Department of Chemical Engineering, Indian Institute of Technology, Guwahati, 781039, Assam, India.
Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, 781039, Assam, India.
Environ Res. 2020 Sep;188:109825. doi: 10.1016/j.envres.2020.109825. Epub 2020 Jun 20.
Adsorptive removal of emerging contaminants like antibiotics from aqueous systems having one or more antibiotics using acid activated carbon have rarely been studied and reported. Current study deals with the adsorptive removal of individual antibiotic species i.e. Ciprofloxacin (CIP) and Amoxicillin (AMX) from single (CIP and AMX) and binary (CIP + AMX) adsorption systems using acid activated carbon prepared from Prosopis juliflora wood (PPJ). Binary adsorption system involved the synergistic and antagonistic influence of one antibiotic over the adsorption of other antibiotic. Physico-chemical alterations of PPJ surface due to acid activation and after adsorption were characterized for any surface modification. Parameters influencing the efficient adsorption of CIP and AMX viz. Initial pH of antibiotic solution, dosage of PPJ, sorbent-sorbate incubation temperature and initial concentration of antibiotic species were optimized. Sorbate-sorbent interaction studies for single system revealed sorbate's monolayer formation over adsorbent's surface and the involvement of chemisorption as verified by Langmuir isotherm model and pseudo-second order model respectively. For single system, Langmuir maximum adsorption capacity of PPJ was 250 mg/g for CIP and 714.29 mg/g for AMX. Meanwhile, competitive Langmuir model was used to investigate adsorption capacity of individual antibiotics in binary system i.e. 370.37 mg/g for CIP and 482.14 mg/g for AMX thus verifying CIP has antagonistic effect on AMX adsorption and AMX has synergistic effect on CIP adsorption on PPJ surface. Recyclability studies verified the PPJ can be used up to 4 cycles and co-existing cationic and anionic salts had minimal effect on the adsorption of antibiotics over PPJ surface. Conclusively PPJ proved efficient in eliminating emerging contaminants like that of antibiotics and thus it can be exploited for other grades of pollutants.
从含有一种或多种抗生素的水溶液中使用酸活化碳去除新兴污染物（如抗生素）的研究很少有报道。本研究采用从刺槐木材（PPJ）制备的酸活化碳，从单一组分（CIP 和 AMX）和双组分（CIP+AMX）吸附系统中去除单个抗生素物种，即环丙沙星（CIP）和阿莫西林（AMX）。双组分吸附系统涉及一种抗生素对另一种抗生素吸附的协同和拮抗影响。由于酸活化和吸附后，对 PPJ 表面的物理化学变化进行了特征描述，以了解任何表面改性。影响 CIP 和 AMX 有效吸附的参数，即抗生素溶液的初始 pH 值、PPJ 的用量、吸附剂-吸附质的孵育温度和抗生素物种的初始浓度进行了优化。单组分系统的吸附剂-吸附质相互作用研究表明，吸附质在吸附剂表面形成单层，化学吸附的参与通过朗缪尔等温线模型和伪二阶模型分别得到验证。对于单组分系统，PPJ 的朗缪尔最大吸附容量为 250mg/g 用于 CIP 和 714.29mg/g 用于 AMX。同时，使用竞争 Langmuir 模型研究了二元系统中单个抗生素的吸附容量，即 CIP 为 370.37mg/g，AMX 为 482.14mg/g，从而验证了 CIP 对 AMX 吸附具有拮抗作用，而 AMX 对 CIP 在 PPJ 表面的吸附具有协同作用。可重复使用性研究验证了 PPJ 可以使用 4 个周期，共存的阳离子和阴离子盐对 PPJ 表面吸附抗生素的影响最小。总之，PPJ 被证明可以有效去除抗生素等新兴污染物，因此可以用于其他污染物的处理。
