Used Batteries in the Municipal Solid Waste Stream: Management of the Challenges and Heavy Metal Contents

Background: Hazardous materials, such as used batteries contain heavy metals and enter the solid waste stream, ending up in landfills. The present study was done to determine the amount of used batteries in Iran and their heavy metal contents in the batteries entering the landfill site in Tabriz. Methods: A questionnaire was applied to assess the current management condition of the used batteries in Tabriz and Ardabil as the representative cities of the entire country. The heavy metal content of 15 AA-sized batteries was determined by inductively coupled plasma. Results: Our findings showed that 14.7% of the used batteries in Iran have been imported, and approximately 76% and 24% of the batteries analyzed at the landfill site were AA-sized and cellphone batteries, respectively. In 60% of the studied batteries, the total heavy metal content was less than 100 mg/kg. Conclusion: The results of this study could be a useful reference for global and local policymakers in developing effective regulations for the use of cleaner materials in the battery industry and controlling the used batteries from their generation to the end of the battery life

Removal of Ni(II) and Cr(VI) Ions From Electroplating Wastewater Using Ferrous Sulfate

Background: In this study, the ferrous sulfate was used to remove Cr(VI) and Ni(II) ions from a real Ni-Cr plating industry wastewater. Methods: This is an applied study. The type of sampling was composite by three 5 L containers. Wastewater chemical and physical characteristics were measured in accordance with the standard methods. The concentration of un-removed metal ions was estimated by ICP-OES. The Jar test was used to carry out the chemical coagulation experiment. The results indicated that the rate of removal depended on the pH of 1.5-11, the diverse contact time of 30-120 min, and the coagulant measurement ranging from 0.5-2 g/l. Results: The optimum removal of Cr(VI) ions was observed at a pH of 7 up to 83.88% in 0.5 g/l of coagulant for 40 min. While the optimum removal of Ni(II) ions was found at a pH of 5 up to 56.33 % in 0.5 g/l of coagulant for 40 min. The scanning electron microscopy results revealed the difference between the coagulant surface while coagulation. Also, the Energy-Dispersive X-ray spectroscopy (EDX) analysis showed the presence of Cr(VI) and Ni(II) ions on the surface of the ferrous sulfate after coagulation. Conclusion: Ultimately, the results indicated that ferrous sulfate could be an operative chemical coagulant to remove Cr(VI) and Ni(II) ions from the plating industry wastewater, especially for Cr(VI) particles. The results of this study can be a useful guide to the real plating industry wastewater treatment operators.

Diazinon Residues in Rice and Associated Health Risks for Human; A Case Study in Rasht, Iran

Background: Rice is the most important agricultural crop and the main food in Gilan and Mazandaran Provinces in northern Iran where organophosphorus pesticides, especially diazinon, are used. The excessive use of this insecticide in the paddy fields of Rasht County is a serious threat to people’s health. Methods: In this study, 30 rice samples were collected from five zones in the paddy fields of Rasht in summer. The samples were analyzed when rice is sold to assess the health risk caused by diazinon residues in rice. Following the digestion process, the samples were injected into a High-Performance Liquid Chromatography (HPLC) instrument. Analysis of Variance (ANOVA) and one-sample t-test were respectively used for analyzing data and the Health Risk Index (HRI) for assessing the risk of rice consumption. Results: According to the results, the mean residual diazinon concentration in the rice crops of the five studied zones at the time of consumption (three months after harvest) was 0.4±0.43 mg/kg-1. This was higher than the Iranian standard for permissible diazinon concentration in rice. The results of the health risk assessment for rice consumption indicated an HRI value of 0.13 for rice consumption, which did not constitute a serious risk for people who consume rice regularly. Conclusion: Although the results of this study showed that there are no potential health risks for consumers, with increasing the use of chemical pesticides for crops, to achieve food safety, regular monitoring of pesticide residues in crops is recommended

Effect of Synthetic and Organic Chelators Application on Copper Phytoextraction by Calendula Officinalis L.

