Mohammad Reza Mehrasbi, Sorur Safa, Amir Hossein Mahvi, Ali Assadi, Hamed Mohammadi,
Volume 5, Issue 3 (10-2012)
Abstract
Backgrounds and Objectives: The base structure of total petroleum hydrocarbons (TPH)
is made of hydrogen and carbon. Widespread use, improper disposal and
accidental spills of this compounds lead to long term remaining of
contaminations such as organic solvents and poly aromatic hydrocarbons (PAHs)
in the soil and groundwater resources, resulting in critical environmental
issues. In this study, an oil-contaminated soil was washed using Tween 80
surfactant and the application of photo-Fenton process (UV/Fe2+/H2O2)
for treatment of the produced wastewater was evaluated.
Materials and Methods: Tween 80 is a yellow liquid with high viscosity and soluble in water. In order
to determine of the photo-Fenton process efficiency, we studied effective
variables including Fe concentration, pH, H2O2 concentration, and irradiation time. The UV irradiation source was a
medium-pressure mercury vapor lamp (400 w) vertically immersed in the solution
within 2L volume glass cylindrical reactor.
Results: The results
showed that efficiency of COD removal depends on the initial Fe concentration, pH,
H2O2 concentration and irradiation time.
Under optimum conditions, (Fe: 0.1mM, H2O2:
0.43 mM, pH: 3 and UV light irradiation time: 2 hours) the removal efficiency
of COD was 67.3%. pH plays a crucial role in the photo-Fenton process such that
the removal efficiency increased with decreasing of pH.
Conclusion: According
to the results of this study, under acidic condition, this process is an
efficient method for COD removal from the wastewater studied.
Sn Alavi Bakhtiarvand, M Ahmadimoghadam, I Parseh, N Jafarzadeh, M Chehrazi, Mostafa Chorom,
Volume 7, Issue 1 (7-2014)
Abstract
Background and Objectives: Soil polluted with total petroleum hydrocarbon (TPHs) is a great threat to human health. Phytoremediation, the use of vegetation for treatment of contaminated soils, is an attractive and cost-effective alternative to reduce pollutant from soil. This paper evaluates the effects of the plant and nutrients on the removal of TPHs from soil. Material and methods: Soils were collected at depth of 0-30 cm, and then polluted with 1 and 2.5 % w/w of crude oil. After preparing the experimental pots, Rhizosphere microbial number, plant biomass, and residual TPHs were determined. TPHs and heterotrophic bacterial number were measured by GC and HPC method respectively. Data were analyzed using the Statistical Package for Social Sciences (SPSS 17 for Windows) software and Excel. Results: It was found that the average percent of TPH removal in planted soil (28.42%) was higher than that in unplanted soil (12.2%) (p<0.05). Moreover, the average percent of TPH removal in treatments received nutrient and free nutrient treatments was 35.5and 17.7% respectively. Conclusion: Generally compared with the other studies, high clay and salinity of the experimental soil had a negative effect on phytoremediation efficiency. Finally, regarding to the high clay and salinity of the experimental soil, the phytoremediation efficiency was relatively desirable.