有机-无机酸复合改性生物炭对3种抗生素的吸附

Adsorption of Three Antibiotics by Biochar Modified with Organic Acid-Inorganic Acid

采用无机酸和有机酸改性莲子草生物炭,分析pH值、离子强度和温度对生物炭吸附抗生素的影响,并在最佳环境条件下对比不同生物炭对抗生素的等温吸附特征。结果显示:生物炭对抗生素的吸附量均随pH值的升高先升高后降低,最适pH值为6;生物炭对抗生素的吸附量随着温度升高和离子强度的降低而升高。相同平衡浓度下,生物炭对3种抗生素的吸附符合Langmuir模型,对抗生素的最大吸附量在2.11 mmol/kg~4.78 mmol/kg范围内,吸附能力依次表现为有机-无机复合改性>无机改性>未改性,抗生素被吸附量大小依次为土霉素>四环素>金霉素。

The effects of pH value,ionic strength and temperature on the adsorption of antibiotics by organic acid and inorganic acid modified biochar(made from Alteranthera philoxeroides)were analyzed,and the isothermal adsorption characteristics of different biochar to antibiotics were compared under optimal environmental conditions.The results showed that the adsorption capacity of biochar to antibiotics first increased and then decreased with the increase of pH value,and the optimal pH value was 6.The adsorption capacity of biochar to antibiotics increased with the increase of temperature and the decrease of ionic strength.At the same equilibrium concentration,the adsorption of three antibiotics by biochar conformed to Langmuir model,the maximum adsorption capacity of antibiotics ranged from 2.11 mmol/kg to 4.78 mmol/kg,and the adsorption capacity was arranged from large to small as organic acid-inorganic acid modification,inorganic acid modification,no modification,the amount of antibiotics adsorbed was ranked from large to small as oxytetracycline,tetracycline,chlorotetracycline.