Removal mechanism of di-n-butyl phthalate and oxytetracycline from aqueous solutions by nano-manganese dioxide modified biochar

• Published in: Environmental science and pollution research international 2018-03, Vol.25 (8), p.7796-7807
• Main Authors: Gao, Minling, Zhang, Yue, Gong, Xiaolei, Song, Zhengguo, Guo, Zeyang
• Format: Article
• Language: English
• Subjects: Adsorption; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Charcoal; Charcoal - chemistry; Chemical interactions; Dibutyl Phthalate - chemistry; Dibutyl Phthalate - isolation & purification; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Kinetics; Manganese; Manganese Compounds - chemistry; Manganese dioxide; n-Butyl phthalate; Oxidation; Oxidation-Reduction; Oxides - chemistry; Oxytetracycline; Oxytetracycline - chemistry; Oxytetracycline - isolation & purification; Photoelectron spectroscopy; Phthalates; Research Article; Sorption; Spectroscopy; Valence; Waste Water Technology; Water Management; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; Water Pollution Control; Water Purification - methods; X ray photoelectron spectroscopy
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-017-1089-5

In this work, nano-manganese dioxide (nMnO 2 )-modified biochar (BC) was synthesized in order to improve BC’s adsorption capacity for di- n -butyl phthalate (DBP) and oxytetracycline (OTC). The results showed that nMnO 2 on the BC surface exhibited a poor crystallinity and oxidation state (Mn (IV)). Sorption experiments showed that, compared to BC, DBP sorption capacity of nMnO 2 -BC (1:20) and OTC sorption capacity of nMnO 2 -BC (1:10) were 0.0364 and 0.0867 mmol/g, respectively, which are significantly higher than that of BC (0.0141 and 0.0151 mmol/g). Kinetics and isotherm experiments indicated that physical adsorption and chemical interactions have both exerted their impacts on the adsorption process. Further X-ray photoelectron spectroscopy (XPS) analysis showed that part of the Mn (IV) in nMnO 2 -BC was reduced to Mn (III) and Mn (II) after DBP or OTC adsorption. Therefore, we suggest the nMnO 2 also acted as an oxidizer on modified BC, which may accelerate the degradation of DBP and OTC.