Sorption of Lead (II) Ions on Activated Coconut Husk

Background: In recent years, various toxic chemicals/compounds have been widely detected at dangerous levels in drinking water in many parts of the world posing a variety of serious health risks to human beings. One of these toxic chemicals is lead, so this paper aimed to evaluate of efficiency coconut husk as cheap adsorbent for removal lead under different conditions. Methods: In the spring of 2015, batch studies were performed in laboratory (Branch of Hamadan, Islamic Azad University,) to evaluate the influences of various experimental parameters like pH, initial concentration, adsorbent dosage, contact time and the effect of temperature on the adsorption capacity of coconut husk for removal lead from aqueous solution. Results: Optimum conditions for Pb (II) removal were pH 6, adsorbent dosage 1g/100ml of solution and equilibrium time 120 min. The adsorption isotherm was also affected by temperature since the adsorption capacity was increased by raising the temperature from 25 to 45 °C. The equilibrium adsorption isotherm was better described by Freuindlich adsorption isotherm model. Conclusion: It is evident from the literature survey that coconut-based biosorbents have shown good potential for the removal of various aquatic pollutants. Coconut husk-based activated carbon can be a promising adsorbent for removal of Pb from aqueous solutions

Determination and Evaluation of Copper, Lead and Zinc in Leek Vegetable from Some Olericulture Farms of Hamedan, Iran

Background & Aims of the Study:  Heavy metals are ubiquitous in the environment, as a result of both natural and anthropogenic activities, and humans are exposed to them through various pathways, especially food chain. So, this study aimed to assess heavy metals (Cu, Pb and Zn) concentrations in different parts of the leek vegetable in Hamedan Province, Iran. Materials & Methods: Leek samples were collected from 3 farms in Hamedan, Iran. Samples were digested, using wet digestion method (HNO3 solution) and the concentrations of total Cu, Pb, and Zn were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AE). Results: The average concentrations of heavy metals in different parts of the root, stalk and leaf of the Leek were in order; Copper (0.34, 0.54, 0.71), Lead (0.03, 0.05, 0.16) and Zinc (1.42, 3.43, 4.5) mgkg-1; So, all samples concentrations were lower than the permissible limits which are recommended by FAO/WHO. Also, most of the heavy metals were positively correlated with each other in concentration. Conclusions:  Pearson correlation test showed that Cu, Pb and Zn are similar naturally and related to the anthropic activities especially chemical fertilizer, implies the same interactions and/or relationships among these metals. According to the results, there is no risk to consumers via consumption of the leek vegetable. Appropriate measures should be taken to an effective control of heavy metal levels in vegetable soils and protect the human health finally

Health Risks of Heavy Metals for Population via Consumption of Greenhouse Vegetables in Hamadan, Iran

Background & Aims of the Study: The last 25 years have seen a remarkable increase in public concern about food contamination. Food and water are the main sources of our essential metals.These are also the media through which we are exposed to various toxic metalsAs such, this study aimed to assess the risks arising from the use of greenhouse vegetables, cucumbers, tomatoes and peppers in Hamadan Province. Materials & Methods: Soil and plant samples were digested using wet digestion method (HClO4/HNO3, 2:1) ratio solution, and the concentrations of total As, Cd, Cu, Pb, and Zn were determined using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AE). Results: High concentrations of elements As, Cd, Cu, Pb, and Zn were found in vegetables sampled from overused phosphate fertilized soils, which increased the daily intake of metals in food. The Health risk assessment values of all tested vegetables (pepper, cucumber and tomato) were below 1 in As and Cd. The health risk index (HRI) value above 1 indicated a relative health risk through the ingestion of contaminated vegetables. Conclusions: Heavy metal concentrations should be periodically monitored in vegetables grown in contaminated soils. This study found that long-term fertilizer use led to a growing accumulation of heavy metals (HMs) in soils. It would also be beneficial to implement effective remediation technologies to minimize possible impacts on human health