Mohammad Saleh Ali Taleshi; Mazaher Moeinaddini; Sadat Feiznia; Reza Shahbazi; Stefania Squizzato
Abstract
Background and purpose: 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, ...
Read More
Background and purpose: 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. Material and methods: 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. Results: 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. Conclusion: 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.
Mohammad Saleh Ali Taleshi; Hamid Reza Azimzadeh; Mohammad Taghi Ghaneian; Seyedeh Mahdieh Namayandeh
Abstract
Background and objective: Every week, hemodialysis patients need to approximately 400 l of water for producing dialysis fluids. So, the quality of water used for treatment of hemodialysis patients is an important factor. This study evaluated the performance of reverse osmosis systems of Yazd educational ...
Read More
Background and objective: Every week, hemodialysis patients need to approximately 400 l of water for producing dialysis fluids. So, the quality of water used for treatment of hemodialysis patients is an important factor. This study evaluated the performance of reverse osmosis systems of Yazd educational hospitalsdialysis centers for improving the quality of water used. Materials and Method: In this study, 48 samples of input and output of reverse osmosis systems collected in two educational hospitals during October to December in 2013. Then samples analyzed from the aspect of the physicochemical parameters such as calcium, magnesium, sodium, potassium, total dissolved solids (TDS), sulfate, chloride, total hardness (TH), EC and pH using standard methods of experiment and the results were analyzed using SPSS v.16. software. Results: The findings of research showed that there is significant difference with 99% confidence between input water to reverse osmosis from aspect of calcium, TDS, EC, pH. Results of paired T-Test and evaluation of performance of reverse osmosis showed that there is significant difference between water quality, before and after of system in the hospital No.1. Except chloride and sodium, there is a significant difference between water qualities in two phases in the hospital No.2. Conclusion: The results of this research showed that reverse osmosis system improves the quality of water used for hemodialysis significantly, but in continuous operation may be faced with reduced efficiency. Thus, using combination methods of water treatment is necessary to prevent the physicochemical pollution for ensuring the hemodialysis with good quality. Paper Type: Research Article