División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, A.C., Camino a la Presa San José 2055, Col. Lomas 4a Sección, C.P. 78216, San Luis Potosí, S.L.P., Mexico.
División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, A.C., Camino a la Presa San José 2055, Col. Lomas 4a Sección, C.P. 78216, San Luis Potosí, S.L.P., Mexico.
J Environ Manage. 2018 Apr 1;211:103-111. doi: 10.1016/j.jenvman.2018.01.041. Epub 2018 Feb 4.
Health and environmental problems associated with the presence of toxic aromatic compounds in water from oil spills have motivated research to develop effective and economically viable strategies to remove these pollutants. In this work, coconut shell (endocarp), coconut fiber (mesocarp) and coconut shell with fiber (endocarp and mesocarp) obtained from coconut (Cocos nucifera) waste were evaluated as biosorbents of benzene, toluene and naphthalene from water, considering the effect of the solution pH (6-9) and the presence of dissolved organic matter (DOM) in natural water (14 mg/L). In addition, the heat capacity of saturated biosorbents was determined to evaluate their potential as an alternative power source to conventional fossil fuels. Tests of N physisorption, SEM, elemental and fiber analysis, ATR-FTIR and acid-based titrations were performed in order to understand the materials' characteristics, and to elucidate the biosorbents' hydrocarbon adsorption mechanism. Coconut fiber showed the highest adsorption capacities (222, 96 and 5.85 mg/g for benzene, toluene and naphthalene, respectively), which was attributed to its morphologic characteristics and to its high concentration of phenolic groups, associated with the lignin structure. The pH of the solution did not have a significant influence on the removal of the contaminants, and the presence of DOM improved the adsorption capacities of aromatic hydrocarbons. The adsorption studies showed biphasic isotherms, which highlighted the strong affinity between the molecules adsorbed on the biosorbents and the aromatic compounds remaining in the solution. Finally, combustion heat analysis of coconut waste saturated with soluble hydrocarbons showed that the heat capacity increased from 4407.79 cal/g to 5064.43 ± 11.6 cal/g, which is comparable with that of woody biomass (3400-4000 cal/g): this waste biomass with added value could be a promising biofuel.
与溢油水中有毒芳香族化合物相关的健康和环境问题，促使人们研究开发有效且经济可行的策略来去除这些污染物。在这项工作中，以椰子（Cocos nucifera）废弃物中的椰子壳（内果皮）、椰子纤维（中果皮）和椰壳纤维（内果皮和中果皮）为吸附剂，从水中去除苯、甲苯和萘，考虑到溶液 pH 值（6-9）和天然水中溶解有机物（DOM）（14mg/L）的影响。此外，还测定了饱和吸附剂的热容，以评估它们作为替代传统化石燃料的潜在能源的可能性。进行了 N 物理吸附、SEM、元素和纤维分析、ATR-FTIR 和基于酸的滴定测试，以了解材料的特性，并阐明吸附剂的烃类吸附机制。椰子纤维显示出最高的吸附能力（苯、甲苯和萘的吸附能力分别为 222、96 和 5.85mg/g），这归因于其形态特征和高浓度的酚类基团，这些基团与木质素结构有关。溶液的 pH 值对污染物的去除没有显著影响，DOM 的存在提高了芳烃的吸附能力。吸附研究表明，吸附等温线呈两相，这突出了吸附在吸附剂上的分子与溶液中残留的芳烃化合物之间的强亲和力。最后，对吸附了可溶性烃类的椰子废弃物的燃烧热分析表明，热容从 4407.79cal/g 增加到 5064.43±11.6cal/g，与木质生物质（3400-4000cal/g）相当：这种具有附加值的废生物质可能是一种很有前途的生物燃料。
