Removal of total petroleum hydrocarbons from polluted urban soils of the outskirts of Ahvaz, southwestern Iran

Earlier phases of economic expansion and urban development have resulted in significant sources of urban soil contamination. Petroleum hydrocarbons are one of the most common groups of persistent organic contaminants in the environment. In this study, two types of treatment in 3 concentrations were prepared that were included plant treated by 1% oil pollution, treatment by 1% contamination without plant (as control), plant treated by 5% oil pollution, the 5% pollution treatment without plant (control), 10% oil pollution treatment with plant and 10% treatment without plant (control) that 3 replicates were prepared for each treatment. The obtained extracts were concentrated to 1 mL under a gentle stream of nitrogen gas, and then 2 μg of the sample was injected into a UNICAM 610 series gas chromatograph equipped with a flame ionization detector. Primary Total petroleum hydrocarbons amount in 1%, 5% and 10% concentration was respectively: 9027.40 mg/kg, 49599.03 mg/kg and 99548.28 mg/kg. After 4 months its amount in different concentration with plant was 126.43 mg/kg, 4463.92 mg/kg and 19611.50 mg/kg. The best total petroleum hydrocarbons removal efficiency was observed in all concentration at 120th day. The results of this study showed that vetiver can remove petroleum hydrocarbons from contaminated soils effective. <br /

Investigation on concentration of elements in wetland sediments and aquatic plants

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

Application of wastewater with high organic load for saline-sodic soil reclamation focusing on soil purification ability

Fresh water source scarcity in arid and semiarid area is limitation factor for saline-sodic soil reclamation. The reusing of agricultural drainage and industrial wastewater are preferred strategies for combating with this concern. The objective of current study was evaluation in application of industrial sugar manufacture wastewater due to high soluble organic compounds in saline-sodic and sodic soil. Also soil ability in wastewater organic compounds removal was second aim of present study. Saline-sodic and sodic soil sample was leached in soil column by diluted wastewater of amirkabir sugar manufacture in Khuzestan Province of Iran at constant water head. Sodium, electric conductivity and chemical oxygen demand of soil column leachate were measured per each pore volume. The experimental kinetics of wastewater organic compounds on two saline-sodic and sodic soil were also investigated by three pseudo second order, intra particle diffusion and elovich model. The results of current study showed that electric conductivity of saline-sodic soil was decreased to 90% during 3 initial pore volumes, from other side exchangeable sodium percent of saline-sodic and sodic soil decreased 30 and 71 percent, respectively. There were no significant different between wastewater chemical oxygen demand removal by saline-sodic and sodic soil in both batch and column studies. Wastewater chemical oxygen demand was decreased to 35% during pass through soil column. The results showed that the adsorption kinetics of wastewater organic compounds were best fitted by the pseudo-second order model with 99 percent correlation coefficient (r2=0.99%)