Effects of Cu and Zn contamination on chicken manure-based bioponics: Nitrogen recovery, bioaccumulation, microbial community, and health risk assessment

Satja Aksorn; Vorapot Kanokkantapong; Chongrak Polprasert; Pongsak Lek Noophan; Samir Kumar Khanal; Sumeth Wongkiew

doi:10.1016/j.jenvman.2022.114837

Effects of Cu and Zn contamination on chicken manure-based bioponics: Nitrogen recovery, bioaccumulation, microbial community, and health risk assessment

J Environ Manage. 2022 Mar 8:311:114837. doi: 10.1016/j.jenvman.2022.114837. Online ahead of print.

Authors

Satja Aksorn¹, Vorapot Kanokkantapong², Chongrak Polprasert³, Pongsak Lek Noophan⁴, Samir Kumar Khanal⁵, Sumeth Wongkiew⁶

Affiliations

¹ Department of Environmental Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
² Department of Environmental Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand; Special Task Force for Activating Research (STAR) of Waste Utilization and Ecological Risk Assessment, Chulalongkorn University, Bangkok, Thailand.
³ Thammasat School of Engineering, Thammasat University, Pathumthani, Thailand.
⁴ Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, Bangkok, Thailand.
⁵ Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI, USA.
⁶ Department of Environmental Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand; Water Science and Technology for Sustainable Environment Research Group, Chulalongkorn University, Bangkok, 10330, Thailand. Electronic address: sumeth.w@chula.ac.th.

PMID: 35276563
DOI: 10.1016/j.jenvman.2022.114837

Abstract

In bioponics, although chicken manure is an efficient substrate for vegetable production and nitrogen recovery, it is often contaminated with high Cu and Zn levels, which could potentially cause bioaccumulation in plants and pose health risks. The objectives of this study were to assess nitrogen recovery in lettuce- and pak choi-based bioponics with Cu (50-150 mg/kg) and Zn (200-600 mg/kg) supplementation, as well as their bioaccumulation in plants, root microbial community, and health risk assessment. The supplementation of Cu and Zn did not affect nitrogen concentrations and plant growth (p > 0.05) but reduced nitrogen use efficiency. Pak choi showed higher Cu and Zn bioconcentration factors than lettuce. Bacterial genera Ruminiclostridium and WD2101_soil_group in lettuce roots and Mesorhizobium in pak choi roots from Cu and Zn supplemented conditions were significantly higher (p < 0.05) than controls, suggesting microbial biomarkers in plant roots from Cu and Zn exposure bioponics depended on plant type. Health risk assessment herein revealed that consumption of bioponic vegetables with Cu and Zn contamination does not pose long-term health risks (hazard index <1) to children or adults, according to the US EPA. This study suggested that vegetable produced from chicken manure-based bioponics has low health risk in terms of Cu and Zn bioaccumulation and could be applied in commercial-scale system for nutrient recovery from organic waste to vegetable production; however, health risk from other heavy metals and xenobiotic compounds must be addressed.

Keywords: Bacterial community; Bioconcentration; Chicken manure; Heavy metal; Hydroponic.