Ultra-high selective removal of Congo red and Ciprofloxacin using unusual LDO modified biochar: Influence of emerging pollutants and application attempts

Abstract

The porous biochar materials serve as effective adsorbents in water treatment. In this study, layered-double-hydroxide (LDH)(MgAl) was dispersed onto waste poplar powder through the co-precipitation method, followed by pyrolysis to prepare layered-double-oxides (LDO)/poplar carbon (CL-800) for ultra-high adsorption of Congo red (CR) and Ciprofloxacin (CIP). The CL-800 adsorbent possessed a well-developed layered porous structure that provides numerous adsorption sites and transport channels for dyes and antibiotics. Notably, CL-800 exhibited a significantly elevated level of selectivity and adsorption capacity towards CR and CIP reaching 93.0, 84.7 % and 4841.2, 744.0 mg/g, respectively. Various factors were considered to investigate the influence on CR and CIP adsorption, such as ion types, microplastics, and perfluorooctanoic acid. The adsorption capacity in complex water systems were also explored where CL-800 presented excellent removal efficiencies for CR (99.0 %) and CIP (89.6 %) in simulated wastewater along with good repeatability. Fixed-bed column tests also confirmed its potential as an effective adsorbent for wastewater purification due to continuous adsorption properties towards CR and CIP over time. Finally, the interaction mechanisms for CR/CIP adsorption processes onto CL-800 were possibly determined via various advanced techniques. This study provides new perspectives for providing a potential low-cost efficient adsorbent for organic wastewater treatment.