Research On Bioremediation Experiment Of Oily Contaminants In Soil-water System

Soil is material base and environmental conditions for human to survive and develop.when oil was brought into soil, it would undergo a series of complex physical, chemical and biological processes in the soil. The scope of oil pollution would be expanded if it infiltrated into the groundwater under gravity and capillary pressure. And the lives and health of animal, plant and human would be endangered directly or indirectly. Therefore, the researches were carried out on the natural migration and transformation law of oil contaminants in soil-water system and the mediation experiment by plants-microbial technology, which had important practical significance for the protection of the soil and water environment.The natural migration and transformation law of oil contaminants in soil-water system is studied in this research. The influencing factors of biological activity of indigenous microorganism were determined by the method of bioslurry. On this basis, the suitable seeds which had be selected through extensive literature survey and field work would be planted in the bioaugmentation soil according to certain laws, thus research on the relationship between the effects of plant-microorganism combined bioremediation and the degradation rate of oil contaminants.1. The migration and transformation law of oil contaminants in soil-water under the natural situationAccording to the experimental purpose, the sampling sites were selected around wells for observing the migration and transformation law of oil contaminants. The results show that the content of petroleum contaminants decreases with increased depth and distance, and only a few hydrophilic contaminants could continue to migrate because of the eluviations. Based on the actual situation in Daqing, the groundwater could not be polluted by petroleum contaminants under the general condition.2. Study on the influencing factors of activating indigenous microorganismThe influencing factors of activating indigenous microorganism were analyzed in the simulated tests in laboratory to determine the concrete method of activating indigenous microorganism. The results indicated that temperature had a great effect to microbial activity, optimal temperature was 40℃. So as the introduction of alien carbon source, and the capacity of various carbon sources were different in activating indigenous microorganism. The result showed that the best effect was when 0.5gC/kg of starch or 0.1gC/kg of glucose were added to Samples. The experiments concluded that the best conditions were: containing water 50%, the proportion of nutrition (N/P) was ten to one, electron accepter(H2O2) was cumulated to 14ml or the content of surfactant equals 50mg/L.However, taking into account the actual operation and the impact on environment , the latter two methods were not be advocated . 3. Research on the bioremediation experiment of plant-microorganismThe basis of preliminary experiments, we would like to select the three plant species: soybeans, alfalfa, and leymus chinensis, according to certain laws in the treated samples. The studies have shown that the samples pre-treated biological activity has been strengthened, with the plant obvious effect of combined bioremediation experiment; after adding starch processing, Planting soybeans - degradation of alfalfa group the best, followed by the soybean; overall, belong to the same legume soybeans - is the best of mixed degradation. But the legume alfalfa and Phocaea Leymus is worst of mixed degradation, this shows that in practical applications with plant selection should focus on the collocations of reasonableness, the results show the same kinds of mixed species of plants are growing well, the degradation effect is prominent.