Environmental Science
A.R. Karbassi; S. Tajziehchi; N. Farhang Adib
Abstract
Estuaries are well known for their potential in removing metal from fresh water to provide micro-nutrients to aquatic life. In the present investigation, we have tried to bring out the metal removal potential of estuaries during accidental spills. For this purpose artificial river water containing high ...
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Estuaries are well known for their potential in removing metal from fresh water to provide micro-nutrients to aquatic life. In the present investigation, we have tried to bring out the metal removal potential of estuaries during accidental spills. For this purpose artificial river water containing high concentration of Mn, Cu, Zn, Ni and Pb were mixed with sea water at different salinity regimes. Water samples were taken from a station on the main branch of Tajan River that flows in to the Caspian Sea. For this purpose, solutions with a concentration of 5 mg/L of each studied metal (Mn,Cu, Zn, Pb) were prepared in Tajan River water. The salinity regimes include 3, 6, 8, 10 and 11 ppt. It was noted that metal concentration decreased by increasing salinity. Metals were flocculated at different rates: Cu (88%) > Ni (86%) > Pb (84%) > Mn (74%).Thus, as average about 80% of total elemental content flocculates. Hence, it was concluded that a large amount of micro nutrients is carried by the river and flocculated in the estuary where the river water mixes with the sea water which may play a vital role in supplying nutrients to the aquatic animals. Cluster analyses have shown that Mn and Ni are governed by EC, pH and salinity.
Environmental Science
Q. Xie; S. Bai; Y. Li; L. Liu; S. Wang; J. Xi
Abstract
This study investigated the microbial community in a full scale anaerobic baffled reactor and sequencing batch reactor system for oil-produced water treatment in summer and winter. The community structures of fungi and bacteria were analyzed through polymerase chain reaction–denaturing gradient ...
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This study investigated the microbial community in a full scale anaerobic baffled reactor and sequencing batch reactor system for oil-produced water treatment in summer and winter. The community structures of fungi and bacteria were analyzed through polymerase chain reaction–denaturing gradient gel electrophoresis and Illumina high-throughput sequencing, respectively. Chemical oxygen demand effluent concentration achieved lower than 50 mg/L level after the system in both summer and winter, however, chemical oxygen demand removal rates after anaerobic baffled reactor treatment system were significant higher in summer than that in winter, which conformed to the microbial community diversity. Saccharomycotina, Fusarium, and Aspergillus were detected in both anaerobic baffled reactor and sequencing batch reactor during summer and winter. The fungal communities in anaerobic baffled reactor and sequencing batch reactor were shaped by seasons and treatment units, while there was no correlation between abundance of fungi and chemical oxygen demand removal rates. Compared to summer, the total amount of the dominant hydrocarbon degrading bacteria decreased by 10.2% in anaerobic baffled reactor, resulting in only around 23% of chemical oxygen demand was removed in winter. Although microbial community significantly varied in the three parallel sulfide reducing bacteria, the performance of these bioreactors had no significant difference between summer and winter.
Environmental Science
H. Janadeleh; A. Hosseini Alhashemi; S.M.B. Nabavi
Abstract
The major aim of the present study was to investigate element (Fe, Ni, Pb, V, Zn) concentrations in sediment and different tissues of Phragmities australis and Typha latifolia in Hor al-Azim Wetland Southwest Iran. Sampling of sediments and aquatic plants was carried out during spring and summer 2014. ...
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The major aim of the present study was to investigate element (Fe, Ni, Pb, V, Zn) concentrations in sediment and different tissues of Phragmities australis and Typha latifolia in Hor al-Azim Wetland Southwest Iran. Sampling of sediments and aquatic plants was carried out during spring and summer 2014. Results showed that the mean concentrations of elements in Phragmities australis in root and stem-leaf were as follows: Iron:4448 mg/kg, Nickel: 28 mg/kg, Lead:8 mg/kg, Vanadium:10 mg/kg and Zinc 15.5 mg/kg in root and: Fe:645 mg/kg, Ni:15 mg/kg, Pb:4 mg/kg, V:4 mg/kg and Zinc 16 mg/kg respectively. Also, the mean concentrations of Fe, Ni, Pb, V and Zn in roots of Typha latifolia were 8696 mg/kg, 34 mg/kg, 5 mg/kg, 19 mg/kg and 27 mg/kg respectively. The mean concentrations of Fe, Ni, V, Pb, Zn in stem-leaves of Typha latifolia were as follows: 321 mg/kg, 3 mg/kg, 7 mg/kg, 2 mg/kg and 14 mg/kg respectively. The mean concentrations of Fe, Ni, V, Pb and zinc were as: 40991 mg/kg, 65 mg/kg, 60 mg/kg, 31 mg/kg, 60 mg/kg respectively in surface sediment of study area. Concentration pattern of elements in sediment were as: Fe>Ni>Zn>V>Pb. The highest concentration of elements in the plant was seen in the roots. Also, Typha latifolia can uptake more concentration of elements than Phragmities australis. Based on the enrichment factor, Ni in summer had the highest EF values among the elements studied and it has a moderate enrichment.
