Parisa Mohammadi, Sepide Ameri Toorzani, Khadije Kiarostami, Sara Gheravi, Zahra Felahti,
Volume 2, Issue 1 (6-2015)
Abstract
Total petroleum hydrocarbons (TPHs) is one of the most important environmental challenges. Phytoremediation of oil-polluted soil depends on microorganisms of the rhizosphere. This study attempts to evaluate the microbial impact of Zea mays rhizosphere during a 60 day period using three different treatments: control soil, oil-polluted soil and oil-polluted soil including fertilizer (NH4No3, K2HPO4). Then, the rhizosphere bacteria were identified. The results showed that CFU per gram of control soil was higher than other treated soils, an indication of oil stress on microbial population. In addition, more bacterial diversity was observed in soils and different bacteria were isolated from the soils. Finally, the most resistant bacteria to the oil pollution were assayed. The assay of isolates indicated that all of those separated from the oil-polluted soil have the ability to produce biosurfactant in different quantities. Further investigation must be carried out to optimize the degradation of oil by these isolates.
Sarehi Ebrahimi, Seyed Mehdi Razavi, Mansour Afshar Mohammmadian,
Volume 10, Issue 1 (6-2023)
Abstract
The increase of the entry of industrial effluents containing various types of heavy metals into water and soil leads to the ever-increasing spread of environmental problems. Therefore, it is necessary to find less expensive solutions to reduce the pollution. In this regard, in order to compare the effect of the removal of heavy elements on some of the morphological and physiological characteristics of C. alternifolius, Ch. zizanioides and Aloe vera plants, an experiment was conducted in the form of a randomized complete block design with three replications for 14 months at the University of Guilan. The results showed that under the treatment of industrial wastewater, the metal accumulation indices (MAI) of zinc, chromium, lead, copper, manganese, nickel, magnesium were higher in Ch. zizanioides and Aloe vera than those in C. alternifolius. In all three studied plants, the indices of root length, shoot length, total biomass and tolerance index (TI) had a significant decrease compared with those in the control plants, and Ch. zizanioides and A. vera plants had the lowest percentage of decrease. In addition, other investigated components including absorption index (UI), total soluble sugar, total phenol content, total flavonoid, total anthocyanin, total tannin, and DPPH free radical inhibition percentage increased in all three plants under industrial wastewater treatment. The highest percentage of increase in all investigated components, except DPPH free radical inhibition percentage, was observed in Ch. zizanioides. In general, it can be said that in terms of MAI and morphological and physiological characteristics, Ch. zizanioides and A. vera were more successful than the C. alternifolius. Therefore, it is recommended to plant the studied plants in the order of priority (Ch. zizanioides ˃ A. vera ˃ C. alternifolius) in soils contaminated with industrial effluents, in order to remediate the soil.
