Pyrolytic synthesis and performance efficacy comparison of biochar-supported nanoscale zero-valent iron on soil polluted with toxic metals

ABSTRACT

Toxic and hazardous metals such as cadmium (Cd) and Lead (Pb) can cause cancer in humans; hence, reducing their bioavailability in the soil is crucial for human health and environmental safety. In this study, biochar modified with nanoscale zero-valent iron (nZVI-BC) was synthesized from low-cost adsorbent waste materials and iron (iii) oxide (Fe₂O₃₎ via carbothermal reduction process for stabilization of Pb and Cd in the soil. Furthermore, an evaluation of treatment efficiency on exposure health hazards for both carcinogenic and non-carcinogenic risks was done. The results revealed that nZVI-modified eggshell biochar was able to reduce the concentration bioavailable of Pb and Cd in soil by (69–75%) and (62–65%), and reduce the toxicity leaching of Pb and Cd by (53–66%) and (68–75%), respectively. The treatments reduced carcinogenic risk (CR) and hazard index (HI) in children and adults by 35–47% for Pb and 25–36% for Cd, respectively. Hence, this study proposes a new way to reduce and modify environmental wastes to make nZVI-supported biochar that can remediate toxic metals from the soil, improve soil nutrients, reduce human exposure health risks, and enhance the environment’s health.

KEYWORDS:

• Remediation
• exposure risk
• environmental health
• toxic metals
• soil

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Research data are available only by the corresponding author based on reasonable request.

Authorship contribution statement

Moses Akintayo Aborisade: Conceptualization, methodology, investigation, data curation, analysis, original draft writing, and review. Aixi Feng: Resources. Belay Tafa Oba and Akash Kumar: Review writing, editing, and data curation. Ashenafi Yohanes Battamo: Visualization and validation. Menglu Huang and Chen Daying: Resources and software. Yongkui Yang and Peizhe Sun: Methodology and resources. Lin Zhao: Administration, funding, resources, and supervision.

Additional information

Funding

Authors appreciate the support received from Tianjin key Scientific and Technological Project (Grant No. 18ZXSZSF00240).