Synergistic Adsorbent Sequence for Dissolved Organic Nitrogen Fractional Removal from Biotreated Pharmaceutical Wastewater

• DOI: 10.1021/acsestwater.0c00256
• Publication Date: 2021-03-09T15:15:32Z
• Authors: Haidong Hu; Yuanji Shi; Kewei Liao; Xinyu Xing; Caifeng Liu; Hongqiang Ren
• Keywords: Carbon fibers

Adsorption has demonstrated great promise for removing dissolved organic nitrogen (DON), but effective solutions to alleviate the competitive adsorption of different types DON are lacking. Herein, a novel sequential technology is designed fractional removal from actual biotreated pharmaceutical wastewater. Three carbon xerogels (CXs) customized via precisely controlling gel process and constructing macropore (CX5.4, 163–647 Å)–mesopore (CX6.2, 80–212 Å)–micropore (CX6.8, 17–136 Å) column. The column exhibits superior performance compared with that single CX columns, which can effectively remove (82.3%), reduce acute toxicity (87.4%), have suitable regeneration ability (14.7% decreased after three cycles). Analysis characteristics [molecular weight (MW) molecular composition] reveals CX5.4 preferentially removes high-MW hydrogen bonding or electrostatic interactions, alleviating irreversible regeneration. CX6.8 enhances low-MW high-unsaturated molecules pore filling π–π further decreasing toxicity. Due coexistence mechanism described above, CX6.2 main unit. Moreover, more cost-effective than activated carbon. Overall, this study provides an sustainable treatment in