Background: Using ornamental plants for phytoremediation of Heavy Metals (HMs) in soil environments has been grown due to its cost-effectiveness and ease of use in urban environments. The aim of this study was to assess the potential use of Calendula officinalis for soil Copper (Cu) phytoremediation in the presence of different types of chelating agents (Ethylene Diamine Tetra-Acetic Acid (EDTA), Citric acid (CIT), and Tartaric Acids (TAR)) at different levels of Cu in a calcareous soil. Methods: To investigate the effects of stress caused by the use of chelating agents on biochemical changes of C. officinalis, the activity of some antioxidants of C. officinalis (Superoxide Dismutase (SOD), Catalase (CAT), Ascorbate Peroxidase (APX), Peroxidase (POD), and Polyphenol Oxidase (PPO)) was evaluated. Results: As results, C. officinalis showed an increase in shoot and root Cu concentration in the presence of all chelating agents compared to the control. The highest accumulation of Cu in the root/shoot was observed in EDTA-treated plants. However, an increased Cu level in plant parts (due to consuming of EDTA) was corresponded to lower dry weight in shoot and root; higher H2O2 and malondialdehyde (MDA) contents, and antioxidant activity (APX, PPO, CAT, SOD, and POD) in plants compared to the control treatment. On the contrary, the application of CIT and TAR primarily increased shoot and root dry weight and Cu concentration. Conclusion: Generally, the results of this study could be suggested that plants possess a well-organized resistance mechanism against oxidative stress caused by using of CIT and TAR.

Evaluation of Trace Element Contaminations in the Skin Tissue of Rutilus kutum (Kamensky, 1901) From the South of the Caspian Sea

Background: The Caspian Sea is surrounded by Kazakhstan, Azerbaijan, Iran, Turkmenistan, and Russia. Rutilus kutum is a highly steamed fish species caught from the South Caspian Sea, but little data available on Trace Element (TE) concentrations in its skin. Methods: We caught 51 R. kutum from three stations (i.e., Anzali, Astara, and Kiashahr) in the southern shoreline of the Caspian Sea from September 2017 to January 2018, and ICP-OES was used to assay TE concentrations in their skin. Results: The Trace Element Concentrations (TECs) measured in the skin (except for potassium) did not display significant differences between the stations and only the concentration of potassium was higher in Kiashahr than in other areas. Conclusion: TE levels in the R. kutum skin were lower than those in the previous reports from the Caspian Sea, which could not result in any risk to human health.

Isothermal and Kinetic Evaluation of Adsorption Fish Farm Effluents by Nanocomposites (Chitosan and Activated Carbon)

Background: In wastewater treatment, removal of phosphate and ammonia is of great importance. Chitosan is a copolymer, which can be applied in low-cost adsorption. Thus, in this study, chitosan and activated carbon nanocomposite adsorbents were prepared to remove organic pollutants from the fish farm effluents. Methods: This study was performed at different physicochemical conditions of pH (5-8), effluent dose (25-100 mg/L), and contact time (15-90 min) minutes. Adsorption isotherm studies were analyzed using Freundlich, Langmuir models, and adsorption kinetics studies. Results: The Langmuir and Freundlich isotherms for nitrite (R2=0.9076, R2=0.5911), phosphate (R2=0.9307, R2=0.5755), and ammonia (R2=0.7288 and R2=0.7549) were respectively obtained. According to the results, the data of nitrite and phosphate pollutants were more consistent with the Langmuir model, but the data of ammonia pollutants were more consistent with the Freundlich. The best optimal adsorption occurred at a pH=7. Elevation of the initial concentration of the pollutant led to the depletion of the removal functions. With increasing the contact time, adsorption efficiency increased. Conclusion: Finally, with respect to the obtained elimination percentage (R=99.98%), chitosan and activated carbon nanocomposites have a high ability to remove organic pollutants.

Assessing the Environmental and Health Adverse Effects of Mercury Released From Dental Amalgam: A Literature Review

This paper reviews the most available data on the possible adverse effects of mercury released from amalgam that comprises 50% pure mercury, 35% silver, 12-13 % tin, 2% copper, and up to 1% zinc, indium, platinum, and palladium. Despite the possible health risks of mercury from amalgam on the nervous, respiratory, renal, and endocrine systems, it is used in some countries; however, Sweden, Denmark, Canada, the United States, and Japan have long banned the use of amalgam. Amalgam restorations are one of the main mercury-releasing sources (1800-2700 tons per year) of contamination. During chewing, grinding, brushing of teeth, breaking down of amalgam, and as the temperature of the oral environment increases, mercury vapor will be released. The mercury vapor enters the atmosphere, wastewater in dental offices, all systemic organs, especially the lower respiratory tract and can affect the renal-urinary system or enters breast milk, fetus, and finally, transmits to infants. The mercury level released from amalgam in blood, urine, hair, and nail of large populations of dentists, dental assistants, and pregnant women is higher than the safe levels. The main neurological and psychological effects of mercury vapor are sleep disorders, amnesia, mental disorders, hair loss, memory disturbances, multiple sclerosis, Parkinson’s disease, kidney diseases, gene toxicity, Alzheimer’s disease, Autism, skin allergies, cancer, infertility, low birth weight, and heart diseases. In order to avoid further amalgam risks to the dentists, dental assistants, pregnant women, and wildlife ecosystem, it is suggested to replace the dental amalgam with composite resins.

