جستجوی مقالات مرتبط با کلیدواژه "cholorophyll" در نشریات گروه "آب و خاک"

Petroleum products are one of the most widely used chemicals in today's modern world. Petroleum hydrocarbons have become a global problem for the environment. These compounds are highly resistant to the environment and are harmful to human health. Application of bioremediation process to remove polyaromatic hydrocarbons from contaminated soils is one of the most economical and desirable options.The purpose of this experiment was to investigate the percentage of hydrocarbon pollution remove of polluted soil with hydrocarbons (crud oil) by sorghum, barely and bermudagrass with and wihout Psudomonas putida and Azosprillum brasilense.

In this study, simultaneous efficiency of phytoremediation and bioremediation in removing crude oil from soil was investigated. For this purpose, a factorial experiment was conducted in a completely randomized design with three replications. The treatments consisted of 3 levels of soil pollution to oil (0, 4 and 8% oil), 4 treatments of plant (no plant, bermudagrass (Cynodon dactylon), sorghum (bicolor Sorghum) and barely (Hordeum vulgare() and 3 treatments of bacteria (no bacteria, Psudomonas putida and Azosprillum brasilense). To do the experiment, samples of five kilograms of soil were polluted with different amounts of crude oil and poured into plastic pots. After 6 weeks and the equilibrium of polluted soils, these soils were inoculated with Pseudomonas putida and Azospirillium brasilense bacteria, then in polluted soils of inoculated with bacteria and no inoculated three gramineae species were planted. Ninty days after planting, plants were harvested.

The results showed that interaction effects of treatments were significant on crude oil removal percentage of soil in probability level of 1%. Removal percentage of crude oil by plant cultivation alone, inoculation of bacteria alone and combined application of plant and bacteria significantly increased compared to control. Cultivation of plants was more effective than soil inoculation with bacteria in removal oil pollution and plant increased bacteria function significantly so that, there were significant difference among treatments of plant alone, inoculation with bacteria alone and plant+ bacteria. The highest removal percentage was observed in combined application of plant and bacteria. At all treatments of soil inoculation with bacteria, with increasing levels of oil pollution, dry weight of plants decreased but, at each level of crude oil pollution, inoculation of soil with bacteria, the dry weight of shoot increased. Incubated soil with bacteria improved dry weight of shoot through removal of oil pollution in soil. With increasing level of crude oil pollution, concentration of leaf chlorophyll decrease significantly but, incubation of soil with bacteria increased it in fresh leaves of plants due to reduce the negative effects of oil pollution and supply nitrogen. With increasing levels of oil pollution, the mean of proline concentration in fresh leaves of plants was significantly higher than that of control. Its highest concentration (in each plant) was obtained at 8% of crude oil pollution. Inoculation of soil with bacteria in polluted soils and non-polluted soils increases the amount of proline in the leaves of plants. In each level of crude oil pollution, inoculation of soil with bacteria, the proline concentration of leaf of plants increased. The highest concentration of proline in the treatment of the highest oil pollution level (8% crude oil pollution) and inoculation with Pseudomonas putida was measured.

Establishment of plant with microorganisms can be considered as a key component of the strategy to remove hydrocarbons. Consequently, these bacterial and plant species can be used for the biodegradation of soils contaminated with crude oil.