS and EC parameters using ANN-PSO model in the test phase is 0.92, 0.918 and 0.955 respectively and using kriging model is 0.902. 0.915 and 0.931 were estimated.

 The results of this study also showed that the combination of intelligent models with optimization algorithms is used as a useful tool to simulate groundwater quality parameters.

Fluoride is one of the important ions in drinking water, which in low or high concentrations causes some problems related to human health, such as tooth decay, dental fluorosis, or skeletal fluorosis. Present study was carried out to investigate the fluoride concentration as well as the effective factors in the fluoride distribution in drinking water supply sources of Golestan province.

For this purpose, Golestan province was divided into four regions according to the distribution of loess. Next, groundwater samples from these areas were collected and chemical parameters of TDS, HCO3-, Cl-, SO42-, NO3-, NO2-, F-, PO42-, Ca2+, Mg2+, Na+, K+ and Fe2+analyzed. After hydrogeochemical and statistical assessment, the relationship between fluoride and loess deposits and some physicochemical parameters were investigated.

Results of four regions showed that the fluoride amount is directly related to the loess deposits spread, so that in region 1 including Maraveh Tappeh, Kalaleh, and Gonbad there is the most spread of loess deposits, the fluoride amount is more than other areas. Results revealed that high correlation of fluoride with some ions such as calcium, bicarbonate, iron, sodium, and phosphate. Also, there is a high correlation between electrical conductivity as a salinity parameter and fluoride concentration in groundwater. So, an increase in salinity, the fluoride amount in the province's water resources has increased significantly. Water-rock reaction is the main factor controlling the groundwater chemistry and as a result, most possible factor for the fluoride leaching into groundwater.

Chemical cement of loess along with some clay minerals is the main source of fluoride in groundwater sources in region 1 with the most spread of loess deposits. Saline water of the lower layers and their intrusion into the fresh water aquifer can be considered as the fluoride second source in Gorgan Plain.

Consumption of vegetables contaminated with heavy metals is dangerous for human health. The present research determined some heavy metals in Portulaca oleracea and assessed its health risk.

P. oleracea was grown in pots using soil polluted with nickel and various amounts of iron nanoparticles (0, 15, and 30 mg/kg). The concentration of heavy metals was determined by ICP-OEC after the samples were extracted. The bioaccumulation and transfer factors in plants, daily intake, and risk indicators of heavy metals for humans were all calculated.

The treatment with 30 mg/kg of iron nanoparticles resulted in the maximum concentration of nickel and iron in the roots and aerial sections of P. oleracea. The nickel and iron TF were below one for the soil-root but above one for the root-stem. For nickel and iron, the BAF in the plant was discovered to be less than one. Human consumption of P. oleracea poses minimal dangers, as indicated by HRI values that are less than 1. Compared to iron, nickel showed higher HRI values. Across all treatments, children demonstrated high HRIs for nickel and iron than adults.

There are no non-cancerous diseases for consumers, according to the hazard ratio of the investigated components in the P. oleracea, which was 1. Overall, the findings demonstrated that the HRI of heavy elements for both analyzed age groups was less than one.

Considering the importance of okra consumption, controlling of heavy elements’ concentration nitrate in foodstuffs is important to ensure the safety of an individual’s health. Therefore, this research was conducted with the aim of studying the concentration of heavy metals and nitrates in greenhouse okra one of the greenhouses in Kermanshah county.

Sampling was done from the okra greenhouse of Kermanshah county in three stages with a time interval of 2 weeks and with a total of 9 samples. The concentrations of heavy metals were evaluated with an atomic absorption spectrometer. To evaluate the risk of consuming vegetables for human health, the health risk index (HRI) of non-cancerous diseases was used.

A significant difference was observed between the three harvest dates of okra with nickel, copper, zinc, iron, cadmium, lead and nitrate, and with the increase in the growth rate of the plant and the number of harvests, the concentration of studied heavy metals and nitrate decreased. The highest amount of nickel (1.386 mgkg-1), copper (16.393 mgkg-1), zinc (54.500 mgkg-1), lead (1.880 mgkg-1), iron (105.887 mgkg-1), cadmium (0.0710 mgkg-1) and nitrate (31.000 mgkg-1) were observed in the first harvest. The concentration of all studied heavy metals, except lead, was lower than the WHO standard. HRI for non-cancerous diseases was less than one for the studied metals and nitrate. As a result, consumption of greenhouse okra in the greenhouse of Kermanshah county does not pose a problem for human health

There is no concern about the non-carcinogenic diseases and carcinogenic risk of consuming heavy metals in okra. Therefore, for optimal management and prevention of further pollution, it is recommended to study the origin and determine the amounts of heavy metals for their potential contamination of foodstuffs from the region’s soil, water, and dust.

Heavy metals, as one of the important groups of pollutants in the aquatic environment, enter aquatic ecosystems as a result of natural and human activities. These metals may be accumulated in the body of aquatic animals, including fish, and are a potential health hazard for ecosystems and living organisms, especially for humans. The present study was conducted with the aim of investigating the concentration of three heavy metals mercury, arsenic and copper in the muscle tissue, liver and skin in two species of two species of Otolithes ruber and Sphyraena forsteri in the fishing ports of Konarak and Pozm.

36 fish samples were collected from Kanarak and Pezem ports. After preparing the samples, the concentration of heavy elements mercury, arsenic and copper was determined by the atomic absorption method. Data analysis was done using SPSS statistical software, version 20 and covariance tests and Pearson correlation test at a significance level of 0.05.

There was no significant difference between the amounts of the studied metals in muscle tissue, liver and inflamed and cauterized skin (p<0.05). The average concentration of heavy metals copper, mercury, and arsenic in the muscle tissue of Otolithes ruber 3.61, 0.01, and 0.02 respectively, and Sphyraena forsteri 2.38, 0.01, and 0.02 μg / g, respectively.

The concentration of heavy metals in the muscle tissue was lower than the international standards of WHO and FAO.

Mosquito-borne diseases are serious health problems in many countries around the world, and the widespread distribution of their vectors has a major impact on the transmission and spread of these diseases. Mosquitoes play a key role in transmitting arboviruses such as West Nile, Dengue Fever, Chikungunya, Sindbis, Zika, Rift Valley Fever, Batai virus, Usutu virus, East Horse Encephalitis (EEE), and West Nile Virus (WNV), and also some suspected emerging viral agents, such as SARS-CoV-2 (causative agent of COVID-190) and the Zika Virus in the world.There are several methods for mosquitoes larval control. An important challenge in mosquitoes control programs is their resistance to different groups of insecticides. The ultrasonic device is a novel and natural friendly approach for controlling insecticide resistance mosquitoes.

In this study, Ultrasonic TI-H5 device of Elma Company were used against 4th instar larvae of Culex pipiens under laboratory condition. Different variables including; Electrical power (50,100,200, 250 watts), exposure times (1, 2.5, 5, 10, 15 minutes) at two frequencies of 35, and 130 Kilohertz were employed.

Mortality of 4th instar larvae at 35 KH and different exposure time with specific Electronic power was 100%. In 130 KH with increasing exposure time, the mortality was increased.

Insecticides are one of the causes of environmental and water pollution. Also, due to the resistance of mosquitoes to insecticides, the new safe, cost-effective and effective method in integrated pest management programs is the control of mosquito larvae using ultrasonic waves.