Impacts of bamboo biochar on the phytoremediation potential of Salix psammophila grown in multi-metals contaminated soil

Abstract

We investigated the effects of bamboo biochar (BBC) as soil amendment on growth and phytoremediation potential of Salix psammophila in soil heavily polluted by Cd and Zn. Bamboo biochar was added to soil at ratios ranging from 1 to 7% (w/w), which significantly increased the organic matter, available potassium (K) content, while decreased the hydrolyzable nitrogen (N) content and the levels of total and bioavailable HMs in soil. The BBC amendment at ratios of 1% to 5% showed little effect on growth of plant, whereas at 7% ratio significantly decreased biomass compared to the control. BBC amendment stimulated the accumulation of Cu, Cd and Zn in plant tissues, meanwhile, Cd and Zn accumulation were more evident, especially in the BBC-3% treatment. BBC amendment improved the TF and BCF values of Cd, Zn and Cu compared to control. Higher BCF for Cd (BCF >1) and TF for Zn (TF >1) values indicate Salix psammophila have considerable potential for phytoremediation efficiency in BBC amended soil treatment. This study provides practical evidence of the efficient BBC–assisted phytoremediation capability of Salix psammophila and highlights its potential as a viable and inexpensive approach for in situ remediation.

Keywords:

• Bamboo biochar
• phytoremediation
• Salix psammophila

Disclosure statement

The authors declare that they have no conflicts of interest.

Novelty statement

Biochar is believed to be a promising material in polluted soil remediation, which can immobilize heavy metals in soil and reduce metal uptake by plants. However, we observed that the bamboo biochar (BBC) amendment at a relatively low application ratio of 3% (w/w) increased Cd, Zn and Cu accumulation (BCF) and translocation (TF) in Salix psammophila grown in alkaline soil, and which is different from most of the current conclusions. We believe this finding will help to fully understand the benefit of biochar on soil remediation. This study also suggests the great potential of BC–assisted phytoremediation using fast growing trees like Salix psammophila to severely polluted land remediation.

Additional information

Funding

This work was financially supported by Fundament Research Funds of CAF [Grant No. CAFYBB2019SZ001] and the Key Research and Development Program of Zhejiang Province, China [Grant No. 2018C03047]. We want to acknowledge anonymous reviewers for their valuable comments.