فصلنامه پژوهش در بهداشت محیط
سال ششم شماره 1 (بهار 1399)

Today, environmental pollution is a major problem for human life. Dye is one of the most important environment pollutants that is found in the industrial wastewater, especially in the textile industry wastewater. Therefore, the aim of this study was to evaluate the photocatalytic effect of green iron nanoparticles as catalyst for Reactive red 198 dye degradation in photocatalytic process.

This study was performed laboratory using a batch reactor under UV A irradiation. In this study, the effect of different variables including pH (3-11), dye concentration (10-100 mg / l), catalyst dosage (0.25-3 g/l) and contact time (2-60 min) were investigated. The characterization of prepared nanoparticles were studied using different techniques such as TEM, FESEM and FTIR analysis. The obtained data were analyzed by Excel software.

Also, the photocatalytic tests showed high performance of NPs for dye degradation as catalyst in photocatalytic process. The highest removal efficiency achieved 96.2% at pH 3, catalyst dosage 1.5 g / L, contact time 15 min, and for dye concentration 25 mg / L.

Additionally the results show that the photocatalytic process using green iron nanoparticles can be used with a suitable function to removal of reactive red 198 from aqueous solutions.

In recent years, concerns have been raised about the presence of a wide range of drug substances and antibiotics in aquatic environments. Usually these materials are due to the inefficiency of conventional wastewater treatment technologies, From various routes such as agricultural runoff, direct discharge from urban wastewater treatment plants, human waste products, direct disposal of medical waste, industry, etc. into aquatic environments. The present study aims at the removal of penicillin G through electrofenton process in the aqueous solution.

The present study was conducted on laboratory scale in tanks made of glass using iron electrodes with useful volume 400 cc. The device is equipped with a flow rate regulator and voltage regulator to control these variables. Urban alternate current forms the input to the devices. The tank was filled with synthetic penicillin G with a concentration of 50-200 mg/L. The removal of penicillin G at potential 26V, the intensity of the 0.05-0.6A, Time 0-120 min, pH: 3-12 and the distance between the electrodes was measured in the range of 1-4cm.

The aim of present study was to the potential of the processes of electrofenton removal of penicillin G in aquatic environments. The results were pH of 3, the electric current density 0.6A, reaction time 20min, the concentration of antibiotic 50mg/l, and the distance between electrodes 1cm with concentration of H2O2 25mmol . in these circumstances, the results showed that electrocoagulation process is the ability to remove 100 percent of the pollutants.

The results of this study illustrate that electrofenton process with iron electrodes is cost-effective removal of organic compounds.

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.

Population growth and the increase in urban migration in the past decades have led to an increase in population density and size of major cities. Unfortunately, this kind of pollution has mostly gone under-noticed. The purpose of this research was to model the correlation between noise pollution level and landscape metrics of urban structures and vegetation. To do so, 67 stations were selected in different parts of Isfahan and noise parameters were measured at peak traffic hours (16 to 19) during the fall season. Sampling stations were located through a systematic-random method based on the amount of construction, green spaces and structural diversity. There were 27 types of landscapes and three stations were randomly selected in each. In most stations, the noise level was above the permitted level(Residential 45-55, Residential-Commercial 50-60). The advanced regression method of random forest was used for the analysis. Through this method, the most effective metrics identified in different buffers were IJI index, FRAC_MN index, CLUMPY index, CONTIG_MN index, SHAPE_MN index, ENN_MN index. Also, checking of the first six metrics in each of the buffers and land uses showed the importance of the metrics is different. Identification of important metrics in each buffer and land use helps better design urban blocks and their arrangement.

Atmospheric dust particles play a significant role in the transfer of chemical elements released from industrial and urban sources. So that the contaminants attached to these particles, can be transported over long distances and are as a function of meteorological conditions, the physical and chemical properties and nature of surface. The aim of this study was to evaluate the metal richness and degree of heavy metal contamination in atmospheric deposited dust in Tehran.

Atmospheric dust samples were collected from eight locations in Tehran in 2018. Heavy metals (Pb, Zn, Cu, Ni, Cr, Mn and Al) were analyzed in dust using ICP-MS. Metal richness and degree of contamination were determined using Enrichment Factor (EF), Geoaccumulation Index (Igeo), degree of Contamination (Cd) and modified degree of contamination (mCd). Paired t-test, Pearson correlation and Hierarchical cluster analysis (HCA) were also used for analysis.

The mean concentration trend of elements in the warm and cold seasons was similar as Al>Zn>Mn>Pb>Cu>Cr>Ni. Results of enrichment factor index in atmospheric deposited dust showed that Pb and Zn in warm season and Pb and Cu in cold season were highly enriched. Paired t-test results showed a significant difference between Cu and Cr between seasons. Cluster analysis also showed Al of natural origin and other elements of anthropogenic origin.

The results of this study showed that atmospheric deposited dust particles of Tehran have high levels of contamination especially in cold season. Therefore, it is necessary to formulate more effective and practical policies to improve Tehran’s air quality.

Increasing agricultural activities and subsequently releasing pollutants from agricultural systems as well as expanding industries cause heavy metals (lead and cadmium) to enter the environment. Application of amendments are suitable methods for the inactivation of heavy metals in contaminated soils.

In order to study the effect of organic amendments (bichar 640 and 420) and inorganic amendments (zeolite, bentonite, leca and pumice) on bioavailability of Pb and Cd during incubation time in a calcareous soil, a factorial experiment was conducted in a completely randomized design with 3 levels of amendments application in soil (0, 1 and 5 %) in three replications. Bioavailability of Pb and Cd in soil was determined using DTPA and EDTA- extractable during 90- and 180-days incubation time.

Results showed that concentration of DTPA-extractable Pb and Cd increased during the time. Application of biochar 640, bentonite and zeolite (5%) decreased concentration of EDTA-extractable Pb during the incubation time. Application of biochar (1%) were the most effective treatment in decreasing Pb concentration EDTA-exchangeable. Application of the organic amendments (biochar 640 and biochar 420) and inorganic amendments (pumice, leca bentonite, and zeolite) increased concentration of EDTA-extractable Cd during the incubation time. Application of 5% of zeolite showed the lowest increasing concentration of EDTA-extractable Cd during the incubation time.

Organic amendments were more efficient in immobilization of Cd and Pb than the inorganic amendments. These results might due to the high amount of organic carbon and cation exchange capacity of the organic amendments than the inorganic amendments.

In recent years, the construction of fish farms on the margins of the Mohammadabad Katoul River has increased significantly. The purpose of this study was to investigate the effects of the effluents of these fields on some of the river water quality factors.

In this study, five sampling stations of 3 rainbow trout ponds were selected for seasonal water sampling in 1396 seasonally with 3 replications, 12 water quality parameters including dissolved oxygen, fecal coliform, pH, biochemical oxygen demand, chemical oxygen demand, temperature, organic phosphate, nitrate, ammonium, turbidity, total dissolved solids and electrical conductivity. Then, fixed effects of data were analyzed using significant test and water quality was evaluated according to IRWQISC.

The results show that the water of Mohammadabad Katoul basin is of medium to relatively good quality. The best water quality in autumn with numerical value of 70.5 and the worst water quality in summer with numerical value of 43.3. The reasons for the relatively poor water quality in summer can be attributed to the high activity of the effluent from the fish ponds, such as reduced river discharge, as well as increased recreational activities in the river, agricultural effluents, rural wastewater discharge, and high livestock density. Area noted.

In all seasons, water quality was higher than that of other stations during station 1 sampling prior to fish farming. According to the obtained index, it can be generally concluded that river water quality is suitable due to aquaculture activities.