Seasonal Fluctuation in Heavy Metal Pollution in Iran´s Siahroud River - A Preliminary Study (7 pp)

Background The management of its available water resources has become a key issue for Iran. During the last few decades, the water quality of Siahroud River in the coastal plain of the Caspian Sea in Gilan Province in Northern Iran has significantly degraded. The scarcity of water has been compounded by rapid population growth and increasing pollution from fertilizers, pesticides, and municipal and industrial wastes. One of the sources of this degradation is the movement of heavy metals from the river's watershed into the various water systems supported by the river, including the water system for Rasht City. Methods To study the magnitude of heavy metal pollution in the Siahroud River, seven heavy metals including Zn, Cu, Pb, Cd, Mn, Fe, and Ni were measured in duplicate from replicated water samples collected over five consecutive seasons and analyzed by Atomic Absorption Spectrometry. In situ measurements of pH were taken with the samples and total organic carbon (TOC) was analyzed by IR gas measurement. Results The results demonstrated that four of the seven heavy metals including Pb, Fe, Cd, and Mn exceeded permissible safe levels as established by the United States Environmental Protection Agency. Multivariate factor analysis suggested that industrial land-use was the main contributing factor for the high levels of Fe and Mn in the Siahroud River, whereas, Cd was principly from agricultural activities in the watershed. The data also suggested that pH and TOC had an important role in the behaviour of Pb and Mn, and that the elevated levels of these two heavy metals in Siahroud River was the consequence of other anthropogenic sources. Only negligible levels of Zn, Cu and Ni were detected. Finally, all the sampling stations were subjected to cluster analysis. The results indicated that three different zones could be distinguished according to the levels of pollution. In addition, it was shown that the urban areas did not have a significant impact on the heavy metal pollution in the river. This observation stems from the fact that the data from the sampling stations before and after Rasht City were not significantly different. Recommendation . Preventive measures need to be undertaken in the land-use systems and watersheds of the Siahroud River to reduce the pollution levels of Pb, Cd, Mn and Fe.     

The formation of aerobic granular sludge for the treatment of real landfill leachate using a granular sequencing batch reactor at a constant volume

Leachate generated in a landfill may not be treated by conventional biological treatment due to its nature and complexity. The process of forming aerobic granules in batch sequencing reactors having features such as; reducing the settling process time and saving energy consumption and high decomposition rate have been noticed by researchers. In the present study, the structure of sequencing batch reactors (SBRs) was evaluated for the formation of granules, which were subsequently utilized for the treatment of landfill leachate. The experiment was initiated by using the GSBR, containing 1200 ml with different apparatuses, to develop granular sludge, and synthetic wastewater was added to reinforcement. The selected parameters for the operational hydraulic retention time (HRT) of the wastewater (6-h cycles) included feeding, idle, aeration, settling, and discharge. Furthermore, the controlled conditions were the dissolved oxygen (DO) range of 2–2.2 mg/L, temperature range of 20–23℃, and pH of 7.5–8.3. The chemical oxygen demand (COD), mixed liquor suspended solids (MLSS), and sludge volume index (SVI) daily were measured at the influent and effluent of GSBR reactor. The main properties of aerobic granular sludge were identified during the research procedures, and the remarkable settling and potent, high-density microbial structure of the granules were confirmed. The mean size of the formulated granules was estimated at 7.46 ± 1.8 mm, and the volume of the biomass also increased from approximately 1607 to 4137 mg/L through the granulation process. Moreover, 98% of the influent chemical oxygen demand (COD) could be removed by the formulated granular sludge, and the final-stage organic loading rate was estimated at 5.65 COD/m³/day. According to the results, GSBRs could be employed for the formulation of aerobic granular sludge for the treatment of landfill leachate.     

Statistical source identification of major and trace elements in groundwater downward the tailings dam of Miduk Copper Complex, Kerman, Iran

Identifying the possible sources of potential harmful metals in groundwater systems plays a crucial role in evaluating the potential risks to residents and local plant cover. An attempt was made to define the origin of Al, Cd, Cu, Fe, Mo, Ni, and Pb in groundwater using multivariate statistic approaches [principal component analysis (PCA), hierarchical cluster analysis], and tailings sequential extraction by the method of Tessier et al. The concentrations of studied elements were measured in 42 samples collected from 15 stations surrounding and downward the tailings dam of Miduk Copper Complex, central province of Kerman, Iran. According to the PCA results, confirmed by cluster dendrogram and metal content measurement of tailings sequential extracts, two components accounting for nearly 73% of the total variance, controlled the heavy metal variability and classified the possible source of groundwater contamination into two categories: (1) upper seepage which controls the variability of Cd, Cu, Fe, Ni, and Pb and (2) toe seepage of tailings dump affecting on Mo and Al concentration in downstream groundwater.     

Ionic Liquids as Environmentally Friendly Solvents in Macromolecules Chemistry and Technology,Part I

With the increasing emphasis on the environment and the need to find environmentally friendly solvent systems, ionic liquids (IL)s have been emerging as promising green solvents to replace conventional solvents in recent years. They possess unique properties such as nonvolatility, low toxicity, ease of handling, nonflammability and high ionic conductivity; thus they have received much attention as green media for various chemistry processes. This report provides an extensive overview of use of ILs in polymers chemistry and technology.     

Ionic Liquids as Environmentally Friendly Solvents in Macromolecules Chemistry and Technology,Part II

With the increasing emphasis on the environment and the need to find environmentally friendly solvent systems, ionic liquids (IL)s have been emerging as promising green solvents to replace conventional solvents in recent years. They possess unique properties such as nonvolatility, low toxicity, ease of handling, nonflammability and high ionic coductivity; thus they have received much attention as green media for various chemistry processes. This report provides an extensive overview of use of ILs in polymers chemistry and technology.     

Protective effect of Zingerone against mouse testicular damage induced by zinc oxide nanoparticles

Environmental Science and Pollution Research - The purpose of the present study was to evaluate the effect of Zingerone (Zing) on zinc oxide nanoparticle (ZNP)-induced spermatogenesis defects in...