Evaluation of the employment of eucalyptus bark in the bioadsorption of contaminant petroleum light hydrocarbons in simulated water bodies

ABSTRACT The contamination of water bodies by petroleum and its derivatives has been one of the main environmental problems nowadays and it causes many losses, such as ecological imbalance by damage to fauna and flora, and the reduction of the sunlight availability in the aquatic environment. Given this context, this paper proposed the employing of eucalyptus bark for the removal of petroleum light hydrocarbons (commercial gasoline type C) contaminant in simulated freshwater and saltwater environments. Therefore, it was verified the bark ability in adsorbing organic compounds when it was submitted to the contact with tartrazine, rhodamine B and methylene blue dyes, and the latter two had confirmed the chemical affinity of the biomaterial with carbon compounds. Then, in the adsorption of the simulated contaminant solution, it was evaluated the influences of: the biomass particle size, observing a trend toward better adsorption with the smallest particle size of the material, the water body temperature, that did not appreciably affect the adsorption capacity, and the reaction time, which benefited the adsorption in freshwater environment and reduced when the biomass was in contact with the saltwater. Furthermore, in a comparison among eucalyptus bark and other commercial adsorbents (activated charcoal, vermiculite and diatomaceous earth), it had higher adsorption capacity than all of them, proving to be a promising material for the decontamination of water containing petroleum hydrocarbons

摘要 石油及其衍生物对水体的污染是当代主要环境问题之一，由此引发诸多危害：诸如破坏水生动植物生存环境导致生态失衡，以及降低水生环境的光照可及性。鉴于此背景，本研究提出采用桉树树皮（Eucalyptus Bark）去除模拟淡水与咸水环境中的石油轻烃（Petroleum Light Hydrocarbons，商用C型汽油）污染物。为此，本研究先验证了桉树树皮对有机化合物的吸附性能：将其与柠檬黄（Tartrazine）、罗丹明B（Rhodamine B）及亚甲基蓝（Methylene Blue）染料接触后发现，后两种染料证实了该生物材料与碳类化合物的化学亲和性。随后，在模拟污染物溶液的吸附实验中，本研究评估了三类因素的影响：其一为生物质粒径，结果显示材料粒径越小，吸附效果越佳；其二为水体温度，其对吸附容量无显著影响；其三为反应时间，该因素可提升淡水环境中的吸附效率，但在咸水环境中则会降低吸附效果。此外，将桉树树皮与其他商用吸附剂（活性炭（Activated Charcoal）、蛭石（Vermiculite）及硅藻土（Diatomaceous Earth））进行对比后发现，其吸附容量优于所有对照材料，证明该材料是处理含石油烃类污染物水体的极具潜力的候选材料。