Assessment of Health Impacts of PM2.5 by AirQ+ Software in the City of Sanandaj, Iran (2018-2019)

Background: Particulate or particle mattes in term of air pollution are particles with a diameter of 2.5 μm or less (PM2.5). PM2.5 is a natural source of air pollution and has harmful effects on citizens in Sanandaj City, located in the west of Iran. Methods: In this study, the hourly data of concentration of PM2.5 were taken from the Kurdistan Environmental Protection Agency. During the study period (2018-2019), the 24-hour concentration of PM2.5 exceeded 339 times the average level. By AirQ+ software, the relationship between data and Relative Risk (RR), Baseline Incidence (BI), and Attributable Proportion (AP) were estimated. Then chronic obstructive pulmonary disease, lung cancer, ischemic heart disease, and brain stroke in the range of over 30 years were estimated. Results: The main target of this study was to survey the relationship between PM2.5 concentration and the death rate of citizens of this non-industrial city. The long-term health effect (more than 6 months) of PM2.5 caused 326 deaths on average (except for accidents and poisoning). Conclusion: Increase the concentration of PM2.5 is one factor that affects a high percentage of mortality rate.

A Comparative Study on the Capability of Tree Species in Urban Afforestation to Accumulate Heavy Metals

Background: The present study investigated the concentrations of lead, nickel, copper, zinc, their toxicity potential, and their ecological hazard in surface soils of Hamedan City, Iran. Also, using the Bio-concentration Factor (BCF), concentration Comprehensive Bio-concentration Index (CBCI), and Metal Accumulation Index (MAI), was evaluated the ability of some tree and shrub species to absorb heavy metals in soil and air. Methods: Sampling of leaves of nine tree species and shrubs (plane, acacia, elm, willow, mulberry, ash, redbud, pine, and cypress) was performed in six stations. After preparation and acid digestion of the samples, the concentrations of heavy metals were determined using an atomic absorption spectrometer. Results: The trend of changes in soil heavy Mean±SD metal concentrations was in the order of nickel> zinc> copper> lead in the amounts of 61.41±11.34˃ 43.04±14.4˃ 42.87±8.36˃ 18.77±6.51 mg/kg. Evaluation of acute toxicity potential indicators and ecological risk of heavy metals indicated low soil pollution status. Findings of BCF, CBCI, and MAI ndices in the leaves of the species showed that the highest levels of BCF of heavy metals, i.e., zinc, copper, lead, and nickel, were in willow, elm, cypress, and pine species, respectively. Results show that heavy metal accumulation in different species. Conclusion: Depends on soil type, tree species, climatic conditions, type of pollutant source, species age, and other factors. In this study, elm and acacia have the highest ability to absorb heavy metals from soil and air.

Assessment of Tolerance of Some Tree Species to Air Contamination Using Air Pollution Tolerance and Anticipated Performance Indices in Isfahan City, Iran

Background: In the present study, the tolerance of plantain tree species (Platanus orientalis, Morus nigra and Ailanthus altissima) to air pollution was evaluated using Air Pollution Tolerance Index (ATPI) and Anticipated Performance Index (API) index in Isfahan city (Iran). Methods: For this purpose, three dominant trees growing at six stations in Isfahan was selected and then sampling of the tree leaves was performed, after being transferred to the laboratory, the ATPI and API index were calculated. Results: The results of calculating the ATPI in the leaves of M. nigra, P. orientalis and A. altissima species showed that the highest values of ATPI index was obtained in M. nigra at 20.77 and then detected in P. orientalis and A. altissima with the values 14.90 and 14.33 respectively. According to API values Morus nigra had the best performance (Score = 6 so it classified as the Excellent) while P. orientalis and A. altissima had very good and intermediate performance, respectively. Conclusion: According to ATPI and API index most tolerant tree species was Morus nigra, so it would be the most suitable species for plantation programme in urban and pollutant areas followed by Platanus orientalis and Ailanthus altissima. As well as our results suggest that Platanus orientalis and Ailanthus altissima can be used as bio-indicators of air pollution due to their low ATPI scores (lower than 16). The present study suggests that the combination of both the ATPI and API indices for identifying and selection of plant species is very useful for plantation in urban areas.