Improved removal performance of Gram-negative and Gram-positive bacteria in sand filtration system with arginine modified biochar amendment. (1st March 2022)

• Record Type: Journal Article
• Authors: Zhang, Mengya; He, Lei; Zhang, Xiangwei; Wang, Shuai; Zhang, Boaiqi; Hsieh, Lichun; Yang, Kun; Tong, Meiping
• Is Part Of: Water research. Volume 211(2022)
• Publication Date: 2022-03-01
• Subjects: Bacterial removal -- Sand filtration -- Biochar -- Arginine-modified biochar -- Bacterial adsorption capacity -- Quartz sand; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2021.118006
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: Biochar enhanced bacterial removal under fast and slow filtration conditions. Arg-modified biochar could further improve bacterial capture performance. Great bacterial removal of modified biochar due to the high adsorption capacity. Arg-modified biochar removed all bacteria with HA and bacteria in actual water. Excellent performance of modified biochar during longtime filtration process. Abstract: Bacterial removal by sand filtration system is commonly inefficient due to the low bacterial adsorption capacity of sand. To improve the bacterial removal performance, biochar fabricated at different temperatures (400 °C, 550 °C and 700 °C) and arginine modified biochar were added into sand filtration columns as filter layers (0.5 and 1 wt%). Addition of biochar into sand columns could improve the removal efficiency for both Escherichia coli and Bacillus subtilis under both slow (4 m/day) and fast (240 m/day) filtration conditions. Bacterial removal efficiency in sand columns with the addition of biochar fabricated at 700 °C were higher than those fabricated at 400 °C and 550 °C due to its best bacterial adsorption capacity. Modification of biochar with arginine could further improve the bacterial removal performance. Specifically, complete bacterial removal (1.35 × 10 7 ± 10% cells/mL) could be achieved under both slow and fast filtration conditions in sand columns with 1 wt% arginine functionalized biochar amendment. The enhanced bacterial adsorption capacity mainly contributed to the increased bacterial capture performance in columns with addition of arginine-modified biochar. Bacteria more tightly bounded with arginine-modified biochar than bulk biochar. Moreover, complete bacterial removal with the copresence of 5 mg/L humic acid in suspensions was acquired in columns with addition of 1 wt% arginine-modified biochar. Efficient bacterial removal in actual river water, multiple filtration cycles as well as longtime injection duration (100 pore volumes injection) was also obtained. The results of this study demonstrated that arginine-modified biochar had great potential to treat water contaminated by pathogenic bacteria. Graphical abstract: Image, graphical abstract