کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6331306 1619793 2014 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of humic acid source on humic acid adsorption onto titanium dioxide nanoparticles
ترجمه فارسی عنوان
اثر منبع اسید هومیک اسید بر جذب اسید هومیک بر روی نانوذرات دی اکسید تیتانیوم
کلمات کلیدی
اسید هومیک خاک و رسوبی، نانوذرات دی اکسید تیتانیوم، ثابت جذب، رسوبگذاری،
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
چکیده انگلیسی
In many studies, different humic acid (HA) sources are used interchangeably to evaluate the effect of organic matter on geochemical processes in the environment. This research looks more specifically at the effect of HA source on HA adsorption onto nano-TiO2 and how HA adsorption affects the fate and transport of nano-TiO2. In this study, six humic acids (HAs) were studied which were derived from soils (SLHA), or from sediments (SDHA) all originating from the state of Florida. Humic acid adsorption onto titanium dioxide nanoparticles (nano-TiO2) and the sedimentation of HA-coated and uncoated nano-TiO2 were monitored by Ultraviolet-visible (UV-vis) spectroscopy. Synchronous scan fluorescence (SSF) spectroscopy was used to complement the study of HA adsorption onto nano-TiO2. Phosphate buffer was found to reduce the amount of HA adsorbed onto nano-TiO2 relative to solutions of NaCl of the same pH and ionic strength. Adsorption constant values (Kads) for HAs varied in the order SLHA > FSDHA (freshwater sedimentary HA) > ESDHA (estuarine sedimentary HA). SSF results suggested that the more highly conjugated fractions of HA, which are more prevalent in SLHAs versus SDHAs, were preferentially adsorbed. In order to better understand the relationship between adsorption and aggregation, sedimentation studies were conducted and it was found that the percentage of nano-TiO2 sedimentation was preferentially enhanced in the order of the presence of SLHA > FSDHA > ESDHA. The extent of nano-TiO2 sedimentation was decreased with increasing HA concentration. TEM imaging of nano-TiO2 confirmed that nano-TiO2 was aggregated in the presence of HAs. The findings in this study suggest that HAs from different sources influence the fate and transport of nano-TiO2 in the environment differently.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Science of The Total Environment - Volumes 470–471, 1 February 2014, Pages 92-98
نویسندگان
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