کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4408755 1618858 2014 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of anions and humic acid on the performance of nanoscale zero-valent iron particles coated with polyacrylic acid
ترجمه فارسی عنوان
اثر آنیون ها و اسید هومیک بر عملکرد ذرات آهن نانو ذرات پوشش دهنده با اسید پلی اکریلیک
کلمات کلیدی
آهن نانوساختار صفر ارزشمند، پوشش پلی اکرلیک اسید، اسید هومیک، آنیون، آبهای زیرزمینی
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
چکیده انگلیسی


• Polyacrylic acid (PAA) coating impeded the Fe(0) core oxidation by humic acid.
• PAA-coated NZVI showed 2.3-fold greater TCE degradation capacity than uncoated NZVI.
• At a very low molar ratio of anions/NZVI, a reactivity increase of NZVI was observed.
• A hydrodechlorination pathway for TCE was observed in the absence of metallic catalysts.

Effects of anions (NO3−, HCO3−, Cl−, SO42−) and humic acid on the reactivity and core/shell chemistries of polyacrylic acid-coated nanoscale zero-valent iron (PAA-NZVI) and inorganically modified NZVI (INORG-NZVI) particles were investigated. The reactivity tests under various ion concentrations (0.2–30 mN) revealed the existence of a favorable molar ratio of anion/NZVI that increased the reactivity of NZVI particles. The presence of a relatively small amount of humic acid (0.5 mg L−1) substantially decreased the INORG-NZVI reactivity by 76%, whereas the reactivity of PAA-NZVI decreased only by 12%. The XRD and TEM results supported the role of the PAA coating of PAA-NZVI in impeding the oxidation of the Fe(0) core by groundwater solutes. This protective role provided by the organic coating also resulted in a 2.3-fold increase in the trichloroethylene (TCE) reduction capacity of PAA-NZVI compared to that of INORG-NZVI in the presence of anions/humic acid. Ethylene and ethane were simultaneously produced as the major reduction products of TCE in both NZVI systems, suggesting that a hydrodechlorination occurred without the aid of metallic catalysts. The PAA coating, originally designed to improve the mobility of NZVI, enhanced TCE degradation performances of NZVI in the presence of anions and humic acid.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 113, October 2014, Pages 93–100
نویسندگان
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