The Effects of Irrigation Regime and Hydrogel Application on Phytoremediation of Petroleum Contaminated Soil Elham Ghaheri e.ghaheri@ag.iut.ac.ir March 9, 2009 Department of Water Engineering. Isfahan University of Technology, Isfahan 84156-83111, Iran . Degree:M.Sc Language:Farsi J. Abedi-Koupai, koupai@cc.iut.ac.ir S. S. Eslamian, saeid@cc.iut.ac.ir The industrial revolution of the past century has resulted in significant damage to environmental resources such as air, water and soil. Petroleum contamination of soil is a serious problem throughout the oil producer countries. Total petroleum hydrocarbons (TPHs) are one of the most common groups of persistent organic contaminants in the environment and are important sources of soil and environmental pollution in our country especially around oil refineries such as Tehran or Ahvaz oil refinery plant. There are many sources of TPH contamination in soils including petroleum extraction, traortation and consumption. Remediation of petroleum contamination of soils is generally a slow and expensive process. Phytoremediation is defined as the use of plants to remove, contain, or render harmless environmental contaminants. Phytoremediation is a potentially less-damaging, cost-effective, but needs longer-term method for remediation of contaminated land compared to the alternative method such as soil washing, incineration or disposal to landfill. In this research, at the first stage topsoil were collected from the crude-oil contaminated area around Ahvaz refinery plant in the south of Iran . Ryegrass ( Lolium perenne ) planted in 1 to 2 cm of depth in the pots. The plants were irrigated during the growth period so that soil moisture was kept near field capacity. Soil samples were collected at 0, 40, 50, 60, 70, 80, 90, 100, 110 and 120 days after the start of the experiments. TPHs was extracted from soil sub samples by Soxhlet using a 1:1 v:v dichloromethane and n-hexane (150 ml) mixture. The results of TPH concentration was fitted with zero-order kinetic, first-order kinetic and Higuchi model. The result indicated that degradation of TPHs with presence of plants as a function of
