RESUMEN
Hydrogels are often claimed as optimal adsorbents for water treatment; however, their efficiency towards the removal of hydrophobic pollutants is still limited. As an alternative, hydrogels prepared from polymers functionalized with siliceous materials can overcome this issue. Here, a composite hydrogel (denoted as GEL-SBA15) was prepared using alginate grafted with mesoporous silica (SBA15) and poly(vinyl alcohol) for benzene and toluene adsorption from aqueous solutions. Adsorption studies demonstrated that a low dosage of GEL-SBA15 (10 mg) has a high adsorption capacity for benzene (1482.8 mg/g) and toluene (596.6 mg/g) under mild experimental conditions (pH 7.0, at 25 °C). Besides, the adsorption capacities of GEL-SBA15 for both pollutants were enhanced compared to the conventional hydrogel. Kinetic analysis showed that the adsorption of benzene and toluene follows a pseudo-second order model, while the experimental adsorption data were well-fitted by the Freundlich isotherm. According to this isotherm, the adsorption occurs via a collaborative process, and weak physical forces (π-π interactions, van der Waals and hydrophobic) are involved. Hence, the post-utilized GEL-SBA15 can be recycled and reused up to 6 times without losing adsorption performance. Although hydrogels are not common adsorbents for aromatic hydrocarbons, the results reported here rank GEL-SBA15 as a promising adsorbent for the removal of these pollutants from water.
Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Alginatos , Benceno , Hidrogeles , Cinética , Dióxido de Silicio , Tolueno , Contaminantes Químicos del Agua/análisisRESUMEN
The male of Mangora brokopondo Levi, 2007 is described and illustrated for the first time. Variation in the color pattern of the females is documented. Mangora woytkowskii Levi, 2007 is considered a junior synonym of M. hirtipes (Taczanowski, 1878). New records of M. alinahui Levi, 2007 and M. pia Chamberlin & Ivie, 1936 are presented.
O macho de Mangora brokopondo Levi, 2007 é descrito e ilustrado pela primeira vez. Variação no padrão de coloração da fêmea é documentada. Mangora woytkowskii Levi, 2007 é considerado sinônimo-júnior de M. hirtipes (Taczanowski, 1878). Novos registros de M. alinahui Levi, 2007 e M. pia Chamberlin & Ivie, 1936 são apresentados.
Asunto(s)
Masculino , Animales , Arañas/anatomía & histología , Arañas/clasificación , DemografíaRESUMEN
The male of Mangora brokopondo Levi, 2007 is described and illustrated for the first time. Variation in the color pattern of the females is documented. Mangora woytkowskii Levi, 2007 is considered a junior synonym of M. hirtipes (Taczanowski, 1878). New records of M. alinahui Levi, 2007 and M. pia Chamberlin & Ivie, 1936 are presented.(AU)
O macho de Mangora brokopondo Levi, 2007 é descrito e ilustrado pela primeira vez. Variação no padrão de coloração da fêmea é documentada. Mangora woytkowskii Levi, 2007 é considerado sinônimo-júnior de M. hirtipes (Taczanowski, 1878). Novos registros de M. alinahui Levi, 2007 e M. pia Chamberlin & Ivie, 1936 são apresentados.(AU)