Relationship between concentrations of heavy metals in wet precipitation and atmospheric PM[10] particles in Zanjan, Iran

In this article the heavy metal concentrations in atmospheric wet precipitation and its relationship with the particles [PM[10]] in the air of the city of Zanjan are reported. Two hundreds samples of rain water and snow were collected with 45 particle samples collected monthly. Heavy metals in wet and dry samples were determined by atomic absorption spectrophotometery. The use of enrichment factors and correlation coefficients allowed us to predict the major sources of these metals. The ranges of concentration of Pb, Zn, Cr and Cd in rain water [micro g/L] were 5.8-22.2, 29.26-70, 1.4-4 and 0.25-1.2, respectively. The results showed that the concentrations of Pb, Zn, Cr and Cd in wet precipitation and [PM[10]] in samples collected in southern parts of the city where the traffic load and industrial activities are very high [zone 4], were 22.2, 70, 1.2 and 4 [micro g/L] and 840, 16233, 32 and 54.8 [ng/m[3]], respectively. These values were higher than those measured in the other parts of the city. Most of the calculated enrichment factors higher than 10 were attributed to the traffic and industrial activities. The enrichment factor and correlation coefficient values showed that the heavy metals in the air of Zanjan originate from similar sources. The concentration of particulate matter in 30 air samples of total 45 samples were found to be higher than 50 micro g/m[3]. The average concentrations of Pb and Cd in the city center and near the industrial complexes were higher than World Health Organization standards

[Study of heavy metals in the atmospheric deposition in Zanjan, Iran]

Heavy metals in dust can enter to the human body through ingestion and inhalation. They can pollute the water and soil resources via atmospheric precipitation and accumulate in the plants tissue and enter human body by water and food. The aim of this study was measurement of the heavy metals in wet and dry atmospheric precipitation and effects of pollution sources at the ground surface on the concentration of heavy metals in the atmospheric precipitations. In this study the zanjan city was divided into 5 zones and wet and dry precipitations were collected in autumn, winter and spring [2008-2009] from zones. The concentrations of Pb, Cd, Cr and Zn the collected precipitations were determined by Atomic Absorption spectroscopy method. The averages of concentrations of Pb, Cd, Cr and Zn were 0.082, 0.286, 0.018, and 0.009 [mg/m 2.d] respectively. The correlation coefficients between Pb-Zn was 0.8 [P<0.01] and for Cr-Cd, Cd-Pb, and Cr-Pb were 0.89, 0.58 and 0.61 respectively. The results showed that the industrial sources of heavy metals play the main role in concentration of heavy metals in wet and dry atmospheric precipitation in Zanjan.The correlation coefficients showed that the lead and zinc result from a common source. This source can be the lead and zinc factories locating around the city. The measurement of heavy metals in atmospheric precipitation shows the effects of anthropogenic sources in air quality. The heavy metals concentration in atmospheric precipitation can be use as air pollution index

[Biosorption of lead by active biomass of fungi isolated from lead polluted effluent and soil]

Lead is one of the heavy metals which releases into water and soil resources through industrial wastes and poses serious harmful effects on human health. This study was conducted to determine the biosorption capacity of lead by active biomass of lead resistant fungi. In this study the lead -resistant fungi were isolated from effluent of Zanjan Lead and Zinc factory and lead biosorption capacities of isolated fungi were studied by biosorption experiments. A collection of fungi colony was isolated in SDA media and then every colony was cultured in separate media. The fungi colonies were identified via morphological characteristics and Lacto phenol Caten Blue. The MIC of fungi was determined and their lead biosorption capacities were measured by culturing the fungi in SDB media that were polluted with 50-200 mg/L of lead. The isolated fungi were one Spp. of Rhizopus, two Spp. of Penicillium and one Spp. of Aspergillus. The MIC of Rhizopus was 2500 and for others was 3000 mg/L. The maximum lead biosorption capacities were 51,5, 19.2, 25.6 and 12.5 [mg per g of dry weight of fungi biomass] for Rhizopus, two Spp. Of Penicillium and Aspergillus respectively. The maximum lead biosorption capacity of Penicillium and one Spp. of Aspergillus was higher than 70%, thus biosorption of lead is an efficient method for treatment of lead polluted effluents

[Heavy metal removal from aqueous solution by adsorption on modified banana shell]

Heavy Metals in Water resources is one of the most important environmental problems of countries. Up to now various methods of removing of these metals is considered, which is including using of low prices materials. In this study the potential of banana shells was assessed for adsorption of heavy metal ions such as Pb and Cd from aqueous solution. Banana shells were pretreated separately with 0.4 mol/L NaOH, 0.4 mol/L HNO and distilled water and their adsorption ability were compared. Batch adsorption experiments were carried out as a function of the initial ion concentration, pH and adsorbent dosage. Adsorption isotherms of metal ions on adsorbents were determined and correlated with common isotherm equations such as Lungmuir, Freundlich and BET models. The maximum adsorption capacities were achieved by alkali modified banana shells [36 mg/g] for Pb and by acidic modified banana shells [16 mg/g] for Cd. Experimental results showed that the best pH for adsorption was 6 and the adsorption values decreased with lowering pH. Isotherm models indicated best fit for Freundlich model for modified banana shells. In comparing the parameters of models, it was observed that the capacity of banana shells for adsorption of lead is higher than for adsorption of cadmium, but the adsorption of cadmium is stronger than the adsorption of lead

[Biodegradation of the soils polluted with ethyl benzene, toluene and naphtalene]

Aromatic hydrocarbons are produced by incomplete combustion of fossil fuels and pollute the soil following the emission into the atmosphere by precipitation. Numerous studies suggest that microbial inoculation has contributed to biodegradation of aromatic hydrocarbons. However, other studies have not confirmed the efficacy of this procedure in biodegradation. Regarding the contradictory findings, this study was conducted to evaluate capability of microorganisms isolated from oil-polluted soils in biodegrading aromatic hydrocarbons through separate or mix culture in Zanjan in 2004. In this experimental study naphthalene, toluene and ethyl benzene were used as aromatic hydrocarbons indexes. These substance, as the sole source of carbon were added to the soils which had been inoculated with microbial colonies isolated from polluted areas and four months later microbial count was performed as microbial activity index. The extent of biological and non-biological removal of substances was assessed through gas chromatography procedure and the results were analysed by Mann-Whitney test. Mean colony counts in which toluene, ethyl benzene and naphthalene had been used as the sole carbon source were 19.7×10[6], 69.4× 10[5] and 41.2×10[6] colony/gr. soil respectively. In the culture containing a mixture of three hydrocarbons the number of colonies was 34×10[6] in one gram soil. The percentages of biodegradation for three studied hydrocarbons which had been exposed to microorganisms separately were 51, 45 and 69 for toluene, ethyl benzene and naphthalene respectively and when the mixture of the substances was added to the media culture the percentages of removal were 80.1, 65.7 and 63.6 for naphthalene, ethyl benzene and toluene respectively. Aromatic hydrocarbons are biodegradable by isolating microbial population from oil-polluted soils and preparation of inoculation liquid. Since evaporation is an appropriate method in removal of hydrocarbons, soil rehabilitation through aeration together with microbial inoculation seems a proper method for removal of soil aromatic hydrocarbons