Phytoremediation of Soil Impacted With Hydrocarbons and Heavy Metals

• Main Author: Aisyaidil, Hanri
• Format: Thesis
• Language: English
• Published: Universiti Malaysia Sarawak (UNIMAS) 2014
• Subjects: Q Science (General); QD Chemistry
• Online Access: http://ir.unimas.my/id/eprint/26724/1/Aisyaidil%20Binti%20Hanri%20ft.pdf; http://ir.unimas.my/id/eprint/26724/

Phytoremediation is the application of plants and their associated microorganisms to degrade, sequester or contain contaminants in soil. Four plant species namely Kaempheria rotunda, Jatropha podagrica, Asystasia coromandeliana and Phyllanthus amarus were evaluated for their ability to survive and adapt in soil contaminated with heavy metals and mixture of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs). These plants were also evaluated for the ability as metal hyperaccumulator and their ability to degrade aliphatic hydrocarbons and PAHs in their rhizosphere. Bacteria were isolated fTom the soil rhizosphere to determine whether degradation of aliphatic hydrocarbons and PAHs are related to the number of bacteria in the rhizosphere. P. amanls could not survive in soil contaminated with heavy metals and a mixture of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs). The bioconcentration factor (BCF) of the plants showed that K. rotunda is more potential as cadmium and zinc accumulator with BCF values of 5.28 and 0.90, respectively. Addition of ethylenediaminetetraacetic acid (EDTA) as chelating/mobilizing agent only affect the accumulation of chromium in J. podagrica, and chromium accumulated was 2-3 times higher in EDTA-treated plants compared to non-EDT A-treated plants. The colony forming unit present in the rhizosphere soil of K. rotunda, .J. podagrica and A. coromandeliana were 9.6 x 10\ 9.3 x 104 and 3.8 x 104 , respectively. K. rotunda, J. podagrica, A. coromandeliana planted in soil contaminated with aliphatic hydrocarbons and PAHs have shown the ability to degrade hydrocarbons in their rhizosphere. K. rotunda showed better potential for the degradation of aliphatic hydrocarbons ,in the rhizosphere due to the high number of bacteria present in the rhizosphere and consistently decreased concentration of aliphatic hydrocarbons throughout the experimental period. A. coromandeliana, in the other hand poorly degraded aliphatic hydrocarbons, although the plant highly adapted in the contaminated soil. However, A. coromandeliana showed potential to degrade PAHs in the rhizosphere, where dissipation of PAHs in soil planted with A. coromandeliana was in the range of 81.82 - 100%. Moreover, A. coromandeliana showed higher tolerance to PAHs compared to other plants tested, as well as fibrous root that could contribute good maintenance of the rhizosphere.