الفهرس | Only 14 pages are availabe for public view |
Abstract Contamination of soil with petroleum hydrocarbons causes many problems for the surrounding environment. Many methods are carried out to treat such contaminated soil such as phytoremediation, bioremediation, and a combination of them. The current research aims at studying the performance of different insitu remediation methods for the removal of total petroleum hydrocarbons (TPH) from sandy soil at different levels of contamination. These methods include remediation using plants, Bacteria or plants and Bacteria. All experiments were carried out in a field environment. Sandy soil was collected from a site near Port-Said which belongs to a gas production company. The collected soil was spiked with petroleum hydrocarbons at different levels (2.5%, 5.0% and 10.0%). Four types of treatments were used in the experiments as follows: - Treatment 1: bioremediation only (Pseudomonase) - Treatment 2: phytoremediation only (Alfalfa) - Treatment 3: bioremediation + phytoremediation (Pseudomonase +Alfalfa) - Treatment 4: no remediation (control) All experiments were carried out in plastic cylindrical pots. Each pot was filled with approximately 800 g of contaminated soil. Alfalfa, -Medicago sativa L., was used in Treatment 2 and 3. A solution of aerobic bacterial culture (Pseudomonase putida), with a concentration of 108 CFU/g of solution, was added to the soil in the Treatments 1 and 3 (100 ml was add in each pot). The TPH solution used to contaminate the soil was collected from a gasoline storage tank at Petrobel (Petroleum Company). It is composed of 62% organics in the gasoline range (C-6 to C-12), and 27% organics in the diesel range (C-13 to C-28). Soil samples were collected from pots throughout the experiment after 15, 30, 60, and 90 days. This is in addition to the samples collected at the beginning of the experiments. Samples were analyzed for TPH according to U.S. EPA, 1998 (Method 9071B). During the duration of the experiments, concentration of TPH in the different treatments (Treatment 1 and 3) were significantly lower than that in the control (Treatment 4). It was observed that the different remediation treatments (Treatment 1 to 3) were at the highest rate during the 1st month of remediation for all initial contamination levels, except Treatment 1 of 10% initial contamination that reached the highest rate of remediation during the 2nd month. By the end of the experiments, within a period of 3 months, the different treatments were able to reduce the level of contamination in the sandy soil with efficiencies up to a maximum of 98.7% for initial concentration of 10%, 99.9% for initial concentration of 5% and 99% for initial concentration of 2.5%, for Treatment 1,2 and 3, respectively. |