Rice husk and its derived biochar assist phytoremediation of heavy metals and PAHs co-contaminated soils but differently affect bacterial community

• Published in: Journal of hazardous materials Vol. 466; p. 133684
• Main Authors: Shang, Xingtian, Wu, Sirui, Liu, Yuli, Zhang, Keke, Guo, Meixia, Zhou, Yanmei, Zhu, Jiangwei, Li, Xuhui, Miao, Renhui
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.03.2024
• Subjects: Assisted phytoremediation; Bacterial community; Co-contaminated soil; Polycyclic aromatic hydrocarbon; Rice husk biochar; Rice husk biochar; Co-contaminated soil; Polycyclic aromatic hydrocarbon; Bacterial community; Assisted phytoremediation
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.133684

In order to evaluate the feasibility of rice husk and rice husk biochar on assisting phytoremediation of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) co-contaminated soils, a 150-day pot experiment planted with alfalfa was designed. Rice husk and its derived biochar were applied to remediate a PAHs, Zn, and Cr co-contaminated soil. The effects of rice husk and biochar on the removal and bioavailability of PAHs and HMs, PAH-ring hydroxylating dioxygenase gene abundance and bacterial community structure in rhizosphere soils were investigated. Results suggested that rice husk biochar had better performance on the removal of PAHs and immobilization of HMs than those of rice husk in co-contaminated rhizosphere soil. The abundance of PAH-degraders, which increased with the culture time, was positively correlated with PAHs removal. Rice husk biochar decreased the richness and diversity of bacterial community, enhanced the growth of Steroidobacter, Bacillus, and Sphingomonas in rhizosphere soils. However, Steroidobacter, Dongia and Acidibacter were stimulated in rice husk amended soils. According to the correlation analysis, Steroidobacter and Mycobacterium may play an important role in PAHs removal and HMs absorption. The combination of rice husk biochar and alfalfa would be a promising method to remediate PAHs and HMs co-contaminated soil. [Display omitted] •The effects of rice husk and biochar on phytoremediation of co-polluted soil were studied.•Rice husk biochar did better in PAH removal and HM immobilization than rice husk.•Rice husk and biochar selectively promoted different bacterial growth in soils.•Rice husk and biochar mainly promoted the uptake of HM by plant before 75 days.